1. health and fitness
2. disease
3. cancer

1
2005 Abstracts
Please note: The following abstracts have not been edited for content. They appear as submitted by the authors.
Sunday, October 30, 2005
Soy Isoflavones and Cognition: A Review of the
Clinical Data. L. Dye and C. Hill, Human Appetite Research
Unit, Institute of Psychological Sciences, University of
Leeds, Leeds, LS2 9JT, UK.
The aim of this presentation is to provide a detailed examination of
the human experimental studies of the effects of soy derived isoflavones
(soy IF) on cognitive function in females. In contrast to the vast number
of studies of health effects of soy IF, there have been only a small number of intervention studies of soy IF with cognitive endpoints. There have
been three intervention studies in young adults. One study (File et al.,
2001) examined young men and women and found that a high soy diet
(100mg/d) for 10 weeks improved verbal and non-verbal episodic memory and mental flexibility. Gender specific effects were noted for verbal
fluency and planning ability, with improved performance in females on
the high soy diet, but not males. Another found effects on spatial performance after consumption of 900g of soybeans within 1 week,
although this study suffers from the lack of a control group (Celec et al.,
2005). In the only double-blind randomised placebo-controlled trial in
young adults, Hill et al. (2005) administered 68mg/d soy IF (aglycone
weight, 116mg/d conjugated weight) in a soy food matrix across two
consecutive menstrual cycles. An improvement in long-term verbal memory in the first and last week of the intervention was observed. There
have been 4 published RCTs of soy IF in postmenopausal women varying
in duration from 3-12months with a variety of intake forms and doses
(ranging from 60 to 110mg/d). Three further unpublished data sets will be
reported upon. Generally soy IF appear to exert stronger cognitive effects
in postmenopausal women compared to premenopausal women and
effects seem to be mainly confined to improvements in memory and certain aspects of frontal lobe function. Variables such as age, time of exposure, dose and administration of isoflavones may be important mediating
factors in the effects observed. Whilst these studies have provided some
evidence of significant effects on cognition which are more pronounced
in postmenopausal than younger women, it is not possible to know
whether the effects reported in these relatively short term interventions
will be sustainable in the long-term. The intriguing preliminary data warrant the funding of long-term trials
Absorption of Soy Bioactives
Long-Term Dietary Habits Affect Soy Isoflavone
Metabolism and Accumulation in Prostatic Fluid in
Caucasian Men. T. Hedlund1, P. Maroni1, P. Ferucci1, R.
Dayton1, S. Barnes2, K. Jones2, R. Moore2, L. Ogden1, K.
Wahala3, H. Sackett1, and K. Gray1, 1University of Colorado
Health Sciences Center, Aurora, CO, USA, 2University of
Alabama at Birmingham, Birmingham, AL, USA, 3Univ. of
Helsinki, Helsinki, Finland.
The soy isoflavones daidzein and genistein are believed to reduce
prostate cancer risk in soy consumers. However, daidzein can be metabolized by the intestinal flora to form a variety of compounds with different bioactivities. In the current study, we investigated the influence of
long-term dietary habits on daidzein metabolism in healthy Caucasian
men (19-65 y old). A secondary goal was to compare plasma and prostatic fluid concentrations of 5 isoflavonoids: genistein, daidzein, equol,
dihydrodaidzein, and O-desmethylangolensin. Baseline plasma levels of
isoflavonoids were quantitated in 45 men by HPLC/electrospray ionization/ mass spectrometry. Participants then consumed a soy beverage
daily for 1 wk, and post-soy isoflavonoid levels were quantitated in
plasma and prostatic fluid. Equol was the only metabolite that appeared
to be influenced by routine dietary habits. Stratified analyses revealed
that men who had consumed ≥30 mg/d soy isoflavones for at least 2 y
had 5.3-times the probability of producing equol than men who had
consumed ≥5 mg/d (P=0.014). Additionally, those men who consumed
animal meat regularly had 4.7-times the probability of producing equol
than men who did not consume meat (P=0.023). Equol production was
not linked to age, BMI, or the consumption of yogurt, dairy, fruit or
American style fast food. Daidzein and its metabolites (but not genistein) were typically present at higher levels in prostate fluid than plasma (median = 4-13 times that in plasma). In conclusion, our data suggest that the ability of Caucasian men to produce equol is favorably
influenced by the long-term consumption of high amounts of soy, and
the consumption of meat. Lastly, the high concentrations of
isoflavonoids in prostatic fluid increases the potential for these compounds to have direct effects in the prostate.
Bioavailability of the Cancer Preventive Soy Peptide
Lunasin in Animals. B.O. de Lumen1, C. Lim1, I. Reyes1, P.
Vichayavilas1, H. Chu1, J. Lee1, R. Hurwitz1, Y. Fang1 M. Fitch1
and H. Jeong2 , 1Division of Nutritional Sciences & Toxicology,
University of California, Berkeley, CA, USA, 2Andong
University, Andong, Korea.
Oral bioavailability of the cancer preventive soy peptide lunasin
was determined in mice and rats. 3H-lunasin was administered by gavage to male and female CD-1 mice with lunasin-enriched soy (LES) and
organs were collected at 3,6,9,12, and 24 hrs post-administration. 3Hlunasin is absorbed and distributed in the various tissues collected
including those that are targets for the most common cancers such as
lungs, mammary gland, prostate and colon. At 3 hrs, approximately 30%
of the total dose is accounted in all the tissues collected, extrapolation
to 1 hr gives a value of approximately 38% absorption. Sprague-Dawley
rats were fed LES for 4 weeks. Lunasin extracted from the blood and
liver of these rats are intact and bioactive.
Inflammatory Diseases
Dietary Soy Protein During Pregnancy and Lactation
Reduces Renal Inflammation and Disease
Progression in Young Adult Rat Offspring with
Genetically Determined Kidney Disease. H. Aukema1,2,
L. Cahill1, C. Peng1, D. Sankaran1, N. Bankovic-Calic1, and
M. Ogborn1,2, 1University of Manitoba, Winnipeg,
Manitoba, Canada, 2Manitoba Institute of Child Health,
Winnipeg, Manitoba, Canada.
Dietary soy protein ameliorates disease progression in several ani-
Oral Presentation Abstracts
Oral Presentation Abstracts
6th International Symposium on the
Oral Presentation Abstracts
2
Role of Soy
in Preventing and Treating Chronic Disease
mal models of kidney disease when soy exposure is initiated at weaning or later in life. We previously have demonstrated the beneficial
effects of dietary soy protein exposure initiated at weaning in the
Han:SPRD-cy rat, a genetic model of renal disease characterized by
renal cyst growth and the common renal pathologies of inflammation
and fibrosis. Therefore, the objective of the current study was to determine whether exposure to soy protein in the diet earlier in life would
have further benefits. Han:SPRD-cy rats were given either soy protein or
casein based diets from 2 wk prior to conception up to weaning and/or
in the post-weaning period in a 2x2 design. During young adulthood (at
70 d of age), the progression of renal disease was examined by histology. As previously shown, soy protein compared to casein in the postweaning diet reduced disease progression, as evidenced by less inflammatory cell infiltration, renal cyst growth and epithelial cell proliferation. With respect to maternal effects, renal inflammatory cell infiltration was reduced by dietary soy protein exposure in the pregnancy/lactation period alone, and was even lower when maternal exposure was
combined with soy protein feeding in the post-weaning period. For cell
proliferation, maternal exposure to soy protein was just as effective as
post-weaning exposure in lowering renal cell hyperproliferation in diseased kidneys. Maternal soy protein compared to casein also resulted in
less proteinuria, indicating better renal function. In conclusion, these
studies demonstrate that maternal soy protein exposure has long-term
beneficial effects on renal inflammation and disease progression in
young adult offspring in this model of genetically determined renal disease. • Supported by the Manitoba Instute of Child Health
Isoflavonoid-Free Soy Shows Anti-Inflammatory
Activity in an Experimental Model for Chronic
Nonbacterial Prostatitis. M. Kauppila1, J. Bernoulli1, E.
Yatkin*1, N. Saarinen2, and R. Santti1, 1Dept. of Anatomy,
Institute of Biomedicine, University of Turku, Turku, Finland,
2Functional Foods Forum, University of Turku, Turku, Finland.
There is emerging evidence to support a role for non-bacterial
chronic inflammation in prostate carcinogenesis. Because of the fragmentary and conflicting information available about anti-inflammatory
properties of soy in prostate, we studied the effects of soy in an animal
model reproducing the clinical picture of men with chronic non-bacterial prostatitis. Prostatic inflammation was induced in Noble rats with
combined treatment with testosterone and estradiol known to induce
prostate cancer. When kept on soy-free diet, rats developed gradually
perivascular, stromal, and glandular inflammation in dorsolateral
prostate. The inflammatory cells consisted mainly of T-lymphocytes
(CD3+ cells). At six weeks, the inflammation proceeded to glandular
form and subset of T-lymphocytes, cytotoxic (CD8+) cells were observed
intraepithelially. Testosterone concentration and prostate size remained
within the normal range while estrogen and prolactin concentrations
were elevated. At 9 weeks, a gradual decline was measured in serum
testosterone concentration and prostate weight. Dietary soy reduced
inflammatory changes in each category (perivascular, stromal and glandular) while body weight gain, prostate size and hormone concentrations in serum remained unaltered. When rats were kept on isoflavonoidfree soy, the content of isoflavones in urine markedly decreased, yet an
equivalent decrease in the number of inflammatory foci was observed at
3 and 9 weeks. Neither soy nor isoflavonoid-free soy showed any signs
of anti-estrogenic potency. If inflammatory etiology is found important in
prostate carcinogenesis, anti-inflammatory therapy based on regular
consumption of soy or isoflavonoid-free soy could be enhanced. •
Supported by Raisio Group Foundation, Raisio, Finland.
Monday, October 31, 2005
Equol
A Review of the Equol Hypothesis. M. Kurzer, University
of Minnesota, Saint Paul, Minnesota, USA.
It has been proposed that the isoflavone metabolite equol may be
largely responsible for the biological effects of soy consumption. This is
of particular interest, given that only 20-40% of the population produces this metabolite after soy consumption. Studies have shown that
equol producers have hormone profiles consistent with lowered risk of
breast cancer, and that in some cases equol producers may respond better than non-producers when it comes to soy benefits on indicators of
cardiovascular disease, bone health, cancer risk, and menopausal symptoms. At the same time, other studies have shown no differences in
effects of soy consumption between subjects who produce equol and
those who do not. Thus, the relevance of equol production remains controversial, although the wide variability in production is not. Since equol
is produced via bacterial metabolism, it has generally been assumed
that this wide variation in equol production is due to differences in
colonic microflora. If equol is critically important, the large variability in
equol production could explain some of the inconsistencies in results
among studies that have evaluated the biological effects of soy consumption. In addition, if it is true that equol production improves
response to soy, it becomes even more important to understand the factors that influence isoflavone metabolism, and to determine whether it
is possible to turn an equol non-producer into a producer. This talk will
briefly summarize the factors influencing equol production, its mechanisms of action, and data related to the equol hypothesis.
Equol: A Comparison of the Effects of the Racemic
Compound with that of the Purified S-Enantiomer on
the Growth, Invasion and DNA Integrity of Breast
and Prostate Cells in vitro. P. Magee1, M. Raschke2, C.
Steiner2, J. Duffin1, B. Pool-Zobel2, T. Jokela3, K. Wahala3,
and I. Rowland*2, 1University of Ulster, Coleraine, UK,
2Friedrich Schiller University, Jena, Germany, 3University of
Helsinki, Helsinki, Finland.
The ability of soy isoflavones to protect against hormone-dependent
cancers, such as those of the breast and prostate has been intensively
studied to date. Equol, an isoflavan, is produced by approximately 3040% of the population via the bacterial conversion of the soy isoflavone
daidzein in the gut. Due to the presence of a chiral centre, equol exists as
two distinct optically active isomers, R- and S-equol, though the enantiomer produced by metabolic reduction from isoflavones is known to be
S-(-)equol. It has been postulated that the R- and S- enantiomers have
different biological properties, given their different binding affinities for
the estrogen receptor. In this study we have compared the biological
effects of the purified S-equol enantiomer to that of racemic (R and S)
equol on breast and prostate cancer cells in vitro. Effects on cell proliferation, invasion through matrigel and DNA integrity using the Comet
assay were studied. Both racemic and S-equol inhibited the growth of the
breast cancer cell-line MDA-MB-231 (>10mM) and the prostate cancer
cell-lines LNCaP (>5mM) and LAPC-4 (>2.5mM) with both compounds
exerting similar effects as assessed by DAPI staining. The compounds also
showed equipotent effects in inhibiting the invasion of MDA-MB-231 and
PC-3 cancer cells through matrigel. S-equol (1, 10, 30mM) was, however,
unable to prevent DNA damage in MCF-7 or MCF-10A breast cells follow-
3
2005 Abstracts
Probiotic and Prebiotic Effects on Soy Isoflavone
Metabolism, Equol, and Lipids. T. Larkin1,3, L.
Astheimer1,3, and W. Price3, 1Department of Biomedical
Science, University of Wollongong, Wollongong, NSW,
Australia, 2Department of Chemistry, University of
Wollongong, Wollongong, NSW, Australia, 3Smart Foods
Key Centre, Wollongong, NSW, Australia.
Due to the essential role of gut microflora in isoflavone metabolism, particularly that to equol, it was hypothesized that concurrent
intake of soy with either a probiotic (yoghurt) or prebiotic (resistant
starch) may affect isoflavone metabolism and lipids. Thirty-one hyperlipidemic men and postmenopausal women completed this randomised,
crossover study of two 5-week dietary periods separated by a 4-week
washout. Intake of soy alone was compared with either probiotic (soy +
probiotic) or prebiotic (soy + prebiotic) treatments for effects on plasma
and urinary isoflavones and plasma lipids following a test soy meal. Five
weeks of soy intake significantly increased circulating plasma daidzein
and genistein levels, but did not affect plasma or urinary isoflavones
after the test soy meal. There was a trend for increased plasma daidzein
and genistein levels with both probiotic and prebiotic treatment, but no
overall significant effects. Neither treatment induced or increased equol
production, though there was a trend with probiotic treatment for
increased plasma equol in equol-positive subjects (n = 12). Despite a
lack of significant effects on isoflavone bioavailability, total cholesterol
was significantly decreased with both probiotic and prebiotic treatment
(-4.7 ± 2.0%, p = 0.038 and -5.5 ± 1.6%, p = 0.003, respectively) and
LDL cholesterol was most significantly decreased with prebiotic
treatment (-7.3 ± 2.2%, p = 0.005). Independent of the potential for
probiotic or prebiotic treatment to affect isoflavone bioavailability, the
synergistic action between soy and probiotic or prebiotic intake for
lipid-lowering effects suggests these combinations may be useful in
lipid management. • Specialty Cereals Pty Ltd., Paul’s Dairy, So Natural
Foods, Penford Australia, Dr. Barbara Meyer, Maria de los Angeles.
Urinary Excretion of Equol and the Risk of Breast
Cancer in Japanese Women. C. Nagata1, T. Ueno2, S.
Uchiyama2, K. Urata2, Y. Nagao3, C. Shibuya3, Y. Kashiki3, and
H. Shimizu1, 1Gifu University Graduate School of Medicine,
Gifu, Japan, 2Saga Nutraceuticals Research Institute, Otsuka
Pharmaceutical Co., Ltd., Saga, Japan, 3Gihoku General
Hospital, Gifu, Japan.
The association between urinary excretion of equol and the risk of
breast cancer was examined in a case-control study among Japanese
women. The case subjects were 160 women newly diagnosed and histologically confirmed with breast cancer between 2000 and 2002 at a general hospital in Japan. A total of 456 controls individually matched to
cases on age, menopausal status, and the date of sample collection were
selected from those who attended a breast cancer mass screening at this
hospital. Diet before the date of diagnosis for the cases and the date of
the screening visit for the controls was assessed by a validated semiquantitative food frequency questionnaire. Spot urine samples from each subject were analyzed for urinary excretion of isoflavonoids. Urine samples
from breast cancer cases were collected before cancer therapy. Dietary
intake of soy products or soy isofolavones did not differ significantly
between cases and controls. The percentage of women with detectable
levels of equol (>1.13nmol/ml) in urine was significantly greater in controls than that in cases (19.6 vs 8.2%). Urinary levels of daidzein and
genistein were significantly higher in cases than in controls. The status of
excretion of equol (+ or -) was moderately positively associated with urinary levels of daidzein and genistein in controls. Urinary equol or the ability to produce equol may be associated with the risk of breast cancer.
Treatment of Postmenopausal Monkeys with Equol
Did Not Improve the Plasma Lipid Profile. S. Appt, T.
Clarkson*, and H. Chen, Wake Forest University School of
Medicine, Winston-Salem, North Carolina, USA.
Background: Monkeys fed soy protein, compared to casein, have
markedly improved plasma lipid profiles (increased HDLC and decreased
LDL+VLDLC). Soy consumption results in high plasma equol concentrations, which might account for the large lipid benefits in monkeys compared to much smaller benefits observed in women in (only about a
third of which produce equol).
Materials and Methods: Fifteen postmenopausal monkeys, all fed
a casein-lactalbumin based diet containing some added cholesterol
(0.20 mg/Cal), were randomized into a control group (n=7) or an equol
group (n=8). Racemic equol was added to the diet of the equol group
in an amount in which the s-anisomer would be equivalent to the
amount of daidzein in our previous soy protein studies (52.4 mg/1,800
Cals). Plasma HDLC, LDL+VLDLC and triglycerides (TG) were measured
at baseline, 3, 6 and 8 months. Repeated measures ANCOVA, adjusting
for baseline, was used to analyze the data.
Results: Postprandial total plasma equol concentrations were
about 470 nmol/L, comparable to monkeys fed soy protein containing
daidzein equivalent to the equol s-anisomer fed in this study. After 8
months of treatment, there were no significant effects of equol on
HDLC, LDL+VLDLC or TG.
Discussion: We found no evidence that equol per se is the mediator of the plasma lipid benefits of soy protein fed to monkeys. There are
limitations to the study: synthetic equol may be handled differently by
the gut, may act differently administered with soy protein or the effects
may be due to dehydrodaidzein or tetrahydrodaidzein.
Cancer
Developing a Soy Food Based Intervention Among
Healthy Men. G. Maskarinec1, S. Hebshi1, Y. Morimoto1, S.
Sharma1, A.A. Franke1, and F.Z. Stanczyk2, 1Cancer
Research Center of Hawaii, Honolulu, HI, USA, 2University
of Southern California, Los Angeles, CA, USA.
Increasing prostate cancer risk among men who migrated from
Asia to the United States led to the hypothesis that soy foods may be
protective through an effect on circulating sex steroids. This pilot study
Oral Presentation Abstracts
ing exposure to 2-hydroxy-4-nonenal, menadione or benzo(a)pyrene-7,8dihydrodiol-9,10-epoxide. In contrast, DNA damage in MCF-10A cells was
significantly reduced following exposure to 2-hydroxy-4-nonenal or
menadione when cells were pretreated with racemic equol (10, 30mM).
These findings suggest that racemic equol has strong antigenotoxic activity in contrast to the purified S-equol enantiomer implicating the R-,
rather than the S-enantiomer as being responsible for the antioxidant
effects of equol, a finding that may have implications for the in vivo
chemoprotective properties of equol.
This study was carried out with financial support from the
Commission of the European Communities specific RTD programme
“Quality of Life and Management of Living Resources” (project no QLK2000-00266). It does not necessarily reflect its views and in no way
anticipates the Commission’s future policy in this area.
6th International Symposium on the
Oral Presentation Abstracts
4
Role of Soy
in Preventing and Treating Chronic Disease
examined the feasibility of recruiting healthy men for a soy food based
intervention, developed a dietary protocol that could achieve compliance, obtained preliminary hormonal data, and assessed emotional status during the intervention. Invitations were sent to 1000 Kaiser
Permanente Hawaii members, ages 40-69 years, who had a normal PSA
test. We received replies from 90 (9%) interested men and identified 25
eligible subjects. After a run-in period, 24 men (92% of eligible) were
randomized and 23 subjects completed the study. In a cross-over
design, half of the subjects completed either a high soy diet or maintained their usual diet. In the high soy diet, dairy, meat, and snacks were
replaced with approximately 75mg of isoflavones as 2 servings of soy
milk, tofu, or soy nuts. After 3 months and a 1-month washout period,
participants crossed over to the other diet. Compliance was assessed by
24-hour recalls, soy logs, and urinary isoflavone excretion measured by
high pressure liquid chromatography. Each subject donated 3 blood
samples and 5 overnight urine samples and completed the Profile Of
Mood States questionnaire. Testosterone and PSA were quantified in
serum by highly specific immunoassays. The intervention and all laboratory analyses were completed recently. The statistical analysis will apply
t-tests and mixed models to examine differences by diet while incorporating the repeated measures. • This pilot stuy was supported by a
developmental grant from the Cancer Research Center of Hawaii.
Soy Intake, Use of Menopausal Hormones, Body Size,
and Breast Cancer Risk in Asian-American Women. A.
Wu1, M. Yu2, C. Tseng1, and M. Pike1, 1University of
Southern California, USA, 2University of Minnesota, USA.
We conducted a large population-based case-control study of
breast cancer among Asian American women in Los Angeles County
which included 1386 women with breast cancer (494 Chinese, 384
Japanese, 508 Filipino) and 1226 control women without breast cancer
(515 Chinese, 331 Japanese, 380 Filipino). Participants provided detailed
information on menstrual and reproductive factors, use of exogenous
hormones, family history, body size, dietary history, and other lifestyle
factors in a structured in-person interview.
Established risk factors such as nulliparity, family history of breast
cancer, and use of menopausal hormones are significant risk factors in
Asian-American women as in other western populations. Risk of breast
cancer is significantly inversely associated with soy intake during adolescence and adult life; the significant risk reductions were found in
both premenopausal and postmenopausal women after adjustment for
relevant dietary and non-dietary variables. However, further analyses in
postmenopausal women showed that the benefits of soy intake are
found only in certain subgroups; namely women with low body size and
non-users of menopausal hormones. These results and our interpretation of the findings will be discussed.
This work was supported by grants (1RB-0287, 3PB-0102, 5PB0018) from the California Breast Cancer Research Program. Incident
breast cancer cases for this study were collected by the USC Cancer
Surveillance Program (CSP), which is supported under subcontract by
the California Department of Health. The CSP is also part of the
National Cancer Institute’s Division of Cancer Prevention and Control
Surveillance, Epidemiology, and End Results Program, under contract
no. N01CN25403
Antiestrogen Effects of Soybean Glyceollins in
Postmenopausal Monkeys. C. Wood1, S. Appt1, T.
Clarkson1, A. Franke2, S. Boue3, M. Burow4, and J.M. Cline*1,
1Wake Forest University School of Medicine, Winston-Salem,
NC, USA, 2Cancer Research Center of Hawaii, Honolulu, HI,
USA, 3Southern Regional Research Center, United States
Dept. of Agriculture, New Orleans, LA, USA, 4Tulane
University School of Medicine, New Orleans, LA, USA.
Estrogens have an important role in the development of breast
and uterine cancer. Glyceollins are isoflavonoid pterocarpans, present in
stressed soybeans, which have potential estrogen-antagonist effects. In
this short-term study we used a primate model to evaluate the antiestrogen effects of glyceollin-enriched soy protein (GLY) on biomarkers
for cancer risk. Thirty ovariectomized adult female cynomolgus
macaques were randomized to one of three dietary treatments
(expressed as equivalent doses for women): (1) estradiol (E2, 1 mg/day)
+ casein lactalbumin (control); (2) E2 + soy protein isolate (SPI) containing 180 mg/day isoflavones; and (3) E2 + GLY containing 189 mg
isoflavones and 134 mg glyceollins (I-III). Experimental diets were given
for 3 weeks. Breast and uterine measures were taken before and after
each treatment. Serum glyceollin concentrations were 134.2 nM (40.0%
of daidzein+genistein) 4 hours after feeding and <1 nM 24 hours after
feeding. Compared to baseline, E2 treatment induced significantly
greater breast proliferation in the control group (p=0.02 in lobules;
p=0.002 in ducts) and SPI group (p=0.04 in lobules; p=0.02 in ducts)
but not in the GLY group (p=0.09 in lobules; p=0.93 in ducts). E2 significantly increased uterine area in all groups (p<0.01 for all); however, the
change in uterine area was significantly lower in the GLY group versus
the control (p=0.01) and SPI (p=0.049) groups. These findings demonstrate that soybean glyceollins are absorbed and rapidly cleared following dietary intake. Preliminary data suggest that glyceollins may
enhance the antiestrogenic properties of standard soy protein isolate in
the breast and uterus. • This work was supported by the NIH/NCCAM
R01-AT00639 (JMC).
Phytoprevent: A European Project on the Prevention
of Breast and Prostate Cancer by Phytoestrogens. I.
Rowland, University of Ulster, Coleraine, UK.
Phytoprevent is a 3 year multi-disciplinary project funded by the
European Union with the aim of investigating the role of foods rich in
phytoestrogens (isoflavones and lignans) on reduction of risk of breast
and prostate cancer. In analytical studies, HPLC CoulArray methods have
been validated for the analysis of food, plasma, urine and faecal and an
ID-GC-MS-SIM method has been established for the measurement of
plasma estrogen/phytoestrogen levels. In vitro methods were used to
study effects of isoflavones on various stages of cancer. Preincubation
of breast and prostate cell lines with low concentrations of isoflavones
decreased hydrogen peroxide-induced DNA damage. Isoflavones were
found to significantly enhance tight junction integrity in the breast cancer cell-lines MCF-7 and MDA-MB-231 suggesting a beneficial effect on
tumor promotion. Isoflavones inhibited invasion of MDA-MB-231 breast
cancer cells through Matrigel at concentrations as low as 2.5uM. The
anti-angiogenic activity of 16 synthetic phytoestrogen metabolites has
been determined. Two synthetic phytoestrogens were shown to possess
anti-angiogenic activity using proliferation and differentiation assays.
Studies in the Tg.NK transgenic mouse mammary cancer model showed
that perinatal exposure to isoflavones had no effect on tumor development, while post weaning and life long exposure to isoflavones delayed
tumor development and reduced tumor incidence. In a human intervention study (22 days) with foods containing soy, changes in urinary estrogen profile were seen in the soy consumers that were consistent with
lower breast cancer risk.
This study was carried out with financial support from the
Commission of European Communities specific RTD programme
5
2005 Abstracts
The Combination of Soy and Flaxseed or Their Phytoestrogens Can Better Reduce the Growth of Breast
Tumors than Soy or Genistein Alone While Causing
Little Effects on Bone Health in Ovariectomized Nude
Mice. L. Thompson, K. Power, N. Saarinen, J. Chen, and W.
Ward, Department of Nutritional Sciences, University of
Toronto, Toronto, ON, Canada.
Phytoestrogen (PE)-rich diets have been associated with a lower
risk of breast cancer (BC) and osteoporosis. In previous studies in ovariectomized (OVX) mice, flaxseed (FS), rich in lignan PE, reduced the growth
of human MCF-7 estrogen receptor positive (ER+) BC, while the soy
isoflavone PE, genistein (GEN), stimulated tumor growth. In this study, we
determined whether the combination of soy and FS or their respective PE,
isoflavone genistein (GEN) or the lignans enterolactone (EL) or enterodiol (ED), can more effectively reduce the growth of ER+ BC in OVX mice
than soy or GEN alone while maintaining protective effects on bone. OVX
mice with established MCF-7 tumors were fed the basal diet, 20% soy
protein isolate (SPI), 10% FS, or 20% SPI + 10% FS for 25 weeks. All mice
exhibited tumor regression but SPI induced late stage tumor growth,
which was negated by combining it with FS. SPI maintained femur bone
mineral density (BMD) and strength but FS slightly attenuated this effect
when combined with SPI. Using the same model, mice with MCF-7
tumors were given daily injections of GEN, EL, ED, EL+ED+GEN, or vehicle control for 22 weeks. All mice showed tumor regression but GEN
caused the least effect. The effect of combined PE on bone did not differ
from the control and GEN. Tumor cell proliferation and apoptosis data
agreed with the observed changes in tumor size. In conclusion, combining PE or PE-rich foods resulted in a better control of tumor growth while
causing little effects on bone health. • Funded by NSERC
Tuesday, November 1, 2005
Cardiovascular Disease
Hypocholesterolemic Effect of Soy Proteins—Only
Due to Protein and Only in Hypercholesterolemics.
Cesare R. Sirtori, Dept. of Pharmacological Sciences and
University Center for Dyslipidemias, Niguarda Hospital,
Milano, Italy.
The concept that animal proteins may be atherogenic versus the
case of vegetable proteins dates back to Ignatowsky (1908) and had a
formal proof in 1977 in a “model” study. This was: a) carried out in
hypercholesterolemic individuals (lowest starting cholesterolemia 270
mg/dl); b) on in-patients, followed in metabolic ward conditions; c)
based on a direct comparison according to a cross-over protocol of an
exclusively soy protein and an animal protein based diet (Sirtori et al,
Lancet 1977; i: 275). In a second part of the study the addition of cholesterol was tested on similar in-patients on the soy diet, proving no
change in the remarkable cholesterol lowering activity of the experimental regimen (ie around 23% LDL-C reduction). No other study ever
fulfilled all these qualifications. In a larger outpatient study in
Italy/Switzerland the same soy product (later found to be phytoestro-
gen-free) was given to 130 patients all with cholesterolemia >300
mg/dl (Descovich et al 1980; ii: 709); both similar reductions of total and
LDL-C levels as well as a clear correlation between these reductions and
baseline cholesterolemia were reported. A large number of studies have
been, unfortunately, carried out in normolipidemic individuals with, as
expectable, negative findings; in addition, essentially all published studies have been on dietary supplements.
The cholesterol lowering mechanism of soy protein is by way of
stimulation of LDL-receptor activity, as shown in animal (Lovati et al, J
Nutr 2000; 130:2543) and in clinical studies (Lovati et al, J Clin Invest
1987; 80: 1498). LDL-receptor activity is normal in normolipidemic individuals, unlikely to respond to this treatment. The mechanism thus differs from that of statins, working on cholesterol biosynthesis and active
also at low levels of cholesterolemia, and is somewhat similar to that of
berberine, also an LDL-receptor upregulator (Kong et al, Nature Med
2004 ; 10: 1344).
A matter of confusion in the field was the belief that phytoestrogens might be in some way responsible for cholesterol lowering. This
belief was based on primate studies and also on human findings using
ethanol extracted soy products. This drastic chemical treatment most
likely destroys active protein components, since a more appropriate column extraction procedure maintains the hypocholesterolemic activity in
the absence of phytoestrogens (Fukui et al, J Agric Food Chem 2002; 50:
5717). Due to this ill fated belief, US distributed soy proteins show
grossly altered structure, as assessed from a proteomic evaluation
(Gianazza et al, J Nutr 2003; 133: 9); surprisingly they still cause some
reduction of cholesterolemia. A reputable meta-analysis (Anderson et
al, N Engl J Med 1995; 333: 276) clearly showed that soy proteins
(mainly supplements) reduce cholesterolemia to a minimal extent in
normolipidemic individuals (mean reduction -5.2 mg/dl; - 3.3% ) versus
a high effect in patients with marked cholesterol elevations (up to -71.5
mg/dl; - 19.6%). This type of findings allowed the preparation of a “predictive nomogram” for assessing the individual benefit of treatment:
the cholesterol reductions reported in recent American studies
(Lichtenstein et al, ATVB. 2002; 22: 1852; Jenkins et al, JAMA 2003; 290:
502) fit well with the nomogram. It is thus unfortunate that a recent US
Report (Evidence Report Technology Assessment, No.126, Effects of Soy
on Health Outcomes), pooling together all sorts of studies and eliminating many (including our early ones) came to negative conclusions.
Indeed the majority of the studies were in normolipidemics, frequently
treated with chemically unsuitable proteins.
Superficial comments such as “Evidence suggests that initial estimates on the potency of soy protein were too high” have no basis: there
was never an estimate, since it was clear from the onset that the cholesterol lowering activity is based first on the patient characteristics,
second on the soy product and third, most likely, on the daily amount.
Soy proteins are active only in hyperlipidemics; this may reduce their
appeal, ie considering the present indication of statins in normolipidemic coronary patients. It leaves, however, ample space for clinical use
(children, renal patients, etc.). In addition, similar to the case of milk
proteins providing ACE-inhibitory peptides for hypertension (FitzGerald
et al, J Nutr 2004; 134: 980S), it should not be long before soy protein
varieties from adequate cultivars or fractions thereof may turn out to
provide effective “pill like” cholesterol reducers.
7S Soy Globulin Peptide and Cholesterol Homeostasis:
in vitro and in vivo Data. M. Lovati, C. Manzoni, S.
Castiglioni, and E. Disconzi, Dept. of Pharmacological
Sciences, University of Milano, Milano, Italy.
7S soy globulin and its alfa’ subunit have been shown to positively modulate LDL receptor activity and to decrease triglyceride synthesis
Oral Presentation Abstracts
‘Quality of Life and Management of Human Resources’ (Project No
QLK1-2000-00266.It does not necessarily reflect its views and in no way
anticipates the Commission’s future policy in this area
6th International Symposium on the
Oral Presentation Abstracts
6
Role of Soy
in Preventing and Treating Chronic Disease
both in vitro (HepG2 cells) and in vivo (rats fed cholesterol-rich diet).
The aim of the present investigation was to evaluate the effect of a synthetic peptide, corresponding to a sequence which differs between the
alfa and alfa’ subunits from 7S soy globulin, on cell cholesterol homeostasis both in HepG2 cells and in rats fed casein-cholesterol diet.
HepG2 cells were incubated for 24 hr in minimum essential medium
(MEM) + 5% LPDS in the presence/absence of whole 7S globulin (0.5
mg/mL) or its alfa’ subunit (0.125 mg/mL) or the synthetic peptide (105 M). At the end of incubation, cell membranes and nuclei were separated by validated procedures. Aliquots of membrane and nuclear fractions were run on 7.5-15% SDS-PAGE gels, transferred onto nitrocellulose, and overlaid with a polyclonal antibody against SREBP-1. Cell
preincubation with whole 7S soy globulin caused an increase in the
mature forms of SREBP-1, both in membranes (+ 90%) and in the nuclei
( + 130%), vs that found in the control HepG2 cells (MEM + 5% LPDS).
Moreover, a lower level of mature nuclear SREBP-1 was detected in
HepG2 cells exposed to both the alfa’ subunit and the synthetic peptide,
compared to that found after exposure to whole 7S globulin. The oral
administration (14 days) of synthetic peptide (5 mg/Kg b.w.) to caseincholesterol fed rats resulted in lower plasma lipid levels (cholesterol, 25%; triglycerides, -28%) vs values recorded in rats fed casein-cholesterol diet alone. These results represent the first in vivo evidence of the
plasma lipid-lowering properties induced by the synthetic peptide;
moreover, these data suggest that alfa’ subunit from 7S soy globulin,
and its synthetic peptide, are responsible for the direct up-regulation of
LDL receptors. The mechanism of this effect is likely to be through the
SREBP-2 transcriptional factor, the activity of which we are currently
investigating. • Supported in part by a grant from MIUR of Italy.
Effect of Two Types of Soy Milk and Dairy Milk on
Plasma Lipids in Hypercholesterolemic Adults: A
Randomized Trial. C.D. Gardner1, J. Morris1, M. Messina2,
A. Kiazand1, A. Varady1, and A. Franke3, 1Stanford University,
Stanford, California, USA, 2 Loma Linda University, Loma
Linda, California, USA, 3Cancer Research Center of Hawai‘I,
1236 Lauhala St., Honolulu, HI 96813, USA.
Background–The literature on the hypocholesterolemic effect of
soy proteins is inconsistent. The effect of soy proteins may differ by dose
and by the level of hypercholesterolemia.
Objective–To contrast plasma lipid responses between two commercially available soy milks, one made using whole soy beans and the
other using soy protein isolate, and low-fat dairy milk.
Design–Randomized clinical trial, cross-over design.
Patients–Adults (n=28), 30-65 years of age, with pre-study LDLcholesterol concentrations of 160-220 mg/dL, not on lipid lowering
medications and with overall Framingham risk score of< 10%.
Intervention–Participants were required to consume sufficient milk
to provide 25 g protein/day from each milk source, preferably distributed over three times/day. The protocol included 3 four-week milk consumption phases, each separated from the next by wash-out periods of
at least four weeks.
Results–The average LDL-C concentration at the end of each phase
(mean +/- SD) was 161 +/- 20, 161 +/- 26 and 170 +/- 24 mg/dL for the
whole soy bean milk, the soy protein isolate milk, and the dairy milk,
respectively (p=0.9 between soy milks, p=0.02 for each soy milk vs.
cow’s milk,). No significant differences by type of milk were observed
for HDL-cholesterol or triacylglycerols. The only pair-wise difference in
total-C/HDL-C ratio was a significantly lower ratio for the soy protein
isolate milk relative to the dairy milk (p=0.02).
Conclusion–The results of this study support a modest, 5% LDLcholesterol lowering effect of either type of soy milk, relative to dairy
milk, when provided in amounts yielding 25 g protein/day to adults with
elevated LDL-cholesterol concentrations for four weeks.
Soy Food Effects on Serum Lipoproteins in Humans:
Updated Meta-Analysis. J.W. Anderson, VA Medical
Center and University of Kentucky, Lexington, KY, USA.
Soy foods significantly affect serum lipoproteins by decreasing
LDL-cholesterol (LDL-c) and triglycerides (TG) while increasing HDL-cholesterol (HDL-c). Since our 1995 meta-analysis, most studies have
reported less impressive alterations in serum lipoproteins than the
12.9% decrease in LDL-c then reported for soy foods. Since 1995 at least
55 randomized controlled trials with soy foods have reported serum
lipoprotein changes. To examine possible causes of differences in
lipoprotein responses, we have analyzed these studies with a focus on
LDL-c. Weighted changes for different soy foods are presented as
changes from baseline (to estimate maximum effects) and net changes
(adjusted for control diet changes). In 55 trials, soy protein consumption
averaged 44 g/d fed for an average of 29 days. Serum LDL-c decreased
8.5% with net change of 4.5% (95% CI, 2.8-6.3%). In 16 studies soy
was baked or cooked with LDL-c changes of -0.9% and net changes of
-1.4% (not significant). Using soy protein once daily and <25 g/d was
less effective than use of > 25 g/d and > 2x/d. In 24 studies with 25-50
g/d soy protein given > 2x/d, LDL-c reduction was 9.3% with a net
reduction of 5.4% (95% CI, 4.1-6.8%). These studies reported significant changes in HDL-c (+3.7%, 95% CI, 0.4-4.1%) and TG (-8.0%, 95%
CI, -2.8 to -13.1%). Further subgroup analyses will be presented. Recent
studies indicate that soy peptides have potent hypocholesterolemic
effects and that soy proteins with more intact peptides have significantly greater hypocholesterolemia than more fragmented preparations. Soy
protein extraction or baking may fragment the most active hypocholesterolemic peptides.
Effect of Soy Isoflavone Protein and Soy Lecithin on
Endothelial Function in Healthy Postmenopausal
Women. Z. Faridi, M. Evans, V. Njike, M. Hoxley, and D.
Katz, Yale Griffin Prevention Research Center, Derby,
Connecticut, USA.
Objective: To assess the effects of soy isoflavone protein concentrate and soy lecithin on endothelial function measured as flow mediated dilation (FMD) of the brachial artery in healthy postmenopausal
women.
Design: Randomized, double-blind, placebo controlled crossover trial.
Subjects/Setting: 25 subjects (mean age 61 years; BMI 25.46 kg/m2)
were recruited from the general population of Southwestern Connecticut.
Intervention: Subjects underwent endothelial function testing at
baseline and following 4 weeks of randomly assigned treatments with
intervening 4-week washout periods. Treatment assignments included:
Soy isoflavone protein (25gm/day) and soy lecithin (20gm/day); soy
isoflavone protein (25gm/day) and placebo lecithin; placebo protein and
soy lecithin (20gm/day); and double placebo.
Outcome Measures: FMD of the brachial artery, and serum lipid levels
Results: 22 women completed the trial; pre-treatment FMD was
8.60 ± 7.20. No statistically significant difference was seen in FMD
between treatment assignments. However, FMD was highest after treatment with soy protein plus lecithin (7.50 ± 9.85), followed by soy protein plus placebo lecithin (5.51 ± 10.11), placebo protein plus soy
lecithin (5.35 ± 6.13), and lowest after double placebo (4.53 ± 7.84).
7
2005 Abstracts
Workshop Presentation
Role of Soy Foods in the Management of Obesity and
Related Chronic Diseases: Summary of a Symposium
at the University of Illinois. John W. Erdman Jr., Keith
Cadwallader and Barbara P. Klein, Department of Food
Science and Human Nutrition, University of Illinois,
Urbana, IL, USA.
Obesity among American adults has doubled over the past two
decades and has nearly tripled for children and adolescents. The consequences of obesity include increased risk of a host of chronic diseases
including diabetes, cardiovascular disease, cancer and bone and joint
degeneration. Enhanced obesity rates are not limited to westernized
countries, as most societies world-wide are now reporting higher proportions of severely overweight citizens. Soy foods have the potential for
assisting in obesity management and reduction of subsequent chronic
disease development. To address these issues, a two-day forum was held
on May 25 and 26, 2005 at the University of Illinois featuring leading
researchers from universities and the food industry. They reviewed the
current state of knowledge regarding the management of obesity and
related diseases and the roles of soy and its components. Presentations
focused upon the state of knowledge of obesity incidence, effectiveness
of weight loss programs, and impacts of obesity on cardiovascular disease, diabetes and other co-morbidities. It is well accepted that consumption of soy can improve serum lipid profiles. There is emerging evidence suggesting that soy-containing isoflavones may also affect adipogenesis and may be beneficial for diabetics. An industry panel discussed
their experiences in utilization of soy foods for weight loss. This presentation will review the scientific outcomes from the symposium. In addition, gaps in current knowledge for the roles of soy in the management
of obesity and related diseases will be discussed.
Immune Function
Soy Isoflavones Modulate Immune Function in
Healthy Postmenopausal Women. T. Ryan-Borchers, J.
Park, B. Chew, M. McGuire, L. Fournier, and K. Beerman,
Washington State University, Pullman, WA, USA.
Background: After menopause, the immune system may be compromised due to effects of aging and diminishing concentrations of estrogen,
an immune-modulating hormone. Isoflavones, plant-derived compounds
that possess antioxidant, anti-estrogenic and pro-estrogenic actions, may
offer immunological benefits to women in this stage of life.
Objective: The objective of this study was to evaluate the effects of
soy isoflavones, both soymilk and supplement form, on markers of
immunity and oxidative stress in postmenopausal women.
Design: Postmenopausal women aged 50-65 y (n = 52) enrolled in
this 16 wk double-blind, placebo-controlled trial were randomized to
one of three experimental groups: 1) Control - 706 mL/d cow’s milk plus
a placebo supplement; 2) Soymilk - 71.6 mg isoflavones derived from
706 mL/d soymilk plus a placebo supplement; and 3) Supplement - 70
mg isoflavones in a supplement plus 706 mL/d cow’s milk. Plasma and
24-h urine samples were obtained at baseline and at 16 wk. Immune
variables included lymphocyte subsets, cytokine production, as well as
markers of inflammation and oxidative damage.
Results: Baseline immune variables did not differ among groups.
Both isoflavone interventions increased (p < 0.05) β cell populations and
concentrations of plasma interferon-gamma (IFN-γ) and decreased (p <
0.05) concentrations of 8-hydroxy-2- deoxy-guanosine (8-OHdg), an
oxidative marker of DNA damage. Isoflavone treatments did not influence
concentrations of urinary 8-isoprostane (8-iso), plasma interleukin-2 (IL2), tumor necrosis factor-alpha (TNF-α) or C-reactive protein (CRP).
Conclusions: Soymilk and supplemental isoflavones modulate β
cell populations and IFN-γ concentrations, and appear protective
against DNA damage in postmenopausal women.
Supported by a grant from the Washington State Attorney
General’s office; soymilk provided by White Wave, Inc. and isoflavone
(Novasoy®) and placebo supplements provided by the Archer Daniels
Midland Co.We thank Bridgett Mathison for lab assistance; Heather
Gardner, Livia Wagner and April Broderick for delivery of study treatments and data entry; and all of the women who graciously participated in this study.
Effects of ImmuSoy as a Food Supplement for
Altering Peanut Allergic Reactions. T. Zhang1, W. Pan2,
M. Takebe3, H. Sampson1, and X. Li*1, 1Pediatrics, Allergy &
Immunology, Mount Sinai School of Medicine, New York,
NY, USA, 2Surgery, Harvard Medical School, Beth Israel
Deaconess Medical Center, Boston, MA, USA, 3Nichimo
Co., Ltd., Tokyo, Japan.
RATIONALE: Probiotic foods were only recently clinical trials conducted to evaluate probiotics in the treatment of atopic dermatitis and
food allergy, Lactobacillus rhamnosus GG (LGG) had some effect on the
prevention of early atopic disease in high-risk infants. Recent studies
shown that soy as a kind of allergen-specific immunotherapy can be
used to desensitize/downregulate peanut-specific response in peanutallergic mice. ImmuSoy is a koji fungus (Aspergillus oryzae) and lactobacteria soybean fermentation product, based on traditional Japanese
fermentation technology. It is believed that this unique food supplement
would be beneficial for the immune system when food allergy happened. We hypothesized that ImmuSoy may be effective for treating
peanut allergy.
METHODS: This study was undertaken in mice to investigate
whether specific doses of ImmuSoy would has better effect than LGG
for desensitization peanut allergic mice. Peanut allergic mice (C3H/HeJ,
n=8-10/group) were fed ImmuSoy containing chow (0.5 % and 1 %),
LGG 0.5% containing chow or regular chow (control) for 4 weeks beginning at week 10 following peanut sensitization, and then were challenged with peanut. Anaphylactic scores, plasma histamine, serum
peanut specific-IgE levels and splenocyte cytokine production to peanut
stimulation were determined.
RESULTS: All control mice developed anaphylaxis (median score
3.3) following peanut challenge, in contrast, 50% and 25% of low and
high doses of ImmuSoy treated-mice developed anaphylaxis (median
scores 1.0 and 0.33 respectively) while LGG treated mice have 80% and
mean score around 2. The low and high dose ImmuSoy treated-mice
showed 50.4 % and 80.7% reduction respectively in plasma histamine(LGG 20%), and 47.1% and 73.9% reduction respectively in serum
IgE levels as compared to untreated mice (p<0.05)(LGG 20% P>0.05).
Oral Presentation Abstracts
Soy isoflavone protein and soy lecithin significantly increased HDL/LDL
relative to baseline value (soy isoflavone protein and soy lecithin, 0.64
± 0.19; soy isoflavone protein and placebo lecithin, 0.58 ± 0.17; placebo protein and soy lecithin, 0.65 ± 0.18; baseline, 0.49 ± 0.15).
Conclusion: In this sample of healthy postmenopausal women, soy
isoflavone protein and soy lecithin significantly improved the lipid profile. Improvement in endothelial function could not be confirmed.
The study was funded by a grant from Health & Nutrition Group of
Eridania Béghin-Say America, Inc.
6th International Symposium on the
Oral Presentation Abstracts
8
Role of Soy
in Preventing and Treating Chronic Disease
Furthermore, IL-4, IL-5 and IL-13 production by splenocytes of high dose
ImmuSoy-treated mice were reduced by 74.1% and 77.0% (LGG 75%)
whereas IFN-γ production was increased by 34.8%(LGG increased 10%)
compared to control splenocytes.
CONCLUSIONS: LGG of 0.5% containing chow shown some protective effects on peanut allergic mice, but when we increase the dose
of LGG even to 5 times higher than ImmuSoy 1%, no dose dependent
or no better effects shown (data not shown here). Compared with LGG,
ImmuSoy used as a food supplement has dose dependent protective
effects against peanut-induced anaphylaxis in mouse peanut allergic
model, which is associated with down downregulation of Th2 responses. This approach might be a potential novel therapy for peanut allergy.
Diabetes
Habitual Soyfood Consumption Improves Glycemic
Control Among Postmenopausal Chinese Women: A
One-Year Follow-up Study. S. Ho and Y. Chen, The
Chinese University of Hong Kong, Hong Kong SAR.
Objectives: Previous studies show soy supplementation improves
glycemic control in animals and in diabetic subjects. Little data are
available on their effects among healthy adults. We examined the effect
of habitual soyfood intake on changes in serum fasting glucose over a
one-year followup period.
Methods: This study included 173 community-based postmenopausal
Chinese women aged 48-62 years who had been recruited into a one-year
randomized controlled trial of three doses of isolated soy isoflavones (0, 40
and 80 mg/d) on bone changes. Habitual soyfood intake was assessed
using a validated food frequency questionnaire. Fasting serum glucose (FG)
was measured at baseline and at the end of one-year.
Results: The mean intake of habitual soy protein among the study
subjects was 5.3g/d (sd = 4.46). Soy protein intake, changes in body
mass index, and baseline glucose were significantly correlated with
changes of FG over one year. Stepwise regression analysis showed that
habitual soy protein was significantly and inversely associated with the
absolute and percent changes in FG in women with initial glucose over
the median (92.1mg/dl) rather than in those below the median after
adjusting for supplemental isoflavones and other potential confounders
(including age, years since menopause, baseline FG, changes in body
mass index, dietary intakes of total fat, fruits, vegetables, and physical
activities). Soy protein accounted for 14.1% (p=0.002) and 12.8%
(p=0.003) of the variations of absolute and percent changes of FG,
respectively; and it was estimated that a daily increase of ten-gram soy
protein was associated with 13.5 mg/dl (or 9.3%) decreases in fasting
glucose (p<0.001) in women with higher initial FG.
Conclusion: Habitual soyfood intake improves glycemic control in
women with higher baseline FG.
Beneficial Metabolic Effect of Soy-Rich Diets in
Young Firefighter Trainees. Y. Yamori1,2, M. Shibata1, M.
Mori3, N. Ishiwata4, M. Tokoro2, and Y. Yamamoto1, 1Hyogo
Prefecture Health Promotion Association, Kobe, Japan,
2Mukogawa Women’s University, Nisinomiya, Japan,
3Research Institute for Production Development, Kyoto,
Japan, 4Atomi Junior College, Tokyo, Japan.
Purpose: To investigate the effect on the indices related to lifestylerelated disease risks, of continuous daily soy-rich diet intake in healthy
young Japanese men.
Method: A randomized, cross-over controlled dietary intervention
study on metabolic effects of soy-rich diets was carried out in cooperation with 100 healthy firefighter trainees aged 18-25. After informed
consent was obtained, they were randomized into soy rich (S) and ordinary control (C) diet groups during the first and second intervention
periods (45 and 44 days, respectively) with an interval of the washout
period of 25 days. S diets consisting of common Japanese soy products,
such as tofu, soymilk, etc. contained more soy protein (29.4g in average) a day than regular Japanese C diets (soy protein 8.6g), and both
diets were nearly the same in daily total energy (2800-3300 Kcal) and
total protein (105-120g) intakes. Questionnaires about dietary custom,
body mass index (BMI), body fat (F), blood pressure (BP), and blood and
24-hour urine were examined 4 times before and at the end of both
intervention periods.
Results: From among 95 male participants, 43 completed all tests
including 4 times of 24-hour urine collection. S group (18) showed significant increases in urinary isoflavones (ISO: 19.2→87.4µmol) after the
intervention and significant reduction in systolic and diastolic BP, fasting glucose (G), BMI and F. In contrast, C group (25), whose urinary ISO
excretions were not changed, showed no significant changes in these
parameters. Significant inter-group differences were noted in changes
from the baseline levels of G and HOMA-IR (homeostasis model assessment insulin resistance index: G×immuno reactive insulin).
Conclusion: Daily intake of soy rich diets containing about 30g of
soy protein decreased G and improved HOMA-IR significantly in comparison with regular diets, suggestive of the beneficial effect of soy-rich
diets on insulin resistance even in young healthy men. (This study was
supported by Hyogo Prefecture Government)
Menopausal Symptoms
The Effects of 100mg Soy Isoflavone Supplements on
Menopausal Symptoms and Quality of Life: A DoubleBlind, Randomised, Placebo-Controlled, Crossover
Trial in British Postmenopausal Women. C. Hill1, A.
Cassidy2, J. Powell3, D. Talbot3, and L. Dye1, 1Institute of
Psychological Sciences, University of Leeds, Leeds, West
Yorkshire, UK, 2School of Medicine, Health Policy and
Practice, University of East Anglia, Norwich, East Anglia,
UK, 3Unilever R&D, Sharnbrook, Bedfordshire, UK.
Research into the efficacy of soy isoflavones (soy IF) to relieve
menopausal symptoms has yet to produce a unanimous conclusion.
Attention has been largely focused on hot flushes, with other psychological, vaso-somatic and general somatic symptoms typically assessed
before and after an intervention. The conflicting findings on these endpoints could be attributed to the methodological issues surrounding retrospective reporting and the use of psychometrically weak scales.
Therefore this study adopted a prospective assessment of the severity
and frequency of menopausal symptoms. Retrospective measurements
of quality of life were also taken, which tapped into a non-symptomatic
consideration of well being. This study employed a double-blind, randomised, placebo-controlled crossover trial of 100mg soy IF supplement
over 8 weeks in 21 British postmenopausal women. No significant difference was noted between soy IF and placebo for total symptom score
or for the psychological, vaso-somatic or general somatic subscales.
However, specific reductions were observed in the frequency of feeling
easily stirred up and the severity of early morning awakenings and
sleeplessness. Daily counts and severity measures of hot flushes were
also significantly reduced across all weeks of soy IF intervention, with
greater efficacy in women with > 5 hot flushes/day. There were no interactions with time on treatment, with a generally lower level of these
9
2005 Abstracts
Isoflavone Supplements Predominantly Containing
Genistin/Genistein Reduce Hot Flushes: A Critical
Analysis of Published Studies. P. Williamson-Hughes1, B.
Flickinger1, M. Messina2, and M. Empie1, 1Archer Daniels
Midland Company, Decatur, IL, USA, 2Nutrition Matters,
Inc., Townsend, WA, USA.
Several reviews and meta-analyses have evaluated the clinical evidence relating isoflavone treatment to menopausal hot flush symptom
relief. The majority of these reviews and meta-analyses have included a
range of isoflavone sources; often without differentiating the chemical
identity of individual isoflavone molecules contained in the study product or the compositional ratio of isoflavones. We conducted a re-evaluation of the published literature specific to studies utilizing well characterized isoflavone-containing supplements to determine if observed
effects, or lack thereof, were attributable to specific isoflavones. Eleven
studies were stratified in relation to their specific isoflavone composition. Six studies described isoflavone products which provided greater
than 10 milligram genistein per treatment (calculated as aglycone
equivalents), administered to a total of 188 subjects. These six studies
consistently reported a statistically significant effect in reducing hot
flushes in post-menopausal women. In contrast, the remaining five
studies (total of 167 subjects) used supplements containing high
daidzein or formononetin and low genistin/genistein content; only one
of these (30 subjects) reported an effective reduction in hot flush.
Hence, reports finding that the relationship between isoflavone consumption and hot flush reduction inconclusive suffer from over generalization by including any product with the term isoflavones. Lack of discrimination between individual molecular entities contained in heterogeneous isoflavone sources can be misleading. In light of our observations, we conclude that higher genistein ratio extract products with a
minimum genistein dose level are effective in reducing hot flushes and
that evaluation of isoflavone effects should be related to content of
individual isoflavones within supplements.
Comparison of Isoflavones and Tibolone Regarding
Vaginal Estrogenicity in Peri and Postmenopausal
Women. U.D. Rohr1 and A. Jungbauer2, 1AHS, 1090 Vienna,
Austria, 2Department of Biotechnology, BOKU, 1090
Vienna, Austria.
Isoflavones are promising agents in chemoprevention. Clinical
effects in peri- and postmenopausal women of isoflavones and tibolone
in postmenopausal women are compared to binding affinities to a yeast
estrogen receptor model. Tibolone a compound used in postmenopausal
hormone therapy, is metabolized into 3 further active compounds. 80mg
isoflavone per day were applied in 11 perimenopausal women and 36
postmenopausal women for 3 month. Competitive radio-ligand binding
assays of different dilutions of the Isoflavone preparations resulted in a
binding to estrogen receptor (ER)-alpha and beta in a dose-dependent
manner. 2.5 mg Tibolone was applied daily in 24 post-menopausal
women for 6 months. Tibolone and its delta-isomer did predominantly
bind and transactivate progesterone receptor and androgen receptor,
whereas its 3alpha-hydroxy- and 3beta-hydroxy-tibolone predominantly bind and transactivate ER-alpha. Isoflavones did show a preference
for binding to the ER-beta. The PAP-smear test, to control for inflammation and cancer risk of the vagina and portio of the uterus, was conducted after 3 month application of either tibolone or isoflavones.
Isoflavone reduced vaginal PAP-test (superfiscial cells) for
perimenopausal women from 37578 to 16758 counts and for postmenopausal women from 49417 to 22875 counts. Tibolone increased
cell counts in postmenopausal women in the PAP-test. Hypertrophic
effects in the vagina as well as endometrium are believed to be facilitated by the ER-alpha and suppressed by ER-beta: Our in vivo results
correlate with our in vitro results: ER-beta affinity of isoflavones could
explain the reduction of cells in the PAP smear test and ER-alpha affinity of tibolone may be correlated to the increase of cells in the PAP
smear test by tibolone.
Wednesday, November 2, 2005
Can Soy Isoflavones Cause Endometrial Cancer? J.M.
Cline1, C. Wood1, A. Franke2, D. Bland1, D. Foth3; 1Wake
Forest University School of Medicine, USA, 2University of
Hawaii, USA, 3University of Cologne, Germany.
Estrogens markedly increase the risk of endometrial cancer in
women, and uterotrophic effects of estrogens are well-documented in
animal models including nonhuman primates. As many investigators
have shown, high-dose soy-derived isoflavonoids have estrogen-agonist
activity on the uterus in rodent models, including the induction of estrogen-dependent hyperplastic and neoplastic changes. A recent 5-year trial
of isolated soy isoflavones given in pill form to postmenopausal women
found a slight but significant increase in the incidence of endometrial
hyperplasia. This observation and its interpretation should be carefully
considered. Human observational studies show no evidence of estrogen
agonist effects of soy food consumption, and several short-term trials of
soy isoflavonoids in women have not shown any proliferation-inducing
effect on the uterus. Similarly, our nonhuman primate studies spanning
up to 3 years (~10 years of equivalent human lifespan) have shown no
evidence of isoflavonoid-induced endometrial hyperplasia at dietary
doses of soy isoflavonoids. We have shown a lack of uterotrophic effect
in short-term nonhuman primate studies using up to 10 times the dietary
exposure of soy isoflavonoids or purified equol. We have also demonstrated estrogen-antagonist effects of soy isoflavone supplementation
on estrogen-induced increases in uterine size, a finding which parallels
the pattern of endometrial cancer risk in the Shanghai breast cancer
study. Finally, in a 2-year trial of women given soy protein isolate supplementation at 58 mg/day, we found no association between serum
isoflavonoid concentrations and endometrial proliferation. These findings give us some confidence that there is not a significant uterotrophic
effect of dietary soy isoflavonoids in the human or nonhuman primate
endometrium, and in fact that there may be a protective effect in the
presence of higher endogenous or exogenous estrogens. However, the
potential remains for differences in risk:benefit ratio based on isoflavone
formulation or individual characteristics.
ACKNOWLEDGEMENTS • The Solae Company; NIH Grants NIH
HL45666; NIH AT00639
Oral Presentation Abstracts
symptoms across all weeks of soy IF. Health, sexual, emotional and
occupational quality of life was not significantly improved with soy IF,
and there was no difference between treatments on the Cognitive
Failures Questionnaire. However, frequency of sleep problems was significantly reduced after 4 weeks of soy IF, with no further improvements
at week 8. Increases in circulating levels of oestrogen were significantly correlated with the reduction of hot flushes, with no clear relationship
with other symptoms. Therefore, whilst this study was able to detect
some effects on specific symptoms, generally this more methodologically rigorous approach validated findings from earlier methodologically
weaker studies.
6th International Symposium on the
Oral Presentation Abstracts
10
Role of Soy
in Preventing and Treating Chronic Disease
Osteoporosis
Effects of the Phytoestrogen Genistein on Bone Loss,
Cardiovascular Risk Prevention and Climacteric
Symptoms: A Two Year Double Blind Placebo
Controlled Study. Interim Evaluation at One Year. F.
Squadrito, R. D’Anna, F. Corrado, A. Gaudio, M. Atteritano,
A. Bitto, D. Altavilla, and N. Frisina, University of Messina,
Messina, Sicily, Italy.
To confirm our previous findings on the phytoestrogen genistein
(1,2) 389 postmenopausal women with a BMD at the femoral neck of
<0.795 g/cm2 were randomly assigned to receive either genistein (54
mg/day) (n=198; age = 55±4; BMI= 24±3 ) or placebo (n. 191; age
=54±3; BMI = 25±4) in a two years double blind study.
Bone loss: Genistein reduced at 12 months the urinary excretion of
deoxypiridinoline (-35±13 %; p< 0.01) and increased the serum levels
of the bone-specific ALP (18±6%; p<0.01) and bone G1a protein (16±5
%). Genistein increased BMD in the femur and lumbar spine. Placebo
treatment did not affect any of those parameters.
Cardiovascular risk factors: By comparison with placebo, genistein
treatment at 12 months decreased fasting glucose (-14%; p<0.01), fasting
insulin (-51%; p<0.01) and HOMA-IR (-43%; p< 0.01) Genistein administration reduced fibrinogen (-18%; p< 0.05), urinary F(2) isoprostanes (24%; p<0.05) and plasma soluble ICAM (-16%; p<0.01).
Climacteric symptoms: By comparison with placebo, genistein caused a
reduction from baseline in both the mean number (-34%; p<0.01 vs placebo) and the mean severity score (-40%; p<0.05 vs placebo) of hot flushes.
Safety assessment: After a 12-months genistein treatment no significant difference in endometrial thickness was observed and vaginal
cytology (using the karyopycnotic index or the maturation value score)
showed no change.
Our 1-year data confirm that genistein is an effective and safe
alternative in postmenopausal women.
1) Morabito N. et al. J Bone Miner Res. 2002;17(10):1904-12.
2) Squadrito F. et al. Am J Med. 2003;114(6):470-6.
This work was supported by grant from MIUR (Ministero dell’Istruzione
dell’Università e della Ricerca).
Effects of Long Term Soy Dietary Supplementation on
Bone Mineral Density. F. Lovrien1, J. Williams2, B. Meyer1,
and D. Erger1, 1Sioux Valley Hospital, Sioux Falls, South
Dakota, USA, 2University of South Dakota, Vermillion,
South Dakota, USA.
A few studies in postmenopausal (PMP) women suggest that a
diet that includes soy may reduce bone loss. Findings in some studies
may be confounded by short study periods. We examined whether a diet
with soy protein for 2 y reduces losses in bone mineral density (BMD) in
PMP women. Subjects 1-5 years PMP were randomly assigned: soy/hormone replacement therapy (HRT; n=34), casein/HRT (n=33), soy/no-HRT
(n=28), casein/no-HRT (n=20). For 2 y, subjects ate a normal diet supplemented with 40 g soy (90 mg aglycone isoflavone) or casein daily.
Isoflavones (mg/g soy): genistein, 2.1; daidzein, 1.1; glycitein, 0.2. Both
supplements provided 1400 mg calcium. DEXA scans of hip and spine
were taken before and after 1 and 2 years. Comparisons (% change)
were made in BMD between soy/HRT and casein/HRT and between
soy/no-HRT and casein/no-HRT groups with an unpaired t-test. In the
spine, after 1 year BMD decreased 1.26±0.72% (mean±SE) and
2.21±0.56% in soy/no-HRT subjects and casein/no-HRT subjects (NS)
and 0.02±1.00% and 2.73±0.71% after 2 years (P<0.05). Changes in
BMD were similar between soy/HRT and casein/HRT after 1 and 2 years.
In the hip, no differences occurred after 1 or 2 y when comparisons were
made between soy/HRT and casein/HRT and between soy/no-HRT and
casein/no-HRT groups. Our findings indicate that long-term dietary supplementation with soy can reduce bone loss in PMP women, but this
protection may be selective for certain bones.
Supported by the South Dakota Health Research Foundation and
the South Dakota Soybean Research and Promotion Council
Effect of Soy Protein With or Without Isoflavones on
Bone Mineral Density in Postmenopausal Women. J.C
Gallagher, Prema Rapuri, Sue Longsdon, Jeff Detter;
Creighton University Medical School, Omaha NE 68131, USA.
Soy protein or its isoflavones have been suggested to have a positive effect on bone that may help to prevent the development of osteoporosis. The objective of the present study was to determine the effect
of soy protein with or without isoflavones on bone mineral density
(BMD) in postmenopausal women aged 55-72 years over 24 months.
Two hundred and thirty women were enrolled into the study. They were
randomly assigned to one of the three supplement groups, 25 g soy protein without isoflavones, 25 g soy protein containing 90 mg of
isoflavones (genistein and daidzein) or 25 g casein. Twenty four women
did not receive any supplemental protein and served as non protein
control. Spine, femoral neck, trochanter, total femur and total body BMD
measurements were performed by dual energy absorptiometry at baseline and at the end (24 months) of the study. The percent change in BMD
over baseline was calculated at the end of the treatment period. Data
was analyzed by ANOVA and Bonferroni correction was used for multiple comparisons. There were no significant differences between the
groups with respect to their age and body mass index. The baseline
BMD was not significantly different between the four groups. Bone loss
occurred in al three groups; our preliminary analyses indicate that the
unadjusted percent change in BMD was not significantly different
between the treatment groups and none of the protein treatment
groups prevented bone loss.
ACKNOWLEDGEMENTS • This work was supported by funding
from Solae Company.
Cognitive Function
Cognitive Effects of Soy Isoflavones in Older Adults:
Influence of Gender and ApoE Genotype. C.
Gleason1,2, S. Meade1,2, N. Lane1,2, T. Ohrt1,2, and S.
Asthana1,2, 1University of Wisconsin, Dept. of Medicine,
Sect. of Geriatrics, Madison, WI, USA, 2Madison VA GRECC,
Madison, WI, USA.
Evidence from basic science suggests that estrogen has neuroprotective and neuromodulatory effects; however, findings from the
Women’s Health Initiative Memory Study (WHIMS) have raised concerns
over the feasibility of traditional hormone therapies because of the
increased risk of serious adverse effects, including cognitive declines.
Soy isoflavones may serve as a critically needed alternative therapy to
traditional hormone therapy. The few human research projects that have
examined the cognitive effects of soy isoflavones offer intriguing, but as
yet preliminary support for isoflavones’ beneficial actions. Careful and
systematic study is needed to ascertain the merit of this potential therapeutic. This randomized, placebo-controlled, double-blind design clinical pilot study evaluated the effects of soy isoflavones on cognition in
older men and postmenopausal women. It was hypothesized that
11
2005 Abstracts
brains. Protein carbonyls in brain homogenates were derivatized with
dinitrophenylhydrazine (DNPH), then analyzed by 2D gel proteomics
and Western blots with anti-DNP antibody. While the overall patterns of
gel spots were similar, the 2D Western blots of brain proteins from the
GSE-fed animals were reduced (20-40% of controls). Gel spots reactive
with the anti-DNP antibody were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry. In view of the common proteins affected by GSE and SPI, we predict that proteins similar
to those protected by GSE from oxidation will be protected by SPI and
studies are ongoing to examine these effects. The DNP-reactive proteins
reported here are the first protein oxidations identified, using proteomic technologies, to be affected by dietary polyphenols. GSE, SPI, and
related polyphenols may have pleiotropic actions, including on gene
expression, protein modifications, and anti-oxidant activity.
These studies were supported in part by a subcontract of grant
P50-AT00477 from Purdue University (Connie Weaver, PI), by a grant
from the United Soybean Board, and by grant DAMD17-01-0469 from
the Dept of Defense Medical Research and Materiel Command Breast
Cancer Research Program. The grape seed extract preparation was generously provided by Kikkoman Corporation (Chiba, Japan), and the soy
protein preparations provided by Protein Technologies, Inc. (now Solae,
Ltd.). The operation of the UAB Comprehensive Cancer Center
Proteomics/Mass Spectrometry Shared Facility was supported in part by
a grant (P30 CA13148) from the National Cancer Institute to the UAB
Comprehensive Cancer Center (A. LoBuglio, PI). Purchase of proteomic
and mass spectrometry instrumentation in the Shared Facility was
enabled by Shared Instrumentation Grants to HK and SB from the
National Center for Research Resources.
Weight Control
16-Week Randomized, Controlled Trial of Soy vs.
Casein Meal Replacements for Weight Management
of Obese Women. J.W. Anderson 1, J. Fuller1, E. Konz1, and
A. Tabor2, 1University of Kentucky, Lexington, KY, USA,
2Revival Soy, Kernersville, NC, USA.
NIA grant K23 AG24302 Research staff and study volunteers from the
Wisconsin Comprehensive Memory Program The General Clinical
Research Center: grant M01 RR03186 from the National Center for
Research Resources, National Institutes of Health; Madison GRECC of
the Department of Veterans Affairs; Archer Daniels Midland provided
Novasoy® brand isoflavones tablets and matching placebo.
Prediction of Direct Anti-Oxidant Activity for Soy
Isoflavones in Mammalian Brain. S. Eliuk, J. Deshane, L.
Wilson, M. Kirk, S. Barnes, and H. Kim*, University of
Alabama at Birmingham, Birmingham, Alabama, USA.
Soy isoflavones protected against ovariectomy-induced cognitive
dysfunction in rats, however the molecular basis for this is unknown.
Proteomics of brains from animals given grape seed extract (GSE) or soy
protein isoflavones (SPI) indicated that there were common proteins
among those affected in the brains of animals that received either
polyphenol mixture. Since polyphenols have been shown to have antioxidant activity, we hypothesized that dietary GSE or SPI would attenuate brain protein oxidations. We studied a transgenic mouse model of
dementia, the Tg2576 mouse, which overexpresses amyloid precursor
protein in the brain, and the animals become cognitively impaired over
time, concomitant with the deposition of amyloid plaques in their
Meal replacements (MR) are very effective adjuncts to lifestyle
changes for weight loss and weight maintenance. Soy protein has specific effects on fat, glucose and lipid metabolism and promotes weight
loss in animals. This randomized, controlled trial compared effects of soy
meal replacements vs. casein meal replacements on body weight for
obese women participating in an intensive lifestyle intervention.
Volunteers consumed three MR shakes, either soy or casein, one MR
entrée, and five fruits or vegetables daily. Soy protein consumption was
62 g/d with 147 mg/d of isoflavones (aglycones); casein intake was ~68
g/d. 43 subjects enrolled and 35 (17 soy, 18 casein) completed the 16week study. Soy and casein shakes were well tolerated with good
adherence. With soy, subjects lost more visceral adipose tissue and had
greater reductions in LDL-cholesterol than with casein but differences
were not statistically significant. Outcome changes at 16 weeks for soy
and casein, respectively, with mean (SE) and significance from baseline*
were: weight, -12.8% (1.4)*,-14.0% (1.2)*; DEXA total fat, -21.8%
(2.4)*, -23.7% (2.0)*; visceral fat by mid-abdominal computerized
tomography, -30.3% (4.2)*, -27.2% (3.7)*; LDL-cholesterol, -12.5%
(4.2)*, -7.7% (4.4)*; and serum triglycerides, -12.5% (8.1), -6.7% (7.7).
This intensive intervention was associated with significant weight loss
averaging 17 pounds at 8 weeks and 28 pounds at 16 weeks with total
fat losses averaging 23% and visceral fat losses averaging 29%.
Including 3 MR shakes, either soy or casein, with one portion-control
entrée and 5 fruits or vegetables is a very effective weight loss intervention. • Supported in part by Revival Soy.
Oral Presentation Abstracts
isoflavone supplements would ameliorate age-associated cognitive
declines for healthy older adults (i.e., decrease rate of decline, stabilize
or enhance cognitive abilities) as compared with subjects on placebo.
Data were obtained from 30 cognitively healthy older adults (50%
women). Subjects received either 100 mg/day of soy isoflavones or a
placebo for 6 months. Cognitive evaluations were conducted at baseline
and at 1, 3, and 6 months after initiation of study medications.
Cognitive data, collected while on treatment with either isoflavones or
placebo were used to calculate ‘change from baseline’ scores. Women
on isoflavones outperformed women on placebo on a test of category
fluency (χ2 = 5.4, p=0.02). Men on treatment did not differ significantly from those on placebo in category fluency performance. The accompanying figure depicts these data. In addition to sex-differences, a
genetic risk factor for Alzheimer’s disease, the ApoE gene was also
found to influence response to isoflavone treatment. Presence of one or
two copies of the ApoE 4 allele increases a person’s risk for Alzheimer’s
disease by three- and nine-fold, respectively. Only men without this
genetic risk factor appeared to benefit from isoflavone treatment on a
measure of executive function, the Trail Making Test (χ2 = 3.94, p
=0.05). Although preliminary, these data suggest that isoflavone treatment is associated with improvements in language and executive function when compared with placebo. However, these beneficial effects are
moderated by subject characteristics, such as sex and ApoE genotype.
6th International Symposium on the
Poster Abstracts
12
Role of Soy
in Preventing and Treating Chronic Disease
Poster Presentation Abstracts
Please note: The following abstracts have not been edited for content. They appear as submitted by the authors.
Session I
Sunday, October 30, 2005 ..............1:00–7:00 p.m.
Monday, October 31, 2005 .....7:30 a.m.–12:30 p.m.
Athletic Performance
Post-Exercise Consumption of Soy Protein Promotes
General Protein Synthesis and mRNA Translation
Factor Activity in Skeletal Muscle. T. Anthony1 and M.
McNurlan2, 1Indiana University School of Medicine,
Evansville, IN, USA, 2State University of New York, Stony
Brook, NY, USA.
The objective of this study was to comparatively assess the stimulation of skeletal muscle protein synthesis and mRNA translation initiation following postexercise ingestion of various protein-containing
meals. Treadmill-acclimated rats (n = 6-8 per group) were randomly designated as nonexercised controls (NEX) or run for 2h at ~75%VO2max
and then orally administered one of four isocaloric meals: EC, purely
carbohydrate; ESI, carbohydrate plus 20% soy protein isolate; ESC, carbohydrate plus 20% soy protein concentrate (~3.5X elevated phytochemical content compared to ESI); EW, carbohydrate plus 20% whey
protein concentrate. One hour following exercise, all protein-containing
meals promoted the fractional rate of muscle protein synthesis to a similar extent above EC. Additionally, all protein-containing meals reduced
association of the mRNA cap binding protein, eIF4E with the translational repressor, 4E-BP1, and promoted formation of the eIF4E-eIF4G
active mRNA cap binding complex similarly. In contrast, phosphorylation of 4E-BP1 and the 70kD ribosomal protein S6 kinase (S6K1), a
factor involved in regulating cell size but whose exact role in protein
synthesis is unclear, was highest in EW. Insulin concentrations among
postexercise-fed rats were similar, but serum concentrations of
isoleucine, leucine, methionine, and threonine were highest in EW. Thus,
short-term recovery of protein synthesis and formation of the eIF4
active complex is promoted in muscle by both soy and whey protein in
exercised rats. However, acute phosphorylation of proteins downstream
of the mammalian target of rapamycin (mTOR) kinase is greatest in
response to whey protein, which is likely related to its higher branchedchain amino acid content. • This project was funded by Solae, Inc.
Soy Protein Intake Has Broad Positive Interactions
with Exercise. R. DiSilvestro, Ohio State University,
Columbus, OH, USA.
Previously, our laboratory has shown that in men, intake of high
isoflavone soy protein can impact biochemical indices of exercise recovery, and promote exercise training-induced lean body mass gain. More
recently, these results have been extended by finding the following
actions of soy protein intake:
• In aerobically, recreationally trained males, antioxidant functional
improves without depression of serum testosterone;
• There is improvement of aerobic performance recovery in some,
though not all of a group of recreationally trained males;
• A lowering of cortisol responses to resistance exercise occurs in recreationally resistance exercise trained men;
• In recreationally resistance exercise trained women, an enhancement
is produced in recovery from a moderately intense resistance exercise
session (based on a number of parameters);
• In recreationally resistance exercise trained women, a depression is
produced in oxidant stress between exercise sessions.
These results show that soy can exert a variety of positive interactions with exercise in both genders without a previously perceived
adverse effect in males (testosterone lowering). In addition, this work
shows that soy antioxidant effects can extend beyond immediate recovery, and that soy protein intake can impact not just biochemical indices,
but also physical performance. However, much more research is needed
in this last area.
Part of this work was supported by research gifts from Solae.
Cancer
Phytoestrogen Intake Prior to Diagnosis is Associated
with Improved Indicators of Breast Cancer Survival in
a Group of Newly-Diagnosed Australian Women. J. Ha1,
P. Lyons-Wall*2, D. Moore3, D. Tattam3, J. Boyages4, O. Ung4,
and R. Taylor1, 1School of Public Health, The University of
Sydney, Australia, 2School of Public Health, Queensland
University of Technology, Australia, 3Faculty of Pharmacy,
The University of Sydney, Australia, 4New South Wales
Breast Cancer Institute, Westmead Hospital, Australia.
Breast cancer incidence is lower and survival is higher in Asian
compared to Caucasian women and dietary phytoestrogens have been
examined as a possible reason for the disparity. The aim of this analytical cross-sectional study was to examine the associations between phytoestrogen intake prior to diagnosis and indicators of breast cancer survival. Subjects were 128 women aged 40-79 yr, newly-diagnosed with
invasive breast cancer at the New South Wales Breast Cancer Institute,
Westmead Hospital, Sydney. Intakes of dietary and supplemental phytoestrogens (isoflavonoids and lignans) were obtained using a specially-designed 112-item frequency questionnaire that estimated intake
over the previous year. Outcome variables relating to tumour characteristics, collected from pathology reports, included estrogen and progesterone receptor status, tumour size, histological grade and degree of
spread; lymphovascular invasion and positive axillary lymph nodes were
used as proxy indicators for breast cancer survival.
Results showed that after controlling for confounding factors, the
odds of being diagnosed with: a positive progesterone receptor increased
by a factor of 2.42 [95%CI 1.03-5.68] (p=0.04), a positive lymphovascular invasion decreased by 0.32 [0.12-0.85] (p=0.02), or smaller size
tumour decreased by 0.50 [0.26-0.94] (p=0.03), for each unit increase in
lignan consumption. The odds of being diagnosed with: any stage of cancer other than stage 1 decreased by 0.83 [0.70-0.98] (p=0.03) or a positive progesterone receptor increased by a factor of 1.22 [1.00-1.49]
(p=0.05), for each unit increase in isoflavonoid consumption. These
results suggest that higher phytoestrogen intake prior to diagnosis is
associated with improved prognosis in women with breast cancer.
13
2005 Abstracts
Objective: To investigate the effects of genistein (Gen) on the proliferation, DNA synthesis, nitric oxide (NO) production, nitric oxide synthase
(NOS) activity, induced nitric oxide synthase (iNOS) gene transcription
and expression of human gastric carcinoma cell line SGC-7901.
Methods: MTT method, 3H-TdR incorporation, DNA electrophoreses, spectrophotometric measurement, immunohistochemistry method,
western blot method, and RT-PCR were used to evaluate the possible
mechanism of cell growth inhibition.
Results: Gen at 20 µg/mL significantly inhibited the proliferation of
human gastric carcinoma cell line SGC-7901, inhibited DNA synthesis of
SGC-7901 and induced cell apoptosis. Exposure of SGC-7901 cells to Gen
resulted in statistically significant increase in iNOS mRNA transcription,
accompanied with increased iNOS protein expression, NO production and
NOS activity in the dose-dependent and time-dependent manners.
Conclusions: The increased expression of iNOS may contribute to
the growth inhibitory as well as apoptotic effects of Gen on gastric carcinoma cells. The results provide evidence for the potential usefulness of
Gen in the prevention and treatment of human gastric cancer.
This work was supported by research grants from the National Nature
Science Foundation of China.
The in vitro Metabolism of Estrogens by Human Fecal
Bacteria: A Comparison of Equol-Producers and NonProducers. C. Atkinson1, S. Berman2, W. Thomas1, and J.
Lampe1, 1Fred Hutchinson Cancer Research Center, Seattle,
WA, USA, 2Bastyr University, Kenmore, WA, USA.
Determinants of circulating levels of estrogens and estrogen metabolism are among the primary risk factors for breast cancer. Hormone
metabolism in humans involves several steps including intestinal bacterial metabolism. Thus, inter-individual differences in intestinal bacteria
may contribute to variation in disease susceptibility through effects on
metabolism and subsequent exposure to estrogens. One-third to onehalf of the population harbor bacteria that metabolize daidzein to
equol. Studies suggest that equol production may be associated with
reduced breast cancer risk, but mechanisms for this relationship are
unknown. Our aim was to determine whether fecal bacterial metabolism of estrogens differs according to equol-producer phenotype. Frozen
fecal samples from 34 women were available. According to previously
analyzed urine samples (collected after soy consumption) 20 were
equol-producers (EP), 12 were equol non-producers (ENP), and 2 had
trace amounts of equol in their urine. Thawed feces was incubated
anaerobically in media for 5d at 37°C with daidzein or the following
estrogens: estrone, estradiol, estriol, 2-hydroxyestrone, 16alpha-hydroxyestrone, and 2-methoxyestrone. After incubation, estrogens and
isoflavones were extracted and quantified by gas chromatography-mass
spectrometry. EP, compared to ENP, metabolized significantly more
estrone to estradiol, and 16alpha-hydroxyestrone to estriol (p≤0.05).
Although differences between EP and ENP in the amount of 2-hydroxyestrone metabolized to 2-hydroxyestradiol were non-significant, EP
were more likely than ENP to metabolize 2-hydroxyestrone to 2-hydroxyestradiol (χ2=4.1, p=0.04). All other differences were non-significant.
These preliminary findings suggest that differences in fecal bacterial
estrogen metabolism may exist between EP and ENP.
This work was supported by a Department of Defense Breast Cancer
Research Program Concept Award (DAMD17-03-1-0604), and Fred
Hutchinson Cancer Research Center.
Phytoestrogens do not Affect the Growth of Breast
Cancer Tumors in Mice. D. Gallo1, C. Ferlini1, M. Fabrizi1,
S. Prislei1, A. Riva2, P. Morazzoni2, E. Bombardelli2, and G.
Scambia1, 1Department of Obstetrics and Gynecology,
Catholic University of the Sacred Heart, Rome, Italy, 2INDENA S.p.A., Milan, Italy.
Consumption of soy-derived products has been encouraged for
post-menopausal women as a natural alternative to hormone replacement therapy. One group of women most in need of and who frequently use alternatives consists of breast cancer patients; however, the estrogenic effects of isoflavones observed in some experimental systems
have recently led to considerable controversy among health professionals over the use of soy by breast cancer patients.
The present study was designed to investigate the effects of a standardized soy extract (Soyselect®, SSE) on the growth of estrogen dependent (MCF-7) and estrogen-unresponsive (MDA-MB-231) human breast cancer xenografts in athymic mice. Results obtained provided evidence that
MCF-7 tumors did not grow over the treatment period (five weeks) in
ovariectomized females receiving 50 or 100 mg/kg/day SSE (oral route);
administration of SSE also did not affect the 17β-estradiol-sustained
growth of MCF-7 tumors in mice. Similarly, no effect on tumor growth was
observed in SSE-treated mice bearing MDA-MB-231 xenografts. Data from
pS2, PR and cyclin D1 mRNA expression in tumors suggest that SSE was
able to induce a moderate estrogenic effect in MCF-7 cells without increasing cellular proliferation and tumor growth. Besides, when used in association with low dose 17β-estradiol, it displayed anti-estrogenic activity. The
expression of other genes involved in tumor progression and angiogenesis,
such as Thrombospondin 1 and Transforming Growth Factor β2, was also
evaluated in tumor samples, results showing a decrease in mRNA expression upon SSE treatment. Biological effects will be also discussed in relationship with plasma levels of isoflavones.
Prospective Survey Evaluating the Use of Soy
Products in Women with Breast Cancer. J. Franciose, C.
Lammersfeld, J. Grutsch, P. Vashi, and S. Walker, Cancer
Treatment Centers of America, Zion, IL, USA.
Introduction: Many studies have investigated the potential role of
soy in the prevention of breast cancer. A number of components in soy
appear to have anticancer properties, including the isoflavones genistein
and daidzein. The use of soy by women with breast cancer is currently
being questioned because of the estrogen-like effects of isoflavones and
possible interactions with tamoxifen. Clinicians providing nutrition counseling for these women are concerned because the availability of soy
foods and supplements has increased dramatically in the past few years.
The goal of this study was to quantify the intake of isoflavones in women
with breast cancer to determine if their intake is of clinical significance.
Methods: We evaluated a consecutive case series of 100 women
with breast cancer treated at Cancer Treatment Centers of America
between 09/03 and 02/04. After obtaining informed consent, each
patient was asked to complete a soy food frequency questionnaire (FFQ)
that was scored by Fred Hutchinson Cancer Research Center, the institute that developed and validated the FFQ.
Results: The mean age was 50.5 years (std. dev. = 9.4; range 3170) and the mean BMI was 27.3kg/m2 (std. dev. = 6.75; range 17-59).
Poster Abstracts
Effect of Genistein on iNOS Expression and its Relation
to Proliferatory Inhibition of Gastric Carcinoma Cells.
D.F. Song1,2, S.K.C. Chang1, and H.B. Cui2, 1Department of
Cereal & Food Sciences, North Dakota State University, 376
IACC, Fargo, ND, USA, 2Department of Food Nutrition &
Hygiene, Public Health College, Harbin Medical University,
Harbin, Heilongjiang Province, China.
6th International Symposium on the
Poster Abstracts
14
Role of Soy
in Preventing and Treating Chronic Disease
Genistein and daidzein consumption was limited to 65 (65%) patients
with a mean intake of 81.5 mg/week (std. dev. = 153; range 0.02-682)
and 52.9 mg/week (std. dev. = 98.8; range 0.02-482) respectively.
Conclusions: Our study suggests that the isoflavone intake of
breast cancer patients treated at our hospital was quite variable. Thirtyfive patients (35%) reported no soy intake. The mean daily intake translates into 11.6 mg genistein and 7.4 mg daidzein, which is the equivalent of less than 1⁄4 cup of tofu per day. This amount is slightly higher
than has been previously reported in non-Asian American women.
Dietary Soy Isoflavones have no Adverse Effects on
the Non-Human Primate Prostate, Testis, or Mammary
Gland. D. Perry1, J. Spedick1, M. Adams1, A. Franke2, S.
Walker1, and J. Cline1, 1Department of Pathology, Section on
Comparative Medicine Wake Forest University School of
Medicine, Winston-Salem, NC, USA, 2Cancer Research
Center of Hawaii, Honolulu, HI, Honolulu, HI, USA.
In mice, dietary isoflavone supplementation at an equivalent of 120
mg/person/day has produced marked prostatic atrophy. In human prostatic cancer cell lines, isoflavones have induced antiproliferative and apoptotic effects. Some Asian diets contain 50 mg/day isoflavones compared
to some traditional Western diets which deliver 2 to 3 mg/day. It has been
suggested that this may explain why Asian men have approximately one
tenth the incidence of prostate cancer. Yet, no evidence of prostatic atrophy or reduced reproductive function is seen in these populations. We
assessed the effects of dietary soy isoflavones on mammary, prostatic,
and testicular morphology and function in age matched, adult male
cynomolgus monkeys. Diets differed only by protein source: 1) a soy-free,
casein/lactalbumin based diet or 2) and 3) soy protein isolate diet containing an equivalent of 75 or 150 mg/person/day soy-derived
isoflavones. Total serum isoflavones were 67+/-23 (soy-free diet), 799+/44 (75 mg/person/day equivalent diet), and 1458+/-80 nM (150 mg/person/day equivalent diet) (mean+/-sem, p<0.0001). Diet did not alter
serum estradiol and testosterone concentrations, epididymal or testicular
sperm counts nor prostate, testicular, epididymal, or seminal vesicle
weights. Mammary gland morphometric and histopathologic analysis
revealed no gynecomastia. We conclude there was no morphologic evidence of adverse reproductive effects of soy isoflavones at doses equivalent to 75 to 150 mg/person/day in adult male monkeys.
Beneficial Effects of Regular Consumption of Whole Soy
Foods on Serum Lipids, Lipid Peroxidation, High
Sensitivity CRP and Blood Pressure in Perimenopausal
Women: A Randomized, Controlled, Crossover Trial. S.
Songchitsomboon1, K. Chanda2, D. Danboonchant2, J.
Manonai3, J. Hong4,And S. Komindr5, 1Research Center, Faculty
of Medicine, Ramatibodi Hospital, Mahidol University,
Bangkok 10400, Thailand, 2Graduate Program of Nutrition,
Faculty of Medicine, Ramatibodi Hospital, Mahidol University,
Bangkok 10400, Thailand, 3Department of ObstetricGynecology, Faculty of Medicine, Ramatibodi Hospital,
Mahidol University, Bangkok10400, Thailand, 4School of Food
and Life Science, Inje University, Korea, 5Department of
Medicine, Faculty of Medicine, Ramatibodi Hospital, Mahidol
University, Bangkok 10400, Thailand.
Background: Hypercholesterolemia, menopausal symptoms and
osteoporosis are the major health problems in middle-aged Thai women
and elsewhere. Meanwhile, little is known about the effects of commonly consumed soy foods on cardiovascular risk factors in Thai people.
Objective: To determine whether incorporating reasonable amount
of soy foods in a self selected diet, low in saturated fat and cholesterol
would reduce markers of cardiac risk in perimenopausal women
Method: Thirty-seven perimenopausal women aged 40 - 59 years participated in a randomized crossover trial with two 12-wk diets and 4-wk
washout period before and between treatments. The study diets consisted of a control diet (soy-free diet) and an isocaloric soy-rich diet with
their own recipes (25 g soy protein as soymilk, tofu, texture soy protein
and sausage contained more than 50 mg isoflavones daily). Subjects
were asked to fill-in daily eaten soy food lists. Blood levels of lipid profile,
lipid hydroperoxides, conjugated dienes, high sensitivity c-reactive protein (hs CRP), antioxidant capacity in water- and lipid-soluble substances,
glucose, and isoflavones were measured at the start and end of each diet.
Results: It was noted that at the beginning of the study, general
characteristics of both groups were similar. Good compliance to the diet
was shown by the significant elevation of serum levels of daidzein and
genistein during the soy-rich diet period. Compared with baseline, significant improvement in the blood levels of the following FBS, LDL-C,
HDL-C, total cholesterol/HDL-C, LDL-C/HDL-C, total antioxidant capacity
of water-soluble substances and diastolic blood pressure were observed
after both diets. Moreover, a soy-rich diet resulted in significantly lower
total cholesterol, lipid hydroperoxides, hs CRP and systolic blood pressure. In addition, the changes of total cholesterol and 10-yr coronary
heart disease risk in the soy-rich diet differ significantly from the
changes in the control diet.
Conclusions: This study provides evidence that long-term ingestion
of soy foods has beneficial effects on blood lipid and CRP concentrations. This study was support in part by a grant from the Thai Health
Promotion Foundation. The analysis of isoflavones in food and blood
samples were supported by NutraTech Co, Ltd, Thailand and Unifood
Tech Laboratory, Korea.
Using Biomarkers to Assess Phytoestrogen Intake in
Breast Cancer Patients During a Dietary Intervention
Study. T. Rawjee1, G. Spahn2, C. Kennemann2, A. Blake3, J.
Mackinnon1, G. Dobos2, and M. Ritchie1, 1Bute Medical School,
University of St. Andrews, Fife, Scotland, 2Dept. of Internal and
Integrative Medicine, University Duisburg-Essen, Essen,
Germany, 3Scottish Crop Research Institute, Dundee, Scotland.
OBJECTIVE: To determine phytoestrogen (PE) intake by urine analysis in 20 German breast cancer patients following either A) a
Mediterranean diet within a 10 week structured multimodal day clinic
programme or B) an home based exercise programme without nutritional intervention.
MATERIALS AND METHODS: Urine samples (24 hour urine collections as well as timed urine samples) were collected before and after
each intervention. Group A attended a nutrition day within the Dept. of
Integrative Medicine which included a single meal high in soy and other
PE rich foods. Analysis for the isoflavones (genistein and daidzein) was
carried out by Liquid Chromatography-Mass Spectrometry
RESULTS: Dietary PE intake increased significantly in breast cancer
patients ingesting the PE-rich meal (from a mean intake of 11.7mg/d to
a mean intake of 28.7mg/d). No difference in PE intake was observed
between the exercise group and the multimodal intervention group in
the day clinic at the end of the study.
CONCLUSIONS: This study shows clearly that a diet rich in PE could
raise urinary PE concentrations threefold if breast cancer patients would
15
2005 Abstracts
Are Phytoestrogens Beneficial in Breast Cancer
Patients? Use of a Newly Validated Biomarker to Assess
Phytoestrogen Intake in Women With Breast Cancer and
Controls. J. Mackinnon1, T. Rawjee1, A. Blake3, G. Spahn2, G.
Dobos2, and M. Ritchie1, 1Bute Medical School, University of
St. Andrews, Fife, Scotland, 2Dept. of Integrative Medicine,
University Duisburg-Essen, Essen, Germany, 3Scottish Crop
Research Institute, Dundee, Scotland.
OBJECTIVES: To compare phytoestrogen (PE) intake in women with
non-metastatic breast cancer, women with metastatic breast cancer and
healthy controls.
METHODS: Timed urine samples were obtained from German
breast cancer patients with non-metastatic disease who had completed
treatment, and age matched healthy Scottish controls. Urinary PE concentrations are valid biomarkers of PE intake and LC-MS urinalysis was
used to determine dietary PE intake. Patients with metastatic breast
cancer are currently being recruited and results of urinalysis are expected by Sept 2005.
RESULTS: Urinalysis to date indicates mean PE intake in breast cancer patients was significantly higher than mean PE intake in age-matched
controls (p<0.0001). Mean PE intake in breast cancer patients (n=17)
was 10.46mg/day compared with 2.76mg/day in controls (n=11).
DISCUSSION: This is the first study to use a validated biomarker to
compare PE intake in different populations and patient groups. Despite
dietary variation between countries, the use of validated biomarkers
enables the influence of specific dietary phytochemicals on disease risk
and disease characteristics to be identified. Although the data are preliminary, this study supports the hypothesis that increasing PE intake
may not prevent the occurrence of breast cancer in adult women.
However, it also supports the hypothesis that a higher PE intake may
help to restrain tumour progression and metastasis, since breast cancer
patients with a higher PE intake than the general population did not
show disease progression. Comparison with PE intake in women with
metastatic breast cancer will provide further evidence to confirm or
refute this hypothesis.
This study was funded by the Carstens Foundation, Essen,
Germany and the Melville Trust for the Care and Cure of Cancer,
Edinburgh, Scotland.
Phytoestrogen-Gene Associations with Sex Hormone
Levels Among Postmenopausal Women in EPIC-Norfolk.
Y. Low1, A. Dunning2, M. Dowsett3, and S. Bingham1, 1MRC
Dunn Human Nutrition Unit, Cambridge, United Kingdom,
2Cancer Research UK - Department of Oncology, Cambridge,
United Kingdom, 3Institute of Cancer Research, London, UK.
Phytoestrogens have been hypothesised to stimulate sex hormone-binding globulin (SHBG) production and modulate sex hormone
levels through inhibiting enzymes involved in estrogen metabolism. In
this large cross-sectional study, we investigated the relationship
between phytoestrogen exposure and plasma sex hormones and SHBG
levels in postmenopausal women and their relation with polymorphisms in genes involved in estrogen signalling and metabolism.
Plasma estradiol, testosterone, androstenedione, estrone and
SHBG were measured in 1968 free-living healthy postmenopausal
women in the Norfolk arm of the European Prospective Investigation
into Cancer and Nutrition (EPIC) study. We have previously shown that
urinary phytoestrogen levels correlated strongly with serum phytoestrogen levels (R=0.81 to 0.91, p<0.001) and can serve as suitable dietary
biomarkers (1). Urinary levels of seven phytoestrogens (daidzein, genistein, glycitein, O-desmethylangolensin (O-DMA), equol, enterodiol and
enterolactone) were measured and used as biomarkers for dietary phytoestrogen intake. Nineteen single nucleotide polymorphisms (SNPs) in
the HSD17B1, CYP19, SHBG, ESR1 and NR1I2 genes were genotyped
using end-point Taqman assays.
After adjusting for potential confounders, O-DMA was positively
correlated with plasma estradiol (R=0.059, p=0.009), equol was negatively correlated with plasma estradiol (R= -0.050, p=0.029) and
enterodiol was negatively correlated with estrone (R= -0.076, p=0.013)
and testosterone levels (R= -0.057, p=0.016). Genistein and enterolactone were positively correlated with plasma SHBG (R=0.046, p=0.047
and R=0.110, p=0.0000015 respectively). The relationships between
phytoestrogens and plasma sex hormone levels were significantly different among women with different genotypes for selected polymorphisms in genes involved in estrogen signalling and metabolism, suggesting phytoestrogen-gene interactions.
Even in Western populations with low habitual soy consumption,
phytoestrogen exposure exerts modest effects on plasma sex hormone
levels in postmenopausal women and diet-gene interactions may be
involved.
Reference 1. Grace PB, Taylor JI, Low Y-L, Luben RN, Mulligan A,
Botting NP, et al. Phytoestrogen concentrations in serum and spot urine
as biomarkers for dietary phytoestrogen intake and their relation to
breast cancer risk in European Prospective Investigation of Cancer and
Nutrition-Norfolk. Cancer Epidemiol Biomarkers Prev 2004;13:698-708.
Grant support: UK Medical Research Council, Cancer Research UK
and the Agency for Science, Technology and Research, Singapore.
Microarray Analysis of Gene Expression Regulation By
Equol in MCF-7 Cells. J.S. Kim1, J.H. Kim1, J.R. Kim1, C.H.
Jang1, H.A. Lim1, S.J. Lee3, and D.Y. Kwon2, 1Department of
Animal Science & Biotechnology, Kyungpook National
University, Daegu, S. Korea, 2Korea Food Research Institute,
Sungnam, Kyunggi, Republic of Korea, 3Division of Food
Science, Korea University, Seoul, Republic of Korea.
Equol, a metabolite produced from daidzein by gut fermentation,
drew much attention due to the stronger potential in preventing chronic diseases than parent compound. We examined the effect of equol on
the gene expression in mammary tumor MCF-7 cells using microarray.
The expression of 1122 genes out of total 33766 genes probed
appeared to be changed by more than 2-fold. We also performed Kmeans clustering for 1122 genes whose expression was significantly
modulated, and also assigned each of those genes to one of 10 kinds of
biological processes according to their function. Twelve clusters in
which each cluster had unique expression pattern were obtained.
Eighteen genes involved in apoptosis changed significantly their expression and most of them were upregulated by equol treatment in MCF-7
cells. Forty six genes among the significantly regulated 1122 genes were
associated with cell cycle. A large proportion of genes whose expression
Poster Abstracts
continuously adhere to such a diet. At present, no such recommendation
can be made, but if beneficial effects of PE should be substantiated for
breast cancer patients, the study shows the value of a nutritional intervention. A diet rich in fruit and vegetables which is generally recommended and followed by health conscious German breast cancer
patients conveys a significantly higher PE content than in age-matched
healthy controls from Scotland.
The study was funded by the Carstens foundation, Essen, Germany
and the Melville Trust for Care and Cure of Cancer, Edinburgh, Scotland.
6th International Symposium on the
Poster Abstracts
16
Role of Soy
in Preventing and Treating Chronic Disease
was changed belonged to the family of signal transduction, nucleoside,
nucleotide and nucleic acid metabolism. Half of genes involved in cell
proliferation and differentiation were upregulated while 68 percent of
genes involved in amino acid metabolism were increased in MCF-7 cells
treated with 100 uM equol. In conclusion, equol appears to have potential to cause cell growth inhibition by upregulating genes associated
with apoptosis in mammary tumor cells.
This study was supported by a grant of the Korea Health 21 R&D
Project, Ministry of Health & Welfare, Republic of Korea (A050376).
Isoflavones
Discrepancy Between Self-Claimed and Actual Soy
Intakes. M. Sagara1, M. Mori1, H. Mori2, and Y. Yamori*3,
1Research Institute for Production Development, Kyoto,
Japan, 2Institute for Health Restoration, Nishinomiya,
Japan, 3International Center for Research on Primary
Prevention of Cardiovascular Diseases, Kyoto, Japan.
Objective: Recent reports indicate the importance of soy
isoflavones for the risk reduction of lifestyle-related diseases. This
knowledge is becoming popular among the general public in Japan. To
investigate a discrepancy between self-claimed and actual soy intakes,
we carried out a questionnaire survey asking the frequency of soy intake
and the depth of concern in soy, while we measured 24-hour urinary
isoflavone excretion to estimate the dietary intake.
Design and Methods: One thousand Japanese in total, 500 of each
gender and 250 of each decade at the age range from 20 to 59, were
randomly selected from Eastern and Western Japan to respond to the
questionnaire through the Internet in Japan, 2005. After obtaining
informed consent, we collected 24-hour urine for the measurement of
isoflavone excretion from 49 men and 56 women living in the same districts in Japan as the respondents to the questionnaire.
Results: According to the analysis of the questionnaire, 62.8% of
the respondents thought they should take soy products every day and
45.7% believed they were taking soy products every day. 84.8% of the
respondents like soy products and 97.0% thought soy products were
good for health, but only 20.3% knew about the effects of soy
isoflavones. From the analysis of 24-hour urinary isoflavone excretion,
however, 66.0% of the whole volunteers for the urine collection and
38.1% of those who claim to take soy products every day were taking
less than 40mg/day of isoflavones, which should be recommended for
the prevention of lifestyle related-diseases from our world-wide survey
on the association of 24-hour urinary isoflavone excretion with the mortality rates of coronary heart diseases and breast and prostate cancers
as well as isoflavone effects on risk reduction by our nutritional intervention studies.
Conclusions: The significant proportion of Japanese are not taking
desirable amount of soy products which are recommended for the prevention of lifestyle-related diseases, although the large portion of
Japanese know the importance of soy intake and believe they are taking soy products every day.
Genetic Manipulation of Soybean Seed Isoflavones.
V. Lozovaya, O. Zernova, A. Lygin, and J. Widholm, Dept. of
Crop Sciences, University of Illinois at Urbana-Champaign,
Urbana, IL, USA.
A number of soybean transgenic lines has been generated via
bombardment of embryogenic cultures (cv. Jack) with mixtures of cassettes, harboring the important genes of the phenylpropanoid pathway,
such as PAL5 (phenylalanine ammonia- lyase), CHS6 (chalcone synthase) , IFS( isoflavone synthase) under the seed specific lectin promoter and a selectable marker HPT gene under 35 S promoter. The segregation of genes in the T1 generation was found in 3 out of 8 lines analyzed. One line transformed with PAL5, CHS6, IFS and HPT has been followed in 4 generations until homozygous. This line showed the expression of the target genes in RT- PCR tests of immature seeds and had a
reduced total isoflavone level, a higher proportion of glycitein and a
lower proportion of daidzein in mature seeds compared to the untransformed control. We found that the cotyledons of untransformed seeds
contain about 70-80% of the isoflavones, and embryos, that account for
about 3% of the whole seed weight, contain 20-30% of the total seed
isoflavones. The main isoflavones of cotyledons are genistein and
daidzein and only trace amounts of glycitein were detected in cotyledons. However, embryos contain a high glycitein proportion.
Interestingly, the expression of phenolic genes (PAL5, CHS6, IFS)
resulted in decreased total isoflavone content in cotyledons only, while
there were no changes in total isoflavone content in embryos of seeds
collected from transgenic plants compared to controls. This indicates
that the lectin promoter drives genes in cotyledons and not in embryos.
This project was carried out with funds from the United Soybean Board,
Illinois Soybean Program Operating Board, and Soybean Disease
Biotechnology Center.
Effect of Ipriflavone on the Growth Performance and
Related Physiological Function in Rats. H. Ma, Z. Han*,
G. Wang, and S. Zou, Key Lab of Animal Physiology &
Biochemistry, Ministry of Agriculture, Nanjing Agricultural
University, Nanjing, Jiangsu, China.
Ipriflavone is a synthetic daidzein-derived compound able to modulate the oxidative phosphorilation and to exert a direct inhibitory effect
on osteoclast activity and possibly to stimulate the osteoblast activity.
At present, ipriflavone is mainly used in the treatment of osteoporosis in clinic. The aim of the present investigation was to evaluate
the effect on growth performance.
The experiment was conducted with 20 rats of 28 days old fed ipriflavone at dosage of 5 mg/kg in diet for 5 weeks. Compared with those
of male control group, the body weight gain increased by 38.82
(p<0.01), the average daily body weight gain increased by 38.65%
(p<0.01) and feed intake/daily body weight gain was lowed 62.17 %;
The relative percentage to the body weight of muscle increased by
56.84% (p<0.05), fat relative percentage was lowed 5.71% (p>0.05);
The serum urea-N was low 10.17 % (p<0.05), but the activity of glutamic pyruvic transaminase and alkaline phosphatase and the level of
testoterone increased by 33.67 % (p>0.05) and 43.76 % (p<0.05) and
773.53% (p<0.01), respectively. The ratio of RNA/DNA of muscle
increased by 10.40 %. Compared with those of female control group,
there were no significant effect of ipriflavone on the average daily body
gain and feed intake/daily body weight gain. The relative percentage to
the body weight of muscle increased by 2.22% (p>0.05), fat relative
percentage was lowed 16.92% (p<0.05); The activities of glutamic pyruvic transaminase and alkaline phosphatase, the levels of serum urea-N
and estrogen were decreased.
Effects of Isoflavone on Aromatase Activity and
Muscle Growth in Male Rats. H. Ma, Z. Han*, G. Wang,
and S. Zou, Key Lab of Animal Physiology & Biochemistry,
Ministry of Agriculture, Nanjing Agricultural University,
Nanjing, Jiangsu, China.
17
2005 Abstracts
Mechanism of Soybean Isoflavone on Regulation of
Testosterone Secretion in Rat Leydig Cell. H. Ma, Z.
Han*, S. Zou, and G. Wang, Key Laboratory of Animal
Physiology & Biochemistry, Ministry of Agriculture, Nanjing
Agricultural University, Nanjing, Jiangsu, China.
Isoflavones belong to one kind of phytoestrogens occurring naturally in many plants. Isoflavones have structural similarities to human
17β-estradiol and can bind to the oestrogen receptor in many tissues
and exert weak estrogenic activity. The weakly oestrogenic diphenols
formed influence sex-hormone production, metabolism and biological
activity. Also, isoflavone would affect on some of the most important
steroid biosynthetic enzymes may result in beneficial modulation of hormone concentration and action in body. In our laboratory, a series of
research shows that daidzein could enhance the concentration of
testosterone in serum and development of muscle cockerel and rat.
In the present study we have investigated the effects of soybean
isoflavones on the regulation of testosterone secretion in rat Leydig cell
by assaying the concentrations of cAMP, the activities of PKA and aromatase. Result showed that 20~100ng/mL of daidzein and geistein
decreased 3H-TdR incorporation in DNA of rat Leydig cell. Also, daidzein,
genistein and estradiol could promote cAMP accumulation and activate
the activity of PKA and inhibited the activity of aromatase thereby
improved testosterone secretion in rat Leydig cell. Daidzein and genistein have no effect on the activity of adenylate cyclase , but estradiol
could improve the activity of adenylate cyclase.
Temperature and Soil Moisture Effects on Soybean
Seed Isoflavones. A.V. Lygin1, V.V. Lozovaya1, A.V.
Ulanov1, R.L. Nelson2, and J. Daide3, 1Dept. of Crop
Sciences, University of Illinois, Urbana, IL, USA, 2USDAAgricultural Research Service, University of Illinois at
Urbana-Champaign, , Urbana, IL, USA, 3Ecole Supérieure
d’Agriculture de Purpan, Toulouse Cédex 03, France.
The objective of our research was to evaluate the effects of air
temperature and soil moisture conditions during soybean seed fill on
seed isoflavone concentrations of soybean cultivars with known differences in isoflavone concentration. Two French cvs., Imari and Queen,
and three U.S. cvs., Dwight, Jack and Loda, all in maturity group II were
studied. Soybean plants were grown in the greenhouse under intermediate (18/28°C), 9.5 hour night/14.5 hour daytime temperatures with
high soil moisture conditions. Beginning at the R6 growth stage plants
were subjected to either intermediate (18/28°C), low (13/23°C) or high
(23/33°C) 9.5 hour night/14.5 hour daytime temperatures with either
low or high soil moisture conditions. The overall results show that low
temperatures and high soil moisture conditions produced the highest
seed isoflavone concentrations with changes in temperature having the
larger effect. The changes in daidzein and genistein concentrations were
similar to changes in total isoflavones but the glycitein concentration
was much less affected. All cultivars showed a 3-fold increase in total
isoflavone concentrations at the low temperature regime compared to
the high temperature regime. Soil moisture and air temperature have
clear effects on the total isoflavone concentration, but the ranking of
cultivars by average isoflavone concentration remained consistent. This
shows that isoflavone potential is under strong genetic control.
This project was carried out with funds from the Illinois-Missouri
Biotechnology Alliance, the United Soybean Board, the College of ACES
Value-Added Program, the Illinois Soybean Program Operating Board,
the Illinois Agricultural Experiment Station and the USDA Agricultural
Research Service.
Determination of Major Isoflavone Components
Based on HPLC Technology among Southern Soybean
Varieties in China. J.-M. Sun, F.-X. Han, and A.-L. Ding,
Institute of Crop Sciences, Chinese Academy of Agricultural
Sciences, Beijing, P.R. China.
The contents of major isoflavone components in two hundred
forty-nine soybean varieties from southern six provinces of China were
analyzed by HPLC technology. Results showed that six major components of isoflavone could be determined by HPLC in soybean seeds,
including daidzin (D), glycitin (GL), genistin (G), malonyldaidzin (MGD),
malonylglycitin (MGL) and malonylgenistin (MGG). The component with
the highest content was malonyl-isoflavone (61.2%), and correlations
among components were statistically significant. A great variation
among varieties was presented in 249 varieties, and the variation coefficient was 49.6%. Total isoflavone content of cultivar
Haimenhonghuangdouyi was the highest (4932.3µg/g), that of cultivar
Baoyingdengxifeng was the lowest (367.1µg/g). There was significant
difference on isoflavone contents in different varieties among various
provinces. The average content of isoflavone in Zhejiang province was
the highest (2717.2µg/g), and the lowest content (1181.8µg/g ) in
Anhui province. There was a greatly significant positive correlation
between isoflavone content and date of growth (r = 0.319***), a significant positive correlation between isoflavone content and weight of
100 seeds, and two negative correlations between isoflavone content
and oil content (r = -0.45***) and protein content (r = -0.136) in soybean seeds.
Intervention Study of Soy Isoflavone Supplement for
Menopausal Women. N. Ishiwata1, S. Watanabe2, Y.
Omori3, M. Murayama3, W. Mohara3, A. Yamada3, and T.
Wada3, 1Atomi Junior College, Bunkyo-ku, Tokyo, Japan,
2National Institute of Health and Nutrition, Shinjyuku-ku,
Tokyo, Japan, 3Tokyo University of Agriculture, Setagayaku, Tokyo, Japan.
OBJECTIVES: Double-blind, cross-over clinical intervention study
by isoflavone (IF) tablet were carried out on 111 peri-menopausal
Japanese women.
DESIGN: 122 peri-menopausal women participated in the study
after mail invitation to 656 mothers of graduates of women’s college.
Finally 111 women came to the baseline survey, which included questionnaire for job, dietary habit, life habit, menopausal symptoms, menstrual condition, and physical examination including biochemistry.
Poster Abstracts
An experiment was conducted with 20 Sprague-Dawley rats of 28
days of age, supplemented with daidzein, ipriflavone and 7-hydroxyisoflavone 5mg • Kg-1, respectively and 0 mg • Kg-1 in the control group
in diet to investigate the mechanism of daidzein, ipriflavone and 7hydroxyisoflavone on muscle growth. Compared with those of control
group, daidzein, ipriflavone and 7-hydroxyisoflavone can increased the
ratio of RNA/DNA in the leg muscle by 19.09%, 9.09% and 15.45%,
respectively. Meanwhile, the blood level of testosterone was increased
and the level of estradiol decreased with aromatase activity alleviated.
These results suggested that daidzein, ipriflavone and 7-hydroxyisoflavone could promote the animals growth by inhibiting the activity
of aromatase which reduce the conversion of testosterone to estradiol,
thereby increase the content of testosterone in the blood.
6th International Symposium on the
Poster Abstracts
18
Role of Soy
in Preventing and Treating Chronic Disease
Women were divided to 3 groups; placebo (PL), IF tablet 40 mg a day
(IF-L) and 80 mg a day (IF-H). Participants were allowed to take up to
20mg IF from daily ordinary meals.
RESULT: At baseline survey, 49 women were pre-menopausal and
62 were post-menopausal. After 3 months of intervention, serum biochemistry revealed lowering effects of total cholesterol and triacylglycerol. In hormonal response, post-menopausal women showed a different attitude from pre-menopausal women. There was no significant difference in the menopausal symptom score among PL, IF-L and IF-H
groups at baseline. As compared to PL, IF-L in the pre-menopausal
group significantly altered specific symptom category score of motornerve system. The IF-L pre-menopausal group reported a significant
improvement in chill (p=0.05), shortness of breath (p=0.05), excitation
(p=0.02), worry (p=0.04), tiredness (p=0.03) and joint aches and pains
(p<0.01). Nervousness (p=0.02) decreased in the IF-L post-menopausal
group. We would show the final cross-over results at the Conference.
Genistein and Daidzein Reduces Level of Total Serum
Cholesterol in Orhidectomized Middle-Aged Rats. B.
Sosic-Jurjevic1, D. Brkic*2, B. Filipovic1, V. Ajdzanovic1, and
M. Sekulic1, 1Institute for Biological Research, Belgrade,
Serbia and Montenegro, 2Crown Agents, Belgrade, Serbia
and Montenegro.
Soybean consumption during menopause or andropause is associated with potential health benefits, such as prevention of atherosclerosis progression and bone preservation. In this study we examined the
effects of chronic genistein and daidzein treatment on serum level of
total cholesterol in orhidectomized middle-aged rats. Moreover, we
compared the effects of soy isoflavones with corresponding chronic
estradiol and testosterone treatments. Male Wister rats, 14.5 months
old, were orhidectomized (ORH) under Ketamine anesthesia (0.015
mg/kg b.w.). Two weeks after the surgery animals were divided into 5
groups (n = 8), which were subcutaneously treated with genistein (30
mg/kg b.w.), daidzein (30 mg/kg b.w./every day), estradiol dipropionate
(0.625 mg /kg b.w) every day for 3 weeks, or 2 times a week with depotestosterone enanthate (4.76 mg/kg b.w.).The control ORH group
received the vehicle (sterile olive oil) alone. The animals were sacrificed
24h after the last treatment, sera were separated from trunk blood after
decapitation. The total cholesterol level was determined by CHOD-PAP
method. In comparison to control rats, soy isoflavones genistein and
daidzein significantly decreased the level of serum cholesterol (by 23%
and 15%, p<0.05, respectively). However, this decrease was smaller in
comparison to the effects of chronic testosterone treatment, which lowered the same parameter by 27%, p< 0.01. Interestingly, estradiol did
not change the level of serum cholesterol in ORH males. These results
indicate that both soy isoflavones, genistein and daidzein have a positive effect on cholesterol status in middle-aged ORH rats, but genistein
was more efficient than daidzein in decreasing the serum cholesterol.
regard to sensitivity, having a quantitative detection limit of 2-10 nM for
isoflavones and their metabolites from a 1 ml serum sample. In the present study, analysis of isoflavones has been carried out on an ABI-Sciex
4000 Qtrap mass spectrometer using heated nebulizer atmospheric
pressure chemical ionization (HN-APCI)-MRM-MS. Sera from normal
subjects and sera spiked with known amounts of isoflavones and their
metabolites and internal standards were treated with βglucuronidase/sulfatase and extracted with ether. Extracts were analyzed by gradient reverse-phase HPLC-HN-APCI-MRM-MS. RESULTS:
Although sensitivity differences existed between individual isoflavones,
the quantitative detection limit of each isoflavone was 10 fmol or better. This translates to a concentration limit of as little as 0.1 nM from a
1 ml serum sample, or 1 nM from 0.1 ml sample. Unlike previous applications, this analysis was performed using 15 different channels,
enabling a wide range of isoflavones, polyphenols and their metabolites
to be examined simultaneously. Chrysin (5,7-dihydroxyflavone) was
superior to apigenin as an internal standard for this analysis. CONCLUSIONS: Analysis of isoflavones in a modern triple quadrupole mass spectrometer by HN-APCI-MRM-MS permits their accurate and specific
quantification even in sera from subjects on non-soy control diets, or
from small animals.
This research was supported by the Purdue-UAB Botanicals Center
for Age-Related Disease (P50 AT00477) and a NIH/NCRR Shared
Instrumentation Grant (S10 RR19231).
Isoflavone Metabolism
Absorption of Soybean Isoflavones in Isolated Rat Small
Intestine. H. Ma, Z. Han*, S. Zou, and G. Wang, Key Lab of
Animal Physiology & Biochemistry, Ministry of Agriculture,
Nanjing Agricultural University, Nanjing, Jiangsu, China.
The present study aims at investigating absorption mechanism of soybean isoflavones, daidzein and genistein, in the small intestine of male
rats in vitro. The content of daidzein and genistein in and out of the
reverted small intestinal sacs and in the mucous using reverted small
intestinal sacs were determined by RP-HPLC, at the same time the activity of ATPase in the mucous was assayed to study the absorption of
daidzein and genistein. Results showed that the time of the highest
absorption of daidzein and genistein were 2~3 h and 3~4 h in the
reverted small intestinal sacs, respectively. The absorption rate was
gradually decreased with the concentration of isoflavone increasing.
The concentration of isoflavone in the mucous exhibited distinct dosedependent and time-dependent. Daidzein and genistein could significantly enhance the activity of total ATPase in small mucous. This indicates that the absorption of soybean isoflavone in rat small intestine in
vitro was mainly by active transportation.
High Sensitivity, Quantitative LC-MS Analysis of
Isoflavones and Their Metabolites in Physiological
Fluids. K. Jones, R. Moore, S. Barnes, University of Alabama
at Birmingham, Birmingham, AL,USA.
Comparison of the in vitro Metabolism of Isoflavones
by Fecal Flora from Human Flora-Associated Mice
and Human. M. Tamura1 and H. Saitoh2, 1National Food
Research
Institute, Tsukuba,
Ibaraki,
Japan,
2Biotechonology and Food Research Institute, Fukuoka
Industrial Technology Center, Kurume, Fukuoka, Japan.
Quantitative analysis of isoflavones and their metabolites in physiologic samples from clinical and small animal studies is an important
research endpoint. Although LC-electrospray ionization multiple reaction ion monitoring mass spectrometry (LC-ESI-MRM-MS) has been a
gold standard for analysis of many xenobiotics and is very specific, it is
inferior to radioimmunoassay and electrochemical detection with
There has recently been great interest in the biological activity of
equol, especially with regards to the prevention of osteoporosis and
prostate and breast cancer. In this study, we investigated the in vitro
metabolism of daidzein, daidzin, and genistein by fecal flora, in human
flora-associated mice (HFA mice) and a human donor. The in vitro incubation of feces with isoflavones demonstrated that we had successful-
19
2005 Abstracts
Assessment of Dietary Isoflavone Intake by the 24hour Urinary Excretion in Japanese Women. M. Mori1,
M. Sagara1, H. Mori2, and Y. Yamori1,3, 1Research Inst. for
Production Development, Kyoto, Japan, 2Institute for
Health Restoration, Nishinomiya, Hyogo, Japan,
3International Center for Research on Primary Prevention
of Cardiovascular Diseases, Kyoto, Japan.
Objective: Recent reports indicate the importance of soy
Isoflavones(ISO) is the risk reduction of lifestyle related-diseases. Mostly
the amounts of ISO taken form diets are estimated from nutritional survey or by 24-hour urinary ISO excretion. We measured 24-hour urinary
ISO excretion in 137 healthy volunteers given different doses of ISO
tablets (ISO glycosides : 40-150 mg) supplemented in their daily diets in
order to clarify the relationship between the dietary intake and urinary
excretion of ISO.
Design and Methods: After obtaining informed consent 137 healthy
Japanese pre-and-post menopausal volunteer women (40-63 years old)
were asked to restrict the daily intake of common soybean diets such as
tofu, soymilk and fermented soybeans for 7 weeks. From the 3rd to 7th
week different doses of ISO tablets from 40 mg to 150 mg of ISO glycosides (20.9% daidzein, 4.5% genistein, 10.5% glycitein) were given for
4 weeks. Questionnaires about dietary customs were asked and health
surveys including blood sampling and 24-hour urine collection were carried out before and after the ISO tablet administration.
Results: The amount of urinary Isofravone excretion were confirmed to be 6.78±10.98, 21.82±11.62, 42.77±28.41, 62.59±37.98,
and 69.25±38.7 umol/day in the participants given 0, 40, 75, 100 and
150 mg of dietary ISO supplements, respectively. Therefore, the association of the urinary ISO excretion (UI) with the amount ISO intake (DI)
was : DI (mg)=2.22UI (umol/day).
Conclusions: Our study indicates that the daily dietary intake of
ISO (DI) can be estimated by analyzing the amount of 24-hour urinary
ISO excretion(UI) from the equation : DI(mg)=2.22UI (umol/day).
Bioavailability of Soy Isoflavones as Affected by
Gender, Age, and Food Matrix in Rats. E. Sepehr*1,5, P.
Robertson1, G. S. Gilani1, G. M. Cooke2,5, B. P-Y Lau3, And J.
Fournier4, 1Nutrition Research Division, Health Product and
Food Branch, Health Canada, Banting Research Centre,
Ottawa, ON, Canada; 2Toxicology Research Division, Health
Product and Food Branch, Health Canada, Banting Research
Centre, Ottawa, ON, Canada, 3Food Research Division, Health
Product and Food Branch, Health Canada, Banting Research
Centre, Ottawa, ON, Canada, 4Animal Resources Division,
Health Product and Food Branch, Health Canada, Banting
Research Centre, Ottawa, ON, Canada, 5Department of
Cellular and Molecular Medicine, Faculty of Medicine,
University of Ottawa, ON, Canada.
There is considerable interest in consumption of plant-based foods
rich in phytoestrogens, more specifically the isoflavones and their derivatives from soy, due to their reported beneficial effects such as their
potential to prevent breast and prostate cancer as well as prevent coronary heart disease and osteoporosis. However, there is still insufficient
information regarding the pharmacokinetics of the absorption and
excretion of soy isoflavones. Moreover, data on the effects of sex, age
and of the source of isoflavones on their bioavailability are limited. The
present study was conducted to obtain information on the effects of
sex, age and source of soy isoflavones on their bioavailability in a rat
model. Three sources of isoflavones; Novasoy (extracted isoflavones
supplement), a mixture of synthetic aglycosides (daidzein, genistein and
glycitein) and a mixture of synthetic glycosides (daidzin, genistin and
glycitin) were administered once only by oral gavage at 20 or 40 mg/kg
body weight. The first phase of the animal project has been completed,
plasma samples were collected at 0, 10, 30 min and 1, 2, 8, 24, 48hr,
and urine and fecal samples at 0-2,2-8,8-24,24-48hr post dosing. The
second phase of the animal project will measure the concentrations of
isoflavones and their metabolites in plasma following a single intravenous injection of synthetic aglycosides (daidzein, genistein and
glysitein) and synthetic glycosides (daidzin, genistin and glysitin). The
extent of absorption will be determined for each respective dosage form
by comparing the area under the curve (AUC) of the plasma-concentration time curve after intravenous (iv) administration with that following
oral administration. The extent of bioavailability will then be calculated
as: F =AUCoral/ AUCiv x 100. Primarily results showed a significant gender difference in uptake of isoflavones in male and female Sprague
Dawley rats. No equol production was observed within the first 48hr
post dosing in male rats. However, female rats started producing equol
after 24hr post dosing. Uptake of isoflavones was lower in old rats (20
months) compared with young rats (3 months)and old rats were able to
produce equol as early as 8hr post dosing. The bioavailability data will
assist in assessing safety, nutritional quality and health benefits of
dietary phytoestrogens.
Intra-Individual Variability of Phytoestrogen
Excretion During Three Months Soy Consumption. S.
Rebello1, A. Duncan2, K. Wangen1, W. Thomas1, and M.
Kurzer1, 1University of Minnesota, St Paul, Minnesota, USA,
2University of Guelph, Ontario, Canada.
Adaptation to long-term soy exposure has not been well characterized. To better understand this, we studied changes in urinary
isoflavonoid excretion in 11 postmenopausal women (7 equol excretors
and 4 non-excretors) who consumed soy protein isolate containing 65
mg of isoflavones per day for 3 months. Urinary concentrations of Odesmethylangiolensin (ODMA), daidzein, equol, genistein and glycitein
were measured by GC/MS at baseline and at the end of months 1, 2 and
3. Excretion of all phytoestrogens increased from baseline to month 1
(p < 0.05). ODMA and daidzein excretion at month 2 tended to be higher than at month 1 (p < 0.20). At month 3, genistein excretion tended
to be higher (p=0.148) and glycitein excretion was significantly higher
(p < 0.05) than at month 1. When the group was divided into equol
excretors and non-excretors, the trends toward increased ODMA and
glycitein excretion were only observed in non-excretors (p < 0.20). In
Poster Abstracts
ly transferred the potential for equol production from human feces to
HFA mice. There was no significant difference in the concentration of
equol produced by incubation of feces from HFA mice in daidzein or
daidzin. The average equol concentrations were, however, higher in
feces from HFA mice than in those from their donor. In feces from both
HFA mice and their human donor, the ratio equol/daidzein was significantly higher in the suspensions incubated with daidzin than with
daidzein. The amount of genistein produced by incubation with genistein was significantly higher in fecal suspensions from HFA mice than
human. The present study is the first to compare the equol production
by fecal flora from human feces with those from HFA mice in vitro. Our
results suggest that degree of daidzein metabolism by intestinal flora
might be different from the degree of genistein metabolism by intestinal flora. The HFA mice produced in our experiment might also be useful
for investigating the biological activity of equol in detail.
6th International Symposium on the
Poster Abstracts
20
Role of Soy
in Preventing and Treating Chronic Disease
equol excretors, there was a trend toward an increase in equol excretion
throughout the study. One subject did not excrete equol at month one
although she became an equol-excretor at months 2 and 3. Changes in
equol excretion tended to be inversely related to changes in ODMA
excretion in equol excretors (R= -0.64; p=0.119). Within-subject coefficients of variation tended to be low for ODMA (11%), daidzein (7%)
and genistein (11%), and higher for glycitein (19%) and equol (20% in
non-excretors and 39% in excretors). Thus, equol excretion in particular
is highly variable, in both excretors and non-excretors.
Food Matrix-Assisted Control of Urinary Isoflavone
Metabolite Profiles in Humans. K. Riedl1, T. Bohn1, M.
Rogers2, Y. Vodovotz1, S. Clinton1, and S. Schwartz1, 1The
Ohio State University, Columbus, OH, USA, 2University of
Michigan, Ann Arbor, MI, USA.
Health benefits due to soy consumption have been suggested to
result from biotransformation of isoflavones by gut bacteria to biologically active components. Daidzein can be metabolized in sequence to
dihydrodaidzein (dhD) and equol or o-desmethylangolensin (ODMA).
We hypothesized that the food matrix could affect isoflavone metabolism and designed a soy bread and soy-tomato juice to test this hypothesis in a human feeding trial. Subjects (n=18) consumed 3-4 slices of
soy bread (75-100 mg of isoflavone/d) for 3 days collecting a 24 h urine
on the third day and 11 subjects consumed 2 x 177 mL cans of tomatosoy juice (81 mg of isoflavones/d). Isoflavone conjugates in 2 mL urine
(with internal standard 2’,4’ dihydroxy 2-phenyl acetophenone) were
digested enzymatically and extracted twice with diethyl ether. Extracts
were pooled, dried and redissolved in 350 µL MeOH then analyzed by
LC-MS/MS calibrating with authentic standards (genistein, glycitein,
daidzein, ODMA, dhD, equol, dihydrogenistein, 6-OH ODMA). When
comparing the two matrices there was a dramatic difference in the profile of urinary daidzein metabolites: consumers of the tomato-soy juice
showed only 24% accounted for by equol and ODMA in contrast to
58% for consumers of soy bread. In subjects consuming the juice, a portion of daidzein was metabolized to dhD and both compounds readily
absorbed. The bread matrix apparently delayed daidzein absorption
such that more reached the distal gut microflora and was converted to
equol and ODMA. This study demonstrates that the extent of daidzein
metabolism can be modulated by altering the food matrix.
Funding was provided by USDA-grant No M-01-RR00034 and the
University of Michigan General Clinical Research Center, grant #M01RR00042.
Pharmacokinetic Characteristics of Bonistein™
(Synthetic Genistein) in Humans. U. Ullmann1, J.
Metzner2, and H. Oberwittler3, and J. Elliott1, 1DSM
Nutritional Products, Kaiseraugst, Switzerland, 2Galmed,
Halle/Saale, Germany, 3Institute for Clinical Pharmacology,
Bobenheim, Grunstadt, Germany.
Bonistein™ is a novel product consisting of 99.4% synthetic
genistein. It is a dietary ingredient being developed for bone health. Up
to now, Bonistein™ pharmacokinetics (PK) were assessed in three clinical phase I trials in young healthy men and women and in postmenopausal women. Single doses of 30, 60, 150 and 300 mg (bolus)
and repeated dosing OID (up to 2 weeks, steady state (SS)) of 30, 60 and
120 of Bonistein™ were investigated. Plasma genistein (fraction
unbound) and its conjugates (total genistein) were determined by a
standardized LC/MS analytical method using D4-genistein as an internal standard.
Orally ingested Bonistein™ is rapidly absorbed from the gut. In
doses up to 150 mg, AUCs and Cmax values increased dose-proportionally. At higher doses the intestinal absorption seems to be limited and
the plasma increase is less than dose-proportional. Average elimination
half-lives (t1/2) were calculated to be 8.4 h (bolus) and 10.8 h (SS),
respectively. Subgroup analysis (ANOVA) showed a slightly better
bioavailability of Bonistein™ in females. In postmenopausal women
Bonistein™ was more bioavailable and had a prolonged terminal elimination half-life. In all studies the volunteers ingested Bonistein™ after
an overnight fast and remained fasted for several hours p.a.
In conclusion, Bonistein™ reaches PK steady state after 4 to 5
days and behaves dose-proportional up to 150 mg. No systemic accumulation occurs. Bonistein™ was safe and well tolerated.
Further Development of a Biomarker of Isoflavone
Intake. J. Mackinnon1, E. Vink1, A. Blake2, T. Rawjee1, A.
Riches1, and M. Ritchie1, 1Bute Medical School, University
of St. Andrews, Fife, Scotland, 2Scottish Crop Research
Institute, Invergowrie, Dundee, Scotland.
OBJECTIVES: To validate 24-hour urine collections (24hU), timed
spot urine samples and timed blood samples as biomarkers of
isoflavone intake up to 100mg/day.
METHODS: Healthy volunteers consumed 50mg/d or 100mg/d soy
isoflavones (ISF) or placebo (one week of each) in a randomised, double-blind, cross-over study. 24hU, timed spot urine samples and timed
blood samples were obtained at baseline and at two points during each
intervention. ISF content of the samples was assayed by LC-MS.
Background dietary intake was assessed using food diaries and a validated database of the ISF content of foods.
RESULTS: Significant correlation (r = 0.5083, t=3.686, n = 42, p
<0.001) was observed between genistein concentration in timed spot
urines and dietary ISF intake. The correlation between ISF intake and 24hour urinary genistein excretion was also significant (r = 0.59, t = 2.42,
p <0.04). Average urinary excretion of genistein (in timed spot urines)
corresponding to intakes of 100mg isoflavones/day was 1.8 times
greater than that for 50mg isoflavones/day (p = 0.024). Plasma samples
from this group and from a further 40 volunteers are awaiting analysis.
CONCLUSIONS: 24hU, timed spot urine samples and timed blood
samples have previously been validated as biomarkers of ISF intakes up to
60mg/d. This study demonstrates that dietary and/or supplemental intake
of ISF up to 100mg/d can be assessed using timed spot urines and 24hU.
These samples can therefore be used as an accurate, objective measure of
high ISF intakes in future observational and intervention studies.
This study was funded by The Melville Trust for the Care and Cure
of Cancer, Edinburgh, Scotland. Isoflavone tablets were kindly supplied
by Lamberts Healthcare Limited, Kent, England.
Monkeys Exhibit Sex Differences in Behavioral and
Physiological Responses to a High-Isoflavone, SoyBased Diet. J. Kaplan1, M. Adams1, N. Simon2, J. Wagner1,
and A. Franke3, 1Wake Forest University School of
Medicine, Winston-Salem, NC, USA, 2Lehigh University,
Bethlehem, PA, USA, 3Cancer Research Center of Hawaii,
Honolulu, HI, USA.
We have shown previously that male monkeys deriving their
dietary protein from soy are more aggressive and less affiliative than
casein fed controls. Here we systematically compare the social and
physiological responses of group-housed, soy (n = 31) and casein treated (n = 30) male monkeys to the responses of similarly housed pre-
21
2005 Abstracts
Determination of the Factors that Influence the
Ability of Equol Production. S. Vanhemmens, K. Decroos,
and W. Verstraete, LabMET, University of Ghent, Belgium.
Recent research reveals the key role of equol in the beneficial
health effects of a soy diet. This metabolite, formed by colon bacteria
from daidzein, has a superior antioxidative and estrogenic action and a
better absorption compared to its precursor. Unfortunately, only 35% of
the Western population is able to form this metabolite. The identity of
the responsible bacteria, the microbial-ecological mechanisms and the
nutritional factors that influence this conversion are part of our research
at LabMET. We obtained a stable and transferable mixed culture of four
bacteria (EPC4) transforming daidzein into equol. These strains were
identified as Lactobacillus mucosae, Enterococcus faecium, Finegoldia
magna and a yet unknown Veillonella sp. related strain. This mixed culture was used to evaluate the influencing factors during in-vitro equol
production. It was found that hydrogen gas plays a crucial role. The
speed of equol production was related to the hydrogen gas concentration in the headspace and in the absence of hydrogen gas there was no
equol production anymore. Research with the SHIME (Simulator of the
Human Intestinal Microbial Ecosystem) has shown that equol production takes place in the last part of the colon. However, methanogenic
and sulfate reducing bacteria use also a lot of hydrogen gas and are
also established in the last part of the colon. To investigate if there is a
competition for hydrogen gas between equol producing bacteria and
other hydrogen gas consuming bacteria, both in-vitro and in-vivo
research is done at LabMET.
The in-vitro research includes the incubation of pure cultures of
methanogenic and sulfate reducing bacteria with EPC4 in different combinations. These results show that EPC4 has a higher affinity for hydrogen than methanogenic and sulfate reducing bacteria because the production of methane and hydrogen sulfide was reduced while equol production was the same when EPC4 was incubated with the
methanogenic and sulfate reducing bacteria. When 1% of EPC4 was
added to faecal samples from non-equolproducers with either
methanogenic or sulfate reducing abilities, the same results were
obtained. Our current in-vivo research evaluates these results on human
population level. The faecal samples of hundred menopausal women,
consuming soy milk (Alpro Soja) or isoflavone tablets (Acatris) during 4
days, are analysed by real time PCR in order to quantify the
methanogenic and sulfate reducing bacteria. Also other important bacterial groups are quantified. Equol in urine samples is analysed by HPLC.
This could reveal the relation between the diversity in colon bacteria
and the production of equol.
The in-vivo study was conducted in cooperation with Acatris
Holding BV (Giessen, The Netherlands) and Alpro Soya (Wevelgem,
Belgium). S.V. benefits from a FWO scholarship (Fund for Scientific
Research)
Bioavailability of Isoflavones and Flavones
Correlates with Human Gut Microbial Degradation.
A. Simons, M. Renouf, S. Lee, S. Hendrich, and P. Murphy*,
Iowa State University, Ames, IA, USA.
The relationship between flavonoid structure, gut microbial degradation in vitro and human bioavailability in vivo was determined. Gut
microbial fermentations from 33 healthy subjects (20 men, 13 women)
were conducted with 15 flavonoids, genistein, daidzein, glycitein, apigenin, naringenin, kaempferol, luteolin, quercetin, myricetin, hesperetin,
chrysin, flavone, 5,4’-dihydroxyflavone, 6,4’-dihydroxyflavone, 7,4’dihydroxyflavone, & 5,3’-dihydroxyflavone. Flavonoids with 5, 7 and 4’
– hydroxyl groups, genistein, apigenin, naringenin, luteolin, kaempferol
and quercetin, rapidly disappeared compared to the other flavonoids (k
= 0.46 ± 0.10 h−1 vs. 0.07 ± 0.02 h−1, p < 0.0001). The methoxylated
flavonoids hesperetin and glycitein were rapidly demethylated and disappeared with k = 0.24 ± 0.21 h−1. Human bioavailability of flavonoids
was investigated in 10 volunteers (5 men, 5 wome). Subjects ingested
28 mg (104 µmol) genistein and 16 mg (62 µmol) daidzein from
soymilk, 422 mg (1549 µmol) naringenin and 8 mg (26 µmol) hesperetin
from grapefruit juice and 115 mg (381 µmol) quercetin from sautéed
onions with 1 week washout in between foods. Peak plasma concentrations of flavonoids analyzed over the 24 hour period ranged from 0.01
– 1 µM. The bioavailability, calculated as urinary excretion as the percentage of ingested dose, was significantly lower for the rapidly degraded flavonoids, genistein (7.2 ± 4.6 %), hesperetin (7.3 ± 3.2 %),
quercetin (5.6 ± 3.7 %) and naringenin (3.2 ± 1.7 %) compared to
daidzein (43.4 ± 15.5 %, p = 0.02). These data reveal that the chemical
structure of flavonoids affect their gut microbial degradation rate and,
thus, their overall bioavailability.
This work was supported by the Center for Designing Foods to
Improve Nutrition, Iowa State University, USDA Special Grant No. 20030679, Project No. 3302 of the Iowa Agriculture and Home Economics
Experiment Station.
Identification of Human Fecal Microorganisms and
Human Fecal Microbial DNA Sequences Influencing
Isoflavone Degradation: Putative Bioavailability
Biomarkers. M. Renouf, A. Simons, and S. Hendrich*, Iowa
State University, Ames, IA, USA.
High fecal isoflavone disappearance rate, which predicts low
isoflavone bioavailability in humans, may coincide with distinct fecal bacterial species. Fecal DNA was extracted from 33 adults, bacterial 16S
rDNA variable region sequences amplified by PCR and separated by
denaturing gradient gel electrophoresis (DGGE). The four highest genistein and glycitein degraders, as measured by HPLC analysis of in vitro
anaerobic fecal incubations, shared 5 DNA bands of greater intensity
than in feces of the 4 lowest degraders. Some of these fecal microbial
DNA sequences corresponded to known human gut microbes
Poster Abstracts
menopausal monkeys consuming the same soy (n = 46) or casein (n =
45) based diets for comparable periods of time (≥ 20 months). The soy
protein contained 1.88 mg/isoflavones/g, approximately equivalent to a
human consumption of 130 mg isoflavones/day. In contrast to the
males, dietary soy had no significant effects on the aggressive behavior
of females. Furthermore, while soy-fed males exhibited reductions in
affiliation, soy consumption increased sociality among females. Males
and females also exhibited disparate physiological responses to the
diet. Hence, soy significantly increased insulin sensitivity in females
while reducing it in males. Among the plasma lipids, soy increased HDL
and reduced LDL cholesterol concentrations to a significantly greater
degree in females than males. Notably, females also exhibited significantly lower plasma concentrations of genistein, daidzein and equol
than males, despite consuming the same diet. In sum, a soy proteinbased diet relatively high in isoflavones had uniformly salutary effects
on premenopausal monkeys but had effects that were either less beneficial or adverse to males. These sex differences may relate to interactions with ovarian or testicular hormones (which were unchanged by
soy treatment), or to differences in isoflavone metabolism (as reflected
by plasma concentrations).
Supported in part by grants from the National Heart Lung and
Blood Institute (HL045666, HL079421) and the National Cancer
Institute (CCSG CA71789). Soy protein supplied by Solae Corporation.
6th International Symposium on the
Poster Abstracts
22
Role of Soy
in Preventing and Treating Chronic Disease
(Bacteroides, Prevotella and Clostridium groups. But several fecal microbial DNA sequences differing between high and low isoflavone degraders
were not identifiable using BLAST (NIH system for DNA sequence identification). In nutrient-rich and nutrient-poor in vitro fecal incubation systems, Bacteroides ovatus and acidifaciens, Eubacterium ramulus,
Clostridium orbiscindens and Tannerella forsythensis were human gut
microbial species that increased human fecal isoflavone degradation
compared with control under both conditions. These species may be partly responsible for human gut microbial disappearance of isoflavones in
both high and low isoflavone degraders. Prevotella pallens and oralis,
Bacteroides eggerthii, fragilis and uniformis significantly increased fecal
isoflavone disappearance only in nutrient-poor conditions, which may
mimic increased fecal isoflavone degradation in humans with relatively
slow gut transit time, as previously observed. Microbial species such as B.
eggerthii, as well as several DNA sequences we discovered that correspond with currently unknown microbial species, may be useful biomarkers to distinguish subjects of low isoflavone bioavailability.
Supported by Iowa State University Bailey Career Research
Development Award.
Varying Isoflavone Content of Soy Protein Affects
Plasma Isoflavones but not Plasma Lipids in
Surgically Postmenopausal Monkeys. J. Kaplan1, T.
Clarkson1, M. Anthony1, T. Badger2, and H. Chen1, 1Wake
Forest University School of Medicine, Winston-Salem,
North Carolina, USA, 2Arkansas Children’s Hospital
Research Institute, Little Rock, Arkansas, USA.
Background: Soy protein compared to casein improves the plasma
lipid profiles of monkeys, an effect often attributed to the isoflavones.
In this study we fed monkeys diets containing equivalent amounts of
soy protein that was either high or low in isoflavones to determine
directly the effect of isoflavones on plasma lipids.
Materials and Methods: 26 postmenopausal cynomolgus monkeys
were used in a crossover study involving 2, 3-month treatment periods.
During the first period animals consumed a diet deriving 37% of protein
from soy and containing either 65 (Lo) or 141 (Hi) mg total
isoflavones/1800 Cal. During the second treatment period animals
crossed over to the opposite diet. Plasma HDLC, LDL+VLDLC and triglycerides (TG) were measured 3 times in each phase while plasma
isoflavones were determined once in each phase.
Results: Dietary isoflavone content significantly influenced plasma
isoflavone concentrations (total isoflavones: Hi 553 vs. Lo 136 nmol/L,
p<0.0001; genistein: Hi 98 vs. Lo 72, p=0.21; daidzein: Hi 112 vs. Lo 58,
p=0.04; equol, Hi 333 vs. Lo 10, p<0.0001). In contrast, the two treatment diets were not associated with any significant differences in plasma lipid profiles (TG, Hi 44 vs. Lo 36 mg/dl, p=0.44; HDLC, Hi 47 vs. Lo
52, p=0.22; LDL+VLDLC, Hi 266 vs. Lo 293, p=0.13; TPC:HDLC, Hi 8.2 vs.
Lo 8.3, p=0.90).
Discussion: The results suggest that a doubling of dietary
isoflavone content does not provide additional plasma lipid benefits, a
negative outcome that was particularly surprising in view of the 30-fold
difference in equol concentrations.
In Vitro Study of Microbial Transformations of
Daidzein in a Dynamic Model of the Gastrointestinal
Tract. Karel Decroos1, Ellen Eeckhaut1, Steffi Vanhemmens1,
Sam Possemiers1 and Willy Verstraete1, 1Laboratory of
Microbial Ecology & Technology (LabMET), Department of
Biochemical and Microbial Technology, Ghent University,
Coupure Links, 653, B-9000 Gent, Belgium.
Soy isoflavones get a lot of attention for their potential role in preventing chronic disease. An important issue with respect to bioavailability
and bioactivity of dietary isoflavones is the metabolic fate after ingestion,
in particular the microbial transformations in the colon, which are subjected to great interindividual variability. From the soy isoflavone daidzein
about one third of the population forms the metabolite equol, with superior biological activities and better absorption. Up to date, very little is
known about the environmental conditions in the colon, the dietary factors
and the bacteria involved in this important microbial transformation.
At the Laboratory of Microbial Ecology & Technology we developed a five-stage reactor system in which the human gastrointestinal
tract is simulated (SHIME, Simulator of the Human Intestinal Microbial
Ecosystem). This system consists of five reactors which each represent a
particular part of the GIT, with the emphasis on the colonic part. Using
a polyphasic approach we are able to monitor the transformations of
food components (HPLC, LC-MS, IC, GC-MS) and the composition of the
microbial community (PCR-DGGE, real-time PCR, flow cytometry).
Previously, we isolated a unique microbial consortium (EPC4) from
a human faecal sample efficiently transforming daidzein into equol (1).
The microbial metabolism of soy isoflavonoids was examined in the
SHIME with faecal inocula from different volunteers. The different
daidzein-metabolizing phenotypes, observed from in vivo urinary excretion data, were confirmed in vitro. Supplementation of EPC4 to the
SHIME, inoculated with a faecal sample from a non-producing individual
and fed with a diet containing 3,5 g soygerm powder/d, led to high equol
production (150µmol/L) in the distal parts of the colon. These results
prove that the concept of using a probiotic for the stimulation of equol
production is valid. Moreover, the SHIME was shown to be an excellent
tool for the study of microbial transformations of dietary phytoestrogens.
REFERENCES
(1) K. Decroos, S. Vanhemmens, N. Boon & W. Verstraete (2005) Isolation
and characterization of an equol-producing mixed microbial culture
from a human faecal sample and its activity under gastrointestinal conditions. Arch. Micr. (183) 45-55
Effects of Isoflavone Supplements vs. Soy Foods on
Blood Concentrations of Genistein and Daidzein.
Christopher D. Gardner1, Lorraine M. Chatterjee1, Brian M.
Oliveira1, and Adrian A. Franke2, 1Stanford Center for
Research in Disease Prevention and the Department of
Medicine, Stanford University Medical School, Stanford, CA,
USA, 2Cancer Research Center of Hawaii, Honolulu, HI, USA
BACKGROUND: Although interest in soy isoflavones and their possible health benefits have grown substantially, understanding of
isoflavone pharmacokinetics is still limited.
OBJECTIVE: The objective was to examine the pharmacokinetics of
isoflavone concentrations over a 24-hour period among healthy adults
consuming either soy foods or soy isoflavone tablets at different doses.
DESIGN: Twelve generally healthy adults were randomly assigned
to the order of three phases in a crossover trial. The three phases were
isoflavone tablets at 1) 154 mg/day or 2) 308 mg/day, and 3) soy foods
designed to provide a calculated 96 mg isoflavones/day, with daily
intake divided equally among the three main meals (doses in aglycone
equivalents). After 6 days on each of the study phases, plasma
isoflavone concentrations were determined on the seventh day of dosing at 0, 4, 8, 10, 12 and 24 hours.
RESULTS: Average levels of total isoflavone concentrations at the
23
2005 Abstracts
Cardiovascular Disease
Anti-Hypertensive Effects of Nicotianamine in
Spontaneously Hypertensive Rat (SHR) and Tukuba
Hypertensive Mice (THM). T. Sato1, A. Hayashi2, S.
Tokutake1, A. Matsuyama1, M. Kikuchi1, and K. Kimoto2,
1R&D Division, Kikkoman Corporation, Noda City, Chiba,
Japan, 2Dept. of Food and Nutrition, Tokyo Kasei University,
Itabashi-ku, Tokyo, Japan.
Nicotianamine (NA) is found in plants and has anti-hypertensive
effect in vivo. However, the mechanism of its beneficial effect is not fully
investigated. We examined the effects of NA administration on systolic
blood pressure (SBP), NA serum concentration, and organ angiotensin I
converting enzyme (ACE) activity using spontaneously hypertensive Rat
(SHR) and Tukuba hypertensive mice (THM). The THM is a hypertensive
animal model prepared by carrying human renin and angiotensinogen
genes into C57BL/6 mouse. THM is known to cause hypertension by a
single factor, an enhancement of the renin-angiotensin system (RAS). In
SHR, Long-term and single administration of NA significantly decreased
SBP. The serum concentration of NA has its peak at 1 h after oral administration, and there are no differences between feeding and 12-h fasting. In blood and lung, ACE activity was decreased at 2 and 6 h after NA
administration. These data suggest that NA is absorbed directly soon
after administration, is not influenced its absorption by diet, inhibits
serum and lung ACE, and shows antihypertensive effects in SHR. We
also measured NA concentration in the plasma of THM. It was confirmed that, after administration in the stomach, NA has been absorbed
from the intestine and detected into the blood. Consequently, the blood
pressure significantly descended until 6 hours after administration of
NA. In THM, ACE activities in plasma, lung and kidney were also
decreased by administration of NA. It was suggested that NA decreased
SBP by inhibition of RAS in SHR and THM. It is expected that NA is used
as functional compound to prevent and alleviate hypertension.
Modulation of Hepatic Thyroid Hormone and Retinoic
Acid Receptors May be a Novel Mechanism of Soy
Hypolipidemic and Anticarcinogenic Effects. C.W.
Xiao1,3, W. Huang1, C. Wood1, M.R. L’Abbé1, G.S. Gilani1,
G.M. Cooke2,3, and I. Curran2, 1Nutrition Research Division,
Food Directorate, Health Products and Food Branch, Health
Canada, Ottawa, Ontario, Canada, 2Toxicology Research
Division, Food Directorate, Health Products and Food
Branch, Health Canada, Ottawa, Ontario, Canada,
3Department
of Cellular and Molecular Medicine, University
of Ottawa, Ottawa, Ontario, Canada.
Thyroid hormones and retinoic acid (RA) are important regulators
of growth, differentiation, tissue homeostasis and lipid metabolism.
Thyroid hormone receptor (TR) and RA receptor (RAR) are involved in
mediating carcinogenesis and anticarcinogenesis, respectively. Soy consumption has been shown to be hypolipidemic, and linked to lower incidence of certain types of cancers. The objective of this study was to
examine the effect of dietary soy protein isolate (SPI) and soy-derived
isoflavones (ISF) on TR and RAR content and function. Sprague-Dawley
rats were fed diets containing either casein or increasing amounts of
supplemental ISF (5-1250 mg/kg diet) or alcohol-washed SPI (5, 10, or
20%). Protein content and DNA binding abilities of TR and RAR were
measured by Western blot and electrophoretic mobility shift assay,
respectively. The content of TRβ1 and RARβ proteins in liver, but not in
other tissues examined was significantly increased by dietary SPI in a
dose-dependent manner compared with casein. Supplemental ISF had
no effect. The content of other TR and RAR isoforms were not affected
by SPI. In contrast, the binding abilities of hepatic TR and RAR to DNA
were markedly inhibited by SPI. Additionally, plasma triglyceride levels
and hepatic expression of TR-regulated genes for acetyl-CoA carboxylase-β and -β were suppressed by SPI compared with casein. Taken
together, these results suggest that modulation of hepatic TRβ1 and
RARβ, key regulators of gene expression involved in lipid metabolism
and carcinogenesis, by soy proteins may be a novel mechanism by
which soy components lower blood lipid level and prevent carcinogenesis. (Supported by Health Canada)
Effect of Dietary GABA-Enriched Fermented Soybean
(GABA-tempeh) on Blood Viscosity of Rats. Nakamichi
Watanabe*1, Kenichi Nakatsugawa1, Kenshiro Fujimoto2,
and Hideyuki Aoki3, 1Showa Women’s University, SetagayaKu, Tokyo, Japan, 2Koriyama Women’s University,
Koriyama-Shi, Fukushima, Japan, 3Ikeda Tohka Industries
Lab., Fukuyama-Shi, Hiroshima, Japan.
Tempeh, a traditional soybean fermented food made by salt-free
aerobic fermentation with Rhizopus microsporus, was originally developed in Central Java, Indonesia. The GABA-tempeh used in the present
study was prepared by aerobic and successive anaerobic cultivation of
boiled soybean with R. microsporus. The contents of free amino acids
especially GABA (γ-amino butyric acid) and oligopeptides in the GABAtempeh were significantly higher than in the conventional tempeh. In
this study, the blood viscosity of rats fed the GABA-tempeh, conventional tempeh or unfermented soybean were compared. Blood viscosity was
measured using a micro channel array flow analyzer (MC-FAN)
equipped with the same interval interstice siliconized gages, which are
narrower than the average diameter of RBC much like a real capillary
vessel. It has therefore been possible to determine whole blood viscosity with reliability and reproducibility. The blood viscosity of the rats
being fed the GABA-tempeh was significantly lower than those given
the conventional tempeh or unfermented soybean. However, there were
no significant differences in blood ingredients such as hematocrit, triacylglycerol, total cholesterol, and glucose levels. The levels of lipid peroxidation products of serum and red blood cell were similar among the
groups. GABA which is specifically rich in the GABA-tempeh may be
responsible for the lower blood viscosity.
Poster Abstracts
peak time points of 8, 10 and 12 hours were >4 µmol/L for the soy food
phase and for the higher dose tablet phase. Genistein concentrations
were highest overall in the soy food vs. supplement phases of the study
(p<0.05). When comparing plasma concentrations for the two doses of
tablets, saturation appeared more evident for genistein than daidzein.
CONCLUSIONS: Most previous pharmacokinetic studies have
investigated a single daily bolus of isoflavones from just one type of
source. These results contrasting source and dose of isoflavones, when
taken three times daily, indicate important differences in the pharmacokinetics of genistein and daidzein and suggest that soy foods may lead
to higher isoflavone bioavailability than the isoflavone supplements
used in this investigation.
6th International Symposium on the
Poster Abstracts
24
Role of Soy
in Preventing and Treating Chronic Disease
Cognitive Function
Soy Foods Exposure Predicts Better Baseline Cognitive
Function in Healthy Older Adults. S. Meade1,2, N. Lane1,2,
T. Ohrt1,2, S. Asthana1,2, and C. Gleason1,2, 1University of
Wisconsin, Dept. of Medicine, Sect. of Geriatrics, Madison,
WI, USA, 2Madison VA GRECC, Madison, WI, USA.
In this randomized, placebo-controlled, double-blind design clinical pilot study, the effects of soy isoflavones on cognition were studied
in men and women over the age of 60. Data were collected from 30
cognitively healthy older adults (50% women). Subjects received either
100 mg/day of soy isoflavones or a placebo for 6 months.
Neuropsychological testing was administered at baseline and at 1, 3,
and 6 months after starting the treatment phase. In addition, Food
Frequency questionnaires were administered to monitor the intake of
soy foods and products throughout the study. The baseline Food
Frequency questionnaires were used to determine whether the subjects
were exposed to soy isoflavones before entering the treatment phase
(soy-exposed), or not exposed to soy isoflavones (soy naïve). Soyexposed subjects are those having a weekly intake of soy foods
between 6.58 and 4434 grams. Soy-naïve subjects are those having a
weekly intake of soy foods equal to zero grams. There were no significant differences between the two groups in terms of age, education
level, and Mini-Mental State Examination scores. On cognitive data,
however, the soy-exposed group outperformed the soy-naïve group on
tests of executive function and language. Specific findings include better baseline performance on the Trail Making Test (t=2.332, p=0.03),
Letter Fluency test (t=2.539, p=0.017) and Category Fluency test
(t=2.958, p=0.006). Interestingly, the soy-naïve group showed greater
response to one month of isoflavone treatment than the soy-exposed
group on Trail Making Test (F=3.277 p=0.053). It seems that soy exposure may impart cognitive benefits for older adults.
NIA grant K23 AG24302.
Research staff and study volunteers from the Wisconsin Comprehensive
Memory Program.
The General Clinical Research Center: grant M01 RR03186 from the
National Center for Research Resources, National Institutes of Health.
Madison GRECC of the Department of Veterans Affairs.
Archer Daniels Midland provided Novasoy® brand isoflavones tablets
and matching placebo
Saponins
Interaction Between Soybean Saponin and Protein,
and Possible Functionality. M. Shimoyamada1, S. Ikedo2,
R. Yamauchi2, and K. Watanabe3, 1Miyagi University,
Sendai, Miyagi, Japan, 2Gifu University, Gifu, Gifu, Japan,
3Tokyo University of Agriculture, Atsuki, Kanagawa, Japan.
Saponin, which is widely distributed in plant kingdom as well as
soybean, is a kind of natural surfactants, and it is expected to have
some affinity to proteins. So interaction between saponin and protein
extracted from soybean seeds was evaluated by a modified equilibrium
dialysis, gel filtration chromatography and protease hydrolysis. The equilibrium dialysis and gel filtration chromatography of soybean saponin
and protein mixture demonstrated that a large proportion of saponin
interacts weekly with soybean protein.
Soybean acid precipitated protein (APP), which was prepared from
water extract of soybean seeds, contained about 1 % of saponin. Water
extract was subjected to a hydrophobic resin column and removed
almost all of saponin (NS-APP). Three kinds of protein fraction, namely,
APP, NS-APP and a mixture of NS-APP and saponin were incubated with
chymotrypsin. As the result, hydrolysis level by chymotrypsin was shown
to increase by saponin removal and reversibly decrease by saponin readdition. Similar results were shown in tryptic hydrolysis of saponinprotein mixture. As soybean was usually utilized after heat treatment,
each APP fraction with or without saponin was heated, cooled and
hydrolyzed by chymotrypsin. The effect of saponin on hydrolysis level of
the heated APP was similar to the effect on the non-heated APP. These
data may suggest that saponin controls digestion of soybean protein to
change functionality of APP in gut, e.g. cholesterol-lowering activity.
Development of a Saponin Rich Soybean: Relationship
Between Saponin Content and Genes Controlling the
Polymorphism of Saponin Composition. C. Tsukamoto1,
I. Tayama1, Y. Takada2, M. Kamada3, and K. Kitamura3, 1The
Graduate School of Agricultural Sciences, Iwate University,
Morioka, Iwate, Japan, 2National Agricultural Research
Organization, National Agricultural Research Center for
Tohoku Region, Kariwano, Akita, Japan, 3The Graduate
School of Agriculture, Hokkaido University, Sapporo,
Hokkaido, Japan.
The health claims of soybean saponins depend on the total
amount of saponins and on the chemical structure of the individual
saponin molecules. Although the variation in seed saponin composition
is explained by combinations of genes controling the utilization of soyasapogenol glycoside substrate, factors affecting total saponin content
have not been studied. The Sg-4 gene, which controls arabinosylation of
the glucuronic acid residue attached at the C-3 position of sayasapogenols, is expressed in the seed cotyledons of 100% of G. max and
G. soja lines we have tested to date. When we tested the same collections for Sg-4 expression in the hypocotyls, we found only 2% of the G.
max lines expressing Sg-4 in the hypocotyls versus 63% for the G. soja
lines. Saponin content in the hypocotyls of G. soja lines was much higher than that of G. max. To study the relationship between the total
saponin content and the expression of Sg-4, recombinant inbred lines
(RILs) were developed from crosses between lines with and without the
expression of Sg-4 in the hypocotyls. Quantitative saponin analysis in
the cotyledons and hypocotyls of 264 RILs (F7) showed that the total
saponin content was not affected by the Sg-4 gene but that Sg-4 influenced the composition and quantity of individual saponins. Examination
of total saponin content of two mutant lines, one possessing a new
aglycone and the other lacking soyasapogenol A, showed the same tendency. Total saponin content in soybean seeds seems to be dependent
on the supply of soyasapogenols.
Soy Saponins Display High Content and Profile
Variability in Isoflavones Enriched Dietary Supplements. M. Berger1, J. Hubert2,1, and J. Daydé1, 1Ecole
Supérieure d’Agriculture de Purpan, Toulouse, France,
2Genibio Recherche, Lorp Sentaraille, France.
Soybean presents a remarkable phytochemical profile, including
many health-promoting polyphenolic and triterpenoid glycosilated compounds. An increasing number of isoflavone extracts are available and
consumed as dietary supplements in western countries, and the process
employed for the manufacturing of these products can also modulate
their content in soy saponins. Using simple low cost HPLC/UV analyses,
our objective was to investigate the group A and B soy saponin and
isoflavone contents and profiles in various commercial soy-dietary sup-
25
2005 Abstracts
Poster Session II
Tuesday, November 1, 2005 .........7:30 a.m.–5:00 p.m.
Wednesday, November 2, 2005....7:30 a.m.–12:00 p.m.
Diabetes
A Novel Functional Food Ingredient—Soy ProteinCatechins Complex. C. Kuo and S. Chen*, Food Industry
Research & Development Institute, Hsinchu, Taiwan.
The beneficial effects of both soy and tea are well studied, such as
antiangeogenesis, antihyperglycemia, antiobesity, and lowering the
risks of cardiovascular diseases. There have being numerous attempts to
combine these two to provide synergistic effects. Although it has been
shown that isoflavones from soy and green tea have synergistical antitumor effects, soy proteins readily precipitate with catechins. And, it’s
generally believed that the formation of soy protein-catechins precipitates leads to less bioavailabilities/biofunctions and may even hinder
nutrient absorption. In this study, we set out to characterize soy proteincatechins precipitates and their potential as a novel functional food
ingredient. Soy milk, soy okara, or defatted soybean were mixed with
tea under different pHs (4, 7, 9) and temperatures (25 or 80oC). Freeform catechins and caffeine contents in the supernatants were analyzed
by HPLC, and protein patterns by SDS-PAGE. It’s found that more than
70% of EGCG and less than 50% of caffeine of tea solution co-precipitated with proteins when soy milk was mixed with tea catechins at 1:5
under pH 4. Temperature has no effects on both the amounts of freetype catechins and of soy protein-catechins precipitates. Only 10% of
the precipitated EGCG could be extracted by water, suggesting that
EGCG and soy protein precipitates co-precipitate to form complexes.
Surprisingly, more than 70% of EGCG immediately dissociated from the
precipitates when subjecting to simulated gastric fluid. No difference
between the protein banding patterns of both soy milk and soy proteincatechins complexes was observed. These results suggest that (1) the
complexes formation have little effects on the bioavailabilities of ether
EGCG or soy proteins, (2) soy proteins can used as adsorbents for EGCG
partial purification, reducing the usage of organic solvents, and (3)
EGCG-soy proteins complexes may serve as a novel functional ingredient providing additive or synergistic beneficial effects.
Glycemic Response to Selected Soy Foods in Selected
Diabetics and Development of Software on Diabetes
with Special Reference to Soy and Glycemic Index. R.
Chithra and S. Deepa, PSG College of Arts & Science,
Coimbatore-14, Tamil Nad, India.
Anthropometric measurements, food and nutrient intake and other
data related to diabetes were collected from 30 Type - II diabetics of
Chennai city. Soy products incorporated foods like chapathi, pongal and
pancakes were formulated and evaluated organoleptically. Nutritive
value of the recipes and the quantities of recipes to be used for the
study of glycemic response (GR) were ascertained. The GR to standard
and soy foods were studied in the selected patients. User friendly software was developed and the programming was done in such a way that
it gave detailed nformation about diabetes with special reference to
types, etiology, signs, diagnosis, prevention, complications, dietary modifications, foods to be included and avoided etc. Energy expenditure for
various activities, glycemic index of various foods, diabetic diets based
on caloric needs, food exchange lists and importance of soy foods in
glycemic control were also provided. Forty per cent of the diabetics had
grade I obesity and 26 per cent grade II. Most of them were taking oral
hypoglycemic drugs and also had control over their diet. The mean food
and nutrient intake were lower than the recommendations of Indian
Council of Medical Research. The formulated recipes were highly
acceptable recording high protein and low carbohydrates. The mean
incremental blood glucose level on ingestion of the soy recipes was significantly lower than that of the respective standards showing the superiority of soy products in glycemic control. Software developed was
interactive for diet counseling and will be of great help to diabetics and
dietitians.
PSG COLLEGE OF ARTS & SCIENCE
Proximate Composition, Glycemic Index, and
Glycemic Load of Rice, Diabetic Diet Rice and Soy
Incorporated Selected Recipes of India. R. Chithra, S.
Chitralekha, and P. Gayathri, PSG College of Arts & Science,
Coimbatore, Tamil Nadu, India.
Diabetics are recommended foods with low lycemic index (GI). Soy
bean has low GI. Specially processed rice called ‘diet rice’ is claimed to
have undergone a treatment where starch is complexed to reduce the
GI. Common rice based Indian recipes viz., idli, dosa, pancake, appam,
adai, soy dosa, soy pongal, vegetable rice, mint rice, rice with dhal powder, kolaputtu and string hoppers were standardized and organoleptically evaluated. Nutritive value and portion sizes were determined.
Fasting blood glucose levels were studied in 10 suitable volunteers. The
reference food (Glucose) and test foods prepared from ordinary rice (IR20) and diet rice were administered on different days. Blood glucose
levels after 30, 60, 90 and 120 minutes were registered. GI and GL were
determined followed by statistical analysis. All the recipes were acceptable. The GI of vegetable rice made of ordinary rice was 51 and that
made of diet rice reduced to 31 showing a maximum reduction of 39%.
The GI of pancakes and soy dosa reduced by 33% and 31% respectively on diet rice substitution. All the other recipes also uniformly recorded
considerable reduction in GI varying from 13 to 29%. GL also followed
the same trend. Soy Dosa registered significantly lower GI and GL than
ordinary Dosa showing the beneficial effect of soy bean on glycemic
control. Many varieties of rice and more soy recipes may be studied taking all other interfering factors into consideration to arrive at a more
valid conclusion.
PSG COLLEGE OF ARTS AND SCIENCE, COIMBATORE AND
CHAMAN LAL SETIA EXPORTS, HARYANA, INDIA
Dietary Intake of Isoflavones and Lignans is Related
to Lower Prevalence of Metabolic Syndrome and
Improved Insulin Sensitivity. Yvonne van der Schouw,
Poster Abstracts
plements. Very high concentrations of saponins were observed in several products, from 5.5 µmol/g to 107.8 µmol/g. The saponin A/B ratio
ranked from 0.3 to 8.6, reflecting the raw soy material employed during
processing (germ vs cotyledon). Some products contained 4-fold higher
amounts of isoflavones than saponins. Others contained comparable
quantities of both. Interestingly, our results show that some products
contained up to 2-fold higher amounts of saponins than isoflavones.
These significant amounts of saponins in products which are purchased
as isoflavone concentrates only have to be taken into account. Indeed,
soy saponins may interact with isoflavone biological activities or contribute to many of the health benefits attributed to isoflavones. Both of
these soy secondary metabolites have to be clearly determined when
discussing the biological activity of soy- based dietary supplements.
6th International Symposium on the
Poster Abstracts
26
Role of Soy
in Preventing and Treating Chronic Disease
Majon Muller, and Diederick Grobbee, UMC Utrecht,
Utrecht, The Netherlands.
Background: The effect of phytoestrogens on insulin sensitivity and
the metabolic syndrome is largely unknown.
Methods: We studied the association between dietary isoflavone
and lignan intake and characteristics of the metabolic syndrome in a
population-based cross-sectional study comprising 400 independently
living men between 40 and 80 yr of age. Dietary intakes of isoflavones
and lignans was calculated from a validated food frequency questionnaire. The metabolic syndrome was defined according to the National
Cholesterol Education Program definition, and insulin sensitivity was
calculated by use of the quantitative insulin sensitivity check index. We
used logistic and linear regression analysis adjusted for age, smoking,
alcohol intake and physical activity.
Results: Increasing isoflavone intake was associated with
decreased prevalence of the metabolic syndrome [odds ratio (OR) for
fourth versus first quartile 0.46; 95% confidence interval (CI), 0.23-0.92].
Increasing lignan intake was also associated with decreased prevalence
of the metabolic syndrome [OR for fourth versus first quartile 0.39; 95%
CI, 0.19-0.79]. Additional adjustment for insulin attenuated the associations with both isoflavones and lignans. Increasing isoflavone intake was
associated with increased insulin sensitivity [difference (D) between
fourth and first quartile 0.014; SD 0.005]. Increasing lignan intake was
also associated with increased insulin sensitivity [difference (D) between
fourth and first quartile 0.019; SD 0.005].
Conclusions: Higher dietary intake of isoflavones as well as lignans
in aging males are independently associated with a higher insulin sensitivity and a reduced prevalence of the metabolic syndrome. The pathway for this effect might be through decreasing insulin levels.
Genistein Inhibits High Glucose-Induced MonocyteEndothelial Cell Interaction Through a CampDependent Protein Kinase Pathway. W. Zhen, H. Si, and
D. Liu*, Virginia Polytechnic Institute and State University,
Blacksburg, VA, USA.
Atherosclerosis is the major vascular complication in diabetic
patients. Genistein, a soy isoflavone, has anti-diabetic and anti-atherosclerotic effects, but the mechanisms involved are still unclear. Adhesion
of Monocytes to the vascular endothelium is one of the key steps in the
development of atherosclerosis. We investigated the hypothesis that
genistein, at physiological concentrations, inhibits leukocyte-endothelial
interaction under hyperglycemic condition. Following treatment of
human aortic endothelial cells (HAEC) with glucose, release of IL-8 and
monocyte chemotactic protein-1 (MCP-1) was measured by ELISA, and
mononuclear cell adhesion was determined by U937 cell binding.
Protein kinase A (PKA) activity was determined by measuring kemptide
phosphorylation. High glucose (25 mM) induced IL-8 and MCP-1 production by 1.3 and 1.5 fold over the normal glucose (5.5 mM) (n=4,
p<0.01). Genistein (0.01-10 micromole) does dependently inhibited
high glucose-induced IL-8 and MCP-1 production. Genistein also inhibited high glucose-induced U937 cell adhesion at physiologically relevant
concentrations (0.1- 1 micromole) (n=4, p<0.01). This effect was not
blocked by antagonism of estrogen receptor. In addition, genistein at 15 micromole did not change tyrosine kinase activity. Treatment of cells
with selective inhibitors for protien kinase A partially ablated the
inhibitory effect of genistein on IL-8 and MCP-1 production and monocyte adhesion (n=4, p<0.01). Exposure cells to genistein for 30 min
increased the protein kinase A activity 1.7 fold over control (n=4,
p<0.01). These results demonstrate that genistein inhibits high glucoseinduced chemotactic cytokine production and mononuclear cell adherence to human endothelial cells, at least in part, through activation of
PKA, suggesting a novel anti-inflammatory mechanism for genistein
and protective role in hyperglycemia-induced endothelial dysfunction.
The Glycemic Index and Insulin Index of Selected Soy
Foods. Robert M. Blair1, Aaron Tabor1, E.C. Henley2,
1Physicians Pharmaceuticals Inc., Kernersville, North Carolina,
USA, 2EC Henley Consulting, Athens, Georgia, USA.
Foods with a low glycemic index (GI) may provide a variety of
health benefits. The objective of the present study was to measure the
GI and insulin index (II) of selected soy foods. The study was conducted
in two parts with “low-carb” products being tested separately. In
Experiment 1, subjects averaged 23.2 years of age with BMI=22.0,
while subjects in Experiment 2 averaged 23.9 years of age with
BMI=21.6. The reference (glucose) and test foods were served in portions containing 10 grams of carbohydrates in Experiment 1 and 25
grams of carbohydrates in Experiment 2. Subjects consumed the reference food twice and each test food once. For each test, subjects were
instructed to consume a fixed portion of the reference food or test food
together with 250 grams of water within 12 minutes. Blood samples
were collected before each test and at 15, 30, 45, 60, 90, and 120 minutes after consumption of reference or test foods to quantify glucose
and insulin. Two-hour blood glucose and plasma insulin curves were
constructed and areas under the curves were calculated. GI and II values for each subject and test food were calculated. In Experiment 1,
both “low-carb” soy foods were shown to have significantly (P<0.05)
lower GI and II values than the reference food. In Experiment 2, three of
the four test foods had significantly (P<0.05) lower GI and II values than
the reference food. In conclusion, all but one of the soy foods tested had
a low GI (i.e. <55).
Immune Function
Genistin at the Concentration Present in Soy-Based
Infant Formula Inhibits Rotavirus Infectivity in vitro
Through Inhibition of Protein Tyrosine Kinase
Activity. A. Andres1, S.M. Donovan1, T.B. Kuhlenschmidt2,
and M.S. Kuhlenschmidt1,2, 1Div. Nutritional Sciences,
University of Illinois, Urbana, IL, USA, 2Dept. Veterinary
Pathobiology, University of Illinois, Urbana, IL, USA.
Rotavirus (RV) is the most common cause of infantile diarrhea, with
111 million episodes each year worldwide. No RV vaccine is currently
available, thus, it is critical to identify other means to reduce the incidence and severity of RV infection. Isoflavones have anti-viral activity
and we previously evaluated the anti-RV activity of aglycone, glycoside
and acetyl-glycoside forms of genistin, daidzin, and glycitin, as well as
the MIX of all isoflavones at soy formula concentrations and found that
genistin alone and the MIX were effective. Herein, the anti-RV activity of
the MIX, genistin and genistein were further investigated by a focus
forming unit assay in MA104 cells. Genistin (14 µg/ml) and MIX (42
µg/ml) decreased (p<0.05) RV infectivity vs. control over a 16-fold dose
of RV concentrations. In contrast, the MIX without genistin did not inhibit RV infection, implicating genistin as the active component. Further,
genistin and genistein at the same concentration were equally inhibitory, suggestion bioconversion of genistin to genistein and leading us to
investigate the cellular actions of genistein as potential mechanisms of
action. A protein tyrosine kinase inhibitor (Herbimycin), a topoisomerase
II inhibitor (Ectoposide), and an estrogen agonist (17-β estradiol) were
tested. Only Herbimycin decreased (p<0.05) RV infectivity vs. control. In
summary, genistin at the concentration found soy infant formula inhibits
27
2005 Abstracts
Menopausal Symptoms
Soybean Composite Functional Factors Enhanced the
Serum Estradiol Concentration and Superoxide
Dismutase Activity in Postmenopausal Women. Dan
Li*1,2, Changcheng Gao2, Xing Chen2, Yuzhen Huang2, and
Xiaolei Li1, 1Dept of Food Sci.& Eng. in Changchun
University,Changchun 130022, P.R. China, Changchun, Jilin
Province, P.R. China, 2National Reseach and Popularize
Center for Soybean Refined Processing, Changchun
130022,P.R. China, Changchun, Jilin Province, P.R. China.
Soybean composite functional factors (SCFF), containing 0.72%
isoflavones, 1.06% saponin, 24.0% oligosaccharide, 5.2% protein and
7.2% nucleic acid, were extracted using membrane technology. Oral
administration of SCFF at 30mg/day was carried out in 10 volunteers
from postmenopausal women. Radio immune and chemical illuminance
assay were employed respectively to determine the serum estradiol (E2)
concentration and superoxide dismutase (SOD) activity. After 20 days,
the increase of 43.5% for E2 concentration and 55.6% for SOD activity
were found. The maximum tolerance dose of SCFF was 75g/kg body
weight. As a result, SCFF was considered as a dietary supplement for the
reduction of menopause symptoms.
The composition of soybean composite functional factors
ingredients
unit
value
isoflavone
mg/g
7.2
saponin
mg/g
10.6
oligosaccharide
%
24.00
protein
%
5.2
nucleic acid
%
7.2
folic acid
Ìg/g
0.057
nicotinic acid
Ìg/g
340
thiamin
Ìg/g
17
riboflavin
Ìg/g
1870
carotene
Ìg/g
45.8
calcium
mg/kg
629.48
zinc
mg/kg
149.50
iron
mg/kg
73.9
selenium
mg/kg
0.0133
Authors would like to give our many thanks to Changchun People pharmacy Co. Ltd for their support.
Effects of a Novel Extract of Daidzein-Rich Isoflavone
Aglycone on Dehydroepiandrosterone Production in
Japanese Menopausal Woman. Yoshiaki Sato*1 And
Weijun Pan2,3, 1Sophia Ladies Clinic, Kanagawa 229-0033,
JAPAN, 2Beth Israel Deaconess Medical Center, Harvard
Medical School, Boston, MA 02215, USA, 3Nichimo Co.,
Ltd., Tokyo 140-0002, Japan.
Dehydroepiandrosterone sulfate (DHEA-S) level in blood decline
sharply with aging, it may play a protective role in many chronic diseases.
The effects of soy isoflavone on DHEA-S production in menopausal women
are unclear. We determine the effect of a novel of daidzein-rich isoflavone
aglycone extract from soy germ fermentation with Koji fungus (AglyMax),
an effective antioxidant on DHEA-S production in 40 Japanese
menopausal women in relieving menopausal symptoms. An 8-week openlabel feasibility study included 40 Japanese menopausal. All subjects are
taking with a supplement of 20-40 mg/day of AglyMax for 8 weeks.
Subjects recorded their menopausal symptoms score activity weekly by
Koyama’s Simplified Menopause Index (SMI). Routine blood count, chemistry, blood levels of sex hormones and DHEA-S were measured on baseline and 8-week. Blood fluidity were measured by MC-FAN (Micro Channel
Array Flow Analyzer) both baseline and 8-week. Forty subjects completed
the study. AglyMax improved vasomotor symptoms. The score of SMI
decreased from 68 ± 20 at baseline to 40 ± 12 at 8 weeks (p <0.05).
DHEA-S was increased from 890 ± 112 ng/ml at baseline to 2,430 ± 210
ng/ml at 8 weeks (p <0.01). There were no significant changes in the
measured blood chemistries or other hormone levels. 78.1% of the subjects were improved their blood fluidity after 8 week. The study suggests
that daidzein-rich isoflavone aglycone (AglyMax) supplement may be
improve DHEA-S production that may overlap with weak estrogenic effect
of soy isoflavone to preventing treating for menopausal symptoms.
Impact of Supplementation of Soybean Chikki as a Source
of Isoflavin on Plasma Calcium Levels of Menopause
Women. Ch. Kavitha and K. Krishna Kumari*,ANGR Agricultural
University, Hyderabad, Andhra Pradesh, India.
Women during menopause stage undergo physiological and emotional stress and 72% of Indian women (above 40 years) suffer from
osteoporosis. The isoflavins, exclusively present in soybean are found to
relieve menopausal symptoms and considered as an important component for bone health. An investigation has been made to assess the
impact of supplementation of soybean chikkias a source of isoflavin on
bone health of menopause women. The plasma calcium level was
selected as a parameter to assess the bone health.
A traditional recipe chikki was prepared with puffed soybean and
jaggery at 1: 1 proportion. Chikki 100g contains 19.2 g protein, 8g
fat,155mg calcium,370 Kcal energy and 190 mg isoflavins. Soybean
chikki (50g) containing 95 mg isoflavins had been supplemented daily
to two groups (50-55 years and 55-60 years) of menopause women
with 15 subjects in each group for a period of 90 days through careful
monitoring. The effect of supplementation was assessed through food
and nutrient intake, anthropometry, menopausal symptoms and plasma
calcium levels of subjects in the beginning of the study and after 45 and
90 days of supplementation. It was observed that the menopausal
symptoms like backache and irritability disappeared in the subjects after
supplementation. There was no significant change in body weight and
BMI of subjects. Among the nutrients the intake of energy was sufficient
in both the groups, while the intake of protein (63 & 67g), fat (46 & 49g)
and calcium (885 & 894mg) were more than RDA in both the groups in
the beginning and the levels were further increased towards the end of
supplementation. The intake of isoflavins were 95mg from soybean
chikki throughout the study period, though it was nil in the beginning.
The initial plasma calcium level (6.78 & 7.43mg%)of both the
groups were found below normal (8.7mg%) in spite of the diet appears
to supply double the RDA of calcium. The levels were increased from
6.78 to 7.74mg% in group I and 7.43to 8.33 mg% in group II by 45 days
of supplementation. The levels were further increased to 8.65&9.32
mg% respectively by 90 days of supplementation. It is interesting to
observe that in group II (55-60 years), the plasma calcium levels have
Poster Abstracts
RV infection in vitro across a continuum of severity in part via inhibition
of the protein tyrosine kinase signaling pathways.
(Supported by AG 03-34505-13320 and the Illinois Soybean
Program Operating Board)
6th International Symposium on the
Poster Abstracts
28
Role of Soy
in Preventing and Treating Chronic Disease
reached almost the normal levels by 45 days of supplementation. This
increase in calcium level might have been due to the enhanced absorption or altered metabolism of calcium through soy protein and isoflavins
consumed from soybean chikki.
The authors wish to acknowledge the ANGR Agricultural
University,Hyderabad,India for providing the facilities to carry out this study.
Obesity
Effects of Dietary Soy on Adipose Tissue, Adipocytokines,
and Insulin Sensitivity. K. Ingram, J. Kaplan, K. Kavanagh, L.
Zhang, and J. Wagner, Wake Forest University School of
Medicine, Winston-Salem, North Carolina, USA.
Soy supplements are used widely for a number of health benefits.
We have shown previously that soy protein containing isoflavones
improves insulin sensitivity in female monkeys. Our objective in this
study was to determine if changes in adipose tissue mediated the
improvement in insulin sensitivity. Premenopausal female cynomolgus
monkeys consumed either a soy protein diet (n=46) with isoflavones at
human equivalent dose of 130 mg isoflavones/d or a casein/lactalbumin
(n=45) diet for 2 years. Abdominal subcutaneous and visceral fat biopsies were collected for cell size determinations (cellular triglyceride and
DNA quantification). Plasma leptin, adiponectin, and active and desacyl
ghrelin were determined by ELISA. Body fat, as measured by DEXA,
body weight, and thyroid hormone concentrations (T3 and T4) were also
measured. There was no change in body weight or body fat over the two
years. However, soy fed monkeys had fewer (p=0.03) and larger
(p=0.06) subcutaneous adipocytes but no change in visceral adipocytes.
Consistent with the larger adipocytes, soy decreased adiponectin
(p=0.01) and increased leptin (p=0.02). Active (p<0.001) and desacyl
(p=0.03) ghrelin were increased with soy as were thyroid hormones (T4,
p<0.05, T3, p<0.10). Ghrelin is associated with increased appetite, adipogenesis, and growth hormone release, which elevates resting metabolic rate independent of changes in body composition. Leptin and thyroid hormones also regulate energy expenditure, by increasing uncoupling protein 3 in muscle. We propose that soy may affect metabolic efficiency not by changes in adipose tissue, but by effects on other insulin
sensitive tissues such as muscle to improve insulin sensitivity.
Osteoporosis
Effect of Soymilk With and Without Isoflavones on
Insulin-Like Growth Factor 1. Results from a Two-Year
Clinical Study. E. Lydeking-Olsen1, A. Juul2, N.E.
Skakkebaek3, K.D.R. Setchell4, and J.-E. Beck Jensen4,
1Institute for Optimum Nutrition, Denmark, 2Copenhagen
University Hospital, Rigshospitalet, Denmark, 3Childrens
Hospital and Medical Center, USA, 4Copenhagen University
Hospital, Hvidovre, Denmark.
Background: The insulin-like growth factor (IGF) system has been
linked to the process of bone acquisition through epidemiological analyses of cohorts and in vitro studies of bone cells. Earlier, short-term or
epidemiological studies have revealed conflicting results with respect to
the effect of soy and its isoflavones on IGF 1 levels, as studies in males
have revealed that 3 mo consumption of soy+ (88 mg iso) increased
IGF1 significantly, compared to milk protein (Khalil 2002). An epidemiological study demonstrated an association between soy / isoflavone
consumption and increasing levels og IGF1 in males, but not in females
(Probst-Hensch 2003). In postmenopausal women, one 3 mo interven-
tion study have found that if not on HRT, soy+ (88 mg total isoflavones)
increased IGF-1 97% (p<0,05, Arjmandi 2003) and another, that
increasing levels of soy isoflavone intake, decreased levels of IGF -1
(Wangen 2000). No long term studies exist.
Aim: The aim of the study was to compare the long-term effects of
soymilk, with or without isoflavones, on levels of insulin-like growth factor 1, after 2 years and relate this to response to treatment effect on
BMD in postmenopausal women.
Methods: Postmenopausal, Caucasian women with established
osteoporosis or at least 3 risk-factors for osteoporosis, were randomly
assigned, double-blind to two treatment-groups: soymilk containing 76
mg isoflavones as aglycones (soy+, n=23) or isoflavone-poor soymilk,
(control, soy÷ n=21). All subjects received comparable intakes of calcium, minerals and vitamins. Serum IGF-1 were analysed by RIA and bone
mineral content (BMC) and density (BMD) were measured in lumbar
spine and hip by using dual-energy X-ray absorptiometry (DEXA) at
baseline and after 2 years.
Findings: IGF-1 levels are shown in table, demonstrating an inverse
relationship between soy - and soy +, as soy - increases and soy +
decreases IGF-1 levels, respectively. The percentage change in lumbar
spine BMD and BMC respectively, did not differ from zero in the soy+
group (+1,1%, +2,0%) but significant bone loss occurred in the soy/control-group (÷·4,2%, ÷·4,3%).No significant changes occurred for
femoral neck BMD or BMC. No correlation was found between change
in IGF-1 and BMD response in either treatment group.
Interpretation: Daily intake of two glasses of soymilk containing 76
mg isoflavones decreased IGF-1 levels, and soymilk without isoflavones
increased IGF1 levels, but no correlation was found in relation to BMD
response.
Effect of soy milk with and without isoflavones on serum-IGF 1,
after 2 years treatment*
Soy -, control, n=21 Soy+, n=23 p-value**
IGF 1, start, (mcg/L) 190,9±10,7
203,4±14,8 0,50
IGF 1, 2 y, (mcg/L)
204,4±16,9
188,9±13,3 0,47
Difference, (mcg/L)
13,6±8,3
-14,5±7,8
0,02
Relative difference, % 5,4
-5,1
0,05
*means values SEM **t-test
Phytoestrogen Excretion is Associated with Improved
Markers of Bone Health in Australian Women. K. Hanna1,
J. Wong2, G. Eaglesham3, C. Patterson1, S. O’Neill2, and P.
Lyons-Wall*1, 1School of Public Health, Queensland University
of Technology, Australia, 2Betty Byrne Henderson Centre,
Royal Brisbane & Women’s Hospital, Australia, 3Pathology and
Scientific Services, Queensland Health, Australia.
Phytoestrogens may protect against osteoporosis by exerting
estrogenic actions on bone cells in postmenopausal women with low
serum estrogen concentration. The aim was to examine associations
between phytoestrogens and biomarkers of osteoporosis. Subjects were
a cross-section of 141 Australian women aged 40-60 y and participating in the Brisbane Longitudinal Assessment of Ageing in Women
(LAW). Phytoestrogen status was estimated by measuring excretion of
nine isoflavonoids and four lignans in three 24-hr urines, utilizing HPLCMS/MS. Bone mineral density (BMD) of femur, total hip and lumbar
spine was measured by dual energy x-ray absorptiometry. Bone formation was assessed by serum bone alkaline phosphatase (bone ALP) and
osteocalcin (OC); resorption was assessed by urinary-N-terminal crosslinking-telopeptide of type-I-collagen (NTX) and deoxypyridinoline
(DPD). Analyses were conducted in the total group and sub-groups with
29
2005 Abstracts
Effects of Genistein, Polyunsaturated Fatty Acids, and
Vitamins D3 and K1 on Bone Metabolism in the OVXRat Model and the OVX-Dog Model of Osteoporosis.
S. Krammer2, U. Wehr1, W. Rambeck1, and P. Weber2,
1Institute of Animal Physiology, Ludwig-MaximiliansUniversity Munich, Munich, Germany, 2Animal Nutrition
and Health R&D, DSM Nutritional Products, Basle,
Switzerland.
Osteoporosis and low bone mass are currently estimated to be a
major public health concern. Research is focusing on various nutrients
and their effects in the prevention and treatment of osteoporosis.
Trials with laboratory animals have played a major role in recent osteoporosis research. As no animal model represents human conditions in
total, the use of more than one animal species is advisable to get a
broader view.
The aim of the two studies was to evaluate the effects of a combination of Genistein (15 mg Genistein/kg BW), PUFA (5 % of DM), and
Vitamins D3 (1500 IU Vitamin D3/kg BW) and K. (2000 µg Vitamin K1/kg
BW) on preventing the subsequent loss of bone mass in rats and dogs
induced by ovariohysterectomy (OHX).
The dog’s bone resorption measured as urinary pyridinoline excretion doubled in the control group (A) in the weeks after OHX (see
Figure). This strong increase was clearly prevented by the administration
of the combination of the substances (group B). Similar effects were
observed in rats (urinary pyridinoline excretion in nmol/mmol Crea in
week 12 after OHX: 303.7 ± 42.5 versus 417.8 ± 58.2 for treated and
control animals respectively).
*: Statistically significant difference (p<0.05) between the two groups at one time
point
Figure: Urinary pyridinoline excretion in dogs
The results showed that the combination of the tested substances
reduced a high bone turnover and therefore can have a protective effect
on osteoporotic bone. The reproducibility of the results in two different
models of osteoporosis was demonstrated.
Supplement of Soy Isoflavone and/or Calcium Can
Enhance Bone Density in Growing Rats. Yuling Lin*,
Hsuching Cheng, and Jimmy Tsai, Department of
Bioscience Technology, Chung Yuan University, Chung Li
32023, Taiwan.
The aim of this study was to investigate the effect of dietary soy
isoflavone extract and/or calcium on bone growth and density in young
growing rats. Fifty-six 3-weeks-old Wistar female growing rats were
randomly divided into 7 groups, 8 each. Animals were fed 0.18% Ca
(1/4Ca), 0.36% Ca (1/2Ca), 0.72% Ca (AIN93G-mineral mix, Ca), 0.18%
Ca + 0.15% soy extract (0.027% Isoflavone, 1/4CaS), 0.36% Ca +
0.15% soy extract (1/2CaS), or 0.72% Ca + 0.15% soy extract (CaS) diet
for 3 months. Animals in one of the groups were ovariectomized at the
beginning of trial and then fed CaS diet. After feeding the experimental
diets, bone mineral density (BMD) of femurs and tibiae were measured
using dual energy x-ray absorptiometry (DEXA). Data demonstrated that
increasing intake of Ca and/or soy isoflavone enhanced the BMD of
femurs and tibiae (p<0.05). Results also showed that supplement of soy
isoflavone could enhance the numbers of osteoblasts and the thickness
of growth plate in tibiae (p<0.05). Trabecular mineral apposition rates
(MAR) showed a similar trend as BMD (p<0.05). Data also revealed that
ovariectomy in growing rats reduced BMD significantly (p<0.05). In
conclusion, both Ca and soy isoflavone intakes could enhance bone
growth and BMD in growing rats.
Effects of Isoflavone and Calcium on Bone Cell
Activities and Their Biomarkers in Growing Rats.
Hisu-Ching Cheng* and Jimmy Tsai, Department of
Bioscience Techonology, Chun-Yuan Christian University,
Chungli 32023, Taiwan.
Calcium (Ca) is one of the fundamental elements for bone growth
and metabolism. Soy-isoflavone (S) has been reported to act as an estrogen-like compound to prevent bone loss. Effects of various levels of Ca
and S combinations on the activities of osteoblasts (OB) and osteoclasts
(OC) in growing rats were investigated. Fifty-six 3 weeks old female
Wistar rats were housed individually in stainless steel cages. Forty-eight
of them were assigned into 6 dietary groups randomly, 8 each, and fed
1/4Ca, 1/2Ca, Ca (AIN-93G recommendation), or with 0.027% isoflavone
in the diets (1/4CaS, 1/2CaS, CaS). Eight of them were ovariectomized and
fed CaS diet (CaSOx). All rats were fed for 12 weeks. Two bone formation
markers, serum bone-specific alkaline phosphatase (BAP) and C-terminal
propeptide of Type I collagen (CICP), and 2 bone resorption markers,
serum pyrinodiline (Pyd) and N-terminal telopeptide of bone collagen
(NTx) were determined. Bone sections by histomorphometry were also
employed to determine the numbers of OB and/or OC. Results demonstrated that increasing Ca intakes enhanced bone formation and reduced
bone resorption significantly. Data of analyses revealed that supplement
of S promoted the activities of OB and suppressed the activities of OC.
The bone sections also showed that S supplement increased OB numbers
and decreased OC numbers alone the surface of trabecular bone significantly, especially in CaS group comparing with others. It was also
observed that ovariectomized rats had less OB activities and higher OC
activities comparing with normal rats fed same diet (CaS). The conclusion
is that dietary S supplement can enhance Ca bioavailabilities and bone
formation, and reduce bone resorption.
Poster Abstracts
body mass index (BMI) <25 kg/m2 or osteopenia/osteoporosis.
After adjusting for confounders, results showed a negative association between isoflavonoids and NTX in women with lower BMI (r=0.33, P<0.05); a positive association between lignans and bone ALP in
the total sample (r=0.21, P<0.05) and women with osteopenia/osteoporosis (r=0.41, P<0.05); and a trend towards a positive association
between lignans and OC (r= 0.30, P=0.06). There were no associations
between phytoestrogens and BMD. Inverse associations between
isoflavonoids and NTX, and positive associations between lignans and
bone ALP or OC, support a mechanism whereby phytoestrogens act to
suppress bone resorption while stimulating formation. Findings are not
consistent with observed actions of hormone therapy and endogenous
estrogens, which suppress overall turnover by reducing both resorption
and formation.
6th International Symposium on the
Poster Abstracts
30
Role of Soy
in Preventing and Treating Chronic Disease
A Novel Extract of Fermented Soybean Germs
(AglyMax) Promoted Bone Growth in Ovariectomized
Mice Fed a High-Fat Diet. C. Wang1, W. Pan2,3, L. Huang1,
and J. Zhou2, 1Human Nutrition Program, Kentucky State
University, Frankfort, KY 40601, USA, 2Nutrition/Metabolism
Lab, Beth Israel Deaconess Medical Center at Harvard
Medical School, 330 Brookline Ave. Burlington-5, Boston,
MA 02215, USA, 3Biotics R&D Division, Nichimo Co., Ltd.,
Higashi-Shinagawa, Shinagawa-ku, Tokyo 140-0002, Japan.
Daidzein is one of the most abundant isoflavones present in soy
and it is unique as it can be further metabolized to equol, a compound
with greater estrogenic activity than other isoflavones. The aglycone
forms of daidzein may be more potent biologically than its conjugated
form. Our preliminary study showed that a novel extract of fermented
soybean germs (AglyMax) that is rich in daidzein aglycones promoted
bone growth in male mice. Seventy percent of the extract by weight was
isoflavones with daidzein:genistein:glycitein aglycones in the ratio of
7:1:2. The objective of this study was to determine the effects of
AglyMax on bone in ovariectomized mice. The mice (6 weeks old) were
randomly assigned into the treatment groups. A baseline group was
killed at the beginning of the experiment. Group A was sham-operated
but fed the high-fat diet with 60% of the energy from fat; Groups B, C
and D were all ovariectomized and fed the high fat diet containing 0,
1.2 or 5 g of AglyMax per kg diet, respectively. The food intake was kept
similar for all the groups. At the end of the 12-week experiment, femur
bones were analyzed for bone mineral content and density by dualenergy X-ray densitometry (Lunar DPX-IQ). Each bone was also evaluated by a three-point bending test for its breaking strength. Groups A and
D had significantly higher bone mineral content, bone density, breaking
strength, bone ash and calcium content than Groups B and C (all at
P≤0.01). The baseline group was lowest in all the indicators measured.
These results suggest that AglyMax at 0.5% of the high fat diet promoted bone growth in ovariectomized mice.
Soy Protein Isolate and Moderate Exercise
Independently and Additively Impact Bone Turnover
but not Bone Mineral Density in Postmenopausal
Women. Ellen M. Evans, Susan B. Racette, John O. Holloszy,
and Dennis T. Villareal, Division of Geriatrics and
Gerontology, Department of Internal Medicine, Washington
University School of Medicine, St. Louis, MO, USA
Dietary soy protein and exercise are lifestyle approaches used to
manage menopause-related osteoporosis; however the interaction of
these interventions on bone health is unknown. The aim of this study
was to assess the independent and additive effects of soy protein isolate (SOY) and moderate-intensity exercise (EX) on bone turnover and
bone mineral density (BMD). A 2 (SOY vs. milk protein isolate; MLK) by
2 (EX vs. control) study design was used, with 61 women randomized
and 43 (62±5 y) completing the 9 mo intervention (SOY; n = 10: MLK; n
= 12: SOY+EX; n = 11: MLK+EX; n = 10). BMD was measured by DXA.
Serum CTX and BSAP were measured as markers of bone resorption and
formation, respectively. Although no main effects of SOY or EX were evident at 6 mos; SOY reduced CTX (-13.3±15.3% vs. -1.5±21.0%; P =
0.023) and BSAP (-4.7±14.7% vs. 6.5±17.7%; P = 0.016) at 9 mos. EX
attenuated the reduction in S-CTX (-1.9±21.6% vs. -12.4±15.3%; P =
0.038); however, no EX effects were apparent in BSAP at 9 mos
(2.8±16.1% vs. -1.0±18.3%; P = 0.28). Neither SOY or EX impacted
BMD at any site; however, change in BMD was related to the change in
fat mass (r = 0.40, P < 0.05). The data suggests that 1) SOY appears to
reduce bone turnover with no impact on BMD over 9 mos and 2) the
potential benefits of moderate exercise on bone turnover and BMD may
be modulated by change in fat mass.
Other
Isoflavones Do Not Show Astringent Taste in Soy
Foods. M. Abdullah Al, C. Tsukamoto, and T. Ono, The United
Graduate School of Agricultural Sciences, Iwate University,
Japan, Ueda 3-18-8, Morioka 020-8550, Iwate, Japan.
Health beneficial effect of soybean rich in isoflavones have been well
studied. The normal daily requirement of soy isoflavone for health beneficial effect is 50-90mg / day. Normally, isoflavone concentrations (mg/100g
of fresh wt) in soymilk and tofu have 20-40mg. Therefore, more consumption of isoflavone rich soy beverage/food should require as daily basis.
Soymilk and tofu have been consumed as a traditional food in East Asian
countries and is gradually spreading to the Western world. Unfortunately,
soymilk is not well accepted for its bean flavor and astringent taste. The
improvement of the bean flavor was successfully achieved, nevertheless,
factors that impact astringent flavor have remained. Many studies have
revealed that soybean isoflavones are responsible for the astringent taste
in soyfoods. But no consistency was found between an astringent taste
and isoflavone contents. Isoflavone-enriched extract showed no astringency. Soybean foods having large amounts of isoflavones showed less
astringency. Meanwhile, there is no report considering why tofu curd is
less astringent. Phytic acid combines with protein and calcium during tofu
curd formation. Therefore, phytates might have effect of trapping the
astringent components to prevent them from interacting with taste cells
of the mouth and throat. A 0.1% potassium phytate solution at pH 7
showed the very same astringency as soymilk; however, calcium phytate
at the same concentration and pH showed no astringency. Thus soluble
phytic ions in soymilk may cause astringency. The strategy of utilization of
soybean for food should be increased of health beneficial components and
decrease of unfavorable taste.
Study on the Development and Characteristics of
Chinese Soybean’s Health Effects. X. Mingzhong,
Xichang College, Xichang, Sichuan, P.R. China.
The health effects of soybean is a result of the development of
Chinese people’s food culture. It dates back to ancient China’s Zhou,
Qin, Tang and Song Dynasties, and reaches its peak after 1949. There are
three characteristics to Chinese soybean’s health effects. One is the government’s support, another is rich content, the third is the sophisticated
techniques. There are two aspects in its health effects: relieving hunger
and clinical effects. It also features simple and inexpensive processing
methods, extensive application and regional differentiation. According
to traditional Chinese medicine, soybean has a quieting and comforting
effect. It can help spleen function and diuresis, produce blood and add
to strength, balance dry and moisture, reduce heat and detoxicate. Thus,
soybean is effective for symptoms such as a weak spleen and lack of
energy, a weak body and poor appetite, inadequate blood and lack of
strength, oedema and difficulty in urinating, poisoning, during pregnancy and skin ulcer. Black soybean is effective for dizziness, a faint eyesight, early whitening of hair, diarrhea and abdomen on pain, drug poisoning and drunkenness. Therefore, soybean is called “the king among
beans” and “vegetable meat”.
In this paper, the author gives an account of some clinical foods
made of soybean and other ingredients which can be used to cure or
prevent some common diseases. These foods can improve the function
31
2005 Abstracts
Suitable Control Diets for Use in the Study of
Phytoestrogens in, or Derived from, Soybeans. C.
Benton1, J. Odum2, and G. Tobin1, 1Harlan Teklad Madison,
Wisconsin,, USA, 2Syngenta Central Toxicology Laboratory,
Macclesfield, Cheshire, UK.
In recent years there has been considerable interest in the role of
the soybean isoflavones and their metabolites on mammalian physiological systems. Among these effects is the stimulation of uterine
growth in immature or ovariectomized animals and the advance of
puberty in females that occurs when laboratory rodents are fed on diets
containing soybean meal.
To eliminate the contribution of soy isoflavones, it seems reasonable to use a standard purified diet such as AIN-76A as a control for
studies on phytoestrogens or other estrogens. Our studies have shown
that in practice, this may not be a satisfactory alternative.
We, and others, have shown that the uterotrophic response and
timing of vaginal opening are affected as much by a high-energy intake
as by high levels of phytoestrogens. Most standard purified diets such
as AIN76-A and AIN-93G contain a high level of energy, and in a form
that leads to rapid absorption. Thus control animals fed on such diets
may show a pseudo-estrogenic response before the application of an
estrogenic treatment. This may not be recognized by the researcher, and
may mean that the true estrogenic effects of the treatment are underestimated, and perhaps even obscured, in such circumstances.
Such concerns may be assuaged by the use of low-energy purified
diets or low-energy natural-ingredient diets that contain little or no soybean meal as a control or base diet. In our studies both these approaches resulted in minimal stimulation of uterus growth and prevented an
abnormal advance in puberty in female animals.
Isoflavones Protect Mice from Radiation-Induced
Weight Loss. M. Landauer, J. Kramer, and V. Srinivasan,
Armed Forces Radiobiology Research Institute, Bethesda,
MD, USA.
There is a need to develop medical countermeasures to protect
first-responders, remediation workers, and patients undergoing radiotherapy from the harmful effects of ionizing radiation. We previously
demonstrated that the isoflavones genistein and daidzein protect mice
from lethal doses of ionizing radiation when administered 24 hours
before irradiation. In a clinical setting, radiation is administered at sublethal doses to destroy tumor cells. A frequent side effect of sublethal
irradiation in mammals is a reduction of body weight. Moreover, weight
loss has been demonstrated to be a prognostic indicator of reduced survival rates. Therefore, the amelioration of radiation-induced weight loss
is an important objective when using radiation therapy. In the present
study, we characterized the effects of the isoflavones genistein and
daidzein on gamma radiation-induced weight loss in CD2F1 male mice.
A single injection of genistein or daidzein (5 mg/mouse) or vehicle was
subcutaneously administered 24 hr before either sham irradiation or a
sublethal dose of cobalt-60 gamma irradiation (7 Gy at 0.6 Gy/min).
Mice were divided into six groups: (1) vehicle + sham irradiation, (2)
genistein + sham irradiation, (3) daidzein + sham irradiation, (4) vehicle + 7-Gy irradiation, (5) genistein + 7-Gy irradiation and (6) daidzein
+ 7-Gy irradiation. Animals were weighed daily for 30 days after irradiation. We found that mice treated with vehicle or isoflavones that were
sham-irradiated exhibited normal weight gain over the 30 days of the
experiment. In contrast, a significant reduction in body weight for all
groups of irradiated animals was observed. Beginning on day 3 after
irradiation, both the genistein/irradiation and daidzein/irradiation
groups exhibited decreased weight loss compared with the vehicle/irradiation group. By day 20 after irradiation, the body weight of the
isoflavone/irradiation groups had returned to control levels. However,
the body weight of irradiated mice that did not receive genistein or
daidzein remained significantly below that of the other groups. These
results demonstrate that genistein and daidzein can mitigate weight
loss in mice receiving a sublethal dose of gamma radiation.
Soybean Extracts Enhance Elastin in Skin. R. Zhao1, J.C.
Liu2, Ch. Bertin3, J.P. Ortonne4, M. Seiberg1, and V. IotsovaStone*1, 1Skin Research Center, Johnson & Johnson
Consumer Products Worldwide, Skillman , NJ, USA, 2Global
Skin Care Growth Platform, Johnson & Johnson Consumer &
Personal Products Worldwide, Skillman , NJ, USA, 3Scientific
affairs, J&J Consumer Europe, les Moulineaux, , France,
4CPCAD , Hopital l’Archet II, Nice, France.
Elastic fibers are essential extracellular matrix components of the
skin, which contribute to its resilience and elasticity. During chronological aging, synthesis of elastic fibers is reduced, and the existing elastic
fibers are degraded by elastases. Soybean extracts were found to protect the elastic network from degradation, and to restore elastic fiber
synthesis. Using a luciferase reporter assay, soybean extracts were
shown to induce elastin promoter activity in a dose-dependent manner.
Soybean extracts inhibited the activity of human leukocyte elastase in
vitro, and protected elastic fibers of fibroblast cultures from degradation
by exogenous elastase. Human facial skins were treated with non-denatured soy extracts for 8 and 12 weeks, respectively, in two independent
clinical trials. Monthly cutometer measurements demonstrated statistically significant increase in skin firmness as early as 4 weeks, and sustained to the end of treatment in each study. These data suggest the
possible use of soybean extracts in skin care, to improve skin elasticity.
Streamlining the Qualified Health Claim Process. A.S.
Persad and R.A. Isbrucker, Burdock Group,Washington, DC, USA.
Research on soy-based products has revealed a broad spectrum of
potential health benefits, making qualified health claims (QHCs) a valuable tool to the soy industry. Although soy protein is generally recognized as safe (GRAS), this status is not a marker of its suggested efficacy. A QHC allows for the establishment of a relationship between a substance and its ability to reduce the risk of a disease or health-related
condition. These claims, based on the available evidence and suffixed
with tiered qualifiers issued by FDA, allow manufacturers to provide
beneficial health information to their consumers without having to
meet the stringent requirements of “Significant Scientific Agreement.”
Notably, petitions for a QHC, such as the pending claim for soy protein
and certain cancers, are not automatically granted; they must meet the
ever-evolving FDA’s qualifying criteria. We propose a strategy to streamline QHC petitions that involve expert panel review, in which these
experts determine if a threshold of credible evidence is met. This proposed system would parallel the current expert panel GRAS process and
alleviate the potential bottleneck of submitted petitions to the Agency.
The strategy requires: (1)reinforcing the credibility of the panel and supporting data (including meta-analyses) by the Agency; (2) preserving
Poster Abstracts
of liver and kidney, produce blood, help urinating, remove swelling, cure
arthritics, high lipemia and cancer. In treating and preventing the abovelisted diseases, the following are discussed: the recipes of clinical foods,
preparation, ways of applying, function and effects, indiction and points
of attention.
6th International Symposium on the
Poster Abstracts
32
Role of Soy
in Preventing and Treating Chronic Disease
proprietary data; and (3) public recognition of findings. The soy industry
is challenged with navigating the regulatory requirements to establish
efficacy of their products. Understanding these processes and developing this proposed streamlined approach would greatly aid both the soy
industry and the FDA.
Preparation of Extruded Snack Food from Green
Gram Broken and Sawan Blends. Daya S. Singh, Aarti
Patel, Krishna Tiwari, and S.K. Garg, Department of Post
Harvest Process and Food Engineering, College of
Agricultural Engineering, JNKVV, Jabalpur (M.P.) India.
Studies on Antiradical Action of Herbal Extracts From
Seasoning and Their Effect on Foods and Human Health.
Boris Herskowitz*1, Rina Reznik2, Cathie Ioudkevitch2, Rodica
Segal3, and Dana Moraru3, 1Soglowek Food Industries,
Nahariya , Israel, 2Rad Natural Technologies Ltd., Petah Tikva,
Israel, 3University “Dunarea de Jos “, Galati, Romania.
Pulses are the inseparable part of India diet especially for vegetarian and are the major source of protein, when blended with cereals in certain proportion provides with a good protein diet among the consumer.
Green gram (Vigna radita L.) is a major pulse of Madhya Pradesh which
yields well under un-irrigated condition and on cloddy land. Sawan
(Echinochloa frumentacea L.) is good source of starch and when blended
with pulses, provides amino acids that are lacking in pulses. Therefore, the
protein quality of cereals – pulses combination is thus betters than that
of cereals/pulses alone. Extrusion cooking is a high temperature short
time cooking process which could be used for processing of starchy as
well as proteinaceous materials and is accomplished through the application of heat either directly by stream injection or indirectly through
jacket and by dissipation of mechanical energy through shearing occurring within the blend. The results of cooking of ingredients during the
extrusion process are the gelatinization of starch, the denaturation of
protein, the destruction of naturally occurring toxic substance and the
diminishing of microbial counts in the final product.
The present study was undertaken to find the effects of extrusion
cooking parameters and blending ratio on the quality of the extruded
products and to study the overall acceptability through texture of the
extrudates. The extrusion parameters were moisture content of the
green gram broken and temperature of barrel. The extrusion cooking
was done at Department of Food Science and Technology, JNKVV,
Jabalpur. The extruder used was BTPL – Lab. Twin Screw Extruder with
dia opening off 5.0 mm and the screw was driven with a 6 HP electric
motor. Screw speed was kept constant at 100 rpm. Extrusion was carried out at three levels of moisture content (10%, 14% and 18%) of raw
material and at 5 levels of percentage of green gram broken (10%,
13%, 16%, 19% and 22%) and at 3 levels of temperature (80, 90 and
100oC). The properties of the products obtained were evaluated and
prediction models were developed. After analyzing all the attributes for
physical parameters like Sectional Expansion Index, Longitudinal
Expansion Index, Volumetric Expansion Index, Average diameter and
bulk density; Texture Characteristics like Crispness, Hardness and
Cutting strength, it was concluded that best quality of extrudates (products) were obtained at 14% moisture content, 80oC barrel temperature
and 19% blending ratio followed by 10% moisture content, 80oC barrel
temperature and 13% blending ratio.
Meat Analog Schnitzels (MAS), containing Soy proteins, are subject to oxidative quality deterioration, expressing itself in Warmed-over
Flavor (WOF), as result of exposure to high pre-frying and pre-cooking
temperatures. Three stages were performed. In the first stage DPPH
(1,1-Diphenyl-2-picryl hydrazyl) Free Radical Scavenging Activity was
performed. In the second stage we made fried and cooked meat analog
schnitzel (FCS) using Soy protein SUPRO 620 (P2). HS-GC analysis were
performed in order to study the hexanal area of the product and to find
the antioxidant power of the protein (P2-FCS= 477550) . In the third
stage trying to improve the antioxidant capacity of P2 we have tested
the anti-oxidative effect of adding a natural, herbal extract
(OriganoxWS) (500ppm) RAD NATURAL to Soy proteins used in MAS
(P2+WS-FCS=272865). The addition of 500 ppm of Origanox WS
delayed oxidation of MAS by 43 %, as was measured by Hexanal
method using Head Space GC, enhanced taste of food products eliminating WOF, prolongation of shelf life, giving to the final product a natural and healthy image.
Change of Isoflavone Content During Manufacturing of
Chunggukjang, a Traditional Korean Fermented
Soyfood. J.S. Kim1, C.H. Jang1, J.K. Lim1, J.H. Kim2, C.S. Park3,
and D.Y. Kwon4, 1Department of Animal Science &
Biotechnology, Kyungpook National University, Daegu, S.
Korea, 2Department of Food Science & Technology,
Gyeonsang National University, JinJu, S. Korea, 3Department
of Food Science & Technology, Kyunghee University, YoungIn,
S. Korea, 4Korea Food Research Institute, SungNam, S. Korea.
Chunggugjang is one of popular Korean traditional fermented soyfoods. It is manufactured by inoculating steamed soy with Bacillus subtillus or traditional method in which steamed soy is exposed to rice
straw normally rich in Bacilllus species. Chunggukjang made from traditional method was found to have B. subtillus and B. licheniformis. We
analyzed isoflavone composition of Chunggukjang collected at various
fermentation times. Daidzin and genistin, major glycoside forms of
isoflavones present in soy, were decreased by ~50% during 43 hrs. But
the content of glycitein-O- glycoside showed a limited reduction. The
contents of aglycones genistein and glycitein showed dramatic increase
during first 30 hrs after fermentation started, with 5- and 1.7-folds
increase in concentration, respectively. In conclusion, short-term fermentation of steamed soy with Bacillus species caused significant accumulation of aglycone forms of isoflavones, suggesting that
Chunggukjang manufactured by traditional method might be a good
source of readily absorbable isoflavones.
This study was supported by Special Research and Development
Grant from KOSEF (2005).
Preparation of Nutritious Extruded Snacks from SoySorghum Blends to Solve the Problem of
Malnutrition in Trabal Belt of India. Daya S. Singh and
Duda Kalpana, Department of Post Harvest Process and
Food Engineering Faculty Of Agricultural Engineering, J.,N.
Agricultural University, Jabalpur-482004 (M.P.), India.
Soybean (Glycine Max L) which belongs to the family leguminaceae, is considered as a cheapest source of high quality protein and
oil content. In India, soybean is grown in 6.22 million hectares of land
with total annual production of 5.86 million tonnes. Sorghum (sorghum
bicolour L) belongs to the family poaceae, is most important cereal crop
and cheapest source of nutrition for poor. Madhya Pradesh has distinguished it self as major soybean and sorghum growing state by covering 4.32 and 5.14 million hectare of land with 3.62 and 3.99 million
tonnes production per annum (Anon. 2001-2002) respectively. Soybean
33
2005 Abstracts
Skin Health
Sunscreen Active Derived from Soybean Oil and
Ferulic Acid: Synthesis and Applications. J. Laszlo1, D.
Compton1, and R. Willis2, 1USDA, ARS, NCAUR, Peoria, IL,
USA, 2iSoyTechnologies Corp., Cary, IL, USA.
Ferulic acid is a natural plant phenol widely heralded for its ability to serve as a potent antioxidant. However, the low solubility of ferulic
acid in lipids prevents it from protecting lipid membranes and associated structures. In its esterified forms, ferulic acid strongly absorbs light
within the UVB and UVA regions from 290 to 370 nm, which suggests
that it may serve as a natural sunscreen agent. This research describes
the biocatalytic formation of stable (covalent) esters of ferulic acid with
soybean oil. The UV absorbing soybean oil is under investigation for
potential use as an all natural replacement for synthetic sunscreen
active ingredients, as a natural UV protectant for insecticidal biocontrol
agents, as an anti-oxidant in food frying, and as a bio-based industrial
lubricant. Many potential human health applications have yet to be
explored. We welcome inquiries regarding research collaborations.
Soy Peptides
Silicon Accumulation in Soybean Plants in Different
Rhizosphere pH Conditions. L. Oliveira1,2, E. Oliveira1, G.
Korndorfer1, and S. Tsai2, 1Universidade Federal de
Uberlândia, Uberlândia, MG, Brazil, 2Centro de Energia
Nuclear - USP, Piracicaba, SP, Brazil.
The legumes, such as soybean, have the capacity of acidifying the
rhizosphere soil, and this fact could explain the low ability of Si accumulation by this species, since Si absorption is dependent of soil pH. In
acidic conditions Si forms polymers, which are little available for the
plant. This work analyzed rhizosphere acidification with Si accumulation
by soybean. The experiment was installed in the green house in a 5x2
factorial scheme, applying in the plots (vases) 200mg kg-1 N in the following proportions of N-NO3- and N-NH4+: 100% N-NO3-; 75% NNO3- + 25% N-NH4+; 50% N-NO3- + 50% N-NH4+; 25% N-NO3- +
75% N-NH4+; 100% N-NH4+; besides the N treatments there was a
treatment with 200 mg kg-1 (silicon tetrachloride). The sources of nitrogen used were calcium nitrate and ammonium sulfate plus a nitrification
inhibitor - nitrapirin, applied in a Ustoxic Quartzipsamment soil. The use
of nitrate as N source caused an increase in rhizosphere and non-rhizosphere pH, leading to a greater Si availability in the soil. In the rhizosphere soil the pH values were lower than those found in non-rhizosphere
soil. Silicon contents in the soybean above ground parts did not present
any relationship with the availability of this element in the soil, however, in the root this relationship was positive, that is, the higher the pH,
the greater the Si accumulation in the root. Silicon accumulation in soybean is proportionally greater in the root than in the aboveground parts.
Glycine max, silicon, nitrate, ammonium.
Enzymatic Production of Soybean Peptides with
Potential Anti-Cancer Activity. E. de Mjia and W. Wang,
University of Illinois, USA.
Soybean proteins can be sources of bioactive peptides with potential anti-cancer activity. Cancer cells proliferate faster and have higher
topoisomerases expression making this enzyme an ideal anti-cancer target. Thus, topoisomerase inhibition is an indicator of anticancer activity.
The objective of this research was to determine the anti-topoisomerase
potential of soy protein isolate (SPI) hydrolysates produced by commercially available proteases. Five proteases (S, P, N, A, and M, Amano
Enzyme Inc.) were chosen for SPI hydrolysis. DNA human anti-Topo I
and Topo II were carried out with TopoGen human drug screening
assays. Identification and characterization of bioactive peptides were
determined by SDS-PAGE, gel filtration, HPLC and mass spectrometry.
The results showed that hydrolysates (0.14 mg/ml) produced by proteases P, S and N inhibited Topo II (38%, 16%, 21%, respectively).
Subsequent in vitro digestion with pepsin and pancreatin, simulating
gastrointestinal conditions, maintained 50% of the observed Topo II
activity. At 2.45 mg/ml, all five SPI hydrolysates showed only 10% Topo
I inhibition. Protease P hydrolysate contained the most active peptides
with catalytic Topo II inhibition and broad MW (300-3000 Da) with
hydrophilic and hydrophobic characteristics. Under in vitro gastric conditions and after 47% SPI hydrolysis as equivalents of L-leucine, small
hydrophilic peptides (< 2000 Da) with Topo II inhibition activity
(IC50=0.13 mg/ml) were produced. The results suggest anti-cancer
potential of SPI hydrolysates formed by proteases that are available to
the food industry. Furthermore, soybean derived peptides may play an
important role, particularly in the prevention of chronic diseases, such
as cancer.
Poster Abstracts
is rich in lysine but deficient in sulfer bearing amino acids. Sorghum,
which contains adequate quantity of sulfer bearing amino acids is deficient in lysine (Bonyasirikool et al. 1986). Hence the combination of
these sources of protein and starch can be effectively combined into
snacks of high nutritive value, which may be regularly consumed during
tea time/breakfast, will certainly solve the mal nutrition problem not
only in India but in the entire Asiatic Countries.
Protein in just 250 grams of soybean is equivalent to protein in 3
liters of milk or 1 kg of mutton or 24 eggs. The quality of soy protein is
virtually equivalent in quality to that of milk and egg protein. In addition to containing rich nutrients, soy bean has other beneficial compounds such as, phytosterols, lecithins, etc. soy protein has a number of
health benefits such as, cancer prevention, cholesterol reduction, combating asteoporosis and menopause regulation. Human studies suggest
that as littel as one serving of soy foods each day may be protective
against many types of cancers. The health claim states, “consumption of
25 grams of soy protein per day with a diet low in saturated fat may
lower the risk of heart diseases”. Extrusion has become an important
processing technique in an increasing variety of food processes. The
result of cooking of ingredients during the extrusion process are the
gelatinization of starch, the denaturation of protein, the destruction of
naturally occurring toxic substances and diminishing of microbial
counts in the final product. Once cooked the product is forced through
the die at the extruder discharge end where it expands rapidly with
some loss in moisture.
Experiments were conducted to study the effect of processing
parameter i.e. barrel temperature (80, 85, 90, 95 and 100oC), moisture
content of blend (15, 20 and 25% wb) and blending ratio of soy in
sorghum (5:95, 10:90, 15:85, 20:80 and 25:75), on the physical properties like, sectional expansion index, longitudinal expansion index, volumetric expansion index, bulk density; textural properties like crispness,
hardness and cutting strength; protein content and organoleptic test of
the extruded snacks. After evaluation and analysis of all the parameters
for physical, textural and organoleptic characteristics, it was concluded
that snacks produced at 15% moisture content, 85oC barrel temperature and 5% blend ratio was found best followed by product produced
at 15% moisture content, 90oC barrel temperature and 5% blend ratio.
6th International Symposium on the
Poster Abstracts
34
Role of Soy
in Preventing and Treating Chronic Disease
\Are Undigested Soy Peptides the Major
Hypocholesterolemic Components of Soy Protein?
J.W. Anderson and K. Patterson, University of Kentucky,
Lexington, KY, USA.
Soy proteins have many bioactive components including protein
subunits, peptides and isoflavones. Emerging research in animals and
humans indicate that peptides containing 5-20 amino acids (AA) are the
most potent hypocholesterolemic components of soy protein. Isolated
soy protein (ISP) hydrolysates (containing peptides of 5-20 AA) have
substantially greater hypocholesterolemic effects than ISP in animals
and humans. Possible mechanisms include decreased cholesterol
absorption and LDL receptor upregulation. Feeding the α' subunit of the
soy 7S globulin to rats has about five-fold greater hypocholesterolemic
potency than the 7S globulin itself. An α' subunit peptide of ~17 AA
upregulates LDL receptors in vitro. Oral administration of 10 mg/kg
body weight of 7S globulin peptide produced significant hypocholesterolemia in rats. Large soy peptides (43 AA) are absorbed intact and
retain biologic activity when extracted from blood or liver. Animal consumption of soy peptides (3-20 AA) exerts distinct effects on lipid
metabolism, blood pressure, energy expenditure and appetite regulation. In humans, Wang et al. (1995) reported that soy protein
hydrolysates decreased serum LDL-cholesterol by 24% more than ISP.
Hori et al. (2001) reported that 3 g/d of soy peptides decreased serum
LDL-cholesterol from baseline by 27% and 6 g/d decreased values by
43%. Thus, small amounts of soy peptides exert dramatic hypocholesterolemic effects in humans. Thus, the recent decline in hypocholesterolemic effects of ISP reported in humans may relate to fragmentation
of bioactive peptides during soy protein isolation or food processing. As
recent studies indicate, providing 3-6 grams of bioactive peptides may
have dramatic hypolipidemic effects.