Genistein,
an isoflavone phytonutrient derived from soybeans, has been the focus of
scientific research since 1966. Studies have shown that genistein can bind
to the same receptor sites as estrogen. Soybeans are the only significant
dietary source of genistein; however, the amount of soy foods necessary to
meet the body's needs can be difficult to incorporate into today's diet.
In Asia, where soy is a staple, the daily intake can be up to 20 times
that of a Western diet. Source Naturals Genistein is made from isoflavone-rich
soybean powder that yields a consistent standardized isoflavone content.
This unique chemical-free process requires approximately 400 pounds of
soybeans to yield just one pound of finished product.Genistein
Supplement Facts:
Amount Per 2 tablets:
Isoflavone-Rich - 2 g
Soybean Powder ( Soylife ) Yielding:
Daidzein - 34 mg
Glycitein - 20 mg
Genistein - 8 mg
Total Isoflavones - 62 mg
Suggested Use: One genistein tablet a few times a week with breakfast, or as recommended by
your health care professional.
Prostate Power
Rx with Genistein and Daidzein
Formulated by Ray Sahelian, M.D.

With Saw Palmetto, Pygeum, Stinging
Nettle, Quercetin, & 9 Key Ingredients for support of normal prostate size
& urine flow
Prostate Power Rx is carefully formulated with important herbs and nutrients to provide optimal prostate health. Significant clinical research on prostate enlargement has been conducted with the potent herbs in Prostate Power Rx. This prostate formula has been designed to support:
Saw Palmetto extract (standardized to contain 45% fatty acids - serenoa repens fruit)
Stinging Nettle 4:1 extract (urtica diocia root)
Quercetin flavonoid extract
Rosemary 4:1 extract (Rosemarinus officinales leaf)
Beta Sitosterol
extract, see also
Beta-Sitosterol to purchase this
supplement by itself.
Pygeum 4:1 bark extract (Pygeum Africanum)
Daidzein (standardized to contain 40% isoflavones)
(treatment with the
isoflavones daidzein and genistein, the estrogen-like compounds found in
soy, block prostate growth in rats)
Genistein (standardized to contain 40% isoflavones)
Lycopene (Lycoperscion escatatum fruit)
Genistein and your health
In spite of an extensive literature on the effects of dietary genistein, questions still
exist as to its potential overall benefits as a component of the human diet.
Dietary genistein ingestion has been linked, through epidemiological and animal model
studies, with a range of potential health effects. These include
prevention of breast, colon, and prostate cancers, cardiovascular disease and post-menopausal
ailments. Genistein may also be helpful in decreasing bone loss after menopause.
Genistein and Prostate gland health
Genistein levels in prostate tissue are
lower in those who have prostate cancer or an enlarged prostate.
Asthma and lung
function
Genistein may be associated with improved lung function in asthma.
Atherosclerosis or hardening of the arteries
A rabbit study shows genistein
supplementation reduces the risk for hardening of the arteries.
Genistein and Blood pressure management
Chronic soy milk consumption has modest, but significant hypotensive action in
those with hypertension. This hypotensive action was correlated with the urinary
excretion of the isoflavone genistein. Genistein helps produce more nitric oxide, a powerful chemical in
the blood stream that helps dilate blood vessels.
Genistein, Hot flashes, and menopause
Genistein and other flavonoids do not appear to have a significant effect in
reducing the severity of hot flashes, at least not as much as estrogen.
Gensitein and Osteoporosis
influence, bone health
Genistein, along with other isoflavones, may
help decrease bone loss after menopause.
Genistein and Cancer
Soy isoflavones
may have an important role in reducing the incidence of breast, colon,
cervix and
prostate cancers. Genistein, the predominant isoflavone found in soy, has been
shown to inhibit carcinogenesis in animal models. There is a growing body of
experimental evidence that shows the inhibition of human cancer cells by genistein
through the modulation of genes that are related to the control of cell
cycle and apoptosis.
Sorting out isoflavones and phytoestrogens
Genistein, along with
daidzein, are the best known and studied isoflavones. Isoflavones are types of flavonoids found in plants.
Compounds from plants that have estrogen-like properties are called phytoestrogens.
The six major subclasses of flavonoids include:
Anthocyanidins (e.g., cyanidin, pelargonidin)
Catechins or flavanols (e.g., epicatechin, gallocatechin)
Flavones (e.g., apigenin, luteolin)
Flavonols (e.g., kaempferol, myricetin, quercetin)
Flavanones (e.g., hesperidin, naringenin)
Isoflavones (e.g., genistein, daidzein,
biochanin).
The chemistry of Genistein
Genistein, (also known as 4',5,7-trihydroxyisoflavone) is a common precursor in the biosynthesis
of antimicrobial phytoalexins and phytoanticipins in legumes.
Genistein is
synthesized in plants from the flavanone naringenin. Genistein is a phytoestrogen with a wide
variety of pharmacological effects in animal cells, including tyrosine kinase
inhibition.
Genistein Research studies
Dietary intake of soy genistein is
associated with lung function in patients with asthma.
J Asthma. 2004;41(8):833-43.
To determine if micronutrient intake is associated with asthma severity, we
administered the Block food frequency questionnaire to participants in a
randomized clinical trial of the safety of influenza vaccine for asthmatics. The
nutrition substudy included 1033 participants, aged 12-75. Intake of antioxidant
vitamins, soy isoflavones, total fruits and vegetables, fats, and fiber was
compared with asthma severity at baseline, peak expiratory flow rate (PEF),
asthma symptoms and the rate of asthma exacerbations during the 2 weeks
following influenza vaccination. The only nutrient that had a consistent
association with asthma severity was genistein, a soy isoflavone. None of the
nutrients evaluated were related to asthma exacerbation rate when adjusted for
known confounders. The FEV1 in genistein consumers of at least 250 microg/1000
Kcal per day was 82% predicted, 79% predicted for those who consumed between 1 and
249 microg/1000 kcal, and 76% predicted in genistein nonconsumers; the PEF was
82% predicted, 80.8% predicted, and 78% predicted, respectively. Thus,
increasing consumption of genistein is associated with better lung function in
patients with asthma. Further studies are needed to determine whether dietary
supplementation with genistein can reduce asthma severity.
Anticancer therapeutic potential of soy isoflavone,
genistein.
Adv Exp Med Biol. 2004;546:121-65.
Ravindranath MH, Muthugounder S, Presser N, Viswanathan S. Laboratory of
Glycoimmunotherapy, John Wayne Cancer Institute, 2200 Santa Monica Blvd., Santa
Monica, CA
Genistein (4'5, 7-trihydroxyisoflavone) occurs as a glycoside (genistin) in
the plant family Leguminosae, which includes the soybean (Glycine max). A
significant correlation between the serum/plasma level of genistein and the
incidence of gender-based cancers in Asian, European and American populations
suggests that genistein may reduce the risk of tumor formation. Other evidence
includes the mechanism of action of genistein in normal and cancer cells.
Genistein inhibits protein tyrosine kinase (PTK), which is involved in
phosphorylation of tyrosyl residues of membrane-bound receptors leading to
signal transduction, and it inhibits topoisomerase II, which participates in DNA
replication, transcription and repair. By blocking the activities of PTK,
topoisomerase II and matrix metalloprotein (MMP9) and by down-regulating the
expression of about 11 genes, including that of vascular endothelial growth
factor (VEGF), genistein can arrest cell growth and proliferation, cell cycle at
G2/M, invasion and angiogenesis. Furthermore, genistein can alter the expression
of gangliosides and other carbohydrate antigens to facilitate their immune
recognition. Genistein acts synergistically with drugs such as tamoxifen,
cisplatin, 1,3-bis 2-chloroethyl-1-nitrosourea (BCNU), dexamethasone,
daunorubicin and tiazofurin, and with bioflavonoid food supplements such as
quercetin, green-tea catechins and black-tea thearubigins. Genistein can augment
the efficacy of radiation for breast and prostate carcinomas. Because it
increases melanin production and tyrosinase activity, genistein can protect
melanocytes of the skin of Caucasians from UV-B radiation-induced melanoma.
Genistein-induced antigenic alteration has the potential for improving active
specific immunotherapy of melanoma and carcinomas. When conjugated to B43
monoclonal antibody, genistein becomes a tool for passive immunotherapy to
target B-lineage leukemias that overexpress the target antigen CD19. Genistein
is also conjugated to recombinant EGF to target cancers overexpressing the EGF
receptor. Although genistein has many potentially therapeutic actions against
cancer, its biphasic bioactivity (inhibitory at high concentrations and
activating at low concentrations) requires caution in determining therapeutic
doses of genistein alone or in combination with chemotherapy, radiation therapy,
and/or immunotherapies. Of the more than 4500 genistein studies in peer-reviewed
primary publications, almost one fifth pertain to its antitumor capabilities and
more than 400 describe its mechanism of action in normal and malignant human and
animal cells, animal models, in vitro experiments, or phase I/II clinical
trials. Several biotechnological firms in Japan, Australia and in the United
States (e.g., Nutrilite) manufacture genistein as a natural supplement under
quality controlled and assured conditions.
The effect of genistein supplementation on performance
and antioxidant status of Japanese quail under heat stress.
Arch Anim Nutr. 2004 Dec;58(6):463-71.
Genistein, a phytoestrogen found in soybeans, is a powerful antioxidant. We
evaluated the effects of genistein supplementation on performance, carcass
characteristics, levels of malondialdehyde (MDA), homocysteine, vitamins C, E, A
in Japanese quail (Coturnix coturnix japonica) exposed to high ambient
temperature of 34 degrees C. Results of the present study suggest that
supplementation with genistein can be considered to be protective by reducing
the negative effects of oxidative stress induced by heat stress in quail.
Soy isoflavones suppress invasiveness of breast cancer cells by the inhibition
of NF-kappaB/AP-1-dependent and -independent pathways.
Int J Oncol. 2004 Nov;25(5):1389-95.
High consumption of soy products in some Asian countries has been linked to the
low incidence of breast cancer in women. The chemopreventive effect of the soy
isoflavone, genistein, has been observed through the suppression of cell
proliferation, inhibition of angiogenesis and stimulation of apoptosis in breast
carcinoma cells. Cancer metastasis consists of interdependent processes,
including cell adhesion, migration and invasion. In the present study, we
compare the effect of soy isoflavones in the form of aglycones (genistein,
daidzein and glycitein) and glucosides (genistin, daidzin and glycitin) on the
behavior of highly invasive breast cancer cells. Here we demonstrate that
genistein suppresses cell adhesion and migration by inhibiting the
constitutively active transcription factors NF-kappaB and AP-1, resulting in the
suppression of secretion of urokinase-type plasminogen activator (uPA) in breast
cancer cells. In addition, we show that all tested soy isoflavone
aglycones (genistein, daidzein, glycitein) and glucosides (genistin, daidzin,
glycitin) markedly reduced motility of MDA-MB-231 cells. However, only genistein
and daidzein inhibited constitutively active NF-kappaB and AP-1 and suppressed
secretion of uPA from breast cancer cells. Taken together, our results suggest
that dietary soy isoflavones inhibit adhesion and motility of highly invasive
breast cancer cells by distinct signaling pathways.
Phytoestrogen tissue levels in benign prostate
hyperplasia and prostate cancer and their association with prostate diseases.
Urology. 2004 Oct;64(4):707-11.
Prostate tissue samples of men
consuming a Western diet who underwent surgery for prostate enlargement
or prostate cancer were collected and frozen. In the
tissue samples, the enterolactone and genistein levels were determined. We subsequently compared
the tissue levels in patients with prostate enlargement and prostate cancer and
studied the impact of enterolactone and genistein on prostate volume.
The enterolactone tissue levels were comparable in patients with prostate
enlargement and prostate cancer and revealed no correlation to prostate volume.
The genistein tissue levels tended to be lower in patients with prostate cancer
compared with the entire prostate enlargement group. In addition, the genistein
tissue levels were significantly greater in men with small-volume prostate
enlargement compared with those with large-volume prostate enlargement. Our data suggest an involvement of genistein in the pathogenesis of prostate enlargement and, possibly, of prostate
cancer. The impact of enterolactone is currently unknown.
Cardiovascular effects of the phytoestrogen genistein.
Curr Med Chem Cardiovasc Hematol Agents. 2004 Apr;2(2):179-86.
Phytoestrogenic molecules have received a great deal of attention over the
last few years because of their potentially preventive roles against a few of
today's most prevalent chronic diseases, namely cardiovascular diseases,
osteoporosis and hormone related cancers. Of the several phytoestrogens,
genistein in particular has been shown to be the most efficacious in animal
models and experimental studies. Genistein in vitro relaxes rat arteries by a
nitric oxide dependent mechanism and enhances the dilator response to
acetylcholine of atherosclerotic arteries. Genistein supplementation improves
endothelial dysfunction induced by oophorectomy in rats and reduces infarct size
in an experimental model of myocardial ischaemia-reperfusion injury.
Furthermore, genistein in postmenopausal women increases plasma nitric oxide
breakdown products, reduces endothelin-1 levels and improves endothelial
dependent vasodilation in post-menopausal women. All these findings, taken
together, would suggest that this molecule might represent an attractive
alternative for cardiovascular protection.
Genistein supplementation inhibits atherosclerosis with
stabilization of the lesions in hypercholesterolemic rabbits.
J Korean Med Sci. 2004 Oct;19(5):656-61.
The effect of genistein on aortic atherosclerosis was studied in New Zealand White rabbits. After
provocation of atherosclerosis with hyperlipidemic diet, the rabbits were
divided as hyperlipidemic diet group (HD), normal diet group (ND) and
hyperlipidemic plus genistein diet group (HD + genistein) for 4 and half months.
The average cross sectional area of atherosclerotic lesion was 0.269 mm2 after
provocation. The lesion was progressed by continuous hyperlipidemic diet (10.06
mm2) but was increased mildly by genistein (0.997 mm2), and decreased by normal
diet. The ratio of macrophages to smooth muscle cells in the lesion
was not changed by genistein supplementation. The western blotting showed
reduction of MMP-3 expression in HD+genistein and ND groups than HD group. The
inhibition of atherogenesis by genistein might be due to improved
endothelial function rather than direct action on macrophages and/or smooth
muscle cells in the lesion, since endothelial dysfunction by lipid peroxidation
was the main atherogenic factor in the hypercholesterolemic rabbits. The
genistein supplementation also suggests that it helps the stabilization of the
atherosclerotic lesion by inhibition of MMP-3 expression.
Phytoestrogenic isoflavones daidzein and genistein
reduce glucose-toxicity-induced cardiac contractile dysfunction in ventricular
myocytes.
Endocr Res. 2004 May;30(2):215-23.
Epidemiological evidence suggests a reduction in the incidence of coronary
heart disease, cancer and osteoporosis in populations with a high dietary intake
of plant estrogen or phytoestrogen. The clinical benefit of phytoestrogens in
cereals, vegetables and medicinal plants is attracting increasing attention for
the general public. In the present study, we examined the effect of
phytoestrogenic isoflavones daidzein and genistein on glucose toxicity-induced
cardiac mechanical malfunction simulating diabetic cardiomyopathy. Adult rat
ventricular myocytes were isolated and maintained for 24 hours in normal or high
glucose medium in the absence or presence of isoflavones daidzein or genistein. Collectively, these
data suggest that the phytoestrogenic isoflavones daidzein and genistein may
reduce glucose toxicity-induced cardiac mechanical dysfunction and thus possess
therapeutic potential against diabetes-associated cardiac defects.
Inhibition of proliferation and induction of apoptosis
by genistein in colon cancer HT-29 cells.
Cancer Lett. 2004 Nov 25;215(2):159-66.
Genistein has multiple anticancer properties. However, its mechanisms of action
and its molecular targets on human colon cells remain to be further elucidated.
Here, we demonstrated that genistein reduced proliferation and induced G2/M
phase arrest and apoptotic death in colon cancer HT-29 cells. We then
investigated the effects of genistein on molecules that regulate apoptosis and
cell cycle progress. Genistein increased expression of Bax and p21(WAF1) and
slightly decreased Bcl-2 level. Our results demonstrated that genistein
inhibited the viability of human colon cancer HT-29 cell via induction of
apoptosis mainly through regulation of p21(WAF1) and Bax/Bcl-2 expression. These
data suggested a role of genistein in prevention of colon tumor and might reduce
colon tumor growth.
Inhibitory effect of genistein and daidzein on ovarian
cancer cell growth.
Anticancer Res. 2004 Mar-Apr;24(2B):795-800.
Survival from ovarian cancer has not changed significantly in the
past twenty years requiring development of additional treatment protocols. We
studied the effect of genistein and daidzein on ovarian cancer cell growth.
Five ovarian cancer cell lines from Stage IIIC disease
were evaluated. Sulforhodamine B and colony formation assays were used to
analyze growth inhibitory effects of genistein and daidzein alone and with
cisplatin, paclitaxel or topotecan. Apoptosis induction was studied by
determining caspase-3 activity. Inhibition of growth (50-80%), colony
formation and colony size was seen at 144 microm of genistein, 0-23% reduction
was demonstrated at 9 microm. At 144 microm, the colony size was inhibited >75%;
at 9 microm 4/5 cell lines had >50% reduction. Caspase-3 activity was induced with all concentrations of genistein.
Cisplatin and topotecan combined with genistein resulted in a mostly additive effect, paclitaxel was
slightly less than additive. We demonstrate an inhibitory effect of genistein on ovarian cancer cell growth.
Not all soy products are created equal: caution needed in interpretation of
research results.
Erdman JW Jr et al. University of Illinois, Urbana, IL
J Nutr. 2004 May;134(5):1229S-1233S.
Interest in the health benefits of soy foods has been intense among the
research community, health professionals, and the public. At the same time,
potential concerns associated with soy consumption, especially as related to soy
isoflavones, have tempered the enthusiasm for making public health
recommendations. On both accounts, the primary soybean isoflavone, genistein,
has received the most attention. Because consumers are becoming increasingly
confused by the often conflicting dietary messages, a balanced and accurate view
of the risks and benefits of soy foods and soy food components is essential.
Even among health professionals, confusion exists about proper nomenclature and
about the precise composition of the agents under investigation. Levels of
isoflavones are frequently assumed to be constant within categories of soy
foods, and intakes are estimated rather than being directly analyzed.
Furthermore, all too often research dealing singularly with genistein is
interpreted by both health professionals and the media as equating directly with
soy. Researchers often fail to fully understand the implications of their
research outcomes and the context in which those outcomes should be placed. With
the hundreds of publications yearly on soy and isoflavones, it is especially
important to consider the literature in its entirety when making pronouncements
about health effects.
Soy isoflavones and cancer prevention.
Sarkar FH, Li Y. Wayne State University School of Medicine, Detroit, MI
Cancer Invest. 2003;21(5):744-57.
Epidemiological studies have shown a significant difference in cancer
incidence among different ethnic groups, which is believed to be partly
attributed to dietary habits. The incidences of breast and prostate cancers are
much higher in the United States and European countries compared with Asian
countries such as Japan and China. One of the major differences in diet between
these populations is that the Japanese and the Chinese consume a traditional
diet high in soy products. Soy isoflavones have been identified as dietary
components having an important role in reducing the incidence of breast and
prostate cancers. Genistein, the predominant isoflavones found in soy, has been
shown to inhibit the carcinogenesis in animal models. There are growing body of
experimental evidence that show the inhibition of human cancer cells by
genistein through the modulation of genes that are related to the control of
cell cycle and apoptosis. Moreover, it has been shown that genistein inhibits
the activation of NF-kappa B and Akt signaling pathways, both of which are known
to maintain a homeostatic balance between cell survival and apoptosis. Genistein
is commonly known as phytoestrogen, which targets estrogen- and
androgen-mediated signaling pathways in the processes of carcinogenesis.
Furthermore, genistein has been found to have antioxidant property, and shown to
be a potent inhibitor of angiogenesis and metastasis. Taken together, both in
vivo and in vitro studies have clearly shown that genistein, one of the major
soy isoflavones, is a promising reagent for cancer chemoprevention and/or
treatment. In this article, we attempt to provide evidence for these effects of
genistein in a succinct manner to provide comprehensive state-of-the-art
knowledge of the biological and molecular effects of the isoflavone genistein in
cancer cells.
The effects of phytoestrogen isoflavones on bone density in women: a
double-blind, randomized, placebo-controlled trial.
Am J Clin Nutr. 2004 Feb;79(2):326-33.
Isoflavone phytoestrogen therapy has been proposed as a natural
alternative to hormone replacement therapy (HRT). HRT has a beneficial effect on
bone, but few trials in humans have investigated the effects of isoflavones on
bone. The objective of the study was to determine the effect on bone
density of a red clover-derived isoflavone supplement that provided a daily dose
of 26 mg biochanin A, 16 mg formononetin, 1 mg genistein, and 0.5 mg daidzein
for 1 y. Effects on biochemical markers of bone turnover and body composition
were also studied. Women aged 49-65 y (n = 205) were enrolled in a
double-blind, randomized, placebo-controlled trial; 177 completed the trial.
Bone density, body composition, bone turnover markers, and diet were measured at
baseline and after 12 mo. Loss of lumbar spine bone mineral content and
bone mineral density was significantly
lower in the women taking the isoflavone supplement than in those taking the
placebo. There were no significant treatment effects on hip bone mineral content
or bone mineral density, markers of bone resorption, or body composition, but
bone formation markers were significantly increased in the intervention group compared with placebo in postmenopausal
women. Interactions between treatment group and menopausal status with respect
to changes in other outcomes were not significant. These data
suggest that, through attenuation of bone loss, isoflavones have a potentially
protective effect on the lumbar spine in women
Dietary phytoestrogen intake and premenopausal breast cancer risk in a German
case-control study.
Int J Cancer. 2004 Jun 10;110(2):284-90.
A diet high in isoflavonoids (soy) is associated with lower breast cancer risk
in Asian populations. Due to the low soy intake, dietary lignans may be the more
important phytoestrogen class in Western populations. We used a population-based
case-control study of breast cancer by age 50 in southern Germany to evaluate
the association between dietary intake of different phytoestrogens and
premenopausal breast cancer risk. Dietary information was collected from 278
premenopausal cases and 666 age-matched controls, using a validated FFQ. Using
multivariate logistic regression, the highest vs. lowest intake quartiles of
daidzein and genistein yielded significantly reduced ORs for breast
cancer risk of 0.62 and 0.47, respectively. The
protective effects of daidzein and genistein were found only for hormone
receptor-positive tumors. High intake of other isoflavonoids, e.g., formononetin
and biochanin A, as well as the sum of isoflavonoids were not associated with a
decrease in risk. Breast cancer risk significantly decreased with a high intake
of the plant lignan matairesinol but not secoisolariciresinol or the sum of plant lignans. However, both estimated
mammalian lignans, enterodiol and enterolactone, were inversely associated with
breast cancer risk, with ORs (95% CI) of 0.61and 0.57,
respectively. No effect was found for total phytoestrogen intake. Our results
suggest an important role of dietary intake of daidzein and genistein, despite
low levels, as well as of matairesinol and mammalian lignans to reduce
premenopausal breast cancer risk in this study population.