coumestrol and daidzein

Phytoestrogens are plant compounds that are structurally similar to estrogen and that possess anti-cancer properties. Previous studies have reported that coumestrol, daidzein and genistein could induce cell death by reducing Annexin A1 protein in leukemic cell lines. Annexin A1 (ANXA1) is involved in cell progression, metastasis, and apoptosis in several types of cancer cells. The present study sought to investigate if the effects of phytoestrogens on apoptosis, cell cycle arrest and phagocytosis in ANXA1-knockdown leukemic cells are mediated through ANXA1 or occurred independently.. Transfection of ANXA1 siRNA was conducted to downregulate ANXA1 expression in Jurkat, K562 and U937 cells. Apoptosis and cell cycle assays were conducted using flow cytometry. Western blot was performed to evaluate ANXA1, caspases and Bcl-2 proteins expression. Phagocytosis was determined using hematoxylin and eosin staining.. The expression of ANXA1 after the knockdown was significantly downregulated in all cell lines. Genistein significantly induced apoptosis associated with an upregulation of procaspase-3, -9, and - 1 in Jurkat cells. The Bcl-2 expression showed no significant difference in Jurkat, K562 and U937 cells. Treatment with phytoestrogens increased procaspase-1 expression in Jurkat and U937 cells while no changes were detected in K562 cells. Flow cytometry analysis demonstrated that after ANXA1 knockdown, coumestrol and genistein caused cell cycle arrest at G2/M phase in selected type of cells. The percentage of phagocytosis and phagocytosis index increased after the treatment with phytoestrogens in all cell lines.. Phytoestrogens induced cell death in ANXA1-knockdown leukemia cells, mediated by Annexin A1 proteins. Graphical abstract.

Topics: Annexin A1; Apoptosis; Caspases; Cell Cycle; Cell Death; Coumestrol; Gene Knockdown Techniques; Genistein; Humans; Isoflavones; Jurkat Cells; K562 Cells; Leukemia; Phagocytosis; Phytoestrogens; Proto-Oncogene Proteins c-bcl-2; RNA, Small Interfering; THP-1 Cells; U937 Cells

Isoflavones are a class of polyphonic compounds present in legumes and are called phytoestrogens because of their estrogen-like activity. Estrogen influences the behavior of mammary epithelial cells (MECs) during pregnancy and lactation. In this study, we investigated the direct influences of isoflavones and their metabolites in milk production ability of MECs.. Mouse MECs were cultured with prolactin and dexamethasone (glucocorticoid analog) to induce milk production ability. Subsequently, lactating MECs were treated with each isoflavone. Coumestrol, biochanin A, genistein, and formononetin decreased the intracellular and secreted β-casein. On the other hand, p-ethylphenol, daidzein, and equol did not significantly influence β-casein production at any concentration. Coumestrol, biochanin A and genistein down-regulated the mRNA expression of whey acidic protein (WAP), lactoferrin and α-lactalbumin. In contrast, p-ethylphenol, daidzein and equol up-regulated β-casein and/or WAP with α-lactalbumin. Furthermore, coumestrol and genistein down-regulated the expression of prolactin receptor and signal transducer and activator of transcription 5 (STAT5) accompanied by a decrease in STAT5 phosphorylation.. Isoflavones and their metabolites influence the milk production ability of MECs through different interactions with prolactin/STAT5 signaling. Simultaneous intake of multiple isoflavones by consumption of legumes may induce promotive or adverse effects on lactating MECs.

Topics: Animals; Caseins; Cells, Cultured; Coumestrol; Epithelial Cells; Female; Genistein; Isoflavones; Mammary Glands, Animal; Mice; Mice, Inbred ICR; Milk; Phenols; Phosphorylation; Phytoestrogens; Prolactin; STAT5 Transcription Factor

During lactation, mammary epithelial cells (MECs) form the blood-milk barrier by less-permeable tight junctions (TJs) to prevent the leakage of milk components. Phytoestrogens affect the proliferation, differentiation, and apoptosis of MECs. However, it remains unclear whether phytoestrogens are involved in the blood-milk barrier. Therefore, we investigated the influence of phytoestrogens (coumestrol, genistein, and daidzein) by using an in vitro mouse-MEC-culture model. The results showed that coumestrol and genistein changed the expression of TJ proteins (claudins-3 and -4 and occludin), weakened barrier function, and reduced β-casein production. Daidzein also weakened barrier function without inhibiting β-casein production. Additionally, coumestrol and genistein induced apoptosis in MECs. These results indicate that phytoestrogens weaken the blood-milk barrier by directly affecting TJs and the cellular viability of lactating MECs in different ways.

Topics: Animals; Caseins; Cell Survival; Coumestrol; Epithelial Cells; Female; Genistein; Humans; Isoflavones; Lactation; Mammary Glands, Animal; Mice; Mice, Inbred ICR; Milk; Phytoestrogens; Tight Junctions

The amount of secondary metabolites in plants can be enhanced or reduced by various external factors. In this study, the effect of strontium ions on the production of phytoestrogens in soybeans was investigated. The plants were treated with Hoagland's solution, modified with Sr(2+) with concentrations ranging from 0.5 to 3.0 mM, and were grown for 14 days in hydroponic cultivation. After harvest, soybean plants were separated into roots and shoots, dried, and pulverized. The plant material was extracted with methanol and hydrolyzed. Phytoestrogens were quantified by HPLC. The significant increase in the concentration of the compounds of interest was observed for all tested concentrations of strontium ions when compared to control. Sr(2+) at a concentration of 2 mM was the strongest elicitor, and the amount of phytoestrogens in plant increased ca. 2.70, 1.92, 3.77 and 2.88-fold, for daidzein, coumestrol, genistein and formononetin, respectively. Moreover, no cytotoxic effects were observed in HepG2 liver cell models after treatment with extracts from 2 mM Sr(2+)-stressed soybean plants when compared to extracts from non-stressed plants. Our results indicate that the addition of strontium ions to the culture media may be used to functionalize soybean plants with enhanced phytoestrogen content.

Topics: Cations, Divalent; Cell Survival; Chromatography, High Pressure Liquid; Coumestrol; Genistein; Glycine max; Hep G2 Cells; Humans; Hydroponics; Isoflavones; Methanol; Phytoestrogens; Plant Extracts; Plant Roots; Plant Shoots; Solvents; Strontium

Tamoxifen users sometimes seek complementary and alternative medicine advice for treatment of a variety of illness and co-administer with phytoestrogen-containing herbs, resulting in an increasing concern of its influence in subsequent endometrial cancer risk. Our study aims to determine the prevalence of Chinese herbal products containing coumestrol, genistein, or daidzein and their association with subsequent endometrial cancer risk among tamoxifen-treated breast cancer survivors in Taiwan.. We selected all patients who were newly diagnosed with invasive breast cancer and received tamoxifen treatment between January 1, 1998, and December 31, 2008, from the National Health Insurance Research Database. Among the 26,656 tamoxifen-treated breast cancer survivors, we evaluated the usage, frequency of service, and prescription of Chinese herbal products containing coumestrol, genistein, or daidzein. The logistic regression method was employed to calculate the odds ratios for utilization of those herbal products. Cox proportional hazard regression was set to calculate the hazard ratios of endometrial cancer associated with such usage.. Of the patients surveyed, 36.2% (n=9652) of the tamoxifen-treated breast cancer survivors examined in the study had consumed Chinese herbal products containing coumestrol, genistein, or daidzein during the study period. Exposure to Ge Gen(Puerariae Radix) specifically was the most extensive. For it, the population consumed an average cumulative dose of above 180g. Compared to those who had never used Chinese herbal products, breast cancer survivors who had taken Chinese herbal products containing coumestrol, genistein, or daidzein concurrently with tamoxifen treatment did not have a higher hazard ratio for subsequent development of endometrial cancer.. Among those tamoxifen-treated female breast cancer survivors in Taiwan, consumption of Chinese herbal products containing coumestrol, genistein, or daidzein is negatively correlated with subsequent endometrial cancer risk.

Topics: Adult; Aged; Breast Neoplasms; Case-Control Studies; Coumestrol; Drugs, Chinese Herbal; Endometrial Neoplasms; Female; Genistein; Humans; Isoflavones; Middle Aged; Survivors; Taiwan; Tamoxifen; Young Adult

Phytoestrogens are of interest because of their reported beneficial effects on many human maladies including cancer, neurodegeneration, cardiovascular disease and diabetes. As data on phytoestrogens continues to accumulate, it is clear that there is significant overlap in the cellular effects elicited by these various compounds. Here, we show that one mechanism by which a number of phytoestrogens achieve their growth inhibitory and cytoprotective effects is via induction of the mitochondrial manganese superoxide dismutase (MnSOD). Eight phytoestrogens, including resveratrol, coumestrol, kaempferol, genistein, daidzein, apigenin, isoliquirtigenin and glycitin, were tested for their ability to induce MnSOD expression in mouse C2C12 and primary myoblasts. Five of these, resveratrol, coumestrol, kaempferol, genistein and daidzein, significantly increased MnSOD expression, slowed proliferative growth and enhanced stress resistance (hydrogen peroxide LD50) . When siRNA was used to prevent the MnSOD induction by genistein, coumestrol or daidzein, none of these compounds exerted any effect on proliferative growth, and only the effect of coumestrol on stress resistance persisted. The estrogen antagonist ICI182780 prevented the increased MnSOD expression and also the changes in cell growth and stress resistance, indicating that these effects are mediated by estrogen receptors (ER). The absence of effects of resveratrol or coumestrol, but not genistein, in ERβ-null cells further indicated that this ER in particular is important in mediating these effects. Thus, an ER-mediated induction of MnSOD expression appears to underlie the growth inhibitory and cytoprotective activities of multiple phytoestrogens.

Topics: Animals; Cell Cycle; Cell Line; Cell Proliferation; Coumestrol; Cytoprotection; Estradiol; Fulvestrant; Genistein; Isoflavones; Kaempferols; Mice; Myoblasts; Phytoestrogens; Receptors, Estrogen; Resveratrol; Stilbenes; Stress, Physiological; Superoxide Dismutase

Common bean (Phaseolus vulgaris) is present in the daily diet of various countries and, as for other legumes, has been investigated for its nutraceutical potential. Thus, 16 genotypes from different gene pools, representing seven types of seed coats and different responses to pathogens and pests, were selected to verify their isoflavone contents. The isoflavonoids daidzein and genistein and the flavonols kaempferol, myricetin, and quercetin were found. Grains of the black type showed the highest concentrations of isoflavonoids and were the only ones to exhibit daidzein. IAC Formoso, with high protein content and source of resistance to anthracnose, showed the greatest concentration of genistein, representing around 11% of the content present in soybean, as well as high levels of kaempferol. Arc 1, Raz 55, and IAC Una genotypes showed high content of coumestrol. The results suggest the use of IAC Formoso to increase the nutraceutical characteristics in common bean.

Topics: Brazil; Color; Coumestrol; Flavonoids; Genotype; Isoflavones; Kaempferols; Phaseolus; Seeds

The captive southern white rhinoceros (SWR; Ceratotherium simum simum) population serves as an important genetic reservoir critical to the conservation of this vulnerable species. Unfortunately, captive populations are declining due to the poor reproductive success of captive-born females. Captive female SWR exhibit reproductive problems suggested to result from continual ovarian follicular activity and prolonged exposure to endogenous estrogen. However, we investigated the potential role of exogenous dietary phytoestrogens in the reproductive failure of SWR by cloning and characterizing in vitro phytoestrogen binding and activation of recombinant SWR estrogen receptors (ESR). We compared those characteristics with recombinant greater one-horned rhinoceros (GOHR; Rhinoceros unicornis) ESR, a species that receives similar captive diets yet reproduces relatively well. Our results indicate that phytoestrogens bind rhino ESR in a manner similar to other vertebrate species, but there are no differences found in phytoestrogen binding affinity of SWR ESR compared with GOHR ESR. However, species-specific differences in ESR activation by phytoestrogens were detected. The phytoestrogen coumestrol stimulated greater maximal activation of SWR ESR1 than GOHR ESR1. SWR ESR2 were also more sensitive to phytoestrogens and were activated to a greater extent by both coumestrol and daidzein. The concentrations in which significant differences in ESR activation occurred (10(-7) to 10(-5) m) are consistent with circulating concentrations measured in other vertebrate species. Taken together, these findings suggest that phytoestrogens potentially pose a risk to the reproductive health of captive SWR. However, additional studies are needed to further clarify the physiological role of dietary phytoestrogens in the reduced fertility of this species.

Topics: Animals; Cloning, Molecular; Coumestrol; Estrogens; Female; HEK293 Cells; Humans; Isoflavones; Perissodactyla; Phytoestrogens; Protein Binding; Protein Structure, Tertiary; Receptors, Estrogen; Reproduction

Osteoblast and osteoclast activity is disrupted in post-menopausal osteoporosis. Thus, to fully address this imbalance, therapies should reduce bone resorption and promote bone formation. Dietary factors such as phyto-oestrogens and Zn have beneficial effects on osteoblast and osteoclast activity. However, the effect of combinations of these factors has not been widely studied. We therefore examined the effect of coumestrol, daidzein and genistein in the presence or absence of zinc sulphate (Zn) on osteoclast and osteoblast activity. Osteoclast differentiation and bone resorption were significantly reduced by coumestrol (10- 7 m), daidzein (10- 5 m) and genistein (10- 7 m); and this direct anti-osteoclastic action was unaffected by Zn (10- 5 m). In addition, Zn augmented the inhibitory effect of phyto-oestrogens on the osteoblast-derived stimulus for osteoclast formation, significantly reducing the ratio of receptor activator of NF-κB ligand (RANKL)-to-osteoprotegerin mRNA expression in human osteoblast. We then examined the effect of these compounds on osteoblast activity. Mineralisation was enhanced by coumestrol (10- 5 to 10- 7 m), daidzein (10- 5 to 10- 6 m) and genistein (10- 5 m); and Zn significantly augmented this response. Zn and phyto-oestrogens also significantly enhanced alkaline phosphatase activity and Runt-related transcription factor 2 (Runx2) mRNA expression. On the other hand, Zn blunted phyto-oestrogen-induced type I collagen and osteocalcin expression and suppressed coumestrol and daidzein-stimulated osterix expression. Zn may therefore modify the anabolic action of phyto-oestrogens, promoting characteristics associated with early rather than late stages of osteoblast differentiation. Our data suggest that while Zn enhances the anti-osteoclastic effect of phyto-oestrogens, it may limit aspects of their anabolic action on bone matrix formation.

Topics: Acid Phosphatase; Animals; Bone Resorption; Cell Line; Cell Proliferation; Collagen Type I; Core Binding Factor Alpha 1 Subunit; Coumestrol; Gene Expression Regulation; Genistein; Humans; Isoenzymes; Isoflavones; Ligands; Macrophages; Mice; NF-kappa B; Osteoblasts; Osteoclasts; Osteoprotegerin; Phytoestrogens; Sp7 Transcription Factor; Tartrate-Resistant Acid Phosphatase; Transcription Factors; Zinc

Some forms of estrogen are associated with breast cancer risk as well as with mammographic density (MD), a strong marker of breast cancer risk. Whether phytoestrogen intake affects breast density, however, remains unclear. We evaluated the association between serum levels of phytoestrogens and MD in postmenopausal women. We enrolled 269 women, ages 55-70 yr, who received a screening mammogram and had no history of postmenopausal hormone use. Subjects completed a survey on diet and factors related to MD and provided a blood sample for analysis of 3 phytoestrogens: genistein, daidzein, and coumestrol. We examined whether mean percent MD was related to serum level of phytoestrogens, adjusting for age and body mass index. Genistein and daidzein levels correlated with self-reported soy consumption. Mean percent MD did not differ across women with different phytoestrogen levels. For example, women with nondetectable genistein levels had mean density of 11.0% [95% confidence intervals (CI) = 9.9-12.4], compared to 10.5% (95% CI = 8.0-13.7) and 11.2% (95% CI = 8.7-14.6) for < and ≥ median detectable levels, respectively. In a population with relatively low soy intake, serum phytoestrogens were not associated with mammographic density. Additional studies are needed to determine effects of higher levels, particularly given patterns of increasing phytoestrogen intake.

Topics: Aged; Body Mass Index; Breast Neoplasms; Coumestrol; Diet; Feeding Behavior; Female; Genistein; Glycine max; Humans; Isoflavones; Mammography; Middle Aged; Postmenopause

The current investigations were undertaken to study the mechanism of the adverse effect of phytoestrogens on the function of bovine granulosa (follicles >1< cm in diameter) and luteal cells from day 1-5, 6-10, 11-15, 16-19 of the oestrous cycle. The cells were incubated with genistein, daidzein or coumestrol (each at the dose of 1 × 10(-6) m). The viability and secretion of estradiol (E2), progesterone (P4) and oxytocin (OT) were measured after 72 h of incubation. Moreover, the expression of mRNA for neurophysin-I/OT (NP-I/OT; precursor of OT) and peptidyl-glycine-α-amidating monooxygenase (PGA, an enzyme responsible for post-translational OT synthesis) was determined after 8 h of treatment. None of the phytoestrogens used affected the viability of cells except for coumestrol. The increased secretion of E2 and P4 was only obtained by coumestrol (p<0.05) from granulosa cells from follicles <1cm in diameter and decreased from luteal cells on days 11-15 of the oestrous cycle, respectively. All three phytoestrogens stimulated (p<0.05) OT secretion from granulosa and luteal cells in all stages of the oestrous cycle and the expression of NP-I/OT mRNA in the both types of cells. The expression of mRNA for PGA was stimulated (p<0.05) by daidzein and coumestrol in granulosa cells, and by genistein and coumestrol in luteal cells. In conclusion, our results demonstrate that these phytoestrogens can impair the ovary function in cattle by adversely affecting the synthesis of OT in follicles and in corpus luteum. However, their influence on the ovarian steroids secretion was less evident.

Topics: Animals; Cattle; Cells, Cultured; Coumestrol; Female; Genistein; Granulosa Cells; Isoflavones; Luteal Cells; Mixed Function Oxygenases; Multienzyme Complexes; Neurophysins; Ovary; Oxytocin; Phytoestrogens; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

We developed and validated three different sample preparation and extraction methods followed by HPLC-MS/MS (negative electrospray ionization) analysis for the quantification of estrogenic isoflavones (formononetin, daidzein, equol, biochanin A, and genistein) and coumestrol in red clover, soil, and manure. Plant and manure samples were solid-liquid extracted, whereas soil was extracted with accelerated solvent extraction. Absolute recoveries were between 80 and 93%, 20 and 30%, and 14 and 91% for plant, soil, and manure samples, respectively. Relative recoveries ranged from 75 to 105% for all matrices, indicating that isotope-labeled internal standards (¹³C₃-formononetin, ¹³C₃-daidzein, ¹³C₃-equol, ¹³C₃-biochanin A, and ¹³C₃-genistein) were capable to compensate for losses during analysis. The limits of detection in red clover, soil, and manure were 3-9 μg/g(dryweight(dw)), 0.6-8.2 ng/g(dw), and 34.2 ng/g(dw) to 17.0 μg/g(dw), respectively. Formononetin was the most dominant compound in red clover plants (up to 12.5 mg/g(dw)) and soil (up to 3.3 μg/g(dw)), whereas equol prevailed in manure (up to 387 μg/g(dw)).

Topics: Chromatography, High Pressure Liquid; Coumestrol; Equol; Genistein; Isoflavones; Manure; Phytoestrogens; Soil; Tandem Mass Spectrometry; Trifolium

TNF-α-induced osteoclastogenesis is central to post-menopausal and inflammatory bone loss, however, the effect of phytoestrogens on TNF-α-induced bone resorption has not been studied. The phytoestrogens genistein, daidzein, and coumestrol directly suppressed TNF-α-induced osteoclastogenesis and bone resorption. TRAP positive osteoclast formation and resorption area were significantly reduced by genistein (10(-7)  M), daidzein (10(-5)  M), and coumestrol (10(-7)  M), which was prevented by the estrogen antagonist ICI 182,780. TRAP expression in mature TNF-α-induced osteoclasts was also significantly reduced by these phytoestrogen concentrations. In addition, in the presence of ICI 182,780 genistein and coumestrol (10(-5) -10(-6)  M) augmented TNF-α-induced osteoclast formation and resorption. However, this effect was not observed in the absence of estrogen antagonist indicating that genistein's and coumestrol's ER-dependent anti-osteoclastic action normally negates this pro-osteoclastic effect. To determine the mechanism mediating the anti-osteoclastic action we examined the effect of genistein, coumestrol, and daidzein on caspase 3/7 activity, cell viability and expression of key genes regulating osteoclast differentiation and fusion. While anti-osteoclastic phytoestrogen concentrations had no effect on caspase 3/7 activity or cell viability they did significantly reduce TNF-α-induced c-fos and NFATc1 expression in an ER dependent manner and also inhibited NFATc1 nuclear translocation. Significant decreases in NFκB and DC-STAMP levels were also noted. Interestingly, constitutive c-fos expression prevented the anti-osteoclastic action of phytoestrogens on differentiation, resorption and NFATc1. This suggests that phytoestrogens suppress TNF-α-induced osteoclastogenesis via inhibition of c-fos-dependent NFATc1 expression. Our data provides further evidence that phytoestrogens have a potential role in the treatment of post-menopausal and inflammatory bone loss directly inhibiting TNF-α-induced resorption.

Topics: Animals; Bone Resorption; Cell Differentiation; Cell Line; Cell Survival; Coumestrol; Genistein; Isoflavones; Mice; NFATC Transcription Factors; Phytoestrogens; Polymerase Chain Reaction; Proto-Oncogene Proteins c-fos; Tumor Necrosis Factor-alpha

Phytoestrogens have attracted attention as being safer alternatives to hormone replacement therapy (HRT) and as chemopreventive reagents for breast cancer because dietary soy isoflavone intake has been correlated with reduction in risk. To identify safe and effective phytoestrogen candidates for HRT and breast cancer prevention, we investigated the effects of daidzein, genistein, coumestrol, resveratrol and glycitein on cell growth, cell cycle, cyclin D1 expression, apoptosis, Bcl-2/Bax expression ratio and p53-dependent or NF-kappaB-dependent transcriptional activity in MCF-7 breast cancer cells. Phytoestrogens, except for glycitein, significantly enhanced estrogen-response-element-dependent transcriptional activity up to a level similar to that of 17beta-estradiol (E(2)). E(2) increased cell growth significantly, coumestrol increased cell growth moderately, and resveratrol and glycitein reduced cell growth. Phytoestrogens, except for glycitein, stimulated the promotion of cells to G(1)/S transition in cell cycle analysis, similar to E(2). This stimulation was accompanied by transient up-regulation of cyclin D1. While genistein, resveratrol and glycitein all increased apoptosis and reduced the Bcl-2/Bax ratio, resveratrol reduced this ratio more than either genistein or glycitein. Moreover, resveratrol significantly enhanced p53-dependent transcriptional activity, but slightly reduced NF-kappaB-dependent transcriptional activity. On knockdown analysis, genistein, resveratrol and glycitein all reduced the Bcl-2/Bax ratio in the presence of apoptosis-inducing stimuli, and estrogen receptor (ER) alpha silencing had no effect on these reductions. In contrast, in the absence of apoptosis-inducing stimuli, only resveratrol reduced the ratio, and ERalpha silencing abolished this reduction. Thus, resveratrol might be the most promising candidate for HRT and chemoprevention of breast cancer due to its estrogenic activity and high antitumor activity.

Topics: Apoptosis; bcl-2-Associated X Protein; Breast Neoplasms; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Coumestrol; Estradiol; Estrogen Receptor alpha; Female; Genistein; Humans; Isoflavones; Phytoestrogens; Proto-Oncogene Proteins c-bcl-2; Resveratrol; Stilbenes

Chemical compounds, including plant-based phytoestrogens, can function as hormone mimics and alter endocrine signaling in wildlife. In the present study, the waste streams from 19 plant-processing industries, including biofuel manufacturers, were sampled and analyzed for the phytoestrogens genistein, daidzein, coumestrol, formononetin, biochanin A, and zearalenone, via liquid chromatography/mass spectrometry. Eight of these industries contained phytoestrogens at environmentally relevant levels (≥1,000 ng/L), with the highest at approximately 250,000 ng/L. The influent and effluent streams of three municipal wastewater treatment plants receiving flow from some of these industries also were sampled and analyzed for the same phytoestrogens. It appeared that aerobic biological treatment, such as activated sludge, was able to remove these compounds from the liquid stream. Nevertheless, the effluent stream from one of the wastewater treatment plants had a phytoestrogen concentration above 1,000 ng/L. Results of the present study indicate the need for caution when designing facilities to treat the effluents from biofuel and other plant-processing industries.

Topics: Biofuels; Chromatography, Liquid; Coumestrol; Environmental Monitoring; Genistein; Industrial Waste; Isoflavones; Mass Spectrometry; Phytoestrogens; Sewage; Water Pollutants, Chemical

Estrogens modulate the transcription of sensitive genes either via binding of the activated ER to responsive elements in their promoter region or via binding of the activated ER to transcription factors like NFkappaB. In this study we have analyzed the effects of the phytoestrogens daidzein, coumestrol and genistein in promoter-specific reporter gene systems. The dose-dependent ability to stimulate an ERE-bearing reporter in MVLN breast cancer cells was compared to the dose-dependent ability to repress the IL-1beta-stimulated reporter in U2OS osteosarcoma cells. Coumestrol, daidzein and genistein stimulate the expression of the ERE-dependent reporter in MVLN cells and repress the activity of the IL-6 promoter in U2OS cells in a dose-dependent manner. Interestingly, the relative potency of all phytoestrogens to repress the activity of the IL-6 promoter in U2OS cells was much higher than their potency to stimulate the ERE-dependent reporter in MVLN cells. We assume that the demonstrated promoter-specific potency therefore could be an important mechanism to explain a tissue-specific action of some of these compounds.

Topics: Cell Line, Tumor; Coumestrol; Dose-Response Relationship, Drug; Genes, Reporter; Genistein; Humans; Isoflavones; Phytoestrogens; Promoter Regions, Genetic; Transcription, Genetic

Women approaching menopause increasingly investigate alternatives to hormone replacement therapy. Plant phytoestrogens are being promoted as "natural" alternatives but there is a lack of substantive data to advocate their safe use in breast cancer patients receiving tamoxifen (TAM), or in those who have relapsed. The aim of our study was to investigate the proliferative effects and mode of action of the phytoestrogens genistein, daidzein and coumestrol on TAM-sensitive (-s) and resistant (-r) breast cancer cells under in vitro conditions designed to mimic the hormonal environment of the pre- and post-menopausal breast. At physiological concentrations (<10 microM) and under reduced estrogen (E2) conditions, genistein was mitogenic to TAM-s cells with TAM-r cells generally refractory. Daidzein and coumestrol were growth stimulatory irrespective of TAM sensitivity. Transcriptional activity was ERE-mediated. Combining phytoestrogens with E2 (simulating the pre-menopausal breast environment) had no effect on growth of TAM-s or TAM-r cells. Addition of 4-HT mimicked the hormonal environment in post-menopausal breast cancer patients receiving TAM. The growth inhibitory effects of 4-HT were abrogated in TAM-s cells when combined with genistein and coumestrol, and to a lesser extent, daidzein, where significant growth stimulatory effects were observed. In TAM-r cells, proliferation did not exceed control values. At phytoestrogen concentrations above 10 microM, growth inhibitory effects were seen, irrespective of estrogenic environment or cell sensitivity to TAM. Our in vitro data suggests that phytoestrogens could have potentially adverse mitogenic effects on tumour cells and should probably be avoided by patients who remain sensitive to TAM or in those with pre-existing and possibly undiagnosed breast tumours.

Topics: Antineoplastic Agents, Hormonal; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Coumestrol; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Estrogen Receptor alpha; Estrogen Receptor beta; Estrogens; Female; Gene Expression; Genistein; Humans; Isoflavones; Luciferases; Phytoestrogens; Receptors, Progesterone; Response Elements; Tamoxifen; Transfection

A new 2-arylbenzofuran, puerariafuran (1), as well as three known compounds, coumestrol (2), daidzein (3), and genistein (4), were isolated from a MeOH extract of the roots of Pueraria lobata as active constituents, using an in vitro bioassay based on the inhibition of advanced glycation end products (AGEs) to monitor chromatographic fractionation. The structure of 1 was determined by spectroscopic data interpretation, particularly by extensive 1D and 2D NMR studies. All the isolates (1-4) were evaluated for the inhibitory activity on AGEs formation in vitro.

Topics: Benzofurans; Coumestrol; Genistein; Glycation End Products, Advanced; Glycosylation; In Vitro Techniques; Isoflavones; Magnetic Resonance Spectroscopy; Molecular Structure; Plant Roots; Pueraria; Reference Standards; Stereoisomerism

Phytoestrogens have been described to be weak estrogens, SERMs or exhibit antiestrogenic properties. However, information about their activity in presence of estrogens is limited. Therefore, we have analysed the dose dependent combinatory activity of the phytoestrogens genistein (Gen), daidzein (Dai) and coumestrol (Cou), and 17beta-estradiol (E2) on cell proliferation and apoptosis induction in human MCF-7 breast cancer cells. Neither additive nor antagonistic effects on proliferation could be observed, but in contrast all phytoestrogens possessed the ability to inhibit apoptosis in the presence of 17beta-estradiol. In summary, our in vitro results demonstrate that Gen does not exhibit any antiestrogenic properties. The additive growth stimulatory effects of Gen, Dai and Cou in the presence of E2 are not the result of a stimulation of proliferation; these phytoestrogens, at least in MCF-7 cells, could be characterised as inhibitors of apoptosis.

Topics: Apoptosis; Breast Neoplasms; Cell Proliferation; Coumestrol; Drug Interactions; Estradiol; Estrogen Antagonists; Female; Genistein; Humans; Isoflavones; Phytoestrogens

Epidemiologic data suggest a relationship between dietary intake of phytochemicals and a lower incidence of some cancers. Modulation of steroid hormone metabolism has been proposed as a basis for this effect. It has been shown that aromatase, 3beta-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase (17beta-HSD) are inhibited by the isoflavones, genistein and daidzein, and by coumestrol. In general, the extent of inhibition has been expressed in terms of IC50-values, which do not give information as to the pattern of inhibition, i.e., competitive, non-competitive, or mixed. Less is known of the effects of these compounds on 3alpha-HSD. The human lung is known to have a high level of 17beta-HSD and 3alpha-HSD activity. During the course of studies to characterize both activities in normal and inflamed lung and lung tumors we noted that 3alpha-HSD activity with 5alpha-DHT of microsomes from normal, adult lung was particularly susceptible to inhibition by coumestrol. To clarify the pattern of inhibition, the inhibition constants Ki and K'i were evaluated from plots of 1/v versus [I] and [S]/v versus [I]. Genistein, daidzein and coumestrol gave mixed inhibition patterns versus both 5alpha-DHT and NADH. In contrast, 5alpha-androstane-3,17-dione and 5alpha-pregnane-3,20-dione were competitive with 5alpha-DHT. NAD inhibited competitively with NADH. Our findings demonstrate that phytochemicals have the potential to inhibit 5alpha-DHT metabolism and thereby affect the androgen status of the human lung. The observation of a mixed inhibition pattern suggests these compounds bind to more than one form of the enzyme within the catalytic pathway.

Topics: 3-alpha-Hydroxysteroid Dehydrogenase (B-Specific); Coumestrol; Enzyme Inhibitors; Genistein; Humans; Hydrogen-Ion Concentration; Hydroxysteroids; Isoflavones; Ketosteroids; Kinetics; Lung; Microsomes; Molecular Structure; Structure-Activity Relationship

For the simultaneous assessment of in vitro carcinogenicity and mutagenicity of phytoestrogens, the abilities of 5 phytoestrogens, daidzein, genistein, biochanin A, prunetin, and coumestrol, to induce cell transformation and genetic effects were examined using the Syrian hamster embryo (SHE) cell model. Cellular growth was inhibited by all phytoestrogens in a concentration-related manner. The growth inhibitory effect of the compounds was ranked: genistein, prunetin > coumestrol > biochanin A > daidzein, which did not correspond to their apoptosis-inducing abilities. Morphological transformation in SHE cells was elicited by all phytoestrogens, except, prunetin. The transforming activities were ranked as follows: genistein > coumestrol > daidzein > biochanin A. Somatic mutations in SHE cells at the Na(+)/K(+) ATPase and hprt loci were induced only by genistein, coumestrol, or daidzein. Chromosome aberrations were induced by genistein or coumestrol, and aneuploidy in the near diploid range was occurred by genistein or biochanin A. Genistein, biochanin A or daidzein induced DNA adduct formation in SHE cells with the abilities: genistein > biochanin A > daidzein. Prunetin was negative for any of these genetic endpoints. Our results provide evidence that genistein, coumestrol, daidzein and biochanin A induce cell transformation in SHE cells and that the transforming activities of these phytoestrogens correspond to at least 2 of the mutagenic effects by each phytoestrogen, i.e., gene mutations, chromosome aberrations, aneuploidy or DNA adduct formation, suggesting the possible involvement of mutagenicity in the initiation of phytoestrogen-induced carcinogenesis.

Topics: Animals; Anticarcinogenic Agents; Apoptosis; Cell Line; Cell Transformation, Neoplastic; Chromosome Aberrations; Coumestrol; Cricetinae; DNA Adducts; Dose-Response Relationship, Drug; Embryo, Mammalian; Estrogens, Non-Steroidal; Genistein; Isoflavones; Mesocricetus; Metaphase; Models, Chemical; Mutagens; Mutation; Phytoestrogens; Plant Preparations; Time Factors

In an international context of promoting scientific research on food safety, the interest in molecules having potential hormonal disrupting effects is growing. While industrial endocrine disruptors (phthalates, alkylphenols, PCBs, etc.) have been studied for several years, natural compounds like phytoestrogens remain less investigated. Accordingly, a research project was initiated with its main objectives to develop efficient analytical methods for a wide range of phytoestrogens in various food matrices, and to evaluate their occurrence in food products. Electrospray ionization with tandem mass spectrometric (MS/MS) analysis of isoflavones (genistein, daidzein, equol, formononetin, biochanin A), lignans (enterolactone, enterodiol), and coumestans (coumestrol) was investigated. This study revealed the formation of a large number of fragment ions in both positive and negative modes, corresponding to specific cleavages of the hydroxyl, carbonyl, and/or methoxy groups, and to Retro-Diels-Alder reactions. An LC/ESI-MS/MS method was developed consistent with the 2002/657/EC European decision criteria. An extraction and clean-up method was developed for milk samples. The identification limit for the proposed method appears to be under 1 ng/mL. The developed methodology was applied to various milk samples, and the occurrence of isoflavones (particularly equol) was demonstrated in the concentration range 1-30 ng/mL. The efficiency of the proposed analytical method permitted evaluation of a new and promising approach to a global risk assessment of natural estrogenic active substances including phytoestrogens and their metabolites.

Topics: 4-Butyrolactone; Animals; Cattle; Chromans; Chromatography, Liquid; Coumestrol; Equol; Estrogens, Non-Steroidal; Genistein; Ions; Isoflavones; Lignans; Milk; Molecular Structure; Phytoestrogens; Plant Preparations; Spectrometry, Mass, Electrospray Ionization

Many commercial laboratory diets have detectable levels of isoflavones (e.g., phytoestrogens such as genistein [GN]) that have weak estrogenic activity both in vitro and in vivo. During validation studies of the uterotrophic bioassay, diet samples from 20 participating laboratories were collected and analyzed for three major phytoestrogens: GN, daidzein (DN), and coumestrol (CM). Soy phytoestrogens GN and DN were found at total phytoestrogen levels from 100 to 540 microg/g laboratory diet; a forage phytoestrogen, CM, ranged from nondetectable to 4 microg/g laboratory diet. The phytoestrogen levels were compared with both baseline uterine weights of the control groups and with the relative uterine weight increase of groups administered two weak estrogen agonists: bisphenol A (BPA) and nonylphenol (NP). The comparison uses a working assumption of additivity among the phytoestrogens, despite several significant qualifications to this assumption, to estimate total genistein equivalents (TGE). Some evidence was found that phytoestrogen levels in the diet > 325-350 microg/g TGE could diminish the responsiveness of the uterotrophic bioassay to weak agonists. This was especially true for the case of the intact, immature female version of the uterotrophic bioassay, where higher food consumption relative to body weight leads to higher intakes of dietary phytoestrogens versus ovariectomized adults. This dietary level is sufficient in the immature female to approach a biological lowest observable effect level for GN of 40-50 mg/kg/day. These same data, however, show that low to moderate levels of dietary phytoestrogens do not substantially affect the responsiveness of the assay with weak estrogen receptor agonists such as NP and BPA. Therefore, laboratories conducting the uterotrophic bioassay for either research or regulatory purposes may routinely use diets containing levels of phytoestrogens < 325-350 microg/g TGE without impairing the responsiveness of the bioassay.

Topics: Administration, Oral; Animal Feed; Animals; Biological Assay; Coumestrol; Diet; Dose-Response Relationship, Drug; Endocrine System; Environmental Pollutants; Enzyme Inhibitors; Estrogens, Non-Steroidal; Female; Genistein; Housing, Animal; Isoflavones; Laboratories; Observer Variation; Phytoestrogens; Plant Preparations; Rats; Reproducibility of Results; Research Design; Uterus

Soybeans contain an abundance of phytoestrogens such as genistein and daidzein, and these compounds are thought to protect against bone loss under estrogen deficient conditions. It is possible, however, that phytoestrogens other than isoflavones may suppress bone resorption. The objective of the present study was to determine whether there are any phytoestrogens other than isoflavones in soybeans that can act as antiosteoporotic agents.. The isoflavones genistein and daidzein, and an extract of soybeans that contained very low levels of isoflavones were tested for their ability to reduce bone resorption in ovariectomized rats. The extract of soybeans was further analyzed for its main components by thin layer chromatography and gas chromatography-mass spectrometry.. The soybean extract, as well as the two isoflavones, were effective to reduce urinary excretion of deoxypyridinoline and pyridinoline, typical markers of bone resorption in ovariectomized rats. However the extract, unlike the isoflavones, increased the uterine weight of ovariectomized rats significantly. Analysis by thin-layer and gas chromatography revealed that the main constituent of this extract exhibited a chromatographic profile corresponding to coumestrol. This substance was positively identified as coumestrol by gas chromatography-mass spectrometry.. These results suggest that the phytoestrogens including coumestrol and isoflavones in soybeans may exert effective prevention against bone resorption in estrogen deficient conditions.

Topics: Amino Acids; Animals; Bone Resorption; Cholesterol; Chromatography, Thin Layer; Coumestrol; Ethinyl Estradiol; Female; Gas Chromatography-Mass Spectrometry; Genistein; Glycine max; Isoflavones; Organ Size; Osteocalcin; Ovariectomy; Random Allocation; Rats; Rats, Wistar; Uterus

Daidzein, coumestrol and zearalenone - compounds called phytoestrogens, considered as active biological factors affecting many important physiological and biochemical processes appeared to be also significant regulators of adipocyte metabolism. In our experiments the influence of daidzein (0.01, 0.1 and 1 mM), coumestrol (0.001, 0.01 and 0.1 mM), zearalenone (0.01, 0.1 and 1 mM) and estradiol (0.01, 0.1 and 1 mM) on basal and insulin-stimulated (1 nM) lipogenesis from glucose and acetate was tested in adipocytes isolated from growing (160 +/- 5 g b.w) male Wistar rats. All tested compounds significantly attenuated glucose conversion to lipids. In the case of daidzein and coumestrol, this effect was probably due to inhibition of glycolysis. Daidzein (0.01, 0.1 and 1 mM), coumestrol (0.01 and 0.1 mM) and zearalenone (0.01, 0.1 and 1 mM) affected also basal and epinephrine-stimulated (1 microM) lipolysis. Daidzein (0.01 and 1 mM) augmented basal glycerides breakdown in adipocytes. The epinephrine-induced lipolysis was dependent on daidzein concentration and its stimulatory (0.1 mM) or inhibitory (1 mM) influence was observed. Zearalenone changed lipolysis only at the concentration of 1 mM and its effect was contradictory in the absence or presence of epinephrine (the stimulatory or inhibitory effect, respectively). Results obtained in experiments with inhibitors (insulin, 1 nM and H-89, 50 microM) and activators (dibutyryl-cAMP, 1 mM and forskolin, 1 microM) of lipolysis allowed us to assume that daidzein augmented basal lipolysis acting on PKA activity. The inhibitory effect of daidzein and zearalenone on epinephrine-induced lipolysis is probably due to restriction of HSL action. The influence of coumestrol on glycerides breakdown was less marked. Estradiol augmented only epinephrine-stimulated lipolysis.

Topics: Adipocytes; Animals; Coumestrol; Dose-Response Relationship, Drug; Epinephrine; Estradiol; Estrogens, Non-Steroidal; Isoflavones; Lipolysis; Male; Phytoestrogens; Phytotherapy; Plant Preparations; Rats; Rats, Wistar; Zearalenone

There is widespread concern that fetal exposure to hormonally active chemicals may adversely affect development of the reproductive tract. Therefore, the present study was performed to develop the necessary analytical methods and test the hypothesis that dietary phytoestrogens can be quantified in second trimester human amniotic fluid. Amniotic fluid samples (n=59) from women (n=53) undergoing routine amniocentesis between 15 and 23 weeks of gestation were analyzed by gas chromatography/mass spectrometric (GC/MS). Analytes included the phytoestrogens daidzein, genistein, formononetin, biochanin A, and coumestrol. Dietary phytoestrogens were quantified in 96.2% of second trimester amniotic fluid samples tested. The mean (+/- standard deviation (S.D.)) concentration of daidzein and genistein in amniotic fluid was 1.44 +/- 1.34 and 1.69 +/- 1.48 ng/ml with maximum levels of 5.52 and 6.54 ng/ml, respectively. Second trimester amniotic fluid contains quantifiable levels of dietary phytoestrogens and thus is a marker of mid pregnancy fetal exposure.

Topics: Adult; Amniocentesis; Amniotic Fluid; Coumestrol; Diet; Estrogens, Non-Steroidal; Female; Gas Chromatography-Mass Spectrometry; Genistein; Humans; Isoflavones; Middle Aged; Phytoestrogens; Plant Preparations; Pregnancy; Pregnancy Trimester, Second

Numerous epidemiologic studies revealed that ethnic populations with higher dietary intake of phytoestrogens have the lowest incidence for breast cancer. The molecular mechanisms which may be responsible for this cancer protective action of phytoestrogens are so far only barely characterised. There are some hints that phytoestrogens may act like selective estrogen receptor modulators (SERMs) on the breast. For this reason we have investigated potential SERM-like properties of the phytoestrogens daidzein (Dai), coumestrol (Cou), and genistein (Gen) in the human breast cancer cell line MCF-7. Effects of these substances on progesterone (PR) and estrogen receptor alpha (ER) mRNA expression and estrogen receptor alpha protein levels were studied in comparison to estradiol (E2) and the synthetic SERMs raloxifene (Ral) and faslodex (ICI 182 780). PR mRNA expression was up-regulated after administration of Cou, whereas treatment with Dai and Gen induced only a faint increase. ER mRNA expression was down-regulated by Cou but not affected by Dai and Gen. The content of ER protein in the breast cancer cells was strongly decreased by Gen, only a faint reduction could be observed following administration of Cou, whereas administration of Dai slightly increases ER protein levels. In summary and in comparison to the effects observed after administration of E2, Ral, and ICI it turned out that Cou shows molecular properties which are very similar to an estrogen receptor agonist like E2, whereas the molecular properties of Gen are comparable to the SERMs ICI and Ral. These results clearly indicate that phytoestrogens differ significantly in regard to their molecular action on breast cancer cells and can be subdivided into distinct functional categories.

Topics: Blotting, Western; Breast; Coumestrol; Diet; Estradiol; Estrogen Antagonists; Estrogens, Non-Steroidal; Fulvestrant; Genistein; Humans; Isoflavones; Molecular Structure; Phytoestrogens; Plant Preparations; Raloxifene Hydrochloride; Receptors, Estrogen; Receptors, Progesterone; RNA, Messenger; Selective Estrogen Receptor Modulators; Tumor Cells, Cultured

Previously, a specific dietary supplement, selected vegetables (SV), was found to be associated with prolonged survival of stage III and IV non-small cell lung cancer (NSCLC) patients. In this study, several anticancer components in SV were measured; the anticancer activity of SV was assessed using a lung tumor model, line 1 in BALB/c mice. SV was also used in conjunction with conventional therapies by stage IIIB and IV NSCLC patients whose survival and clinical responses were evaluated. A daily portion (283 g) of SV was found to contain 63 mg of inositol hexaphosphate, 4.4 mg of daidzein, 2.6 mg of genistein, and 16 mg of coumestrol. Mouse food containing 5% SV (wt/wt) was associated with a 53-74% inhibition of tumor growth rate. Fourteen of the 18 patients who ingested SV daily for 2-46 months were included in the analyses; none showed evidence of toxicity. The first lead case remained tumor free for > 133 months; the second case showed complete regression of multiple brain lesions after using SV and radiotherapy. The median survival time of the remaining 12 patients was 33.5 months, and one-year survival was > 70%. The median survival time of the 16 "intent-to-treat" patients (including ineligible patients) was 20 months, and one-year survival was 55%. The Karnofsky performance status of eligible patients was 55 +/- 13 at entry but improved to 92 +/- 9 after use of SV for five months or longer (p < 0.01). Five patients had stable lesions for 30, 30, 20, 12, and 2 months; two of them, whose primary tumor was resected, used SV alone and demonstrated an objective response of their metastatic tumors. In addition to the two lead cases, eight patients had no new metastases after using SV. Three patients had complete regression of brain metastases after using radiotherapy and SV. In this study, daily ingestion of SV was associated with objective responses, prolonged survival, and attenuation of the normal pattern of progression of stage IIIB and IV NSCLC. A large randomized phase III clinical trial is needed to confirm the results observed in this pilot study.

Topics: Adult; Aged; Aged, 80 and over; Animals; Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Coumestrol; Dietary Supplements; Disease Models, Animal; Female; Genistein; Humans; Isoflavones; Karnofsky Performance Status; Lung Neoplasms; Male; Mice; Mice, Inbred BALB C; Middle Aged; Neoplasm Staging; Nutritive Value; Phytic Acid; Pilot Projects; Survival Analysis; Time Factors; Vegetables

Cytochrome P450 102 (CYP102 or Cytochrome P450(BM)(-)(3)) is induced in Bacillus megaterium by barbiturates, perioxisome proliferators, estrogen, and nonsteroidal antiinflammatory drugs. We have previously demonstrated that a CYP102 construct (BMC 143) coupled with a luciferase reporter gene can be used to identify the inducers of CYP102. We now describe the effect of added phytochemicals on the induction of CYP102 by phenobarbital (PB) in B. megaterium. The isoflavones genistein, biochanin A, coumestrol, and equol, the green tea flavanoid epicatechin, and the fungal toxin zearalenone inhibit the induction of CYP102 by PB in a dose-dependent manner. However, the isoflavone daidzein, the phytoalexin glyceollin, and catechin, an epimer of epicatechin, failed to exhibit a similar inhibitory effect on PB-mediated CYP102 induction.

Topics: Bacillus megaterium; Bacterial Proteins; Catechin; Chromans; Coumestrol; Cytochrome P-450 Enzyme System; Equol; Genistein; Glycine max; Isoflavones; Mixed Function Oxygenases; NADPH-Ferrihemoprotein Reductase; Phenobarbital; Tea; Zearalenone

Prostate cancer is one of the most common male cancers in Western countries, yet the incidence of this fatal disease remains low in Asian populations. Environmental factors such as diet play an important role in hormone-dependent cancer etiology, and a high phytoestrogen intake may be one factor contributing to the low prostate cancer mortality in Eastern populations. In this study, we investigated the effects of the phytoestrogens genistein, daidzein, coumestrol, and equol on cell growth and DNA damage (strand breakage) in two human prostate tumor cell lines: androgen receptor-positive LNCaP and androgen receptor-negative PC-3. Each compound caused growth inhibition at physiologically relevant concentrations (<10 microM). Genistein induced DNA damage in both cell lines at <10 microM. Daidzein inhibited cell growth at 10-100 microM yet had no effect on DNA damage at up to 500 microM. Thus, despite their structural similarities, different phytoestrogens inhibit prostate tumor cell growth by independent mechanisms.

Topics: Antineoplastic Agents, Phytogenic; Cell Division; Cell Transformation, Neoplastic; Chromans; Coumestrol; DNA Damage; Equol; Estrogens, Non-Steroidal; Genistein; Humans; Isoflavones; Male; Phytoestrogens; Plant Preparations; Prostatic Neoplasms; Tumor Cells, Cultured

The clastogenic potential of the phytoestrogens coumoestrol (COUM), genistein (GEN) and daidzein (DAI) has been studied in human peripheral blood lymphocytes in vitro. After exposure of the cultured lymphocytes to 50 to 75 microM COUM or 25 microM GEN for 6 h, a clear induction of structural chromosomal aberrations was observed by cytogenetic analysis. The major alterations were chromatid breaks, gaps and interchanges. In contrast, DAI did not induce chromosome aberrations even at 100 microM. These results, together with previously published reports on the induction of micronuclei and DNA strand breaks in cultured Chinese hamster V79 cells by COUM and GEN, but not DAI, suggest that some but not all phytoestrogens have the potential for genetic toxicity.

Topics: Adult; Cell Division; Cells, Cultured; Chromosome Aberrations; Coumestrol; Culture Media, Serum-Free; Dose-Response Relationship, Drug; Estrogens, Non-Steroidal; Female; Genistein; Humans; Isoflavones; Lymphocytes; Male; Mitotic Index; Phytohemagglutinins

In previous investigations it was shown that the synthetic estrogen diethylstilbestrol (DES) induces a rise of the intracellular calcium level ([Ca2+]i) in C6 rat glioma cells [P. Tas, H. Stopper, K. Koschel, D. Schiffmann, Influence of the carcinogenic oestrogen diethylstilboestrol on the intracellular calcium level in C6 rat glioma cells. Toxic. In vitro 5 (1991) 463-465] which is accompanied by changes of the arrangement of the cytoskeleton. In the present study, we compared the induction of these effects in COS (monkey kidney cells) lacking estrogen receptors (ER) with those in RUCA-I (rat endometrial carcinoma) cells containing ER. The [Ca2+]i in RUCA-I and COS cells following 17beta-estradiol (ES), genistein (GEN), daidzein (DZ) and coumestrol (CES) treatment was analyzed. A significant increase of [Ca2+]i induced by all compounds was observed in RUCA-I cells. No effects were detected in COS cells after ES and GEN treatment. The anti-estrogen ICI 182780 completely blocked the ES-and GEN-induced rise of [Ca2+]i. Dose and time dependencies of changes of calcium levels were analyzed and a biphasic response could be observed. The actin staining showed disintegrated stress fibers in RUCA-I cells. The degree of the observed effects correlates with the known estrogenicity of the applied compounds (DES > ES > GEN). It remains to be elucidated whether or not the effects observed are mediated by the "classic" genomic estrogen receptor pathway or by alternate nongenomic or receptor-independent pathways.

Topics: Actins; Animals; Calcium; Chlorocebus aethiops; COS Cells; Coumestrol; Estradiol; Estrogen Antagonists; Estrogens, Non-Steroidal; Female; Fulvestrant; Genistein; Intracellular Fluid; Isoflavones; Phytoestrogens; Plant Preparations; Rats; Receptors, Estrogen; Tumor Cells, Cultured

Phytoestrogens exert estrogenic effects on the central nervous system, induce estrus, and stimulate growth of the genital tract of female animals. Over 300 plants and plant products, including some used in laboratory animal diets, contain phytoestrogens. Therefore, the source and concentration of phytoestrogens in rodent diets were determined.. Twelve rodent diets and six major dietary ingredients were assayed for phytoestrogens (daidzein, genistein, formononetin, biochanin A, and coumestrol), using high-performance liquid chromatography. Three rodent diets recently formulated to reduce phytoestrogen content also were assayed.. Formononetin, biochanin A, and coumestrol were not detected. Soybean meal was the major source of daidzein and genistein; their concentrations were directly correlated to the percentage of soybean meal in each diet.. High, variable concentrations of daidzein and genistein are present in some rodent diets, and dietary phytoestrogens have the potential to alter results of studies of estrogenicity. Careful attention should be given to diet phytoestrogen content, and their concentration should be reported. A standardized, open-formula diet in which estrogenic substances have been reduced to levels that do not alter results of studies that are influenced by exogenous estrogens is recommended.

Topics: Animal Feed; Animals; Animals, Laboratory; Coumestrol; Estrogens, Non-Steroidal; Female; Food, Formulated; Genistein; Glycine max; Isoflavones; Phytoestrogens; Plant Preparations; Rodentia

Isoflavones are present in soybeans and its products in concentrations up to 300 mg/100 g, have estrogenic and antiestrogenic properties, and may be protective against hormone-related cancers. The purpose of this cross-sectional study was to investigate the association between urinary isoflavone excretion and self-reported soy intake. A total of 102 women of Caucasian, Native Hawaiian, Chinese, Japanese, and Filipino ancestry completed a dietary questionnaire for soy products consumed during the last year and during the 24-h period before urine collection. Overnight urine samples were analyzed for coumestrol and the soy isoflavones genistein, daidzein, and glycitein and their main human metabolites by reverse-phase high-pressure liquid chromatography. Soy protein and isoflavone intake (predominantly from tofu) were estimated using published nutritional databases. Wilcoxon's rank-sum test scores and Spearman rank correlation coefficients were computed. Japanese women excreted more daidzein, genistein, and glycitein than did Caucasian women, whereas Caucasian women excreted slightly more coumestrol. Soy intake differed significantly among ethnic groups. Dietary soy protein and isoflavone intakes during the previous 24 h were positively related to urinary isoflavone excretion [rs = 0.61 (P < 0.0001) and 0.62 (P < 0.0001), respectively]. Urinary excretion of isoflavones was also related to annual dietary soy protein and isoflavone intake [rs = 0.32 (P < 0.0012) and 0.31 (P < 0.0016), respectively]. The strong correlation between urinary isoflavone excretion and self-reported soy intake validates the dietary history questionnaire that is now used in a study exploring dietary risk factors for breast cancer.

Topics: Adult; Aged; Aged, 80 and over; China; Coumestrol; Cross-Sectional Studies; Female; Genistein; Glycine max; Hawaii; Humans; Isoflavones; Japan; Middle Aged; Philippines; White People

Coumoestrol (COUM), genistein (GEN) and daidzein (DAI) are major phytoestrogens present in numerous plants eaten by humans and food-producing animals. Little is known about the genotoxicity of these natural compounds. The effects of COUM, GEN and DAI were studied in cultured Chinese hamster V79 cells at various endpoints. None of the substances affected the cytoplasmic microtubule complex or the mitotic spindle. However, COUM and GEN but not DAI proved to be strong inducers of DNA strand breaks and micronuclei containing acentric fragments, as shown with antikinetochore antibodies. The clastogenicity of GEN may be due to its non-intercalative inhibitory effect on topoisomerase II, whereas COUM may act through topoisomerase II inhibition and/or DNA intercalation. COUM was also a clear inducer of hypoxanthine guanine phosphoribosyltransferase (HPRT) mutations in V79 cells; GEN was only marginally active and DAI inactive at this endpoint. This is the first report on the clastogenicity and mutagenicity of COUM in mammalian cells.

Topics: Animals; Cell Survival; Cells, Cultured; Coumestrol; Cricetinae; Cricetulus; DNA Damage; Estrogens, Non-Steroidal; Fibroblasts; Genistein; Hypoxanthine Phosphoribosyltransferase; Isoflavones; Lung; Micronuclei, Chromosome-Defective; Mutagenicity Tests; Mutation

Thirteen isoflavonoids, flavonoids, and lignans, including some known phytoestrogens, were evaluated for their effects on DNA synthesis in estrogen-dependent (MCF-7) and -independent (MDA-MB-231) human breast cancer cells. Treatment for 24 hours with most of the compounds at 20-80 microM sharply inhibited DNA synthesis in MDA-MB-231 cells. In MCF-7 cells, on the other hand, biphasic effects were seen. At 0.1-10 microM, coumestrol, genistein, biochanin A, apigenin, luteolin, kaempferol, and enterolactone induced DNA synthesis 150-235% and, at 20-90 microM, inhibited DNA synthesis by 50%. Treatment of MCF-7 cells for 10 days with genistein or coumestrol showed continuous stimulation of DNA synthesis at low concentrations. Time-course experiments with genistein in MCF-7 cells showed effects to be reversed by 48-hour withdrawal of genistein at most concentrations. Induction of DNA synthesis in MCF-7 cells, but not in MDA-MB-231 cells, is consistent with an estrogenic effect of these compounds. Inhibition of estrogen-dependent and -independent breast cancer cells at high concentrations suggests additional mechanisms independent of the estrogen receptor. The current focus on the role of phytoestrogens in cancer prevention must take into account the biphasic effects observed in this study, showing inhibition of DNA synthesis at high concentrations but induction at concentrations close to probable levels in humans.

Topics: Anticarcinogenic Agents; Breast Neoplasms; Coumestrol; DNA; Estradiol; Estrogens, Non-Steroidal; Flavonoids; Genistein; Humans; Isoflavones; Kinetics; Lignans; Phytoestrogens; Plant Preparations; Tumor Cells, Cultured

The intake, as well as serum and urinary concentrations, of phytoestrogens is high in countries where incidence of prostate cancer is low, suggesting a chemopreventive role for phytoestrogens. Their significance could be explained by the ability to antagonize the action of more potent endogenous estrogens in initiation or promotion of tumor formation. We have studied estrogenicity and antiestrogenicity of dietary soy and two phytoestrogens, coumestrol and daidzein, in our neoDES mouse model for the study or prostatic neoplasia. Soy was chosen because it is rich in phytoestrogens, is widely used in Oriental diets, and has antiestrogenic and anticarcinogenic properties in the neoDES mouse when given from fertilization onward. In short-term tests with adult animals, no evidence for estrogenicity or antiestrogenicity (capability to antagonize the action of 17 beta-estradiol) of soy was found when development of epithelial metaplasia and expression of c-fos protooncogene in prostate were used as end points of estrogen action. Estrogenic activity of coumestrol and daidzein on c-fos expression was subtle. Coumestrol, either given alone or in combination with 17 beta-estradiol, had no effect on development of epithelial metaplasia. These marginal or missing effects in adult males could be interpreted by assuming that the neonatal period is more critical for estrogenic or antiestrogenic action of soy and phytoestrogens. Once initiated, estrogen-related lesions would develop spontaneously. Alternatively, the chemopreventive action of soy is not due to antiestrogenicity of soy-derived phytoestrogens.

Topics: Animals; Anticarcinogenic Agents; Coumestrol; Diet; Diethylstilbestrol; Disease Models, Animal; Estradiol; Estrogens; Estrogens, Non-Steroidal; Glycine max; Isoflavones; Male; Metaplasia; Mice; Plant Growth Regulators; Proto-Oncogene Proteins c-fos; Receptors, Estrogen

Some of the isoflavonoids present in human diet as well as in urine are expected to exert biologic effects as they have been reported to bind to estrogen receptors and to be estrogenic in other species. This report describes the in vitro assessment of estrogenic effects of isoflavonoids using human endometrial cells and tissue. The relative estrogenic potencies (EC50 values) of estradiol, 3 dietary isoflavonoids (coumestrol, genistein and daidzein) and one of their metabolites (equol), were estimated by using a recently developed multiwell plate in vitro bioassay based on the estrogen-specific enhancement of alkaline phosphatase (AlkP) activity in human endometrial adenocarcinoma cells of the Ishikawa-Var I line. The maximal AlkP activity elicited by the isoflavonoids tested was as high as that achieved with estradiol and their effects were suppressed by the antiestrogens 4-hydroxytamoxifen and ICI 164,384. These results indicate that estradiol and the isoflavonoids exert their effects on AlkP by similar interactions with the estrogen receptor, with potencies depending on binding affinities. The estrogenic effect of equol was confirmed by another in vitro bioassay, based on the estrogen-stimulated enhancement of prostaglandin F2 alpha output by fragments of human secretory endometrium.

Topics: Adenocarcinoma; Alkaline Phosphatase; Biological Assay; Chromans; Coumestrol; Dinoprost; Endometrial Neoplasms; Endometrium; Equol; Estradiol; Female; Genistein; Humans; Isoflavones; Polyunsaturated Alkamides; Tamoxifen; Tumor Cells, Cultured

Various phytoestrogens such as formononetin, daidzein, genistein and equol were synthesized. Their purity was assessed by various analytical techniques including melting point determination, thin-layer chromatography (TLC), infra-red spectra (i.r. spectra), nuclear magnetic resonance (1H- and 13C-NMR) and gas chromatography coupled with mass spectrometry (GC-MS). The estrogenic activity of these compounds, as well as biochanin A and coumestrol, was biologically tested by the induction of vitellogenin secretion in yearling sturgeon and compared to the activity of estradiol-17 beta. Pure daidzein, biochanin A, genistein, equol and coumestrol all had estrogenic activity as assessed by their induction of hepatic synthesis of vitellogenin when administrated intraperitoneally to yearling Siberian sturgeon. Coumestrol seemed to be the most potent compound, inducing the most vitellogenin secretion with the lowest dose administered. Formononetin was inactive when administered by the intraperitoneal route. All the phytoestrogens tested were considerably less potent than estradiol-17 beta.

Topics: Animals; Chromans; Chromatography, Thin Layer; Coumestrol; Equol; Estrogens; Estrogens, Non-Steroidal; Fishes; Gas Chromatography-Mass Spectrometry; Genistein; Isoflavones; Liver; Magnetic Resonance Spectroscopy; Phytoestrogens; Plant Preparations; Spectrophotometry, Infrared; Vitellogenins

Topics: Animals; Coumestrol; Estrogens; Female; Genistein; Glycine max; Isoflavones; Mice; Uterus