cytellin and daidzein

Compounds with estrogenic potencies and their adverse effects in surface waters have received much attention. Both anthropogenic and natural compounds contribute to overall estrogenic activity in freshwaters. Recently, estrogenic potencies were also found to be associated with cyanobacteria and their blooms in surface waters. The present study developed and compared the solid phase extraction and LC-MS/MS analytical approaches for determination of phytoestrogens (8 flavonoids - biochanin A, coumestrol, daidzein, equol, formononetin, genistein, naringenin, apigenin - and 5 sterols - ergosterol, β-sitosterol, stigmasterol, campesterol, brassicasterol) and cholesterol in water. The method was used for analyses of samples collected in stagnant water bodies dominated by different cyanobacterial species. Concentrations of individual flavonoids ranged from below the limit of detection to 3.58 ng/L. Sterols were present in higher amounts up to 2.25 μg/L. Biological potencies of these phytoestrogens in vitro were characterized using the hERα-HeLa-9903 cell line. The relative estrogenic potencies (compared to model estrogen - 17β-estradiol) of flavonoids ranged from 2.25E-05 to 1.26E-03 with coumestrol being the most potent. None of the sterols elicited estrogenic response in the used bioassay. Estrogenic activity was detected in collected field water samples (maximum effect corresponding to 2.07 ng/L of 17β-estradiol equivalents, transcriptional assay). At maximum phytoestrogens accounted for only 1.56 pg/L of 17β-estradiol equivalents, contributing maximally 8.5% of the total estrogenicity of the water samples. Other compounds therefore, most likely of anthropogenic origin such as steroid estrogens, are probably the major drivers of total estrogenic effects in these surface waters.

Topics: Cholestadienols; Cholesterol; Cyanobacteria; Estradiol; Estrogens; Estrone; Fresh Water; Genistein; HeLa Cells; Humans; Isoflavones; Phytoestrogens; Phytosterols; Receptors, Estrogen; Sitosterols; Sterols; Tandem Mass Spectrometry; Water; Water Pollutants, Chemical

Although many dietary studies have focused on breast cancer risk, few have examined dietary influence on tumor characteristics such as estrogen receptor (ER) status. Because phytoestrogens may modulate hormone levels and ER expression, we analyzed ER status and phytoestrogen intake in a case-case study of 124 premenopausal breast cancer patients. We assessed intake with a food-frequency questionnaire and obtained ER status from medical records. Rather than focusing on risk, we evaluated whether low intakes were more strongly associated with ER-negative tumors than with ER-positive disease. In logistic regression adjusting for potential confounders, threefold greater risks of ER-negative tumors relative to ER-positive tumors were associated with low intake of the isoflavones genistein (odds ratio, OR=3.50; 95% confidence interval, CI=1.43-8.58) and daidzein (OR=3.10; 95% CI=1.31-7.30). Low intake of the flavonoid kaempferol (OR=0.36; 95% CI=0.16-0.83), the trace element boron (OR=0.33; 95% CI=0.13-0.83), and the phytosterol beta-sitosterol (OR=0.42; 95% CI=0.18-0.98) were associated with decreased risk of ER-negative tumors relative to ER-positive disease. Other phytoestrogens were not significantly associated with ER status. Thus, in premenopausal patients, some phytoestrogens may affect breast carcinogenesis by influencing ER status. Such findings suggest new directions for mechanistic research on dietary factors in breast carcinogenesis that may have relevance for prevention and clinical treatment.

Topics: Adult; Anticarcinogenic Agents; Boron; Breast Neoplasms; Diet; Female; Genistein; Humans; Hypolipidemic Agents; Isoflavones; Kaempferols; Middle Aged; Nutritional Status; Odds Ratio; Phytoestrogens; Premenopause; Receptors, Estrogen; Risk Factors; Sitosterols; Surveys and Questionnaires

The aim of this study was to investigate whether plant derived estrogens have the same relaxing effects in vitro as estradiol-17beta on arterial smooth muscle. The mesenteric arterial rings of female and male Wistar rats were studied. The relaxing effects of estradiol-17beta, genistein, daidzein and beta-sitosterol were determined, with particular focus on the role of endothelium. B-sitosterol had no relaxing effect on the arteries. Estradiol-17beta, genistein and daidzein relaxed noradrenaline, potassium chloride and calcium chloride precontracted arterial rings endothelium-independently. The relaxation responses were also independent of gender. Neither the removal of endothelium, nor the inhibition prostacyclin or nitric oxide synthesis, had any effect on the relaxation responses. The exact mechanism of these findings is still unclear.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Calcium Chloride; Estradiol; Estrogens; Female; Genistein; Indomethacin; Isoflavones; Male; Mesenteric Arteries; Muscle, Smooth, Vascular; NG-Nitroarginine Methyl Ester; Norepinephrine; Plant Extracts; Potassium Chloride; Rats; Rats, Wistar; Sitosterols; Vasoconstrictor Agents; Vasodilation