Biochemical and molecular mechanisms of beneficial effects for human health by phytoestrogens

在这项研究中，双酚A和植物雌激素，如染料木黄酮在人乳腺癌MCF-7细胞中的雌激素活性进行了比较，使用所谓的E-screen分析。我们还建立了诱导表达的pS2基因，一个雌激素反应基因，暴露后的MCF-7细胞的化学物质与雌激素。大豆苷元、柚皮素、山萘酚的雌激素活性较染料木素弱。对于雌激素类化合物的解毒途径，研究了人肝微粒体催化双酚A与植物雌激素的磺基结合反应。根据Km值，双酚A对磺基转移酶的亲和力似乎高于植物雌激素。ST 1A 3是一种热稳定的苯酚硫酸化磺基转移酶，被鉴定为双酚A硫酸化磺基转移酶，但植物雌激素与双酚A的雌激素作用机制尚不清楚。通过分析MCF-7细胞暴露于植物雌激素和双酚A（由于其雌激素作用而怀疑其毒性作用）后的基因表达，这是可能的。

In this study, estrogenicity of bisphenol A and phytoestrogens such as genistein was compared in human breast cancer MCF-7 cells using so called E-screen assay. We also established induction of expression of pS2 gene, an estrogen-resposive gene, after exposure of MCF-7 cells to chemicals with estrogenicity. Estrogenic activities of daidzein, naringenin, kaempfenol were weaker than that of genistein. For detoxification pathway of estrogenic compounds, sulfoconjugation of bisphenol A and phytoestrogens was catalyzed by human hepatic microsomes. On the basis of Km values, affinity of bisphenol A to sulfotransferase seemed to be higher than that of phytoestrogens. A form of thermostable phenol-sulfating sulfotransferase, ST1A3, was identified as a bisphenol A-sulfating sulfotransferase.Difference in the mechanisms of estrogenicity between phytoestrogens and bisphenol A was not, however, achieved. It would be possible by analyses of gene expression after exposure of MCF-7 cells to phytoestrogens, and bisphenol A whose toxic action is suspected due to its estrogenic action.