Endocrine Abstracts

Phytoestrogens bind weakly to oestrogen receptors and can initiate oestrogen-dependent transcription. They are promoted as natural alternatives to HRT and yet epidemiological evidence suggests that they may protect against breast and prostate cancer. Studies in cell-free preparations have shown that phytoestrogens can inhibit the activity of aromatase and that the inhibition is, at least partly, competitive with androgen substrates. The question as to whether chronic exposure ...

Phytoestrogens (PEs) have a weak affinity for the oestrogen receptor. There is, however, no consistent evidence that, on a normal diet, circulating levels of PEs reach sufficient concentrations to exert significant oestrogenic/anti-oestrogenic effects. Phytoestrogens have been implicated in other cellular actions, not all of which necessarily involve the oestrogen receptor. Studies on cell-free systems and cell lines have demonstrated dose-dependent inhibitory effects of PEs o...

Extracts of black cohosh (BCE) are frequently used as an alternative to conventional HRT to treat menopausal symptoms, particularly in Germany and the United States. In fact, BCE is the 14th most popular herbal product in the US and in 2003 sales were at least $15.7 million. Evidence for an increased incidence of breast cancer in long-term users of HRT has reduced its use and may increase the use of alternative treatments. These still require rigorous scientific investigation,...