ABSTRACT

Estrogens are compounds which produce a number of predictable responses when administered to animals. The estrogens which are naturally produced by plants are commonly referred to as phytoestrogens and would not include compounds such as estrone or estriol, both of which have been reported in plants, but are normally produced by the ovaries. The compounds which are most likely to be responsible for the estrogenic activity of plants or plant products are the isoflavones, the coumestans, and the resorcyclic acid lactones. Estrogenic compounds occurring in plants may be associated with plant diseases. Since estrogens are implicated in a number of malignancies, it is not surprising to find some studies conducted to determine the possible role of phytoestrogens in the induction of cancer. The isoflavones most likely to account for the estrogenic activity of plants are genistein, genistin, daidzein, biochanin A, formononetin, and pratensein.