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Phytoestrogen

Phytoestrogen compounds are naturally occurring plant hormones and consist of a number of classes including isoflavones, coumestans, lignans and resorcylic acid lactones. Phytoestrogens occur in a variety of plants, including vegetable protein materials such as soybeans. Phytoestrogens are plant-derived compounds that display estrogenic activity in a bioassay system, previously described hereinabove. Sources of these phytoestrogens include red clover blossom, wild yam extract, black cohosh, soya extract, and licorice root extract. There are three main groups of nonsteroidial dietary estrogens which are the isoflavones, the coumestans and the mycoestrogens (fungal). The class of isoflavones consists of among others genistein, daidzein, equol, glycitein, biochanin A, formononetin, and O-desmethylangolesin. The isoflavones genistein and daidzein are found almost uniquely in soybeans. The phytoestrogen exhibits a similar action to female hormones in an organ specificity viewpoint, such as interacting with a receptor of estrogen which is a female hormone and inhibiting resorption of the bone. The property of local vulvar/vaginal tissue estrogen activity by the phytoestrogens allows treatment and even prevention of atrophic vulvitis/atrophic vaginitis by use of these phytoestrogens typically in the vulvar/vaginal tissues. The phytoestrogen applicable to the prophylactic, therapeutic agent for osteoporosis of the invention may be in a form of the above food itself or a fabricated one thereof as well as an extracted semipurified one. As representative components thereof, genistein and daidzein are known, which are isoflavons of soybean, and enterolactone and enterodiol are further known, which are lignars contained in rye, blueberry, sesame, tea and etc.

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