Abstract

PHYTOESTROGENS: RECENT PERSPECTIVES ON THEIR CHEMISTRY AND BIOLOGY

Parna Das Sarma, Sanchita Bhattacharjee, Nivedita Bhattacharjee and Sauryya
Bhattacharyya*

Abstract

Polyphenols are present in all plants and the main classes of compounds that show phytoestrogenic activities are the isoflavones, the lignans, the coumestanes, the stilbenes and the mycotoxins. These compounds have structural and functional similarities with 17β- estradiol, which is the basis for their hormonal activity towards cellular estrogen receptors having beneficial role in humans against deficiency of estrogen. It has also been seen that different phytoestrogens exert their biological functions through different type of tissue specific receptors involving different mechanism of actions. Plant derived phytoestrogens bind with two types of estrogen receptors (ER) to put forth their mechanism of action: estrogen receptor α (ERα) and estrogen receptor β (ERβ), restricted in cytoplasm and nucleus. Phytoestrogens may exert their biological activity by one of the following mechanisms: mimicking the action of endogenous estrogen, functioning as estrogen antagonists, influencing the synthesis and metabolism of endogenous hormones, or by modifying hormone receptor biochemistry. A similarity between three dimensional arrangement of carbon atoms with estradiols might be the reason behind the pro-estrogenic action of the phytoestrogens.

Keywords: Phytoestrogen, 17?-estradiol, Isoflavones, Estrogen receptors, hormone.