Phytoestrogens in Cell Signaling
Phytoestrogens are polyphenolic nonsteroidal plant-derived compounds that structurally and functionally mimic mammalian estrogen 17-ß-estradiol and therefore are considered to play an important role in the prevention of cancer, heart disease, menopausal symptoms, and osteoporosis. Considering the large spectrum effects that estrogens have on the human body, it is important to determine the potential of phytoestrogens for human health as they mimic endogenous estrogens and cause estrogenic effects. Phytoestrogens with a stable structure and low molecular weight can pass through cell membranes, and they have been shown to interact with enzymes and receptors. Receptors are the gatekeepers for cellular signaling and they exhibit specific and high-affinity binding to their corresponding ligands. High cell proliferation is a common characteristic of most cancer cells. The soy proteins genistein and daidzein are primary phytoestrogens, which have been shown to act as cancer chemopreventive agents via modulation of cellular signaling at different levels.