ANTIESTROGENIC ACTIVITY OF ANTHROPOGENIC AND NATURAL CHEMICALS

A number of natural and man-made chemicals possess antiestrogenic acti vity, i.e. they antagonize a broad spectrum of estrogen-induced respon ses in vertebrates. Examples of antiestrogens include dioxin, furan an d PCB congeners, certain PAHs, pesticides and indol-3-carbinol derivat ives. Major mechanisms of antiestrogenicity are antagonistic action of chemicals at the estrogen receptor, or binding of chemicals to the ar ylhydrocarbon (Ah) receptor and subsequent interaction with estrogen-r esponsive genes. Toxicological consequences resulting from antiestroge nic activity have not been conclusively demonstrated to date, although antiestrogenic compounds could critically affect sensitive reproducti ve and developmental processes.