Estrogenic/antiestrogenic and scavenging properties of ( E)- and ( Z)-resveratrol

Abstract

Resveratrol, natural compound found in grapes and wine, has been reported to have a variety of health benefit properties. Based on the structural similarity to the synthetic estrogen diethylstilbestrol, we investigated estrogenic/antiestrogenic effects on human breast cancer cell lines, MCF-7 and MVLN, and scavenging properties using DPPH of both ( E)- and ( Z)-isomers. Both isomers increased the in vitro growth of MCF-7 cell lines at medium concentrations (10 and 25 μM) whereas the low concentrations (0.1 and 1 μM) had no effect and the high concentration (50 μM) decreased the cell growth and was cytotoxic. The 25 μM ( E)-isomer alone was able to reduced the proliferation induced by the estradiol. Low concentrations of ( E)- and ( Z)-resveratrol (0.1 and 1 μM) and medium concentration 10 μM ( Z)-resveratrol did not interfere with the estrogen receptor. In contrast, medium concentrations of ( E)-resveratrol (10 and 25 μM) and ( Z)-resveratrol (25 μM) functioned as superagonists of estradiol. Whatever the model used, MCF-7 or MVLN cell lines, ( Z)-resveratrol was less effective than ( E)-resveratrol. Extinction of DPPH and Fe(III) reduction experiments showed that both isomers of resveratrol could act as free radicals scavengers or pro-oxidant compounds. The properties of low concentrations of resveratrol raise the possibility that structure-function studies could lead to the development of more selective estrogen receptor agonists and antagonists, which could be useful as a therapeutic agent.