Molecular and pharmacodynamic properties of estrogenic extracts from the traditional Chinese medicinal herb, Epimedium.

The Chinese medicinal herb, Epimedium, used traditionally for bone health exerts estrogenic activity (EA) in vitro. A genetically characterized Epimedium brevicornum (EB) extract induced biphasic responses in the mRNA and protein expression of the estrogen-regulated progesterone receptor gene in breast cancer (MCF-7) cells. These changes were mirrored changes in estrogenic receptor (ERalpha) content. In male Sprague-Dawley rats, administration of the estrogenic prodrug, estradiol valerate increased area-under-curve of serum effects for ERalpha (AUC difference: 18,900EA(ERalpha) min; 95% CI: 0-37,800; p = 0.05) and breast cancer cell (MCF-7) growth (AUC difference: 30,200EA(MCF-7) min; 95% CI: 24,200-36,200; p<0.001), compared to placebo. Oral administration of Epimedium brevicornum increased ERalpha activity (1320EA(ERalpha) min, p<0.01). Our data indicate that estrogen-responsive bioassays can measure the pharmacokinetic/pharmacodynamics of estrogenic activity in serum. Epimedium brevicornum extract increases estrogenic activity in serum and human studies are required to evaluate whether Epimedium extracts have utility for estrogen replacement therapy.