Mestranol

Mestranol is the 3-methyl ether of ethinylestradiol. It was the estrogen used in many of the first oral contraceptives. It is a biologically inactive prodrug of ethinylestradiol to which it is demethylated in the liver with a conversion efficiency of 70%. (In Vitro) :Mestranol is a low potency synthetic estrogen that has been shown to be much more stable than 17β-Estradiol (HY-B0141) in hepatoma cell culture.Mestranol (10 μM; 6 days) stimulates the growth of ERpositive MCF-7 WS8 cells up to 250% of control levels, growth stimulation could be partially reversed by tamoxifen.However, in Hep G2 hepatoma cells, Mestranol (10 μM; 6 days) inhibits the growth of Hep 3B cells by 40% compared to control cells. Mestranol alone or cotreatment with tamoxifen both can inhibit cell growth. And cotreatment exhibits an additive effect with tamoxifen on growth inhibition.