2-Hydroxyestrone

2-Hydroxyestrone (Catecholestrone) is a specific receptor-mediated antiestrogenic agent. 2-Hydroxyestrone is anticarcinogenic^[1][2]. IC50 & Target:Estrogen Receptor/ERR^[1] In Vitro: 2-Hydroxyestrone exhibits antiestrogen action on MCF-7 human breast cancer cells. Addition of 2-Hydroxyestrone to the cell cultures in concentration of 1-1000 nM has no effect on cell growth and proliferation because of rapid O-methylation of the catechol estrogen by catechol O-methyltransferase which is highly active in these cells. In the presence of quinalizarin, a potent catechol O-methyltransferase inhibitor which reduces the O-methylation of the steroid, 10 and 100 nM 2-Hydroxyestrone markedly suppresses the growth and proliferation of the cells^[2]. In Vivo: Levels of both 2-Hydroxyestrone (2-OHE1; 2 mg/kg; administered ip.)?and ?2-Hydroxyestrone 4-N-acetylcysteine thioether (2-OHE1?4SR) in rats treated with 2-Hydroxyestrone?were significantly different between the induced and noninduced groups^[3].