Antioxidant action of estrogens in rat hepatocytes.

The in vitro addition of 17 beta-estradiol (0-100 microM) to isolated rat hepatocytes efficiently prevented cellular lipid oxidation induced by the Fe(III)/ADP complex. 17 beta-estradiol was found to be less effective than its metabolic derivative 2-hydroxyestradiol. The presence of specific inhibitors of cytochrome P450 activity significantly diminished the antioxidant capacity of estradiol. These observations support the hypothesis that estradiol, in the micromolar range, inhibits iron-induced lipid peroxidation in liver cells by diverting reducing equivalents from the peroxidative process to its own metabolism.