Effects of estrogens on the redox chemistry of iron: a possible mechanism of the antioxidant action of estrogens.

The preventive effects of estrogens on FeSO4-induced lipid peroxidation are closely correlated with their inhibition of Fe(II) oxidation during peroxidation. Estrogens affected the redox status of iron in aqueous solution with varying degrees of effectiveness. 2-Hydroxyestradiol substantially decreased the oxidation of Fe(II) and was the most potent Fe(III) reductant. Diethylstilbestrol and 4-hydroxyestradiol also exhibited reduction properties, whereas the phenolic estrogens 17 beta-estradiol, estrone, and 17 alpha-ethynylestradiol displayed slighter or no effects. Present results demonstrate that catecholestrogens and diethylstilbestrol directly alter the iron redox chemistry, this fact probably being involved in the antioxidant effects of these molecules.