Antimutagenic effects of natural and synthetic hormonal steroids

Among the steroid molecules, bile acids have been shown to have either a co- or an antimutagenic activity toward various direct and indirect acting mutagens in the Ames test. The present report extends such observations to other steroids having hormonal activity. The main effect of the active hormones is an inhibition of the genotoxicity of both direct and indirect acting mutagens. This effect is strictly structure-related. Moreover, both ethinyl oestradiol and mestranol, which are synthetic derivatives of beta-oestradiol largely used in contraceptive pills, are strong inhibitors of the mutagenicity, acting at nanomolar concentrations. The present article emphasizes the possible role of compounds with steroid structure as modulators of genotoxicity.