Effects of β-ionone on mammary carcinogenesis and antioxidant status in rats treated with DMBA.

Recent chemopreventive studies from our group showed that dietary β -ionone inhibited 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinogenesis by the inhibition of cell proliferation and apoptosis initiation. In this study, we examined the chemopreventive effects of varied doses of dietary β -ionone on the development and growth of DMBA-induced rat mammary tumors as well as plasma antioxidant status. β -ionone treatment groups were given 9, 18, and 36 mmol/kg in the AIN76A diet starting 2 wk prior to DMBA administration and continuing for the 24 wk. Results showed that tumor incidence was dose dependently reduced by 35.4, 68.3, and 87.8%, respectively, compared to the positive control. Tumor sizes were dose dependently smaller, and tumor weight was less in each group, each rat, and each tumor compared to the positive control ( P < 0.05). A significant decrease in lipid peroxidation was observed in the tumor-induced rats treated with dietary β -ionone, whereas the plasma activities of antioxida...