Related Experiment Video
Updated: Jun 17, 2026
Changes in Mammary Gland Morphology and Breast Cancer Risk in Rats
Published on: October 16, 2010
Effects of beta-ionone on mammary carcinogenesis and antioxidant status in rats treated with DMBA
Jia-Ren Liu1, Hong-Wei Dong, Xiang-Rong Sun
1Public Health College, Harbin Medical University, NanGang District, Harbin, P. R. China.
Abstract:
Recent chemopreventive studies from our group showed that dietary beta -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 beta -ionone on the development and growth of DMBA-induced rat mammary tumors as well as plasma antioxidant status. beta -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 beta -ionone, whereas the plasma activities of antioxidant enzymes such as glutathione peroxidase, glutathione reductase, superoxide dismutase, and the nonenzymatic antioxidant glutathione were increased in the beta -ionone treated rats when compared to control. The levels of catalase and lactate dehydrogenase were remarkably decreased in the beta -ionone treated groups compared to the positive control group. These results suggest that dietary beta -ionone has biologically relevant antioxidant activity and plays a chemopreventive role against DMBA induced mammary gland tumors.
Insights
Dietary beta-ionone significantly reduced mammary tumors in rats induced by 7,12-dimethylbenz(a)anthracene (DMBA). This compound demonstrated antioxidant activity, lowering lipid peroxidation and enhancing antioxidant enzyme levels.
Area of Science:
- Carcinogenesis
- Chemoprevention
- Nutritional Biochemistry
Background:
- Dietary beta-ionone has shown chemopreventive properties against 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinogenesis.
- Previous studies indicated inhibition of cell proliferation and apoptosis initiation by beta-ionone.
Purpose of the Study:
- To investigate the chemopreventive effects of varied dietary doses of beta-ionone on DMBA-induced rat mammary tumors.
- To assess the impact of beta-ionone on plasma antioxidant status in rats with induced mammary tumors.
Main Methods:
- Rats were fed diets containing 9, 18, or 36 mmol/kg beta-ionone starting 2 weeks before DMBA administration and continuing for 24 weeks.
- Tumor incidence, size, and weight were measured.
- Plasma antioxidant enzyme activities (glutathione peroxidase, glutathione reductase, superoxide dismutase), nonenzymatic antioxidant (glutathione), lipid peroxidation, catalase, and lactate dehydrogenase levels were analyzed.
Main Results:
- Tumor incidence dose-dependently decreased by 35.4%, 68.3%, and 87.8% with increasing beta-ionone doses.
- Tumor size and weight were significantly reduced in beta-ionone treated groups compared to controls (P < 0.05).
- Lipid peroxidation decreased, while plasma antioxidant enzymes and glutathione levels increased in beta-ionone treated rats. Catalase and lactate dehydrogenase levels were reduced.
Conclusions:
- Dietary beta-ionone exhibits significant antioxidant activity.
- Beta-ionone plays a chemopreventive role against DMBA-induced mammary gland tumors in a dose-dependent manner.
