46F-3 |
Anticarcinogenic activity of lycopene in colon of Fisher 344 male rats |
M. MARTÍNEZ-FERRER, M. Verghese, L. T. Walker, C. B. Chawan, and L. Shackelford. Department of Food and Animal Sciences, Alabama A&M University, Nutrition and Carcinogenesis Laboratory, P.O. Box 1628, Normal, AL 35762 Epidemiological studies have shown an inverse relationship between lycopene intake and cancer incidence. Glutathione-S-transferases (GST) are a family of enzymes known to play an important role in the detoxification of several carcinogens. This study was conducted to determine the effects of dietary lycopene and its interactions with fat levels on azoxymethane (AOM) induced colon tumors in Fisher 344 male weanling rats and its relation with GST activity. After an acclimatization period of 1 wk, groups of rats were assigned to: Control (C)-AIN93G (7% and 14% fat) and AIN 93G(7% and 14% fat)containing 200 and 400 ppm lycopene . All the rats except saline controls received 16 mg/kg body weight of AOM at 7 and 8 wk of age. The rats were sacrificed at 46 wk of age and samples collected. GST activity in liver and colonic mucosa was measured in all groups. Weight gains and feed intakes were comparable for all groups. Tumor incidences (%) in the small intestine and colon of rats in the C (7% and 14% fat), lycopene 200 and 400 ppm (7% and 14% fat) was: 31, 29, 0, 0, 0, 0: and 57, 92, 36, 33, 8 and 21, respectively. GST activity was elevated in the rats fed lycopene compared to controls. These findings suggest that increased lycopene intake in the diet may reduce the incidence of colon tumors. Inhibition of colon carcinogenesis by lycopene may be associated with increased activity of Glutathione-S-Transferase, a crucial detoxification enzyme.
Session 46F, Nutrition
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