Colorectal
malignancies continue to be one of the most frequent and life-threatening diseases throughout the world.
Pronyl-lysine, a product obtained from bread crust, is a potent
free radical scavenging
antioxidant exerting chemopreventive activity by reducing oxidative stress. This study was conducted to investigate the effects of
pronyl-lysine supplementation on the formation of colonic precancerous lesions, circulatory lipid peroxidation, and enzymic
antioxidant status in 1,2-dimethylhydrazine-induced colon
carcinogenesis. Male Wistar rats were randomized into seven groups; group 1 was control rats, group 2 received
pronyl-lysine (2 mg/kg
body weight orally) everyday, rats in groups 3-7 were administered subcutaneous
1,2-dimethylhydrazine (20 mg/kg
body weight) once a week for 15 consecutive weeks. In addition, group 4 (pre-initiation), 5 (initiation), 6 (post-initiation), and 7 (entire period) received
pronyl-lysine (2 mg/kg
body weight orally) everyday. At the end of 34 weeks, indicative markers of lipid peroxidation and changes in
antioxidant defense system were measured in circulation. The results showed that
1,2-dimethylhydrazine significantly increased total
aberrant crypt foci formation, total number of dysplastic foci,
beta-catenin accumulated crypts and
proliferating cell nuclear antigen labeling index in the colon, and enhanced lipid peroxidation markers and decreased enzymic
antioxidant activities in the plasma and erythrocyte lysate as compared with untreated controls.
Pronyl-lysine supplementation significantly reversed the changes as compared with the rats treated with
1,2-dimethylhydrazine alone. The effect of
pronyl-lysine was more pronounced when supplemented throughout the study period (group 7). These findings suggest that
pronyl-lysine suppresses 1,2-dimethylhydrazine-induced colon
carcinogenesis effectively.