Curcuma longa (Curcumin) Abrogates Hyperhomocysteinemia and Oxidative Stress in a Rat Model of Colon Cancer

Abstract

Background: Hyperhomocysteinemia is involved in the pathogenesis of oxidative stress, a well-known etiological factor for different types of cancer, including colon cancer. Although Curcuma longa (curcumin) is a well-known antioxidant shown to prevent oxidative stress in different experimental models, yet its preventive role against hyperhomocysteinemia has not been addressed in experimental model for colon cancer. Objective: This study aimed to assess the protective role of C. longa (curcumin) as a natural antioxidant against the development of hyperhomocysteinemia-mediated oxidative stress and its associated carcinogenesis in rat colon. Methods: Forty-eight adult male Sprague Dawley rats were divided into four groups (12 rats/group): control, curcumin-supplemented group which received a daily dose of 200 mg curcumin/kg body weight, azoxymethane (AOM)-induced colon cancer group, and AOM group + curcumin supplementation. At the end of the experiment, 16 weeks, rats were sacrificed and colon tissues were collected to measure homocysteine level, oxidative stress markers [glutathione (GSH), total antioxidant capacity (TAC), lipid peroxides, and nitric oxide], and antioxidant enzymes (catalase, glutathione peroxidase, glutathione reductase, and superoxide dismutase). Colon histological sections were also examined for any histopathological changes. Results: The study results revealed that the colon tissue of the AOM-injected group had higher levels of homocysteine and markers of oxidative stress (GSH depletion, impairment of TAC, and inhibition of antioxidant enzymes) as compared to the control group, P < 0.05. Curcumin supplementation in the AOM + curcumin group significantly alleviated antioxidant enzymes activities as well as hyperhomocysteinemia, P < 0.05. AOM has also caused a significant increase in the size and numbers of aberrant crypt foci, marker lesions of colon tumors. Conclusion: Hyperhomocysteinemia results in the generation of reactive oxygen species, and thereby contributing to the oxidative stress-associated colon cancer pathogenesis. Curcumin as a functional food might be used as a preventative nutritional strategy against colon dysfunction that leads to cancer process.