Effects of Grape Juice in Superoxide Dismutase and Catalase in Colorectal Cancer Carcinogenesis Induced by Azoxymethane

Background: The intestinal mucosa is commonly exposed to oxidant nutrients and carcinogens, which can lead tothe generation of free radicals. The antioxidants present in the diet assume great importance as possible protectiveagents, reducing the oxidative damage. In this way, we evaluated the antioxidant action of grape juice on preneoplasticlesions induced by azoxymethane (AOM) in Wistar rats. Methods: The colorectal carcinogenesis was induced by twointraperitoneal injections of 15mg/kg of AOM in Wistar rats. The animals were divided in 7 groups and treated with1 and 2% concentrations of grape juice before and after carcinogen administration. After euthanasia, the expression ofantioxidant enzymes catalase (CAT), copper-zinc superoxide dismutase (Cu/Zn-SOD) and manganese superoxidedismutase (Mn-SOD) CAT, SOD1 and SOD2 were evaluated by immunohistochemistry. Results: AOM decreased theexpression of CAT and Mn-SOD enzymes, but not for Cu/Zn-SOD. We observed an increase expression of CAT andMn-SOD after grape juice administration in some concentrations according to the time of administration of the grapejuice before the carcinogen or just after the carcinogen. Conclusion: Our results suggest an independent action of eachenzyme and a possible antioxidant action of the grape juice components in the diet being able to balance the body toneutralize the superoxide radicals and not leave them in the cell-damaging form.