The effects of feeding with different levels of zinc and chromium on plasma thiobarbituric acid reactive substances and antioxidant enzymes in rats.

This study was designed to investigate the effects of supplementation and deficiency of dietary chromium (Cr), zinc (Zn) and combination of zinc and chromium on lipid peroxidation and antioxidant enzymes. A total of 84 male Wistar albino rats were fed rat chow containing different levels of Zn and Cr throughout the 84 days. Blood samples were collected for analysis of Thiobarbituric acid reactive substances (TBARS), Superoxide dismutase (SOD), Catalase (CAT) and Glutathione peroxidase (GSH-Px). TBARS concentrations in rats fed high-Cr diet, high-Zn and Cr diet and low-Zn diet were significantly higher than those determined in the control group (p < or = 0.05). CAT activities in rats fed high-Cr diet were significantly higher than those observed in the control group. Cu-Zn SOD and GSH-Px activities were significantly higher in rats fed high-Cr diet, high-Zn and Cr diet, low-Zn diet, and low-Zn and Cr diet when compared to the activities found in the controls. These results suggest that trivalent chromium supplementation increase antioxidant enzymes by enhancement of lipid peroxidation, but Zn supplementation does not have any effect on lipid peroxidation. Also Zn deficiency resulted in increased lipid peroxidation, SOD and GSH-Px activities because of the oxidative stress caused by zinc deficiency.