Zinc improves antioxidative enzymes in red blood cells and hematology in lithium-treated rats

The present study was designed to evaluate the protective role of zinc in attenuating the adverse effects induced by lithium in blood of female Wistar rats. Female Wistar rats received lithium in the form of lithium carbonate in diet at a dose level of 1.1 g/kg diet, zinc alone in the form of zinc sulfate in drinking water at a dose level of 227 mg/L drinking water, or lithium plus zinc treatments in the combined group for a total duration of 2 months. Effects of the treatments were studied on antioxidant defense system, various hematologic parameters, and percentage of (65)Zn-specific activity. Lithium treatment resulted in a significant increase in lipid peroxidation levels but caused a significant decrease in reduced glutathione levels and the activities of catalase, glutathione S-transferase, and superoxide dismutase. Lithium treatment also caused a significant decrease in the activities of aminolevulinic acid dehydratase and Na(+) K(+) adenosine triphosphatase. However, it resulted in a significant increase in total leukocyte counts, neutrophils, and lymphocyte counts as well as zinc protoporphyrin levels, whereas a significant decrease in counts of monocytes, eosinophils, and percentage specific activity of (65)Zn in blood and its various fractions was noticed. Furthermore, lithium treatment caused a significant decrease in serum zinc levels. However, zinc supplementation to lithium-treated rats effectively raised the reduced glutathione levels and also normalized lipid peroxidation and the activities of antioxidative enzymes, which included catalase, glutathione S-transferase, and superoxide dismutase. Moreover, zinc supplementation could raise the activities of the enzymes aminolevulinic acid dehydratase and Na(+) K(+) adenosine triphosphatase as well as the percentage uptake values of (65)Zn in blood and its fractions. The study suggests that zinc, as a nutritional supplement, has the potential in attenuating most of the adverse effects induced by lithium in rat blood.