The effects of copper supplement on zinc status, enzymes of zinc activities and antioxidant status in alloxan-induced diabetic rats fed on zinc over-dose diet

The aim of this study was to investigate the effect of copper supplementation on over-dose zinc in experimental diabetes. Male alloxan-induced diabetic Wistar albino rats of 12 weeks of age were divided into three groups. The first group received a diet containing 54 mg zinc/kg (control group), the second group received a diet containing 231 mg zinc/kg (Zn group), and the third group received a diet containing 231 mg zinc/kg supplemented with copper (30 mg/kg diet) (Zn+Cu group). Body weight gain of all rats was recorded regularly over a period of three weeks. On day 21, after overnight fasting, animals were sacrificed and blood glucose, zinc concentration, and amylase, aldolase, lactate dehydrogenase and alkaline phosphatase activities and parameter antioxidants were determined on tissues and serum samples. Body weight gain of copper supplementation diabetic animals at the end of three weeks of dietary manipulation was significantly lower with a percentage of 41.09% than that of zinc over dose diabetic animals. The administration of copper significantly altered blood glucose with a percentage of 22.98%, serum and tissues zinc concentration (P < 0.01) and all enzymes zinc dependants in animals. Copper added significantly increased glutathione (GSH) concentration (P < 0.05) and glutathione peroxydase (GPx) activity (P < 0.01) in rats. In contrast, liver malondialdehyde (MDA) and testis glutathione S transferase (GST) activity levels were lower with a percentage of 13.52 and 29.78%, respectively. There is no statistically change in liver GST activity in (Zn+Cu) group. It was concluded that supplementation of copper diet have significantly reduced the zinc status, disrupt the activity of zinc-dependent enzymes and altered in the chemical and oxidative parameters in diabetes.