Zinc is one of the most important trace elements in biological systems. It has critical effect on oxidative stress which is implicated as an important cause of degenerative diseases including diabetes.
Objective: This study was set to determine if there is a difference in serum and pancreatic zinc concentrations between normoglycemic and diabetic rat groups. Another aim was to evaluate, whether the hyperglycemia and oxidative stress could be ameliorated by zinc therapy.
Materials and Methods: Forty eight male albino rats weighing 150-200 grams were randomly allocated to four groups each contained 12 animals. Group 1: control group received saline. Group 2: was given zinc sulfate orally 100 mg/kg/day. Group 3: diabetic control rats induced by alloxan (150 mg/kg, I.P.) as a single dose. Group 4: in which diabetes was induced by alloxan was given zinc sulfate orally. Six rats from each group were sacrificed by decapitation after 2 weeks and the other six rats after 4 weeks of treatments for estimation of blood glucose level, and blood and pancreatic zinc (Zn), superoxide dismutase (SOD), catalase (CAT), and malondaldhyde (MDA).
Results: There were significant increase in blood glucose as well as serum and pancreatic MDA levels. While serum and pancreatic Zn, SOD, CAT levels were significantly reduced after 2 and 4 weeks of single I.P. alloxan administration compared to control group. Treatment of diabetic rats with zinc sulfate led to significant decrease in blood glucose level and elevation in serum Zn levels only after 4 weeks of treatment. However, significant decrease in serum and pancreatic MDA levels, and increase in serum and pancreatic SOD and CAT and also in pancreatic Zn after 2 and 4 weeks of treatment compared to diabetic untreated groups.
Conclusion: Serum and pancreatic Zn concentrations in diabetic rat groups were significantly lower than control rats. Although zinc therapies can partially ameliorate the alloxan- induced changes in diabetic rat after 2 weeks of treatment, significant recovery occurred in the measured parameter after 4 weeks of treatment due to its antioxidant effect.