Oral Zinc Supplementation Protects Rat Kidney Tissue from Oxidative Stress in Diabetic Rats

Abstract

Zinc (Zn) is a trace element possessing a wide range of functions and antioxidant properties. This study was undertaken in order to illuminate the conflicting data on the status of zinc in diabetes, present in literature. Female Swiss albino rats were randomly divided into 4 groups: Group I, control; Group II, control + zinc sulfate; Group III, streptozotocin (STZ)-diabetic; Group IV, STZ-diabetic + zinc sulfate. Diabetes was induced by intraperitoneal injection of STZ (65 mg/kg body weight). Zinc sulfate was given daily by gavage at a dose of 100 mg/kg body weight every day for 60 days to Groups II and IV. At the last day of the experiment, rats were killed under anesthesia, kidney tissue was taken and homogenized. Antioxidant enzyme activities such as catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST), superoxide dismutase (SOD) and myeloperoxidase (MPO), were determined in tissue homogenates as well as protein carbonyl content (PCC). Carbonic anhydrase (CA) was also determined as a functional enzyme for kidney. It was shown that kidney tissue antioxidant enzyme activities which were significantly impaired in the untreated diabetic group, were reversed in zinc treated diabetic groups, thus showing the beneficial effect of Zn treatment in diabetes via its antioxidant effect.