Failure to detect the anti-mutagenic effect of insulin in experimental type-2 diabetic rats

Abstract

Background:The oxidative stress is known to cause mutation-related disorders in diabetic patients. Materials and Methods: The present study was designed to investigate the anti-mutagenic effect of insulin in nicotinamide (NA: 230 mg/kg, i.p.) and streptozotocin (STZ: 65 mg/kg, i.p.) induced nuclear defects. Bone marrow micronucleus (MN) test and caudal epididymal sperm abnormalities were detected to find the somatic and germinal cell mutations, respectively. The antioxidant status was determined by estimating serum lipid peroxidation, catalase, superoxide dismutase and glutathione peroxidase levels. Results: The experimental type diabetes significantly (P < 0.001) reduced the antioxidant status and enhanced MN frequency and sperm defects compared to control animals. Although administration of insulin (1, 3, 5 and 7 IU/kg, s.c. for 4 weeks) significantly (P < 0.001) reduced hyperglycemia, it did not alter the antioxidant status, and somatic and germinal cell defects in diabetic rats. Conclusion:The results suggest that insulin did not have protective effect against the genotoxicity induced by NA-STZ diabetes.