Oral hypoglycaemic agent metformin reduces oxidative stress and improves kidney histologyin streptozotocin-induced diabetic rats

ABSTRACT Background: Persistent hyperglycaemia results in complications in diabetes mellitus (DM) and metformin is the baseline drug used in diabetic management. The effect of metformin on fasting blood glucose (FBG), homogenized kidney tissue malonyldehyde (MDA), protein carbonyls (PCO), total antioxidant capacity (TAC) and histology in streptozotocin-induced diabetic rats was investigated. Methods: Eighteen Sprague Dawley rats were assigned into three groups (n= 6 rats per group i.e. A; negative control on distilled water, B; positive control on distilled water and C; on 100 mg/kg/day metformin groups. Diabetes mellitus (DM) was induced using streptozotocin 65 mg/kg intraperitoneally and treatments were given daily by oral gavage for 3 weeks. Plasma fasting blood glucose (FBG), kidney tissue oxidative stress markers and histology were determined. Results: The results showed that FBG, MDA, and PCO levels were significantly higher in B group compared to A group, and lower in C group compared to B. The TAC level was significantly lower in B compared to A and higher in C compared to B group of rats. However, though histological study shows improvement in kidney histology in all treatments, kidney weight did not differ. Conclution: The results suggest that, metformin reduces oxidative stress in streptozotocin-induced diabetic rats possibly through its antihyperglycaemic effect.