The comparative effects of metformin, pioglitazone and rosiglitazone on the sciatic nerve of alloxan-induced diabetic male rats

Diabetes mellitus is the most common metabolic disease with neuropathy as its most common complication. In the present study, the effects of oral hypoglycaemic drugs (metformin, pioglitazone and rosiglitazone) on the morphology of the sciatic nerve were investigated. Forty male Wistar rats (140 g) divided into 5 groups control, diabetic, and 3 experimental groups (n=8) were used for the study. The 3 experimental groups were rendered diabetic by intraperitoneal injection of alloxan (150 mg/kg body weight) and subsequently treated with metformin (150 mg/kg/d), pioglitazone (3 mg/kg/d) and rosiglitazone (10 mg/kg/d) respectively. At 28 days of treatment, sciatic nerve morphology was studied by the Bielschosky’s Silver Nitrate (BSN) and Luxol Fast Blue (LFB) techniques. Blood glucose levels were monitored and recorded throughout the experiment. In the diabetic rats with oral hypoglycaemic interventions, blood glucose was not significantly different (P>0.05) from the control at 28 days of treatment. The body weight of Rosiglitazone-treated rats showed significant increase when compared with the control and other oral hypoglycaemic drug-treated rats. The axon and myelin fibers showed relatively strong affinity for BSN and LFB in the control and oral hypoglycaemic drugtreated diabetic rats contrary to the weak affinity for the stains in the untreated diabetic rats. These results suggest that oral hypoglycaemic drugs exerted positive effects on the treatment and improvement of sciatic nerve morphology of alloxan-induced diabetic rats.