To evaluate neuropathy, retinopathy and antioxidant properties of a polyherbal formulation (PHF) aqueous extract in Streptozotocin- nicotinamide induced diabetic rats.
Methods: Fasting blood glucose (FBG), serum insulin and glycated haemoglobin (HbA1C) levels were determined in normal and Streptozotocin- nicotinamide induced diabetic rats after oral administration of the PHF for 45 days. Neuropathic analgesia was assessed by tail-flick and hot-plate methods and to assess retinopathy, increase levels of vascular endothelial growth factor (VEGF) and intracellular adhesion molecule (ICAM-1) were measured. Antioxidant property was evaluated by estimating superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) levels in sciatic nerve and retina. Histopathological changes in sciatic nerve and retina were also observed after PHF treatment.
Results: Daily oral administration of PHF (200 and 400 mg/kg, b.w.) and metformin (5mg/kg, b.w.) showed beneficial effect on blood glucose levels (P < 0.001) of diabetic animals. The PHF treatment enhances serum insulin levels and body weight of diabetic rats as compared to diabetic control group. PHF treated animals showed decrease in tail immersion latency time, increase in pain sensitivity and significant decrease in levels of VEGF and ICAM-1, when compared to diabetic group. Furthermore, the PHF has a favourable effect on histopathological studies, in Streptozotocin- nicotinamide induced diabetic animals. Antioxidant enzyme levels were found to be significantly increased and that of MDA were decreased in PHF treated diabetic animals.
Conclusion: PHF showed potent anti-diabetic and protection against associated secondary complications of diabetes like neuropathy and retinopathy and also possesses antioxidant properties. Histopathological studies support these claims of PHF in Streptozotocin- nicotinamide induced diabetic animals.