Biochemical and Histopathological Inflections in Hepato-renal Tissues of Streptozotocin (STZ) Induced Diabetic Male Rats: Impact of Exogenous Melatonin Administration

Objective: To evaluate the therapeutic efficacy of exogenous melatonin (MEL) on hepato-renal tissue in a diabetic rat model. Methodology: Streptozotocin (STZ) was used to establish diabetic rat model. Diabetes was confirmed by monitoring the blood glucose level, animals having glucose level above 250 mg/dl were considered as diabetic and were divided into six different groups. Model control group, diabetic group, melatonin treatment to diabetic rats, melatonin per se group, glibenclamide (a standard hypoglycemic drug) treatment to diabetic rats and glibenclamide (standard control) alone respectively. The model control was given 0.5 ml (0.1 M) citrate buffer, experiment was conducted for one month. After the completion of experiment, rats were sacrificed. Blood was collected and centrifuged at 3000 rpm for 10 minutes to obtain the serum. Serum was kept at -800c for further analysis of liver and renal function tests and lipid profile. Liver and kidney tissues were weighed, fixed in Bouin’s fixative for histopathological studies. Further tissues were processed for Lipid peroxidation (LPO), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT). Major findings: Administration of MEL to STZ induced diabetic rat showed a significant decrease of lipid peroxidation (TBARS) in kidney and liver tissue comparable to the control and GLIBEN group of rats. In addition MEL prevented the decrease in antioxidative enzyme parameters viz. superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) of hepato-renal tissues. Parameters of liver functions (alanine amino transaminase (ALT), aspartate amino transaminase (AST) and alkaline phosphatase (ALP) and renal function (urea, uric acid and creatinine) were noted restored following MEL treatment. MEL administration further maintained the normal levels of lipid profiles i.e., triglyceride, cholesterol, low and high density lipoprotein (LDL, HDL) to that of the control group of rats. Histological architecture of liver and kidney tissues were noted repaired and rescued as judged by cellularity of hepatocytes and renal cells. Conclusion: The present finding strongly indicates the protective effect of exogenous melatonin for hepato-renal tissues form the damages and impairment observed and noted in the experimentally induced STZ male rat model.