Evaluation of protective effects of hydroalcoholic extract of Cassia fistula Linn. Pod on pancreas in streptozotocin-induced diabetic rats

Background: Diabetes mellitus (DM) is associated with oxidative stress. Medicinal plants and herbs are the rich sources of antioxidants which ameliorate oxidative stress-induced diabetic complications and could play an important role in the management of diabetes. Objective: The present study aimed to evaluate the protective effects of 70% ethanolic extract of Cassia fistula pod on pancreas in streptozotocin (STZ)-induced diabetic rats. Materials and Methods: Diabetes was induced in male Wistar rats by single intraperitoneal injection of STZ (60 mg/kg b.wt.). The diabetic rats were administered orally with C. fistula pod extract at three different doses (100, 250, and 500 mg/kg b.wt./day) for 60 days. The results were compared with standard drug glibenclamide (5 mg/kg b.wt./day) treated rats. Relative pancreatic weight and serum insulin level were determined. Histopathological changes and oxidative stress parameters, i.e., lipid peroxidation (thiobarbituric acid reactive substance [TBARS]) and antioxidative defense markers (superoxide dismutase, catalase, glutathione, and ascorbic acid), in the pancreas were investigated. Results: Oral administration of C. fistula pod extract (100, 250, and 500 mg/kg b.wt./day) or glibenclamide in diabetic rats significantly improved serum insulin level, total protein concentration, relative pancreatic weight, and mean diameter of islets of Langerhans as compared to diabetic control rats. Furthermore, treatment with extract also reduced TBARS levels and improved the levels of antioxidant markers in the pancreas. The histomorphological picture of the pancreas showed marked restoration of islets morphology. These results were comparable with glibenclamide. Conclusions: The results of the present study showed that C. fistula pod extract possesses significant antidiabetic activity though enhanced insulin secretion, improvement of antioxidative status of pancreas, and preservation of the integrity of pancreatic islets. Abbreviations used: b.wt.: Body weight; CAT: Catalase; DM: Diabetes mellitus; DNA: Deoxyribonucleic acid; GSH: Glutathione; ROS: Reactive oxygen species; SOD: Superoxide dismutase; STZ: Streptozotocin; TBARS: Thiobarbituric acid reactive substances.