In Vivo and in Vitro Evaluation of Anti Diabetic and Insulin Secretagogue Activities of Capparis zeylanica

Since ancient times, traditional medicines have been in the usage for the treatment of Diabetes mellitus. An edible fruit from traditional medicinal plant Capparis zeylanica (CZ) was studied for its anti diabetic, insulin secretagogue activities and mechanisms involved in it. In Streptozotocin induced diabetes rats, oral administration of Capparis zeylanica methanolic extract (CZME) (200 mg/kg body weight) for 28 days showed a significant reduction in blood glucose levels by 35.53% and enhanced circulating insulin levels by 81.82% than the diabetic control rats. The insulin secretagogue activity mechanisms of the extract were evaluated by using mouse insulinoma beta cell line (MIN6-β). The extract stimulated insulin release in dependent manner of glucose concentration (3 - 16.7 mM) and extract dose (5 - 500 μg/mL). The insulin releasing effect of the extract was significantly enhanced by 3-isobutyl-1-methyl xanthine, glibenclamide, elevated extracellular calcium and K+ depolarized media. This insulin release was significantly reduced in calcium blocking conditions (by nifedipine and EGTA), in the presence of potassium channel opener (diazoxide). Hence, anti diabetic activity of CZME might be a result of its stimulatory effect on insulin release from pancreatic beta cells via KATP channel dependent and independent ways. These results indicate that CZ fruits have the potential to use in diabetes therapy.