Antihyperglycemic and insulin secretagogue activities of Abrus precatorius leaf extract

Abstract

Aim: Abrus precatorius leaves methanolic extract (APME) was evaluated for in vivo antihyperglycemic activity and in vitro insulinotropic effect. Materials and Methods: In vivo antihyperglycemic and insulin secretagogue activities were assessed in streptozotocin-induced diabetic rats by oral administration of APME (200 mg/kg body weight [bw]) for 28 days. In vitro insulin secretion mechanisms were studied using mouse insulinoma beta cells (MIN6-β). In vivo body weight and blood glucose and in vivo and in vitro insulin levels were estimated. Results: In diabetic rats, APME treatment significantly restored body weight (26.39%), blood glucose (32.39%), and insulin levels (73.95%) in comparison to diabetic control rats. In MIN6-β cells, APME potentiated insulin secretion in a dependent manner of glucose (3-16.7 mM) and extract (5-500 μg/mL) concentration. Insulin secretagogue effect was demonstrated in the presence of 3-isobutyl-1-methyl xanthine, glibenclamide, elevated extracellular calcium, and K+ depolarized media. Insulin release was reduced in the presence of nifedipine, ethylene glycol tetra acetic acid (calcium blocking agents), and diazoxide (potassium channel opener). Conclusion: The study suggests that APME antihyperglycemic activity might involve the insulin secretagogue effect by pancreatic beta cells physiological pathways via K+-ATP channel dependent and independently, along with an effect on Ca2+ channels.