Antihyperglycemic and Insulin Secretagogue Activities of Abrus precatorius Leaf Extract

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.