Melittin, a Potential Natural Toxin of Crude Bee Venom: Probable Future Arsenal in the Treatment of Diabetes Mellitus

Figure 1

Basic mechanism of insulin secretion and sequential mechanistic pathway of BV (melittin) leading to an increase in insulin secretion in pancreatic β-cells. (A) Blood glucose (5 mM in concentration) enters the β-cell through the glucose transporter (GLUT2). (B) ATP production rapidly occurs as a result of glycolysis and respiration. (C) Then, ATP-sensitive K⁺ channels are closed, and K⁺ efflux is inhibited. (D) Consequently, plasma membrane depolarizes, and (E) voltage-gated Ca²⁺ channels open. Finally, Ca²⁺ influx increases, which triggers exocytosis of insulin granules. ① Melittin directly depolarizes the cell membrane, ② it increases Ca²⁺ inflow into the cell, ③ it promotes more granule secretion, and ④ it increases insulin secretion into the blood stream. Note: phosphorus: P; calcium: Ca²⁺. Adapted from https://www.dolcera.com/wiki/index.php?title=Diabetes_products_and_services.