The Coffee Diterpene,Kahweol, Ameliorates Pancreatic β-Cell Function in Streptozotocin (STZ)-Treated Rat INS-1 Cells through NF-kB and p-AKT/Bcl-2 Pathways

Kahweol is a diterpene molecule found in coffee that exhibits a wide range of biological activity, including anti-inflammatory and anticancer properties. However, the impact of kahweol on pancreatic β-cells is not known. Herein, by using clonal rat INS-1 (832/13) cells, we performed several functional experiments including; cell viability, apoptosis analysis, insulin secretion and glucose uptake measurements, reactive oxygen species (ROS) production, as well as western blotting analysis to investigate the potential role of kahweol pre-treatment on damage induced by streptozotocin (STZ) treatment. INS-1 cells pre-incubated with different concentrations of kahweol (2.5 and 5 µM) for 24 h, then exposed to STZ (3 mmol/L) for 3 h reversed the STZ-induced effect on cell viability, apoptosis, insulin content, and secretion in addition to glucose uptake and ROS production. Furthermore, Western blot analysis showed that kahweol downregulated STZ-induced nuclear factor kappa B (NF-κB), and the antioxidant proteins, Heme Oxygenase-1 (HMOX-1), and Inhibitor of DNA binding and cell differentiation (Id) proteins (ID1, ID3) while upregulated protein expression of insulin (INS), p-AKT and B-cell lymphoma 2 (BCL-2). In conclusion, our study suggested that kahweol has anti-diabetic properties on pancreatic β-cells by suppressing STZ induced apoptosis, increasing insulin secretion and glucose uptake. Targeting NF-κB, p-AKT, and BCL-2 in addition to antioxidant proteins ID1, ID3, and HMOX-1 are possible implicated mechanisms.