Vanillic acid potentiates insulin secretion and prevents pancreatic β-cells cytotoxicity under H2O2-induced oxidative stress.

Abstract

Oxidative stress is known to impair cellular functions and, therefore, plays a significant role in the pathophysiology of various diseases, including diabetes. The persistently elevated glucose levels may cause enhanced mitochondrial reactive oxygen species generation, which in turn can damage the pancreatic β-cells. In this study, we have investigated the effect of vanillic acid on preventing H2O2-induced β-cells death and retaining its insulin secretion potentiating effect in the presence of H2O2. The insulin secretion from the BRIN-BD11 cells was quantified using ELISA-based assays. The viability of the cells was assessed by estimated by the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) colorimetric assay and DAPI staining. The expression levels of apoptotic and antioxidant proteins were estimated by western blot experiments. Vanillic acid protected pancreatic β-cells viability and function under the H2O2 oxidative stress condition. The Erk1/2 activation appears to play an important role in vanillic acid potentiated insulin secretion and protection of the β-cells in the presence of H2O2. Vanillic acid pretreated cells exhibited enhanced expression of antioxidant enzymes such as catalase and SOD-2 and reduced the expression of proapoptotic markers such as BAX and BAD. In addition, it also enhanced the expression of oxidative stress-sensitive transcription factor Nrf-2 and cell survival protein Akt. The present study shows that vanillic acid potentiates insulin secretion and protects pancreatic β-cells from H2O2-induced oxidative stress.