Sargassum sagamianum extract protects INS-1 pancreatic β cells against high glucose-induced apoptosis

This study investigated the protective effects of Sargassum sagamianum extract (SSE) on INS-1 pancreatic β cells against high glucose-induced oxidative stress and apoptosis. Treatment with glucose at high concentrations (30 mM) caused β cell apoptosis, whereas treatment with SSE protected the β cells from high glucose-induced damage, by recovering the cell viability. Treatment with SSE at concentrations of 10–100 μg/mL decreased lipid peroxidation and intracellular reactive oxygen species and nitric oxide levels, and increased cell viability and insulin secretion in high glucose pretreated INS-1 cells in a dose-dependent manner. Moreover, SSE treatment significantly reduced the expression of pro-apoptotic Bax, cytochrome c, caspase-3, and caspase-9, while the expression of anti-apoptotic Bcl-2 increased. The type of cell death was examined by annexin V/propidium iodide staining, which revealed that SSE treatment markedly reduced high glucose-induced apoptosis. These findings suggest that SSE could be useful as a functional food, protecting pancreatic β cells against high glucose-induced oxidative stress and apoptosis.