Crocin and gallic acid attenuate ethanol-induced mitochondrial dysfunction via suppression of ROS formation and inhibition of mitochondrial swelling in pancreatic mitochondria

Chronic/heavy exposure with ethanol is associated with risk of type 2 diabetes, due to β-cells dysfunction. It has been reported that ethanol can induce oxidative stress directly or indirectly by involvement of mitochondria. We aimed to explore the protective effects of the crocin/gallic acid/L-alliin as natural antioxidants separately on ethanol-induced mitochondrial damage. Intact mitochondria are isolated from pancreas by differential centrifugation and directly treated with toxic concentrations of ethanol (8% v/v) in the presence of different concentrations crocin/gallic acid/L-alliin (100, 500, and 1000 µM). Biomarkers of mitochondrial toxicity including the succinate dehydrogenases (SDH) activity, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), mitochondrial swelling, lipid peroxidation, and glutathione content were assessed. The results showed that 8% v/v ethanol-treated rat pancreas-isolated mitochondria for 1 h resulted in a significant decrease of SDH activity to 81.34 ± 3.48%, a significant increase of ROS formation, MDA content, mitochondrial swelling, and collapse of MMP. Among three tested natural compounds, treatment with crocin and gallic acid significantly reversed the changes of the above indicators and resulted in the increase of SDH activity, improvement of MMP collapse and mitochondrial swelling, and reduction of ROS formation and oxidative stress in pancreas-isolated mitochondria. This study demonstrated that crocin and gallic acid had direct protective effects on the mitochondrial damages induced by ethanol in pancreas-isolated mitochondria, and these natural compounds could be developed as mitochondrial protective agents in the prevention of pancreatic β-cells and diabetogenic effect of ethanol.