Evaluating the Protective Effect of Melatonin on Atorvastatin-induced Mitochondrial Toxicity in Pancreatic Beta Cells

Background: Atorvastatin and other statins belong to a category of cholesterollowering drugs, which may cause some damage to pancreatic cells despite their effectiveness. Aims: The present study investigated the effects of melatonin against atorvastatin-induced toxicity on islets of Langerhans and CRI-D2 cells. Methods: The MTT assay was used to determine cell viability. The effect of various concentrations of melatonin (0,10, 50, 100, 250, 500 and 1000 μM) on CRI-D2 cell viability was evaluated for 24 hours to determine the non-cytotoxic concentrations of melatonin. Additionally, cells were treated with different concentrations of atorvastatin (10, 100, and 150 ng/mL) for 24 hours to determine a concentration that could induce the maximum cell death. After selecting the appropriate concentrations for melatonin, cells were treated with atorvastatin (10, 100, and 150 ng/ml) and melatonin (10 and 100 μM) simultaneously for a period of 24 hours. Malondialdehyde (MDA), reactive oxygen species (ROS), superoxide dismutase, catalase, and glutathione peroxidase activity were assessed as indicators of oxidative stress. To assess mitochondrial function, the ratio of adenosine diphosphate (ADP) to adenosine triphosphate (ATP) and mitochondrial membrane potential (MMP) were measured. Results: Atorvastatin markedly raised ROS and MDA levels. This result was associated with a decrease in MMP, an increase in the ADP/ATP ratio, and a change in the activity of antioxidant enzymes. Atorvastatin (150 ng/mL)-induced mitochondrial damage was alleviated by concurrent melatonin and atorvastatin therapy. Conclusion: These results suggest that melatonin has a protective effect against atorvastatininduced toxicity in the mitochondria of pancreatic cells.