This study aimed to investigate the MC-LR induced oxidative injury and apoptosis in Chinese hamster ovary (CHO) cells, and the protective effects of N-acetylcysteine (NAC) on these cells. Cell viability was determined by MTT assay after exposure to NAC at various concentrations (0, 1, 5, 10, 20, 30, 40, 50, 60 and 80 mmol/L) alone, or NAC (0, 1 and 5 mmol/L) plus MC-LR (0, 2.5, 5 and 10 μg/ml) for 24 h. The reactive oxygen species (ROS) in CHO cells were measured by DCFH-DA, mitochondrial membrane potential (MMP) by fluorescence probe JC-1 staining, and apoptosis index determined by Annexin V-PI staining. Results showed, following exposure to NAC alone for 24 h, cell viability remains higher than 80% at 1 and 5 mmol/L. After exposure to NAC at different concentrations plus MC-LR, cell viability increased, ROS decreased, MMP elevated, and apoptosis index reduced to a certain extent. In conclusion, MC-LR may induce the apoptosis of CHO cells by inducing ROS production which is protected by NAC.
Keywords: Chinese hamster ovary cells; Microcystin-LR; N-acetylcysteine; apoptosis; oxidative damage.