Cytotoxicity of ZnO nanoparticles in rat liver cells and hepatocarcinoma cells

Objective: To explore the potential cytotoxicity mechanisms of ZnO nanoparticles (NPs) in BRL-3A (rat liver cell line) and CBRH-7919 (rat hepatocarcinoma cell line) cells. Methods: We checked cell viability after ZnO exposure at varying concentrations (0.1-100 mg/L) and different exposure periods (12-48 h) and changes in reactive oxygen species (ROS) and glutathione (GSH) levels. Results: Compared to the NP-free controls, ZnO NPs induced cytotoxicity in concentration-dependent and time-dependent manners in both cell lines. We found high cell viability in CBRH-7919 cells, indicating the better tolerance of CBRH-7919 cells to ZnO NPs than to BRL-3A cells. The increased ROS levels had a negative correlation with reduced cell viability and GSH levels, indicating that ZnO NPs could lead to cytotoxicity through oxidative stress in normal and cancer cells. Conclusion: These results suggest that there exist different degrees of cytotoxicity induced by ZnO NPs in normal and cancer cells, which may deserve consideration in future assessment of nanotoxicity and treatment of cancer.