Reduction of PM2.5 toxicity on human alveolar epithelial cells A549 by tea polyphenols

Tea-derived polyphenols have anticancer and antioxidant properties, and they can regulate oxidative stress. This study was designed to quantify both the toxic effects of fine particulate matter with aerodynamic diameter less than 2.5 mu m (PM2.5) and determine whether tea polyphenols could provide a protective effect against PM2.5 toxicity on human alveolar epithelial A549 cells in vitro. Cytotoxic effects of the PM2.5 on A549 cells were measured by means of cell viability, the expression of caspase-3, bax/bcl-2, and C/EBP-homologous protein (CHOP), and the generation of intracellular reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD). The results showed that tea polyphenols ameliorated some of the adverse effects of PM2.5 on A549 cell viability and SOD levels. In addition, tea polyphenols decreased the production of ROS, MDA generation, and apoptosis in response to PM2.5 exposure. Therefore, our results support a role for tea polyphenols in reducing the toxicity of PM2.5, particularly with regard to targeting oxidative stress and apoptosis.