Abstract: Objective: To investigate the cytotoxicity of atmospheric PM2.5 on HTR8-SVneo cells. Methods：The in vitro cultured HTR8-SVneo cells were exposed to PM2.5 at the concentrations of 0, 30, 60, 120 and 200 μg/mL for 24 h. The cells treated with 0 μg/mL PM 2.5 were used as the control group. The cell survival rate was analyzed by the CCK-8 cell proliferation and cytotoxicity test kits. The 3D morphology was observed by the Laser holographic cell analysis and imaging system. The change in the number of cells was also dynamically monitored. The cell cycle was detected by flow cytometry. The level of DNA damage was detected by comet assay. The level of intracellular reactive oxygen species （ROS） was measured by the ROS kits. Results：The survival rate and proliferation ability in three groups treated with 60, 120 and 200 μg/mL PM2.5 were significantly lower than those in the control group （P＜0.05 or P＜0.01）. PM2.5 treatment made the growth cycle arrest in G2/M phase （P＜0.05 or P＜0.01）. The percentage of tail DNA in the PM2.5 exposure groups was higher than that in the control group （P＜0.01）, with a dose-dependent manner. The level of ROS in the PM2.5 exposed groups was higher than that in the control group （P＜0.05 or P＜0.01）. Conclusions: PM2.5 has a certain cytotoxicity on HTR8-SVneo cells via the DNA damage and the cell cycle arrest which is related to the increased oxygen free radicals.

Key words: Air pollutants, Trophoblast cell, Cytotoxicity