Cytotoxicity of nano zinc oxide to human bronchial epithelial cells

The objective of this study was to determine the potential cytotoxicity of ZnO nanoparticles (nano-ZnO) to human bronchial epithelial cell line (16HBE) in vitro. The cell viability of 16HBE exposed to 0-50 íg/mL nano-ZnO for 24, 48, and 72 hours was evaluated using 3-(4,5-dimethylthiazol)-2,5 diphenltetrazoliumh bromide (MTT) assay. Morphologic changes, apoptosis and intracellular production of reactive oxygen species (ROS) of 16HBE induced by 0-50 íg/mL nano-ZnO for 24 hours exposure were assessed by optical microscope, Hoechst33342/PI dying assay, and using the oxidation-sensitive fluoroprobe in situ loading, respectively. Morphologic changes were observed in 16HBE exposed to above 25 íg/mL nano-ZnO for 24 hours. In addition, the cell viability of 16HBE was significantly decreased in a time-and dose-depended manner after 48 hours and 72 hours exposure to nano-ZnO at concentration between 5 íg/mL and 50 íg/mL. After 24 hours exposure to nano-ZnO at concentration of greater than or equal to 5 íg/mL, the intracellular ROS of 16HBE was significantly increased compared to control, and it has a highly positive correlation with the concentration of nano-ZnO. The rate of apoptosis induced by nano-ZnO (g 25 íg/mL) in 16HBE cells was significantly enhanced compared to control. In summary, Nano-ZnO suspensions showed time and dose dependent cytotoxicity reflected in the inhibition of cell viability, oxidative stress and apoptosis of 16HBE cells.

Authors: Fu, Juan; Lu, Gui-Ning; Deng, Yan; Dang, Zhi ;Full Source: Huanjing Yu Jiankang Zazhi 2011, 28(6), 502-504, C3 (Ch) ;