Objective Studies have been proved that Zinc oxide(ZnO)nanoparticles can lead to cytotoxicity in different types of cell lines,and oxidative stress is often hypothesized to be an important factor in cytotoxicity induced by ZnO nanoparticles.As a particulate foreign body,nanoparticles could induce host responses such as reactive oxygen species(ROS)generation,inflammatory cytokine and Manganese Superoxide Dismutase(MnSOD)release which play a major role involved in tissue destruction and resistance mechanism.