Cell apoptosis induced by atmospheric pressure plasma

Reports show that atmospheric pressure cold plasma could induce cancer cell apoptosis in several minutes. However, up to now, only little has been known about the mechanism of plasma inducing cancer cell apoptosis. In this paper, an atmospheric pressure plasma plume is used to treat human hepatocellular carcinoma (HepG2) cell. Experimental results show that plasma can modulate the intracellular reactive oxygen species (ROS), and nitric oxide (NO) concentration. The relationship between the cell apoptosis and the concentrations of ROS, and NO is analysis. The results indicate that, firstly, the plasma generates NO, which increase the NO concentration of the cells outer environment. Secondly, the intracellular NO concentration is increased due to the NO diffusion from the medium. Thirdly, the intracellular ROS concentration is increased due to the increase of the intracellular NO concentration. Finally, the increase of the intracellular NO, and ROS concentrations result in the HepG2 cell apoptosis.