Reactive Oxygen Species Are Involved In Paraquat-Induced Cytotoxicity Of HL-60 Cells And Protection Of Antioxidants

To investigate the role of reactive oxygen species (ROS) in paraquat (PQ) cytotoxity on acute promyelocytic leukemia HL-60 cells, the model of paraquat injury on HL-60 cells has been established in the experiment. PQ was used to treat HL-60 cells, and some indexes were measured to research the cytotoxity of paraquat on HL-60 cells, including cells proliferation and the malondialedhyde (MDA) content and total antioxidation capability (T-AOC). The content of superoxide anion radical and hydrogen peroxide was also measured. The study was also designed to investigate the protective effect of glutathione (GSH), N-Acetyl-L-cysteine (NAC), superoxide dismutase (SOD) and catalase (CAT) to the PQ cytotoxity in HL-60 cells. All the research contents and result were listed as follows:1. The analysis of PQ cyctotoxity on HL-60 cells and the effect of ROS. HL-60 cells were treated by indicated concentrations of PQ. The result showed that PQ evidently restrained the proliferation of HL-60 cells in a dose and time-dependent manner. Low concentration of PQ inhibits the growth of HL-60 cells in varying degree, while high concentration of PQ induces the death of cells. The content of MDA had a dose-dependent increase in all experiment groups. And the content of T-AOC decreased dramatically in all groups. So it indicated that PQ can cause the oxidative injury of HL-60 cells. The measurement of two ROS showed that the content of O₂^·- and H₂O₂ elevated observably compared with contract group. The increase extent of H₂O₂ was even greater and had a liner relationship with the concentrations of PQ.2. The protective effect of several antioxidants and antioxidant enzymes to the PQ. The result showed that they all can protect HL-60 cells from PQ cytotoxity and all can raise the cells proliferation. The protective effect of GSH and NAC could last a longer time than that of SOD and CAT. And they could reduce the content of MDA in cells and enhance the T-AOC of cells. Compared their protection effect, GSH was more effective, and CAT was less effective than others.