Objective: To explore the protective effects of exogenous reduced glutathione (GSH) on the genotoxicity and oxidative stress induced by sodium arsenite (NaAsO2).
Methods: Human lung adenocarcinoma A549 cells were divided into several groups according to the treatments as follow: untreated group, single NaAsO2 or GSH treated group and the groups co-treated with NaAsO2 and different concentrations of GSH. Then the differences of cell viability, level of oxidative stress, DNA and chromosomal damage were compared after single or combined treatments.
Results: The rate of cell survival and colony formation, the contents of GSH and the activity of SOD in NaAsO2 treated group were significantly lower than the non-treated group, whereas, the level of ROS, comet rate, OTM and the frequency of micronucleus in NaAsO2 treated group were significantly higher than that of control group (P < 0.05). At the 0.5-5 mmol/L concentrations of GSH, these indicators of the co-treatment groups did not show any significant difference when compared with single NaAsO2-treated group. However, at the 10 mmol/L and 20 mmol/L concentrations of GSH, the NaAsO2-induced toxic effects were found to be weakened by GSH, but it was still significantly lower than that in the control group (P < 0.05). Moreover, there was no significant difference among co-treated groups and control group on the cell viability, colony formation, level of oxidative stress and DNA and chromosomal damage at the 40 or 50 mmol/L of GSH.
Conclusion: High concentrations of exogenous GSH can significantly decrease the cytotoxicity of NaAsO2, and alleviate DNA and chromosomal damage and the level of oxidative stress.