[Protective effects of exogenous reduced glutathione on sodium arsenite-induced genotoxicity and oxidative stress]

To explore the protective effects of exogenous reduced glutathione (GSH) on the genotoxicity and oxidative stress induced by sodium arsenite (NaAsO2).

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.

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.

High concentrations of exogenous GSH can significantly decrease the cytotoxicity of NaAsO2, and alleviate DNA and chromosomal damage and the level of oxidative stress.