Oxidative stress damage of human peripheral blood lymphocytes in vitro caused by lead acetate

Objective To observe oxidative stress and DNA oxidative damage of human peripheral blood lymphocytes in vitro induced by lead acetate.

Methods Human peripheral blood lymphocytes were exposed to lead acetate in vitro at concentrations of 0, 20, 40, 80 μmol/L for 6, 12, 24 h, respectively. Then the intracellular reactive oxygen species (ROS) levels were detected by DCFH-DA staining and flow cytometry. Meanwhile, the activity of total superoxide dismutase (T-SOD) was detected by WST-1 method, and the 8-OHdG level was detected by ELISA Kit. The correlation analysis was carried out among ROS, T-SOD and 8-OHdG.

Results After exposed to lead acetate in vitro for 6 h, ROS levels of human peripheral blood lymphocytes in each dose group were significantly higher than those in control group (P < 0.01). There was no significant difference of T-SOD and 8-OHdG levels in 20 μmol/L group compared with those in control group(P>0.05), however, T-SOD and 8-OHdG levels of peripheral blood lymphocytes in the 40 and 80 μmol/L groups were significantly higher than those in control group(P < 0.01). After exposed to lead acetate for 12 and 24 h, the levels of ROS, T-SOD and 8-OHdG of peripheral blood lymphocytes in each dose group were significantly higher than those in the control group(P < 0.01). There were significant negative correlations between ROS levels and T-SOD levels(r_{6 h}=-0.865, r_{12 h}=-0.890, r_{24 h}=-0.801, P < 0.01), and there were significant positive correlations between ROS levels and 8-OHdG levels(r_{6 h}=0.840, r_{12 h}=0.829, r_{24 h}=0.866, P < 0.01).

Conclusion The study findings indicate that lead acetate could induce ROS production and inhibit the activity of antioxidant enzyme SOD, and increase oxidative stress state and DNA oxidative damage of human peripheral blood lymphocytes in vitro.