Paraquat induced apoptosis and oxidative damage in human embryonic lung fibroblast.

[Objective] To investigate the toxicity and potential mechanisms of paraqua(tPQ)-induced human embryonic lung fibroblas(tMRC-5)injury.[Methods] The changes of cell viability rates were monitored by the methyl thiazolyl tetrazolium(MTT)method after the MRC-5 cell lines were incubated with PQ(0.00,0.15,0.30,0.60,1.20,2.40,4.80,and 9.60 mmol/L)for 24 h,and the cell apoptosis was detected by flow cytometry.Meanwhile,both the total activity of superoxide dismutase(SOD)and volume of malondialdehyde(MDA)in cell and the activity of lactate dehydrogenase(LDH)in the supernatant were detected by spectrophotometry after the MRC-5 cell lines were incubated with PQ(0.00,0.15,0.30,0.60,and 1.20 mmol/L)for 3,12,and 24 h,respectively.[Results] Compared with the control group,the cell viability rates were inhibited significantly in the groups of PQ≥0.30 mmol/L.With the increased concentration of PQ,the cell viability rates decreased accordingly(P 0.05).Compared with the control group,the total SOD activity decreased significantly in PQ-treated group(except 0.15 mmol/L at 3,12 h),MDA and LDH(except the 3 h,1.20 mmol/L group)level increased with the positive difference at an interval of 3,12 h and 24 h(P 0.05 or P 0.01).Apoptosis rates of MRC-5 increased significantly after exposuring to PQ on concentration 0.60 mmol/L and 1.20 mmol/L.[Conclusion] PQ contributes a dose-dependent relationship on MRC-5 cell activity,furthermore,it can affect the MRC-5 cells on the antioxidant enzyme activity and apoptosis.