[Combined effects of 1-nitropyrene and 1,2-naphthoquinone on cytotoxicity and DNA damage in A549 cells].

: Using human lung epithelial A549 cells, viability was measured by MTT assay after treated with 1-nitropyrene (1-NP); lactate dehydrogenase (LDH) leakage was determined to evaluate the cellular membrane injury; DNA damage was detected with comet assay; reactive oxygen species (ROS) generation was measured with fluorescent probe. The combined toxic effects of 1-NP and 1,2-naphthoquinone (1,2-NQ) on A549 were also evaluated. 1-NP caused a significantly concentration-dependent and time-dependent viability decrease. The LC50 for 24 h and 48 h were 5.2 μmol x L(-1) and 2.8 μmol x L(-1), respectively. DNA damage and intracellular ROS levels were also increased significantly through a dose-dependent manner after exposure to 1-NP. The LDH leakage were not significantly changed. Compared with the groups treated with 1-NP alone, the viability and LDH leakage was not changed significantly in combined-treated groups with 1-NP and 1,2-NQ. However, the DNA damage and ROS levels were significantly reduced in the combined-treated groups compared with the groups treated with 1-NP alone. These results suggest that 1-NP may mediated the genotoxic and cytotoxic effects through ROS generation, and pretreatment with 1,2-NQ, may inhibit the ROS generation induced by 1-NP, and thereby reducing the DNA damage in A549 cells.