[Cytotoxicity induced by gasoline engine exhausts associated with oxidative stress].
OBJECTIVE
To evaluate the relationship between cytotoxic effects of the extracts of condensate, particulates and semivolatile organic compounds from gasoline engine exhausts (EGE) and oxidative stress.


METHODS
After A549 cells were treated with various concentrations of EGE for 2h, and cell viabilities were detected induced by EGE were examined by MTT assay. Meanwhile, the reactive oxygen species (ROS) in A549 cells induced by EGE were examined, 2',7'-dichlorodihy-drofluorescin diacetate (DCFH-DA) was used to catch ROS and its level measured by value of pixel fluorescence intensity. Furthermore, A549 cells pretreated with different concentrations of glutathione (GSH) were exposed to various concentrations of EGE for 2h, and then cell viabilities were examined.


RESULTS
Viabilities of A549 cells significantly decreased in comparison to the solvent group when the concentrations of EGE were more than 3.9 ml/ml (P < 0.05). There were a dose-response relationships between the viabilities and the concentration of EGE (r = -0.81, P < 0.01). At the concentrations of 31.3 ml/ml and 62.5 ml/ml, the values of pixel fluorescence intensity were (125.0 +/- 19.2) and (168.9 +/- 16.9), which were significantly higher than those of control (8.5 +/- 1.4). In addition, the viabilities of cells pretreated with GSH gradually increased with the increases of the concentrations of GSH. There were also a significant difference between the pretreated and non-pretreated group at the concentrations of 0.5 mmol/L and 1.0 mmol/L.


CONCLUSIONS
Oxidative stress could be one of the mechanisms of cytotoxic effects of EGE.
Che
Wangjun
W
West China School of Public Health, Sichuan University, Chengdu 610041, China.
Zhang
Zunzhen
Z
Wu
Mei
M
Wang
Ling
L
D000393:Air Pollutants / Q000633:toxicity*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects*; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D001335:Vehicle Emissions / Q000633:toxicity*
D000393:Air Pollutants; D017382:Reactive Oxygen Species; D001335:Vehicle Emissions