[Combined cytotoxicity mechanism of chlorpyrifos and carbofuran pesticides in vitro].

ABSTRACT

OBJECTIVE: To evaluate the single and combined effects of chlorpyrifos( CPF) and carbofuran( CF) pesticides on cell lines cultured in vitro, and clarify the pattern of joint action. METHODS: Rat pheochromocytoma( PC12 cells) were treated with different concentrations of CPF( 0, 50, 100, 200 and 400 µmol/L) and CF( 0, 25, 50, 100 and 200 µmol/L) for 12 h separately, the combined effects of two kinds of pesticides should be studied respectively in the low dose( CPF 50 µmol/L, CF 25 µmol/L) and high dose( CPF 200 µmol/L, CF 100 µmol/L) levels. After exposure, detectingacetylcholinesterase( ACh E) activity and using fluorescent probe 2', 7'-dichlorfluorescin diacetate( DCFH-DA), thiobarbituric acid( TBA) method, xanthine oxidation, 5, 5 '-dithio-bis-2-nitrobenzoic acid( DTNB) coloration to detect the intracellular reactive oxygen species( ROS) production, lipid peroxidation production malondialdehyde( MDA), activity of antioxidant enzymes superoxide dismutase( SOD) and glutathione peroxidase( GPx), respectively. RESULTS: Compared with the control group, CPF and CF could decrease the ACh E activity, induce ROS overproduction in a dose-effect way and increase the activity of SOD, GPx( P < 0. 01), but MDA content showed no significant change. Factorial ANOVA revealed that the combined effect of CPF and CF, there was no interaction at lower dose level, but interaction existed at higher dose level( P < 0. 01). The main mode of action was synergistic effect. CONCLUSION: Chlorpyrifos, carbofuran single or combined, has cytotoxicity effect. The main combined effect between chlorpyrifos and carbofuran is synergistic effect, oxidative stress damage may be one of the mechanisms.