敌敌畏、乐果和马拉硫磷诱导HepG2细胞微核实验研究

Induction of Micronuclei in HepG2 Cell line by Dichlorvos,Dimethoate and Malathion

目的评价敌敌畏(dichlorvos,DDVP),乐果(dimethoate,DM)和马拉硫磷(malathion,Mal)单独和联合致HepG2细胞微核作用,并用析因设计阐明联合作用模式。方法分别以三种有机磷农药单独染毒HepG2细胞4h,微核试验剂量分别为:敌敌畏3.125～25μg/ml,乐果25～200μg/ml,马拉硫磷50～400μg/ml。观察微核率并计算复制指数(replicative index,RI)。采用2×2析因设计分别研究了3.125μg/ml敌敌畏、25μg/ml乐果与50μg/ml马拉硫磷在低剂量水平下两两组合以及12.5μg/ml敌敌畏、100μg/ml乐果与200μg/ml马拉硫磷在高剂量水平下两两组合联合致HepG2细胞的微核形成。结果微核试验结果显示,细胞微核率随敌敌畏、乐果和马拉硫磷染毒剂量的增高而增加,存在剂量-反应关系(敌敌畏:r=0.955,P<0.01;乐果:r=0.976,P<0.01;马拉硫磷:r=0.950,P<0.01)。RI随敌敌畏染毒剂量的增加而降低,存在剂量-反应关系(r=-0.913,P<0.01)。RI随乐果及马拉硫磷染毒剂量的增加而降低,但无明显剂量-反应关系(P>0.05)。析因分析结果显示,在低剂量水平下,两两农药组合交互作用的方式均为协同;在高剂量水平下,两两农药组合交互作用的方式均为拮抗。结论敌敌畏、乐果和马拉硫磷均可诱导HepG2细胞微核形成,两两组合存在交互作用,作用模式与剂量有关。

Objective Micronucleus test （MNT） was used to evaluate the single and combined genotoxicity of diehlorvos （DDVP）, dimethoate （DM） and malathion （Mal） in HepG2 cell line, and 2×2 factorial design was adopted to elucidate the combined genotoxic effects. Methods In cytotoxicity test, HepG2 cells were exposed to the three OPPs （DDCP, DM, Mal） for 4 h respectively, and the doses at which cell viability above 80% were selected for the MNT, DDVP： 3.125-25 μg/ml, DM： 25-200 μg/ml, Mal： 50-400μg/ml, the micronucleated cell （MNC） rates and the replicative index（RI） were calculated. The combined genotoxicity of them was investigated with their doses as follows： low dose （DDVP： 3.125μg/ml, DM： 25μg/ml, Mal： 50μg/ml）; high dose （DDVP： 12.5μg/ml, DM： 100μg/ml, Mal： 200μg/ml）. Results In MNT, after treatment of HepG2 cells with DDVP, DM or Mal alone for 4 h, the MNC rates were increased in a dose-response manner （DDVP ： r=0.955, P〈0.01 ; DM ： r=0.976, P〈0.01 ; Mal ： r=0.950, P〈0.01）,and the MNC rates were statistically higher than solvent control at the two or three higher doses of DDVP, DM and Mal. RI of HepG2 cells decreased in a dose-dependent manner with increasing DDVP dosage. RI also decreased with increasing DM or Mal dosage,but not revealed dose-response relationships.The 2×2 factorial analysis revealed that at low mixed concentration, DDVP and DM, DDVP and Mal, as well as DM and Mal exhibited interactions （P〈0.05） characterized as synergistic effect; but at high mixed concentration,their interactions （P〈0.05） were characterized as antagonistic effect. Conclusion DDVP,DM and Mal can induce micronucles both in sole way and combined way, but the combined effects is concerned with the combined dosages.