Combined toxic effect of pesticides mixtures in HepG2 cells

After dietary exposure, residues of multiple pesticides will enter human body and cause the potential health risk, which is always worse than that caused by single pesticide.The proliferation inhibition toxicity of abamectin, acetamiprid, carbendazim, chlorothalonil, chlorpyrifos, cyhalothrin, prochloraz and triazophos on HepG2 hepatocytes was determined by the classical MTT colorimetry. The result showed that the effects of different pesticide combinations on the survival rate of HepG2 cells were different after 24 h exposure. The combined toxicity of pesticide mixtures (comprised of two components, three components, four components, five components and six components) demonstrated two types of concentration-response curves towards proliferation inhibition HepG2 cells with the increase of pesticide concentrations. One type was a S type trend, with the increase of the concentration of pesticides, the cell survival rate first rapidly decreased, then slowly decreased. The followings are examples of this type: binary combination (carbendazim + cyhalothrin) at concentration of 0-10.00 mg/L, ternary combination (carbendazim + abamectin + cyhalothrin) at concentration of 0-24.12 mg/L, quaternary combination (triazophos + cyhalothrin + carbendazim + abamectin) at concentration of 0-47.46 mg/L and five-component (chlorpyrifos + abamectin + acetamiprid + cyhalothrin + triazophos) at concentration of 0-62.80 mg/L. The other type was a linear trend, cell survival linearly decreased with the increase of the concentration of pesticides. The followings are examples of this type: binary combination (carbendazim + chlorothalonil) at concentration of 0-8.46 mg/L, ternary combination (chlorpyrifos + acetamiprid + carbendazim) at concentration of 0-39.97 mg/L, quaternary combined (carbendazim + cyhalothrin + chlorothalonil + abamectin) at concentration of 0-25.92 mg/L, and six-component (acetamiprid + chlorpyrifos + triazophos + carbendazim + cyhalothrin + abamectin) at concentration of 0-57.48 mg/L. In this study, different combinations of pesticides showed different types of inhibition to the proliferation of human liver cancer cells, which provided a basis for the mechanism research and cumulative risk assessment of pesticide residues in the future.