Potential threat of Chlorpyrifos to human liver cells via the caspase-dependent mitochondrial pathways

Chlorpyrifos (CPF) has been widely used around the world as a pesticide for both agricultural and residential application. Although various studies have reported toxicity and health-related effects from CPF exposure, the potential threat and the molecular mechanism of CPF toxicity to human liver have not been well-characterized. In this study, we identify cytotoxicity of CPF to human normal liver cells in vitro. We demonstrate that the viability of QSG7701 cells is inhibited by CPF in a time- and concentration-dependent manner. Intracellular biochemical assays showed that CPF-induced apoptosis of QSG7701 cells concurrent with a decrease in the mitochondrial membrane potential, the release of cytochrome c into the cytosol, up-regulate the expression level of Bax/Bcl-2 and a marked activation of caspase-9/-3. These results indicate that CPF has a potential risk to human liver that can induce apoptosis of human liver cells through caspase-dependent mitochondrial pathways.