Abstract：
Chlorpyrifos (CPF), a widely used broad-spectrum organophosphate pesticide, has been associated with various adverse health effects in animals and humans. While its primary mechanism of action involves the irreversible inhibition of acetylcholinesterase, secondary mechanisms have also been suggested. The aim of the present study was to explore the secondary mechanisms of action involved in CPF-induced acute cytotoxicity using human hepatocarcinoma HepG2 cells. In particular, we investigated oxidative stress and mitochondrial function by assessing reactive oxygen species (ROS) generation, lipid peroxidation (LPO) and mitochondrial membrane potential (ΔΨm) alteration. Results showed that 24-h exposure to CPF (78.125-2500 μM) decreased cell viability in a concentration-dependent manner (IC50 = 280.87 ± 26.63 μM). Sub-toxic CPF concentrations (17.5, 35 and 70 μM) induced increases in ROS generation (by 83%), mitochondrial superoxide (by 7.1%), LPO (by 11%), and decreased ΔΨm (by 20%). CPF also upregulated Nrf2 protein expression, indicating the role of the latter in modulating the cellular response to oxidative insults. Overall, our findings suggest that CPF caused hepatotoxicity through oxidative stress and mitochondrial dysfunction. Given the re-emerging use of CPF, this study emphasizes the need for comprehensive analysis to elucidate its toxicity on non-target organs and associated mechanisms.
摘要：
毒死蜱（CPF），一种广泛使用的广谱有机磷农药，与动物和人类的各种不良健康影响有关。虽然其主要作用机制涉及乙酰胆碱酯酶的不可逆抑制，次要机制也被提出。本研究的目的是探索使用人肝癌HepG2细胞进行CPF诱导的急性细胞毒性的次要作用机制。特别是,我们通过评估活性氧（ROS）的产生来研究氧化应激和线粒体功能，脂质过氧化(LPO)和线粒体膜电位(ΔWm)改变。结果显示24小时暴露于CPF(78.125-2500μM)以浓度依赖性方式降低细胞活力(IC50=280.87±26.63μM)。亚毒性CPF浓度（17.5、35和70μM）诱导ROS生成增加（83％），线粒体超氧化物（7.1%），LPO（11%），并降低了Δwm(20%)。CPF也上调Nrf2蛋白表达，表明后者在调节细胞对氧化损伤的反应中的作用。总的来说,我们的研究结果表明,CPF通过氧化应激和线粒体功能障碍引起肝毒性.鉴于公积金的重新使用，本研究强调需要进行综合分析,以阐明其对非靶器官的毒性及相关机制.
