Key Laboratory of Luminescence and Real-Time Analysis, Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People's Republic of China.
Key Laboratory of Luminescence and Real-Time Analysis, Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People's Republic of China.
Food Chem Toxicol. 2014 Feb;64:291-7. doi: 10.1016/j.fct.2013.11.036. Epub 2013 Dec 2.
Tetrachlorobenzoquinone (TCBQ) is an active metabolite of pentachlorophenol (PCP). Although the genotoxic effect of PCP has been comprehensively investigated, there is little known about TCBQ's genotoxic effects. In the current study, TCBQ was tested for its genotoxicity using HepG2 cells as experimental model. To select the exposure concentration of interest, cell viability was measured and three concentrations were used for further investigation. In single cell gel electrophoresis (SCGE) assay, concentration-dependent increase in tail length, tail DNA percentage and tail moment were detected following TCBQ exposure. Micronucleus (MN) assay indicated TCBQ gradually increased MN frequency and decreased nuclear division index (NDI). Enzyme-linked immunosorbent assay (ELISA) and western blotting analyses both showed TCBQ caused histone H2AX phosphorylation (γ-H2AX). Furthermore, the elevation of 8-hydroxydeoxyguanosine (8-OHdG) and reactive oxygen species (ROS) level indicated TCBQ-induced genotoxicity is associated with oxidative stress. On the other hand, N-acetyl-cysteine (NAC) administration significantly protected cells from the genotoxic effect of TCBQ. Overall, our data suggested TCBQ exerted genotoxic effect possibly via an oxidative damage mechanism in HepG2 cells and this toxicity is prevented by pretreatment with NAC.
四氯苯醌（TCBQ）是五氯苯酚（PCP）的一种活性代谢物。虽然已对 PCP 的遗传毒性作用进行了全面研究，但对 TCBQ 的遗传毒性作用知之甚少。在本研究中，我们使用 HepG2 细胞作为实验模型，检测了 TCBQ 的遗传毒性。为了选择感兴趣的暴露浓度，我们测量了细胞活力，并使用三种浓度进行了进一步研究。在单细胞凝胶电泳（SCGE）试验中，随着 TCBQ 的暴露，尾长、尾 DNA 百分比和尾矩呈浓度依赖性增加。微核（MN）试验表明 TCBQ 逐渐增加 MN 频率并降低核分裂指数（NDI）。酶联免疫吸附试验（ELISA）和 Western blot 分析均显示 TCBQ 导致组蛋白 H2AX 磷酸化（γ-H2AX）。此外，8-羟基脱氧鸟苷（8-OHdG）和活性氧（ROS）水平的升高表明 TCBQ 诱导的遗传毒性与氧化应激有关。另一方面，N-乙酰半胱氨酸（NAC）预处理可显著保护细胞免受 TCBQ 的遗传毒性作用。总的来说，我们的数据表明，TCBQ 可能通过 HepG2 细胞中的氧化损伤机制发挥遗传毒性作用，而 NAC 的预处理可预防这种毒性。
