Department of Biology, Faculty of Sciences, Atatürk University, 25240, Erzurum, Turkey.
Cytotechnology. 2012 Jan;64(1):15-25. doi: 10.1007/s10616-011-9386-1. Epub 2011 Sep 22.
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a persistent and ubiquitous environmental contaminant. The health impact of TCDD exposure is of great concern to the general public. Recent reports have implied that eicosapentaenoic acid (EPA) might be a potential chemopreventive agent and influence hepatotoxicity. The aim of the current study was to explore the effectiveness of EPA in alleviating the toxicity of TCDD on primary cultured rat hepatocytes. EPA (5, 10 and 20 μM) was added to cultures alone or simultaneously with TCDD (5 and 10 μM). Rat hepatocytes were treated with TCDD and EPA for 48 h, and then cytotoxicity was detected by [3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide] (MTT) assay and lactate dehydrogenase (LDH) release, while total antioxidant capacity (TAC) and total oxidative stress (TOS) levels were determined to evaluate the oxidative injury. The DNA damage was also analyzed by liver micronucleus assay (LMN) and 8-oxo-2-deoxyguanosine (8-OH-dG). The results of MTT and LDH assays showed that TCDD but not EPA decreased cell viability. TCDD also increased TOS level and significantly decreased TAC level in rat hepatocytes in a clear dose dependent manner. On the basis of increasing doses, the dioxin caused significant increases of micronucleated hepatocytes (MNHEPs) and 8-OH-dG as compared to control culture. Whereas, in cultures treated with EPA alone, TOS level did not change and the level of TAC significantly increased. The presence of EPA with TCDD minimized the toxic effects of the dioxin on primary hepatocytes cultures. Noteworthy, EPA has a protective effect against TCDD-mediated DNA damages.
2,3,7,8-四氯二苯并对二恶英（TCDD）是一种持久性的、无处不在的环境污染物。TCDD 暴露对公众健康的影响引起了极大关注。最近的报告表明，二十碳五烯酸（EPA）可能是一种潜在的化学预防剂，并影响肝毒性。本研究旨在探讨 EPA 对原代培养大鼠肝细胞中 TCDD 毒性的缓解作用。EPA（5、10 和 20 μM）单独添加或与 TCDD（5 和 10 μM）同时添加到培养物中。用 TCDD 和 EPA 处理大鼠肝细胞 48 小时，然后通过 [3-(4,5-二甲基噻唑-2-基)2,5-二苯基四氮唑溴盐]（MTT）测定和乳酸脱氢酶（LDH）释放检测细胞毒性，同时测定总抗氧化能力（TAC）和总氧化应激（TOS）水平以评估氧化损伤。肝微核试验（LMN）和 8-氧-2-脱氧鸟苷（8-OH-dG）分析也分析了 DNA 损伤。MTT 和 LDH 测定结果表明，TCDD 而不是 EPA 降低了细胞活力。TCDD 还明显增加了 TOS 水平，并明显降低了大鼠肝细胞中 TAC 水平，且呈明显的剂量依赖性。基于增加的剂量，与对照培养物相比，二恶英导致微核肝细胞（MNHEPs）和 8-OH-dG 显著增加。然而，在单独用 EPA 处理的培养物中，TOS 水平没有变化，TAC 水平显著增加。EPA 与 TCDD 同时存在可最大限度地减少二恶英对原代肝细胞培养物的毒性作用。值得注意的是，EPA 对 TCDD 介导的 DNA 损伤具有保护作用。
