Liu Changhui, Chang Victor W C, Gin Karina Y H
Department of Civil and Environmental Engineering, National University of Singapore, Singapore.
Environ Toxicol Chem. 2014 Oct;33(10):2323-32. doi: 10.1002/etc.2679. Epub 2014 Aug 28.
Concerns regarding perfluorinated chemicals (PFCs) have risen in recent years because of their ubiquitous presence and high persistency. However, data on the environmental impacts of PFCs on marine organisms are very limited. Oxidative toxicity has been suggested to be one of the major toxic pathways for PFCs to induce adverse effects on organisms. To investigate PFC-induced oxidative stress and oxidative toxicity, a series of antioxidant enzyme activities and oxidative damage biomarkers were examined to assess the adverse effects of the following 4 commonly detected compounds: perfluoro-octanesulfonate, perfluoro-ocanoic acid, perfluorononanoic acid, and perfluorodecanoic acid, on green mussel (Perna viridis). Quantitative structure-activity relationship (QSAR) models were also established. The results showed that all the tested PFCs are able to induce antioxidant response and oxidative damage on green mussels in a dose-dependent manner. At low exposure levels (0 µg/L-100 µg/L), activation of antioxidant enzymes (catalase [CAT] and superoxide dismutase [SOD]) was observed, which is an adaptive response to the excessive reactive oxygen species induced by PFCs, while at high exposure levels (100 µg/L-10 000 µg/L), PFCs were found to inhibit some enzyme activity (glutathione S-transferase and SOD) where the organism's ability to respond in an adaptive manner was compromised. The oxidative stress under high PFC exposure concentration also led to lipid and DNA damage. PFC-induced oxidative toxicity was found to be correlated with the bioaccumulation potential of PFCs. Based on this relationship, QSAR models were established using the bioaccumulation factor (BAF) as the molecular descriptor for the first time. Compared with previous octanol-water partition coefficient-dependent QSAR models, the BAF-dependent QSAR model is more suitable for the impact assessment of PFCs and thus provides a more accurate description of the toxic behavior of these compounds.
近年来，由于全氟化合物（PFCs）广泛存在且具有高持久性，人们对其的关注度不断提高。然而，关于PFCs对海洋生物环境影响的数据非常有限。氧化毒性被认为是PFCs对生物体产生不利影响的主要毒性途径之一。为了研究PFCs诱导的氧化应激和氧化毒性，检测了一系列抗氧化酶活性和氧化损伤生物标志物，以评估以下4种常见检测化合物：全氟辛烷磺酸、全氟辛酸、全氟壬酸和全氟癸酸，对翡翠贻贝（Perna viridis）的不利影响。还建立了定量构效关系（QSAR）模型。结果表明，所有测试的PFCs都能够以剂量依赖的方式诱导翡翠贻贝的抗氧化反应和氧化损伤。在低暴露水平（0 µg/L - 100 µg/L）下，观察到抗氧化酶（过氧化氢酶[CAT]和超氧化物歧化酶[SOD]）的激活，这是对PFCs诱导的过量活性氧的适应性反应，而在高暴露水平（100 µg/L - 10 000 µg/L）下，发现PFCs抑制了一些酶活性（谷胱甘肽S - 转移酶和SOD），此时生物体以适应性方式做出反应的能力受到损害。高PFC暴露浓度下的氧化应激也导致了脂质和DNA损伤。发现PFCs诱导的氧化毒性与PFCs的生物累积潜力相关。基于这种关系，首次使用生物累积因子（BAF）作为分子描述符建立了QSAR模型。与先前基于正辛醇 - 水分配系数的QSAR模型相比，基于BAF的QSAR模型更适合于PFCs的影响评估，从而更准确地描述了这些化合物的毒性行为。
