Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
Environ Toxicol. 2012 Jul;27(7):385-92. doi: 10.1002/tox.20651. Epub 2010 Dec 8.
Triclosan (TCS) is a broad-spectrum bactericide that is used for a variety of antimicrobial functions. TCS is frequently detected in the terrestrial environment due to application of sewage sludge to agricultural land. In the present study, 48-h paper contact and 28-day spiked soil tests were conducted to examine the toxic effects of TCS on the antioxidative and genetic indices of earthworms (Eisenia fetida). The activity of antioxidative enzymes (superoxide dismutase, SOD; catalase, CAT) and the content of the lipid peroxidation product (malondialdehyde, MDA) were determined as biomarkers of oxidative stress in E. fetida. Moreover, single cell gel electrophoresis (SCGE) was used as a biomarker of genotoxicity. The results showed that triclosan induced a significant increase (P < 0.05) in antioxidative enzyme activities and MDA content. Of all of the biomarkers examined, CAT activity was most sensitive to TCS, and the CAT activity increased significantly (P < 0.05) at bactericidal concentrations of 7.86 ng cm⁻² in the contact test and 10 mg kg⁻¹ in the spiked soil test. The comet assay showed that TCS treatments significantly induced (P < 0.05) DNA damage in E. fetida, and that 78.6 ng cm⁻² caused significant genotoxic effects in the acute test (48 h). Clear dose-dependent DNA damage to E. fetida was observed both in contact and spiked soil tests. These results imply that TCS may have potential biochemical and genetic toxicity toward earthworms (E. fetida). A battery of biomarkers covering multiple molecular targets of acute toxicity can be combined to better understand the impacts of TCS on E. fetida.
三氯生（TCS）是一种广谱杀菌剂，用于多种抗菌功能。由于将污水污泥施用于农业用地，因此 TCS 经常在陆地环境中被检测到。在本研究中，进行了 48 小时的纸张接触和 28 天的添加土壤测试，以检查 TCS 对蚯蚓（赤子爱胜蚓）的抗氧化和遗传指标的毒性影响。抗氧化酶（超氧化物歧化酶，SOD；过氧化氢酶，CAT）的活性和脂质过氧化产物（丙二醛，MDA）的含量被确定为赤子爱胜蚓氧化应激的生物标志物。此外，单细胞凝胶电泳（SCGE）被用作遗传毒性的生物标志物。结果表明，三氯生诱导抗氧化酶活性和 MDA 含量显着增加（P <0.05）。在所检查的所有生物标志物中，CAT 活性对 TCS 最敏感，在接触测试中杀菌浓度为 7.86ng cm⁻²和添加土壤测试中 10mg kg⁻¹时，CAT 活性显着增加（P <0.05）。彗星试验表明，TCS 处理显着诱导（P <0.05）赤子爱胜蚓的 DNA 损伤，并且在急性试验（48 小时）中 78.6ng cm⁻²引起明显的遗传毒性作用。在接触和添加土壤测试中均观察到赤子爱胜蚓对 TCS 的清晰剂量依赖性 DNA 损伤。这些结果表明 TCS 可能对蚯蚓（赤子爱胜蚓）具有潜在的生化和遗传毒性。涵盖急性毒性多个分子靶标的一系列生物标志物可以结合使用，以更好地了解 TCS 对赤子爱胜蚓的影响。
