Cell Biology and Genetic Toxicology Laboratory, Centre of Advanced Study, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, 700019, India.
Chemosphere. 2018 Jul;203:307-317. doi: 10.1016/j.chemosphere.2018.03.189. Epub 2018 Mar 29.
The aim of this study was to assess the biomarkers of oxidative stress [reduced glutathione (GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione reductase (GR), aldehyde dehydrogenase (ALDH) and lipid peroxidation (LPO)] in earthworms of different ecological categories [epigeic Eisenia fetida (E. fetida) and anecic Eutyphoeus waltoni (E. waltoni)] exposed to cadmium (Cd)-polluted soil (30, 60 and 120 mg kg) for 28 days. Cd accumulation in earthworms increased significantly with increasing exposure dose and duration. However, E. fetida showed a relatively higher level of Cd accumulation until day 21; thereafter, depletion in the Cd level was recorded for the highest exposure dose. In E. waltoni, the detoxification enzymes and GSH level increased significantly with increasing exposure dose and Cd accumulation for 14 days (acute phase). In contrast, in E. fetida, acute exposure to Cd increased detoxification enzymes with decrease in GSH levels. For both species, sub-chronic exposures (28 days) increased lipid peroxidation with decrease in detoxification enzymes. GPx and ALDH responses of Cd-exposed earthworms showed a similar trend. Thus, these enzymes can be used as general biomarkers in these two species. The consistent variations in GST, GPx and ALDH activities suggest that E. waltoni may be used as a bioindicator species; this further signifies the use of endemic earthworms as a bioindicator to assess the risk of soil contamination. The present investigation indicates that Cd accumulation and biomarker responses in earthworms depend on dose and duration of exposure and on the concerned species.
本研究旨在评估不同生态类群 [表生的赤子爱胜蚓 (Eisenia fetida) 和内栖的威廉环毛蚓 (Eutyphoeus waltoni)] 蚯蚓的氧化应激生物标志物 [还原型谷胱甘肽 (GSH)、谷胱甘肽-S-转移酶 (GST)、超氧化物歧化酶 (SOD)、谷胱甘肽过氧化物酶 (GPx)、过氧化氢酶 (CAT)、谷胱甘肽还原酶 (GR)、醛脱氢酶 (ALDH) 和脂质过氧化 (LPO)] 在暴露于镉 (Cd) 污染土壤 (30、60 和 120mg/kg) 28 天后的变化。随着暴露剂量和时间的增加，蚯蚓体内的 Cd 积累显著增加。然而，E. fetida 在第 21 天之前表现出相对较高的 Cd 积累水平；此后，在最高暴露剂量下记录到 Cd 水平的耗竭。在 E. waltoni 中，随着暴露剂量和 Cd 积累的增加，解毒酶和 GSH 水平在 14 天 (急性阶段) 内显著增加。相比之下，在 E. fetida 中，急性 Cd 暴露会增加解毒酶，但会降低 GSH 水平。对于这两个物种，亚慢性暴露 (28 天) 会增加脂质过氧化，同时降低解毒酶。暴露于 Cd 的蚯蚓的 GPx 和 ALDH 反应呈现出相似的趋势。因此，这些酶可以作为这两个物种的一般生物标志物。GST、GPx 和 ALDH 活性的一致变化表明，E. waltoni 可能被用作生物指标种；这进一步表明使用地方特有蚯蚓作为生物标志物来评估土壤污染风险。本研究表明，蚯蚓体内的 Cd 积累和生物标志物反应取决于暴露剂量和时间以及相关物种。
