Using earthworms as bioindicators of heavy metal contamination in soils is a relevant tool for environmental risk monitoring. This study examines the combined effects of four distinct concentrations mixtures (M1, M2, M3 and M4) containing Cd, Cr, Cu, Ni, Fe and Mn on Aporrectodea giardi earthworms after 12 and 24 days (12 D/24 D) of exposure via the monitoring of certain biomarkers of stress including total protein content, glutathione (GSH), metallothionein (MT), catalase and lipoxygenase (LOX) activities. The results show a decrease in the total protein level for the M3 mixture after 24 D, whereas it increases for all other treatments regardless of exposure time. Glutathione and metallothionine levels increased for M2 and M3 and decreased for M1 and M4 after 12 D; they increased after 24 D for all the mixtures. Regarding enzyme activities, catalase activity was decreased for all the treatments unless for M3 (P > 0.05). However, LOX increased for M1, M2 and M4 except for M3 after 12 D, when inhibition of this biomarker was observed. LOX activity was inhibited for all the mixtures at the end of the treatment. All the mixtures generated oxidative stress in Aporrectodea giardi, which is minimized by increasing MT levels to remove the metal ions and triggering the antioxidant system, composed primarily of GSH and LOX to restore cellular homeostasis. These findings suggest that the species Aporrectodea giardi could be an excellent candidate for ecotoxicological risk assessment of soils contaminated by metal mixtures and it can be used in bioremediation for its fitness which allows it to tolerate high concentrations of metal mixtures.

利用蚯蚓作为土壤重金属污染的生物指示剂是环境风险监测的相关工具。本研究考察了含有 Cd、Cr、Cu、Ni、Fe 和 Mn的四种不同浓度混合物（M 1、M 2、M 3 和M 4）在 12 天和 24 天（12 天/24 天）后对Aporectodea giardi蚯蚓的综合影响。 D) 通过监测某些应激生物标志物来确定暴露情况，包括总蛋白含量、谷胱甘肽 (GSH)、金属硫蛋白 (MT)、过氧化氢酶和脂氧合酶 (LOX) 活性。结果显示，24 天后，M 3 混合物的总蛋白水平下降，而无论暴露时间如何，所有其他处理的总蛋白水平都会增加。12 天后，M 2 和M 3的谷胱甘肽和金属硫氨酸水平增加， M 1 和M 4的谷胱甘肽和金属硫氨酸水平下降；所有混合物在 24 天后均有所增加。关于酶活性，除M 3外，所有处理的过氧化氢酶活性均降低（ P  > 0.05）。然而，12 天后，当观察到该生物标志物受到抑制时，除M 3 外， M 1、M 2 和M 4 的 LOX 增加。在处理结束时，所有混合物的 LOX 活性均受到抑制。所有混合物都会在Aporectodea giard i 中产生氧化应激，通过增加 MT 水平以去除金属离子并触发抗氧化系统（主要由 GSH 和 LOX 组成）以恢复细胞稳态，将氧化应激降至最低。这些发现表明， Aporectodea giardi物种可能是对受金属混合物污染的土壤进行生态毒理学风险评估的绝佳候选者，并且由于其适应性使其能够耐受高浓度的金属混合物，因此可用于生物修复。