Toxicity of silver, copper oxide, and polyethylene nanoparticles on the earthworm Allolobophora caliginosa using multiple biomarkers

Earthworms are used as biomarkers for soil contamination. In the present study, earthworms (Allolobophora caliginosa) were exposed to 100 mg of silver (Ag), copper oxide (CuO), and polyethylene (PE) nanoparticles (NPs) per kilogram of soil for 30 days. We evaluated antioxidant activity using assays for catalase, total antioxidant capacity and malondialdehyde, immune activity (lysozyme and metallothionein), lipid peroxidation, DNA fragmentation, and examining histopathology during exposure and recovery periods. CAT and total antioxidant capacity levels significantly decreased in response to Ag and CuO NPs; however, a response to PE NPs was observed only in catalase levels. MDA level, lysozyme activity, metallothionein, lipid peroxidation (LPO) and DNA fragmentation increased significantly in response to NP exposure. After recovery, only MDA content and metallothionein concentration returned to normal levels and only for worms exposed to PE NPs. NPs caused deleterious effects or damage to the wall of the intestine. [Display omitted]