Ecotoxicity of silver nanoparticles on earthworm Eisenia fetida: responses of the antioxidant system, acid phosphatase and ATPase

Abstract

Ecotoxicity of nanoparticles has received growing attention in recent years. This study investigated the influence of silver nanoparticles (Ag-NP) on earthworm Eisenia fetida. The experiment was performed with five test groups: control (without Ag-NP), 10 nm Ag-NP groups (20, 100 or 500 mg kg⁻¹) and positive control (787 mg kg⁻¹ AgNO₃). After 14-day acute exposure, activities of various enzymes, including glutathione S-transferase (GST), glutathione reductase (GR), acid phosphatase (AP), and Na⁺, K⁺-ATPase were determined. Effects of Ag-NP with different sizes (10 and 80 nm) were also tested. Data showed that the activity of GR was significantly lower at 500 mg kg⁻¹. The activities of AP and Na⁺, K⁺-ATPase were inhibited following the increase of Ag-NP concentration. When treated with Ag-NP with different sizes, activities of AP and Na⁺, K⁺-ATPase of the 10 nm group were significantly lower than the control group, but those of the 80 nm group were similar to the control group. Data indicate that Ag-NP may be harmful to the earthworm E. fetida at 500 mg kg⁻¹, and the toxicity of Ag-NP with 10 nm size is greater than 80 nm. In addition, AP and Na⁺, K⁺-ATPase are sensitive biomakers to the effects of Ag-NP.

Keywords:

• ecotoxicity
• silver nanoparticles
• antioxidant system
• physiological activity
• Eisenia fetida

Acknowledgments

This work was supported by National Natural Science Foundation of China (No. 21077052) and Shandong Outstanding Young Scientist Award Fund (BS2010SF005), China.