Abstract
► We compared toxicities of 30nm metal oxide NPs at environmental relevant concentrations. ► Prolonged exposure (L1-larvae–adult) was performed for NPs toxicity assay in nematode. ► Adverse effects of Ti–NPs and Zn–NPs were detected at the concentration of 0.05μgL−1. ► In vivo toxicity order for the examined NPs was: Zn–NPs>TiO2–NPs>SiO2–NPs. ► Antioxidants treatment inhibited the adverse effects of Ti–NPs, Zn–NPs, and Si–NPs.
Nematode Caenorhabditis elegans has been developed in a variety of environmental studies to address adverse effects of a wide range of toxicants. In the present study, we compared the toxicities of three metal oxide nanoparticles (NPs) including TiO2–NPs, ZnO–NPs, and SiO2–NPs with the same nanosize (30nm) after prolonged exposure from L1–larvae to adult at environmental relevant concentrations. Our data indicated that the adverse effects were detected in nematodes exposed to TiO2–NPs and ZnO–NPs at concentrations more than 0.05μg/L and SiO2–NPs at concentrations more than 5μg/L with locomotion behavior and ROS production as endpoints. With growth, locomotion behavior, reproduction, and ROS production as endpoints, toxicity order for the examined metal oxide NPs was: ZnO–NPs>TiO2–NPs>SiO2–NPs. In nematodes exposed to the examined metal oxide NPs, ROS production was significantly correlated with lethality, growth, reproduction, and locomotion behavior. Moreover, treatment with antioxidants of ascorbate or NAC effectively inhibited the formation of oxidative stress and retrieved the adverse effects of TiO2–NPs, ZnO–NPs, and SiO2–NPs on survival, growth, reproduction and locomotion behaviors in nematodes. Our data demonstrated the subtle toxicity differences of different NPs exposure at environmental relevant concentrations in C. elegans.