Metabolic and oxidative responses in Helix aspersa to iron oxide nanoparticle exposure: individual and combined (Fe₂O₃/SiO₂) effects

Abstract

This study evaluates the toxicity of iron oxide nanoparticles (Fe₂O₃ NPs) alone and in combination with silica nanoparticles (SiO₂ NPs) on Helix aspersa. Snails were exposed to escalating concentrations (0, 5000, 10,000, 15,000 μg/g of flour) of Fe₂O₃ NPs and a mixture of Fe₂O₃ and SiO₂ NPs for 28 days to assess impacts on metabolic parameters, oxidative stress, and neurotoxicity. Fe₂O₃ NPs significantly increased protein levels; the mixture exhibited a more pronounced effect, with significantly increased protein levels, particularly in the hepatopancreas and kidneys. Lipid levels generally decreased across all treatments, suggesting significant metabolic disruption. Carbohydrate responses were tissue-specific and differed significantly between single and combined exposures, highlighting complex responses to nanoparticle treatments. Malondialdehyde (MDA), a marker of lipid peroxidation, demonstrated a significant increase in all treatments compared to the control group. The mixture treatment caused divergent MDA responses, with higher levels observed in the hepatopancreas and lower levels in the kidneys than in single NP treatments. Glutathione (GSH) levels showed complex tissue-specific changes with mixture exposure, with reductions in the hepatopancreas and increases in the kidney. Furthermore, glutathione S-transferase (GST), catalase (CAT), and glutathione peroxidase (GPx) were altered, reflecting cellular stress responses. Notably, acetylcholinesterase (AChE) activity, a marker of neurotoxicity, was significantly reduced in all treated groups. These findings demonstrate that Fe₂O₃ NPs, individually and combined with SiO₂ NPs, induce significant metabolic dysregulation, oxidative stress, and neurotoxicity in H. aspersa. This study underscores the potential ecological risks of NPs contamination and the importance of further research into long-term effects and combined exposures. Further understanding of the possible impact of NPs exposure on agricultural practices and human health is needed.