Alterations in Trace Element and Metabolite Profiles by Graphene Nanosheets and Multi-Walled Carbon Nanotubes as Soil Contaminants in Foot Tissues of the Chinese White Jade Snails (Achatina fulica).

The increasing applications of carbon nanomaterials (NMs) raise concerns about their potential as soil contaminants, yet predictive models for NM-related soil contamination risks remain scarce. This study established the Chinese white jade snails (Achatina fulica) as a novel model to assess the toxicity of two representative carbon-based NMs, namely, graphene nanosheets (GNSs) and multi-walled carbon nanotubes (MWCNTs). Snails of 1-2 weeks old were exposed to coconut substrate containing 1% NMs for 28 days. While the exposure showed no significant effects on food consumption, weight gain, or structural alterations in foot tissues (epidermis, muscle layer, or mucous glands), inductively coupled plasma mass spectrometry (ICP-MS) analysis of foot tissue demonstrated that MWCNTs, but not GNSs, significantly reduced Fe and Co levels. Metabolomic profiling revealed more pronounced metabolic perturbations in MWCNT-exposed snails compared to GNS-exposed counterparts. Both NMs upregulated phosphatidylinositol (38:4). MWCNTs additionally increased phosphatidylcholine (PC) (44:10), tyrosine, gamma-glutamylphenylalanine (38:4), and phenylalanine, while decreasing 15-deoxy-PGJ2 and PC (40:7). Pathway enrichment analysis identified eight significantly affected KEGG pathways exclusively in MWCNT-exposed snails, encompassing lipid metabolism (glycerophospholipid, arachidonic acid, and alpha-linolenic acid metabolism), amino acid biosynthesis and metabolism (phenylalanine/tyrosine/tryptophan biosynthesis and metabolism), and ubiquinone and other terpenoid-quinone biosynthesis. These findings highlight the utility of A. fulica for evaluating NM-induced trace element dysregulation and metabolic reprogramming in soil ecosystems.