Toxicity of engineered nanomaterials to aquatic and land snails: A scientometric and systematic review.

The use of manufactured nanoparticles (NPs) is spreading rapidly across technology and medicine fields, posing concerns about their consequence on ecosystems and human health. The present study aims to assess the biological responses triggered by iron oxide NPs (IONPs) and iron oxide NPs incorporated into zeolite (IONPZ) in relation to oxidative stress on the land snail Helix aspersa in order to investigate its use as a biomarker for terrestrial environments. Morphology and structure of both NPs were characterized. Snail food was supplemented with a range of concentrations of IONPs and IONPZ and values of the hemocyte lysosomal membranes' destabilization by 50% were estimated by the neutral red retention (NRRT50) assay. Subsequently, snails were fed with NPs concentrations equal to half of the NRRT50 values, 0.05 mg L-1 for IONPs and 1 mg L-1 for IONPZ, for 1, 5, 10 and 20 days. Both effectors induced oxidative stress in snails' hemocytes compared to untreated animals. The latter was detected by NRRT changes, reactive oxygen species (ROS) production, lipid peroxidation estimation, DNA integrity loss, measurement of protein carbonyl content by an enzyme-linked immunoabsorbent assay (ELISA), determination of ubiquitin conjugates and cleaved caspases conjugates levels. The results showed that the simultaneous use of the parameters tested could constitute possible reliable biomarkers for the evaluation of NPs toxicity. However, more research is required in order to enlighten the disposal and toxic impact of iron oxide NPs on the environment to ensure their safe use in the future.

Insights into the toxicity of iron oxides nanoparticles in land snails

Physiological and behavioral responses of land molluscs as biomarkers for pollution impact assessment: A review

Risk assessment of iron oxide nanoparticles in an aquatic ecosystem: A case study on Biomphalaria glabrata.

In this study, the potential toxicity of α-Fe2O3-NPs was investigated using a unicellular eukaryote model, Saccharomyces cerevisiae (S. cerevisiae). The results showed that cell viability and proliferation were significantly decreased (p < 0.01) following exposure to 100-600 mg L-1 for 24 h. The IC50 and LC50 values were 352 and 541 mg L-1, respectively. Toxic effects were attributed to α-Fe2O3-NPs rather than iron ions released from the NPs. α-Fe2O3-NPs were accumulated in the vacuole and cytoplasm, and the maximum accumulation (3.95 mg g-1) was reached at 12 h. About 48.6% of cells underwent late apoptosis/necrosis at 600 mg L-1, and the mitochondrial transmembrane potential was significantly decreased (p < 0.01) at 50-600 mg L-1. Biomarkers of oxidative stress [reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)] and the expression of apoptosis-related genes (Yca1, Nma111, Nuc1 and SOD) were significantly changed after exposure. These combined results indicated that α-Fe2O3-NPs were rapidly internalized in S. cerevisiae, and the accumulated NPs induced cell apoptosis mediated by mitochondrial impairment and oxidative stress.

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Mitochondrial impairment and oxidative stress mediated apoptosis induced by α-Fe2O3 nanoparticles in Saccharomyces cerevisiae

In order to evaluate an ecotoxicological approach to assessing toxicological effects caused by iron oxide powder (Fe2O3) nanoparticles, we conducted a bioassay with helix as a biological model since the species is considered bioaccumulator and bioindicator of pollution. In this study, we evaluated the toxicity of Fe2O3 nanoparticles on the embryonic stage of Helix aspersa with different concentrations (1.25mg/ml, 1.5mg/ml, and 2mg/ml). Results reveal a deformation of the egg membrane and accumulation of this molecule at the back of the egg. We have also noted a low rate of hatching in 12th day, the mortality rate is found to be high at the highest concentration of Fe2O3. This bioassay highlights the toxicity of Fe2O3 nanoparticles on eggs of land snail: Helix aspersa.

https://www.entomoljournal.com/archives/2016/vol4issue4/PartE/4-3-135-968.pdf

Fatma Moulka Hadjira Braia

Papers

Embryotoxicity evaluation of iron oxide Fe2O3 on land snails: Helix aspersa