International audience | Per and polyfluoroalkyl substances (PFAS) are persistent compounds that are massively used in industry, consumer goods and fire-fighting foams. Soil contamination by PFAS is a major environmental concern, and there is a lack of knowledge on both their ecotoxicological mechanisms and the concentrations that induce adverse effects especially to non-target organisms, particularly in the case of PFAS mixtures. This study contributes to filling these gaps by assessing and modelling the effects of PFAS (in single and in mixtures for PFOS and PFOA at different environmental doses) on juvenile endogeic earthworms of a common species in European soils (Aporrectodea caliginosa) at different levels of biological organization (sub-individual and individual). The results showed for the first time combined strong ecotoxicological effects of PFAS on earthworm survival, integumental integrity, growth, sexual maturity and on genomic stability notably with the induction of DNA breaks associated with no abnormal oxidative DNA-lesion levels. Our results demonstrated significant effects at 0.3 mg kg − 1 and additive effects in case of mixtures. ☆ This paper has been recommended for acceptance by Jiayin Dai.

Aflatoxin B1 (AFB1) is the most potent natural carcinogen among mycotoxins. Versicolorin A (VerA) is a precursor of AFB1 biosynthesis and is structurally related to the latter. Although VerA has already been identified as a genotoxin, data on the toxicity of VerA are still scarce, especially at low concentrations. The SOS/umu and miniaturised version of the Ames test in Salmonella Typhimurium strains used in the present study shows that VerA induces point mutations. This effect, like AFB1, depends primarily on metabolic activation of VerA. VerA also induced chromosomal damage in metabolically competent intestinal cells (IPEC-1) detected by the micronucleus assay. Furthermore, results from the standard and enzyme-modified comet assay confirmed the VerA-mediated DNA damage, and we observed that DNA repair pathways were activated upon exposure to VerA, as indicated by the phosphorylation and/or relocation of relevant DNA-repair biomarkers (γH2AX and 53BP1/FANCD2, respectively). In conclusion, VerA induces DNA damage without affecting cell viability at concentrations as low as 0.03 μM, highlighting the danger associated with VerA exposure and calling for more research on the carcinogenicity of this emerging food contaminant.

International audience | Aflatoxin B1 (AFB1) is the most potent natural carcinogen among mycotoxins. Versicolorin A (VerA) is a precursor of AFB1 biosynthesis and is structurally related to the latter. Although VerA has already been identified as a genotoxin, data on the toxicity of VerA are still scarce, especially at low concentrations. The SOS/umu and miniaturised version of the Ames test in Salmonella Typhimurium strains used in the present study shows that VerA induces point mutations. This effect, like AFB1, depends primarily on metabolic activation of VerA. VerA also induced chromosomal damage in metabolically competent intestinal cells (IPEC-1) detected by the micronucleus assay. Furthermore, results from the standard and enzyme-modified comet assay confirmed the VerA-mediated DNA damage, and we observed that DNA repair pathways were activated upon exposure to VerA, as indicated by the phosphorylation and/or relocation of relevant DNA-repair biomarkers (γH2AX and 53BP1/FANCD2, respectively). In conclusion, VerA induces DNA damage without affecting cell viability at concentrations as low as 0.03 μM, highlighting the danger associated with VerA exposure and calling for more research on the carcinogenicity of this emerging food contaminant.