Can sustained exposure to PFAS trigger a genotoxic response? A comprehensive genotoxicity assessment in mice after subacute oral administration of PFOA and PFBA

• Published in: Regulatory toxicology and pharmacology 2019-08, Vol.106, p.169-177
• Main Authors: Crebelli, Riccardo, Caiola, Stefania, Conti, Luigi, Cordelli, Eugenia, De Luca, Gabriele, Dellatte, Elena, Eleuteri, Patrizia, Iacovella, Nicola, Leopardi, Paola, Marcon, Francesca, Sanchez, Massimo, Sestili, Paola, Siniscalchi, Ester, Villani, Paola
• Format: Article
• Language: English
• Subjects: Administration, Oral; Animals; Caprylates - administration & dosage; Caprylates - toxicity; Fluorocarbons - administration & dosage; Fluorocarbons - toxicity; Genotoxicity; In vivo; Liver - drug effects; Male; Mice; Mice, Inbred C57BL; Mutagenicity Tests; PFAS; Risk assessment
• ISSN: 0273-2300; 1096-0295
• DOI: 10.1016/j.yrtph.2019.05.005

PFAS (perfluoroalkyl substances) are considered non-genotoxic. However, PFAS exposure has been associated with the induction of oxidative stress in vitro and in vivo, and the possible induction of indirect genotoxic effects under sustained PFAS exposure has not been investigated. In order to shed light on this aspect, in this study a comprehensive assessment of genotoxicity was carried out in mice administered with perfluorooctanoic acid (PFOA, 0.1, 1 and 5 mg/kg body weight) and its C4 analogue perfluorobutyric acid (PFBA, 5 mg/kg body weight) for five weeks through drinking water. Markers of cell toxicity, oxidative stress and DNA strand breaks were measured in liver, the main target of toxicity of PFOA in rodents; systemic genotoxicity was also assessed by the analysis of micronuclei in reticulocytes and spleen lymphocytes, and germ cell effects by the Comet assay on testis cells. PFOA administration at the highest dose (5 mg/kg body weight) induced marked liver hypertrophy with signs of cell injury (elevated ALT and AST), with no concurrent evidence of lipid peroxidation and oxidative stress (decreased antioxidant capacity). Only mild liver hypertrophy, with no other signs of toxicity, was determined by PFBA administration. No evidence of treatment related genotoxicity was observed in any experimental group. Overall, data indicate that under the experimental conditions of this study, severe liver toxicity induced by PFOA administration is not associated with oxidative stress. Accordingly, no genotoxic effect is observed in liver and in the other tissues examined. Milder evidence of liver toxicity, with no genotoxicity, and a lower tendency to bioaccumulation were observed in PFBA treated mice. •The hypothesis that oxidative stress induced by PFAS could trigger genotoxicity was investigated.•PFOA and the C4 analogue PFBA were administered for 5 weeks in drinking water to mice.•PFOA accumulated in serum at a higher degree than PFBA and induced distinct hepatotoxicity.•There was no oxidative damage in liver, and no evidence of genotoxicity in somatic and germ cells.•Subacute oral exposure of mice to PFAS did not trigger oxidative stress and secondary genotoxicity.