Exploring the genotoxic potential of Bisphenol A and its emerging alternatives in an advanced in vitro 3D zebrafish hepatic cell model

With global restrictions on Bisphenol A (BPA), various BPA alternatives are increasingly found in ecosystems, raising concerns. This study focuses on the genotoxic potential of three emerging BPA alternatives - Bisphenol AF (BPAF), Bisphenol AP (BPAP), and Bisphenol PH (BPPH) - using an advanced in vitro 3D model system, spheroids, prepared from a Zebrafish (Danio rerio) liver cell line (ZFL). Their cytotoxicity was evaluated using the CellTiter-Glo® 2.0 assay, while their genotoxic potential was assessed using the comet assay, γH2AX assay, and toxicogenomic analysis. The BPA alternatives were more cytotoxic to ZFL spheroids than BPA. Non-cytotoxic concentrations caused transient DNA damage without a significant increase in DNA double-strand breaks (DSBs). The toxicogenomic analysis confirmed these findings, indicating activation of the TP53 DNA damage response pathway, the nucleotide excision repair (NER) and base excision repair (BER) mechanisms, likely in response to bulky DNA lesions and oxidative DNA damage. In addition, the gene expression analysis indicated the influence of the tested BPs on the endocrine system. Our results indicate that BPAF, BPAP and BPPH have considerable genotoxic potential and pose a significant ecotoxicological risk, underscoring the need for further investigation and careful consideration of these chemicals as BPA replacements.