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Povzetek: Bisphenols (BPs) are industrial chemicals extensively used in polycarbonate plastics and epoxy resins for everyday products, including food and beverage containers, toys, and thermal paper, representing major sources of human exposure. Bisphenol A (BPA) is the most prevalent; however, due to its endocrine-disrupting, reproductive, and genotoxic effects, it is classified as a substance of high concern by the European Chemicals Agency. Regulatory restrictions have prompted the use of structural analogues, including bisphenol AP (BPAP) and bisphenol C (BPC); however, emerging evidence suggests they may pose similar or greater health risks. Comprehensive data on their toxicity and human exposure, especially in mixtures, remain limited. This study assessed the cytotoxic and genotoxic effects of BPA, and less studied analogues BPAP, BPC, and their binary mixtures using a human-relevant 3D HepG2 spheroid model, representing an advanced in vitro system. Spheroids were exposed for 24 and 96 h, and effects were evaluated by ATP-based viability assays, comet assay, and targeted transcriptomics. None of the bisphenols induced significant cytotoxicity, although slight reductions in viability were observed for BPAP, BPC, and mixtures. DNA strand breaks were detected after exposure to BPA, BPC, and mixtures. Transcriptomic analysis revealed modest stress responses and strong upregulation of xenobiotic metabolism genes (CYP1A1, CYP1A2, CYP3A4, UGT1A1, NAT2), indicating cellular recognition of the tested bisphenols as bioactive xenobiotics. Antioxidant and DNA repair genes were largely unchanged, except for upregulation of oxidative stress markers HMOX1 and SRXN1 and a slight increase in OGG1, indicating oxidative DNA damage. Importantly, mixture effects were predominantly additive, with no evidence of synergistic interactions under the tested conditions. Overall, bisphenol exposure primarily triggered oxidative stress and metabolic responses rather than robust DNA damage signalling, suggesting that genotoxicity is largely mediated by reactive oxygen species. By integrating multiple endpoints in a 3D liver model, this study provides a more comprehensive assessment of bisphenol toxicity and highlights potential risks associated with BPA analogues and their mixtures, supporting the need for a comprehensive safety assessment to evaluate their suitability as replacements in consumer products.
Ključne besede: bisphenol, DNA damage, oxidative stress, complex mixtures, metabolism
Objavljeno v DiRROS: 10.07.2026; Ogledov: 168; Prenosov: 179
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Povzetek: In the last decade, it has become evident that complex mixtures of cyanobacterial bioactive substances, simultaneously present in blooms, often exert adverse effects that are different from those of pure cyanotoxins, and awareness has been raised on the importance of studying complex mixtures and chemical interactions. We aimed to investigate cytotoxic and genotoxic effects of complex extracts from laboratory cultures of cyanobacterial species from different orders (Cylindrospermopsis raciborskii, Aphanizomenon gracile, Microcystis aeruginosa, M. viridis, M. ichtyoblabe, Planktothrix agardhii, Limnothrix redekei) and algae (Desmodesmus quadricauda), and examine possible relationships between the observed effects and toxin and retinoic acid (RA) content in the extracts. The cytotoxic and genotoxic effects of the extracts were studied in the human hepatocellular carcinoma HepG2 cell line, using the MTT assay, and the comet and cytokinesis-block micronucleus (cytome) assays, respectively. Liquid chromatography electrospray ionization mass spectrometry (LC/ESI-MS) was used to detect toxins (microcystins (MC-LR, MC-RR, MC-YR) and cylindrospermopsin) and RAs (ATRA and 9cis-RA) in the extracts. Six out of eight extracts were cytotoxic (0.04–2 mgDM/mL), and five induced DNA strand breaks at non-cytotoxic concentrations (0.2–2 mgDM/mL). The extracts with genotoxic activity also had the highest content of RAs and there was a linear association between RA content and genotoxicity, indicating their possible involvement; however further research is needed to identify and confirm the compounds involved and to elucidate possible genotoxic effects of RAs.
Ključne besede: cyanobacteria, algae, extracts, complex mixtures, genotoxicity, cytotoxicity, retinoic acids, microcystins, cyanotoxins, chemical analysis
Objavljeno v DiRROS: 19.07.2024; Ogledov: 1366; Prenosov: 863
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