Genotoxic activity of bisphenol A and its analogues bisphenol S, bisphenol F and bisphenol AF and their mixtures in human hepatocellular carcinoma (HepG2) cells

• Published in: The Science of the total environment Vol. 687; pp. 267 - 276
• Main Authors: Hercog, Klara, Maisanaba, Sara, Filipič, Metka, Sollner-Dolenc, Marija, Kač, Lidija, Žegura, Bojana
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.10.2019
• Subjects: Bisphenol A; Bisphenol A analogues; Combined exposure; Gene expression; Genotoxic; Bisphenol A; Bisphenol A analogues; Combined exposure; Gene expression; Genotoxic
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2019.05.486

The use of bisphenol A (BPA) in manufacturing of plastics is being gradually replaced by presumably safer analogues such as bisphenol S (BPS), bisphenol F (BPF) and bisphenol AF (BPAF). Despite their widespread occurrence in the environment, there is a knowledge gap in their toxicological profiles. We investigated cytotoxic/genotoxic effects as well as changes in the expression of selected genes involved in the xenobiotic metabolism, response to oxidative stress and DNA damage upon exposure to BPs and their mixtures in human hepatocellular carcinoma HepG2 cells. BPS and BPF slightly decreased the viability of HepG2 cells, while BPAF was the most cytotoxic compound tested. BPA, BPF and BPAF induced the formation of DNA double strand breaks determined with γH2AX assay, while BPS was inactive (5–20 μg/mL). All four BPs up-regulated the expression of CYP1A1 and UGT1A1, while BPS up-regulated and BPAF down-regulated also the expression of GST1A. Only BPA up-regulated oxidative stress responsive gene GCLC, while BPAF up-regulated the expression of CDKN1A and GADD45a. At concentrations relevant for human exposure (ng/mL range) BPA and its analogues as individual compounds and in mixtures did not exert genotoxic activity, whereas BPA and BPAF as well as the mixtures up-regulated the expressions of CYP1A1 and UGT1A1. [Display omitted] •BPF and BPAF showed higher cytotoxic/genotoxic potential than BPA in HepG2 cells.•BPS showed the lowest cytotoxic/genotoxic potential compared to BPA.•At low environmentally relevant concentrations, BPs did not induce DNA damage.•At combined exposure, BPs induced additive effects in the expression of specific genes.•Not all BPA analogues present safer replacement for BPA.