The role of cytochromes CYP1A and CYP3A in the genotoxic effect of benzo(a)pyrene

Abstract

Introduction. Benzo(a)pyrene metabolites are genotoxic compounds, the accumulation of which contributes to carcinogenesis. The main mechanism of metabolite formation is the benzo(a)pyrene oxidation by cytochromes P450 (CYP). Inhibitors of the main cytochromes can reduce the rate of metabolite formation and, as a result, to decrease the genotoxic effects of benzo(a)pyrene metabolites. In contrast, inducers of cytochromes contribute to the enhancement of genotoxicity. Objective. The aim of the work was to develop a cell model based on the HepaRG cells to study the role of cytochromes activity in the genotoxic effect of benzo (a) pyrene. Material and methods. To assess the effect of inhibitors of cytochromes CYP3A and CYP1A on the genotoxic effect of benzo(a)pyrene in HepaRG cells, the content of active forms of proteins of the DNA damage detection and repair system, phosphorylated forms of signaling cascade proteins was determined by immunoassay using Luminex xMAP technology. The cytotoxicity of benzo(a)pyrene was assessed by real-time cell analysis on xCelligence analyzer. Results. Inhibitors of CYP3A and CYP1A cytochromes, ketoconazole and α-naphthoflavone demonstrate the ability to diminish the toxic effects of benz (a) pyrene, reduce the activation of the DNA repair system, and have a multidirectional effect on the different tyrosine kinases phosphorylation in signaling pathways. Conclusion. HepaRG human hepatoma cells are a suitable cell model both to assess the contribution of cytochromes to the metabolism of xenobiotics and to study of the cell protection from the genotoxic effect of benzo (a) pyrene by cytochrome inhibitors. Limitations. The study was performed on a cell culture. To extrapolate the data to the organism, it is necessary to take into account the data of toxicodynamics and toxicokinetics.