Inflammatory response is characterized by an increase of several cytokines. Some are known to modify drugs pharmacokinetic by reducing the expression levels of drug-metabolizing enzymes (DMEs) and transporters. This impact of inflammatory signaling is well established in hepatic cells, but not in intestinal cells. EpiIntestinal is a 3D human small intestinal tissue model with epithelial polarity, allowing good evaluation of metabolism and drug transport. This study aimed to analyze the effect of IL-6 on this tissue model. RNA sequencing was performed in cells incubated with 5, 10, or 20 ng/mL IL-6 for 8 h to 72 h to study the impact of IL-6 on drug metabolism and pharmacokinetics gene expression. The influence of IL-6 on the activity of cytochromes P450 (CYPs) was studied by measuring metabolite formation of specific substrates with LC-HRMS. Its impact on ATP-binding cassette (ABC) transport was evaluated by measuring intra- and extracellular substrates using spectrofluorometry. Exposure of EpiIntestinal cells to IL-6 resulted in reduction of some CYP mRNAs, such as CYP2C19, CYP2C9, and CYP3A4, by 40% to 50%. Activities of these CYPs were also decreased in EpiIntestinal cells by 20% to > 75%. IL-6 exposure did not modify ABCB1 and ABCCs transporter activities in this model. This study shows that gene expression levels and activities of drug-metabolizing enzymes and ABC transporters may be altered by the pro-inflammatory cytokine IL-6 in intestinal cells. If these results are confirmed in vivo, it may result in pharmacokinetic modifications, such as pre-systemic metabolism, with clinical effects, and require dosage adaptation.
Keywords: RNA sequencing; inflammation; intestine; metabolism.