CYP and non-CYP drug metabolizing enzyme families exhibit differential sensitivities towards pro-inflammatory cytokine modulation

Compromised hepatic drug metabolism in response to pro-inflammatory cytokine release is primarily attributed to downregulation of cytochrome P450 (CYP) enzymes. However, whether inflammation also affects other phase I and phase II drug metabolizing enzymes (DMEs) like the flavin monooxygenases (FMOs), carboxylesterases (CESs) and UDP glucuronosyltransferases (UGTs) remains unclear. This study aimed to decipher the impact of physiologically relevant concentrations of pro-inflammatory cytokines on expression and activity of phase I and phase II enzymes, in order to establish a hierarchy of their sensitivity as compared to the CYPs. Hereto, HepaRG cells were exposed to interleukin-6 and interleukin-1β to measure alterations in DME gene expression (24h) and activity (72h). Sensitivity of DMEs towards pro-inflammatory cytokines was evaluated by determining IC