The inflammatory
cytokine interleukin (IL)-6, which basically activates the
Janus kinase (JAK)/ signal transducer and activator of transcription (STAT) signaling pathway, is well known to repress expression of hepatic
cytochromes P-450 (P450s) and transporters. Therapeutic
proteins, like
monoclonal antibodies targeting
IL-6 or its receptor, have consequently been demonstrated to restore full hepatic detoxification capacity, which results in inflammatory disease-related drug-drug interactions (idDDIs). In the present study, we investigated whether
ruxolitinib, a small drug acting as a JAK1/2 inhibitor and currently used in the treatment of myeloproliferative
neoplasms, may also counteract the repressing effects of
IL-6 toward hepatic detoxifying systems.
Ruxolitinib was found to fully inhibit IL-6-mediated repression of P450 (
CYP1A2,
CYP2B6, and
CYP3A4) and transporter (NTCP, OATP1B1, and OCT1)
mRNA levels in primary human hepatocytes and differentiated
hepatoma HepaRG cells. Such effects were dose-dependent, with
ruxolitinib EC50 values around 1.0-1.2 μM and thus close to
ruxolitinib plasma levels that can be reached in patients. Moreover, they were associated with concomitant restoration of P450 and drug transporter activities in IL-6-exposed HepaRG cells. By contrast,
ruxolitinib failed to suppress the repression of drug-detoxifying
protein mRNA levels caused by IL-1β The
JAK inhibitor and anti-
rheumatoid arthritis compound
tofacitinib was additionally found to reverse IL-6-mediated suppression of P450 and transporter
mRNA expressions. Taken together, our results demonstrated that small drugs acting as
JAK inhibitors, like
ruxolitinib, counteract IL-6-mediated repression of drug-metabolizing
enzymes and drug transporters in cultured human hepatocytes. These
JAK inhibitors may consequently be hypothesized to restore hepatic detoxification capacity for patients suffering from inflammatory diseases, which may in turn cause idDDIs.