The Xanthine Oxidase Inhibitor Febuxostat Suppresses Adipogenesis and Activates Nrf2.

Xanthine oxidoreductase (XOR) is a rate-limiting enzyme in purine catabolism that acts as a novel regulator of adipogenesis. In pathological states, xanthine oxidoreductase activity increases to produce excess reactive oxygen species (ROS). The nuclear factor erythroid 2-related factor 2 (Nrf2) is a critical inducer of antioxidants, which is bound and repressed by a kelch-like ECH-associated protein 1 (Keap1) in the cytoplasm.

Interleukin-6 and cytochrome-P450, reason for concern?

Interleukin 6 (IL-6) plays a central role in the immunopathogenesis of rheumatoid arthritis (RA) and tocilizumab [TCZ] (an anti-IL-6 receptor antibody) has been shown to be effective in the treatment of the condition. As up-regulation of IL-6 reduces the activity of cytochrome P450 (CYP) enzymes, blockade of this cytokine may enhance CYP function. This may lead to reduced bioavailability of CYP-metabolized drugs.