Paeonol attenuates TNBS-induced colitis by inhibiting NF-κB and STAT1 transactivation

Paeonol, a major phenolic component of Moutan Cortex, is known to have anti-inflammatory activity. However, the effect of Paeonol on colitis has not been evaluated and the molecular mechanism of its anti-inflammatory action remains unknown. The aim of this study was to determine if Paeonol enema attenuates trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. We also investigated the effects of Paeonol in colon cancer-derived CW-2 cells and T cell leukemia-derived Jurkat cells treated with tumor necrosis factor α (TNFα) and/or interferon γ (IFNγ), which play critical roles in TNBS-induced colitis. Paeonol enema attenuated TNBS-induced colitis judging by body weigh reduction, colon length and histological score. Myeloperoxidase activity and inducible nitric oxide synthase (iNOS) production in the colon were also reduced with Paeonol enema. In CW-2 cells, Paeonol inhibited iNOS protein and mRNA expression induced by costimulation of TNFα and IFNγ. Furthermore, Paeonol reduced TNFα-induced NF-κB transactivation and IFNγ-induced STAT1 transactivation in CW-2 cells and also in Jurkat cells. These findings suggest that Paeonol enema may be useful for the treatment of colitis.