Paeoniflorin is traditionally used to treat inflammatory disorders. In our laboratory, we have scientifically validated the anti-inflammatory effect of paeoniflorin. In this study, it has been aimed to evaluate in vivo anti-inflammatory effect of paeoniflorin isolated from the dried peeled root of Paeonia lactiflora Pall. It was further intended to find out the probable mechanism of anti-inflammatory effect of paeoniflorin. The anti-inflammatory effect of paeoniflorin (15, 30 and 45 mg/kg) was measured employing TNBS-induced ulcerative colitis model of acute inflammation. The TNBS injection resulted significant colitis formation when compared with un-injected mice.
The anti-inflammatory effects of paeoniflorin for ulcerative colitis were assessed by body weight, colonic weight and length, macroscopic scores, and histopathological examinations. In addition, the colonic tissue levels of inflammation markers, including myeloperoxidase (MPO), IL-2, IL-6, IL-10, IL-12, IL-1β, TNF-α and IFN-γ were also determined to assess the effect of paeoniflorin. In addition, western blot demonstrated that paeoniflorin inhibited NF-kappaB signaling pathway and apoptosis in TNBS-induced ulcerative colitis tissues. In conclusion, all the findings of this study suggested that paeoniflorin has the anti-inflammatory effect in ulcerative colitis via inhibiting MAPK/NF-kappaB pathway and apoptosis in mice.