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oxazolone-induced colitis by inhibiting the NF-κB pathway Purpose: Tetramethylpyrazine (TMP) is an eective Chinese plant-derived medicine for colitis in the clinic, but the underlying molecular mechanisms of its use remain poorly un-derstood. e purpose of this study was to investigate the mechanisms involved in its therapeutic action. Methods: A colitis mouse model was induced by oxazolone enema. TMP was adminis-tered at 80 mg/kg/day and sulphasalazine (SASP) was used as positive control and admin-istered at 100 mg/kg/day for the treatment of colitis. On the fourth day aer enema, mice were sacriced. e inammatory response was assessed by the disease activity index and histology. Colon mucosa was isolated and biochemically analyzed. In addition, in vitro studies were performed to evaluate the activity of TMP in Caco-2 cells. Results: Our results showed that TMP improved the colonic inammatory status as evi-denced by histological ndings, as well as SASP. ese eects were associated with a de-crease in nucleus translocation of NF-κB. Paired with this inhibitive activity, there was a decrease in downstream signaling, such as C-MYC, iNOS and COX-2. In vitro assays re-vealed that TMP inhibited NF-κB translocation and its downstream production of in-ammatory factors, such as TNF-α, IL-6 and IL-8, and that ROS production that was induced by LPS in Caco-2 cells. Conclusion: TMP improved the colitis induced by oxazoline, and its activity was associ-ated with inhibition of NF-κB translocation, and subsequent inhibition of pro-inammatory factor production and oxidative stress