5-fluorouracil attenuates dextran sodium sulfate-induced acute colitis in mice.

5‑Fluorouracil (5‑FU) has been predominantly used in the clinic for cancer chemotherapy. Previous studies have demonstrated that 5‑FU has an anti‑inflammatory function. In the current study, the potential therapeutic role of 5‑FU in dextran sodium sulfate (DSS)‑induced acute mouse colitis was investigated. Effects on the severity of colitis were studied via histochemical and immunohistochemical staining, cytokine levels were determined by reverse transcriptoin‑quantitative polymerase chain reaction and the effect of 5‑FU on NF‑κB was examined by western blotting. Administration of 5‑FU ameliorated the severity of acute DSS‑induced colitis. The disease activity score was significantly lower in the 5‑FU + DSS‑treated mice compared with the DSS‑treated group (P<0.01). Tumor necrosis factor‑α, interleukin‑1β and interferon γ mRNA expression levels were significantly downregulated in the colon tissue of DSS mice treated with 5‑FU compared with the untreated DSS mice (P<0.05). In addition, the number of CD4+ T cells in the colonic lamina propria and myeloperoxidase activity were significantly decreased in the 5‑FU + DSS‑treated mice (P<0.05). Furthermore, 5‑FU treatment significantly reduced p‑NF‑κB‑p56 protein expression levels in the colon tissue of DSS‑treated mice (P<0.05). The present results demonstrated that 5‑FU minimizes the abnormal immune cytokine response and relieves the pathophysiological disorders associated with experimental acute colitis. Thus, the modulating inflammatory response role of 5‑FU may be partially associated with inhibiting NF‑κB activation and 5‑FU may be a novel therapeutic strategy for the treatment of inflammatory bowel disease.