Sinomenine attenuates 2, 4, 6-trinitrobenzene sulfonic acid-induced colitis in mice.

Sinomenine is a pure alkaloid extracted from the Chinese medical plant Sinomenium acutum. It was demonstrated that sinomenine had anti-inflammatory and immunosuppressive effects in the previous studies. The aim of the present study was to evaluate therapeutic effects of sinomenine on 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) induced colitis in mice. Two hours following colonic instillation of TNBS, sinomenine with several doses (30, 100, 200 mg/kg) was given by gastric gavage once daily for 7 days. Comparing with the saline-treated mice with TNBS-induced colitis, sinomenine (100 mg/kg and 200 mg/kg)-treated mice with TNBS-induced colitis were shown improvements of weight loss, macroscopic score, histological score, and myeloperoxidase activity. Moreover, treatments with sinomenine (100 mg/kg and 200 mg/kg) decreased the up-regulated mRNA and protein levels of tumour necrosis factor-alpha(TNF-alpha) and interferon-gamma (IFN-gamma) caused by TNBS. Our findings suggest that sinomenine attenuates TNBS-induced colitis in mice and the therapeutic mechanism might be related to the reduction of up-regulated colonic TNF-alpha and IFN-gamma production caused by TNBS.