OBJECTIVETo evaluate therapeutic effect of Sishen Wan on experimental colitis, and explore its mechanism by expression of Bax/Bcl-2 mRNA, Fas/FasL in colonic tissue.

METHODExperimental colitis was induced by rectal administration of trinitrobenzene sulfonic acid (TNBS) dissolved in ethanol. The model animals were divided into four groups: the induced colitis but untreated group, the induced colitis groups treated with the high, middle, low dose of Sishen Wan, and the induced colitis group treated with salicylazosulfapyridine (SASP). After 10 day administration, the body weight, colonic wet weight, colonic weight index, colonic damage score and pathological change were evaluated, and the level of Fas and FasL by flow cytometry, Bax mRNA and Bcl-2 mRNA by reverse transcription polymerase chain reaction (RT-PCT).

RESULTCompared with the model group, the colonic wet weight and colonic weight index were remarkably decreased in the middle dose of Sishen Wan group (P < 0.05). The colonic injury scores were significantly reduced after rats were treated with the three doses of Sishen Wan (P < 0.05). Representative restored features were observed including fewer inflammatory cellular infiltration and follicular hyperplasia, superficial and little ulcer with fibroplasia in colonic mucosa from the treated groups. The expression of Fas in the colonic mucosa was obviously down-regulated (P < 0.05) and the ratio of Bcl-2 mRNA/Bax mRNA was significantly up-regulated (P < 0.05) in the groups treated with the three doses of Sishen Wan.

CONCLUSIONSishen Wan might postpone colonic epithelium apoptosis or improve inflammatory cell apoptosis by regulating the expression of Fas/ FasL and Bax/Bcl-2 mRNA in colonic tissue, which is possible potential path to effectively treat experimental colitis by enema.