ObjectiveTo investigate the effects of Aucklandia and Coptis pills on cellular apoptosis and the expression of Bcl-2 and Bax mRNA in model rats with ulcerative colitis (UC). MethodsFifty male Wistar rats at the age of seven weeks were randomly divided into five groups: control group, model group, Chinese medicine group (Aucklandia and Coptis pills), inhibitor group, and Chinese medicine plus inhibitor group. The experiment was performed with rats of UC induced by trinitro-benzene-sulfonic acid enema. AG-490 and Aucklandia and Coptis pills were administrated to them by intraperitoneal injection and gavage. Colonic mucosal tissues in rats of all the five groups were observed and evaluated by light microscope. Cellular apoptosis in colonic mucosal tissues was detected by TUNEL. The expressions of Bcl-2 and Bax mRNA were detected by reverse transcription polymerase chain reaction. ResultsThere were many ulcers in the colon of UC rats, and pathological changes in colonic mucosa such as inflammation, congestion and edema were observed in the colon of UC model rats by naked eye and microscope. Compared with UC rats without treatment, Aucklandia and Coptis pills alleviated colonic mucosal injuries and decreased apoptosis rate of colonic epithelial cells, while the expression of Bax mRNA was decreased in the colonic mucosa in UC rats treated with Aucklandia and Coptis pills, and Bcl-2 mRNA expression was increased. ConclusionAucklandia and Coptis pills can effectively inhibit mRNA expression of apoptosisrelated molecules to down-regulate colonic epithelial cells apoptosis in colonic mucosa in rats with UC.