Abstract: Objective To investigate the experimental therapeutic effect of the Compound Glycyrrhizin on the expression of NF-κB p65 and COX-2 in rats with ulcerative colitis(UC) induced by trinitrobenzene sulfonic acid/ethanol (TNBS/ethanol). Methods Forty adult Sprague-Dawley rats were randomly divided into 4 groups(n=10), Normal control group received no treatment, while the rest groups used trinitrobenzene sulfonic acid/ethanol enema to generate ulcerative colitis models. UC model group received saline water enema and decapitated three days later, Compound glycyrrhizin glycosides treatment group daily received glycyrrhizin glycosides solution enema, 40 mg·kg^-1·d^-1, Continuous enema 7 days and decapitated,, Sulfasalazine (SASP) treatment group daily received SASP solution enema, 0.5 g·kg^-1·d^-1, Continuous enema 7 days and decapitated, Each group received different treatment as described above, NF-κB p65 and COX-2 were detected by immunohistochemistry. Results Compared with Normal control group, the level of NF-κB p65 was significantly increased in UC model group、SASP treatment group and Compound glycyrrhizin glycosides treatment group [0.25±0.11 vs 5.58±0.85 vs 3.36±0.66 vs 3.21±0.58, P<0.01], and the level of COX-2 was significantly increased [0.21±0.13 vs 5.54±0.40 vs 3.23±1.05 vs 3.16±0.94, P<0.01]. Compared with Model group, the level of NF-ęB p65 was significantly decreased in SASP treatment group and Compound glycyrrhizin glycosides treatment group [5.58±0.85 vs 3.36±0.66 vs 3.21±0.58, P<0.01], and the level of COX-2 was significantly decreased [5.54±0.40 vs 3.23±1.05 vs 3.16±0.94, P<0.01]. Conclusion Compound Glycyrrhizin has therapeutic effect on ulcerative colitis in rat. The mechanism is associated with the reduced levels of NF-κB p65 and COX-2.

Key words: Ulcerative colitis, Rats, Trinitrobenzenesulfonic acid/ethanol, Compound Glycyrrhizin