Objective: To observe the curative effect of Tongxie Yaofang on ulcerative colitis(UC)

and identify its underlying mechanism. Method: Sixty SPF Wistar rats were randomly divided into the blank group

model group

Tongxie Yaofang low-

moderate-

high-dose groups and sulfasalazine (SASP) group; Except the blank group

the UC models were established by trinitrobenzene sulfonic acid(TNBS)/ethanol enema; after modeling

the Tongxie Yaofang low-

moderate-

high-dose groups were given at dose of 11

22

44 g·kg-1 by gavage)the SASP group was given at dose of0.3 g·kg-1 by gavage

the blank group and model group were treated with the same volume's physiological saline for 21 days.The morphological injury was observed with the naked eye and scored.Intercellular adhesion molecular-1(ICAM-1)gene and protein expressions were detected by means of RT-PCR and immunohistochemical method. Result: Inflammation and ulceration were found on the colonic mucous membrane of rats in the model group(2.50±1.08)

and compared with the blank group(0.08±0.28)

P<0.05

and the discrepancy was statistically significant

the successful model was proved.The expression amount of ICAM-1 gene and protein of colonic tissues of rats in the model group(0.27±0.05

0.44±0.016 6) was increased than that in the blank group(0.17±0.02

0.32±0.012 3)

and the discrepancy was statistically significant(P<0.01).Compared with the model group(0.27±0.05

0.44±0.016 6)

the expression amount of ICAM-1 in the Tongxie Yaofang high-(0.19±0.03

0.32±0.005 9) and moderate-dose groups(0.20±0.04

0.34±0.010 4) were decreased

and the discrepancy was statistically significant(P<0.05

P<0.01). Conclusion: The prescription probably decreases the expression amount of ICAM-1 mRNA and ICAM-1 protein

inhibit inflammation cell infiltrate

reduce colon tissue damage

play a role in treatment of UC.