Abstract: AIM: To explore the therapeutic effect of dexamethasone Angelica sinensis polysaccharide prodrug(DEX-AP) on trinitrobenzene sulfonic acid (TNBS) induced ulcerative colitis (UC) in rats and its side effects.METHODS: The experimental UC rats were induced by clusis of the solution of TNBS in 45 % alcoho1 (50 mg·ml^-1 ).The UC rats were orally administrated with0.25μmol·kg^-1·d^-1 DEX and 0.05, 0.25, 1.25μmol·kg^-1 ·d^-1 DEX-AP (calculated by carried DEX in DEX-AP) for 7 days, respectively.The rats were killed after the amount of peripheral blood lymphocyte was counted,then the spleen, thymus and colon were separated and weighted.After the ulcerative area of colon was calculated,the colonic myeloperoxidase (MPO) activity was determined and parts of colon were paraffin sectioned and examined under light microscope by HE stain.RESULTS: After the UC rats were administrated with different doses of DEX-AP for 7 days, the ulcerative area, the weight and the MPO activity of colon reduced significantly.The reduction of MPO activity was correlated to the dose of DEX-AP and the MPO activity with DEX-AP at the doses of 0.25, 1.25μmol·kg^-1 ·d^-1 reduced more significantly than that with DEX at the the dose of 0.25μmol·kg^-1·d^-1.The number of peripheral blood lymphocyte,spleen weight and thymus weight of UC rats reduced significantly at the dose of 0.25μmol·kg^-1 ·d^-1DEX (P<0.01, compared with control group).DEXAP showed no significant effect on the number of peripheral blood lymphocyte, spleen weight and thymus weight of UC rats at the doses of 0.05, 0.25 μmol·kg^-1 ·d^-1.With the administration of 1.25 μmol·kg^-1·d^-1 DEX-AP to UC rats, the structure of the colonic mucosal tissue almost recovered.CONCLUSION: DEX-AP has significant therapeutic effect on TNBS induced UC rats and it has no obvious side effects, thus it indicates a great potential in treating UC.

Key words: bladder cancer, adriamycin, polyvinylpyrrolidone, apoptosis