Objective: To observe the effect of Shaohuang Anchang decoction (SAD) on Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor-κB(NF-κB) in colonic mucosa of rats with ulcerative colitis(UC)

and to explore its possible mechanism. Method: The rat UC model was induced by trinitro-benzene-sulfonic acid (TNBS)/anhydrous alcohol.The SD rats were randomized into the normal group

model group

SAD low-dose group

SAD middle-dose group

SAD high-dose group (4.5

9

18 g·kg-1)and the Mesalazine group(5 g·kg-1)

with 10 in each. Since the 2nd day of modeling

corresponding medications were respectively administered to each treatment group by gastrogavage for 10 successive days.Disease activity index (DAI)

colon macroscopic damage score (CMDS) were calculated

The expression of NF-κB in the colonic mucosa was detected by immunohistochemistry.The expressions of TLR4 mRNA and MyD88 mRNA were detected with reverse transcription-polymerase chain reaction. Result: Compared with the normal group

the model group showed significantly increased DAI

CMDS

but the SAD groups showed more lower than the model group. Compared with the normal group

the expressions of NF-κB

TLR4 mRNA

MyD88 mRNA were significantly increased in other groups. Comparing with the control group

the expressions of NF-κB

TLR4 mRNA

MyD88 mRNA were significantly decreased in the SAD low-dose

middle-dose

high-dose groups and the Mesalazine group

especially in the SAD high-dose group. Conclusion: Treatment with DG could reduce inflammatory injury in rats with ulcerative colitis. Its possible mechanism may be through inhibiting the expression of TLR4 and then inhibiting the activation of MyD88 and NF-κB

and finally reducing inflammatory reaction.