Objective: To observe the preventive and therapeutic effect of Banqiao Codonopsis Radix polysaccharide on 2

4

6-trinitrobenzenesulfonic acid (TNBS)-induced ulcerative colitis (UC) in rats and investigate its action mechanism. Method: Sixty Sprague Dawley (SD) rats were randomly divided into six groups with ten in each group:normal group

model group

Banqiao Codonopsis Radix polysaccharide low-dose group (0.25 g·kg-1)

middle-dose group (0.50 g·kg-1)

high-dose group (1.00 g·kg-1) and Guchang Zhixie pills group (1.08 g·kg-1). After 5 days of intragastric administration in various groups

TNBS 60 mg·kg-1was applied in intragastric administration for modeling

once a day for 3 weeks continuously. Disease activity index (DAI) was evaluated on 1st

2nd

3rd and 21st day after modeling. 30 min after the last administration

the rats were decapitated after anesthesia with ethy1 ether and the colon tissues of the rats were collected consequently. After colon mucosa damage index (CMDI) evaluation

half of the colon tissues was used for histopathological examination and grading and the rest half of was used to detect mRNA expression levels of Toll-like receptor 4 (TLR4)

interleukin-6 (IL-6)

nuclear factor-κB (NF-κB)

tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) by real-time quantitative PCR. Result: As compared with the normal group

the colon tissues had hyperemia

edema in rats of model group

with obvious ulcer symptoms;histopathological results indicated that inflammatory cell infiltration was severe;CMDI evaluation and pathological tissue scores were significantly increased;mRNA expression levels of TLR4

IL-6

NF-κB and TNF-α were significantly increased

while mRNA expression of mRNA expression was significantly reduced (P < 0.01). As compared with the model group

hyperemia

edema and ulcer symptoms were improved in rats of Banqiao Codonopsis Radix polysaccharide group;histopathological results indicated that inflammatory cell infiltration was significantly improved;CMDI evaluation and pathological tissue scores were significantly decreased;the mRNA expression levels of TLR4

IL-6

NF-κB and TNF-α were down-regulated

while IL-10 mRNA expression level was up-regulated (P < 0.05

P < 0.01). Conclusion: Banqiao Codonopsis Radix polysaccharide showed a positive preventive therapeutic effect on TNBS-induced UC rats

and the mechanism may be associated with regulating levels of TLR4

IL-6

NF-κB

TNF-α and IL-10.