Objective: To study the protective effect and mechanism of Shenling Baizhu granule (SLBZ) on ulcerative colitis in mice induced by dextran sulfate sodium (DSS). Method: Clean-grade Balb/c mice were randomly divided into control group

3 d model group

3 d SLBZ group

7 d model group and 7 d SLBZ group. 3 d and 7 d SLBZ groups were given SLBZ (9 g·kg-1·d-1) by gavage for 8 days

while control group and two model groups were given the same volume of saline. In all groups except the control group

animal models were established with 4% DSS water in the last 3 days. 3 d model group and 3 d SLBZ group were observed and tested on 3 d after modeling

while control group

7 d model group and 7 d SLBZ group were observed and tested on 7 d after modeling. The changes in body weight

stool index (diarrhea and bloody stool)

pathological score

apoptosis index

mucus expression and occludin protein were observed. Result: Compared with the normal group

the amount of apoptotic epithelial cells in colonic mucosa of 3 d model group increased significantly

the expression of occludin was significantly reduced (P<0.05). In 7 d model group

body weight decreased significantly

stool index increased significantly

the pathological score increased

the amount of apoptotic cells increased

and occludin protein expression was significantly reduced (P<0.05). Compared with the model group

after preventive gavage of SLBZ suspension for 8 days

the amount of apoptotic epithelial cells in 3 d SLBZ group decreased

occludin protein expression increased significantly (P<0.05)

body weight of mice in 7 d SLBZ group increased

diarrhea and bloody stool symptoms improved obviously

pathological score decreased

the amount of mucus secretion increased

apoptotic cells decreased

and the expression of occludin increased (P<0.05). Conclusion: The preventive administration with SLBZ could relieve the symptoms of colitis induced by DSS

which may be closely related to protection of SLBZ on colonic mucosal barrier.