Therapeutic efficacy and mechanism of action of benvitimod on the rat colitis model of inflammatory bowel disease

Objective To investigate the therapeutic efficacy and mechanism of action of benvitimod on the rat colitis model of inflammatory bowel disease (IBD). Methods Dextran sulfate sodium (DSS) was used to induce the rat colitis model. A total of 35 rats were randomly divided into five groups (n=7), including the control, IBD, mesalazine (100 mg/kg·2 d), benvitimod-low (10 mg/kg·2 d) and benvitimod-high (20 mg/kg·2 d) group. During the experimental period, the score of body weight, bleeding and diarrhea, and disease activity index (DAI) were assessed daily. At the end of the experiment, the length of colon was measured. Colonic tissue was stained with hematoxylin and eosin (HE) for histological examination. The enzyme-linked immunosorbent assay(ELISA)was used to determine the concentration of interleukin(IL-6) and tumor necrosis factor(TNF-α)in serum. Results No death was found in each group. At day 8, compared with the IBD group, the benvitimod-high group reversed the lost body weight (t=8.367, P<0.01) and decreased the DAI (t=10.151, P<0.01) and histological scores (t=4.323, P=0.001). The colon in the benvitimod-high group was longer than that in the DSS group (t=3.160, P=0.008). The concentration of IL-6 (t=3.321, P=0.02) and TNF-α (t=2.806, P=0.03) in the benvitimod-high group was lower than that in the IBD group. There was no significant difference among the mesalazine, benvitimod-low and benvitimod-high group. Conclusion Benvitimod can ameliorate DSS-Induced colitis in rats and has a similar effect with mesalazine. Key words: Inflammatory bowel diseases; Benvitimod; Dextran sulfate sodium