The mechanism of alopolysaccharide protecting ulceralive colitis. Lin Hu,Honglang Li,Weifeng Li,Junmin Chen,Jiantao Yang,Junjing Gu Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie The aim of this study is to explain the mechanism of alopolysaccharide protecting ulceralive colitis in cells and animal models. We divided this study into two parts: cell and animal research parts. In the cell research, HT-29 cells were divided into normal group, model group, aloe polysacchride group and positive drug group, the cell model was used by tumor necrosis factor- α (TNF-α) combine with LPS, detecting IL-6 concentration of difference groups by Elisa testing, Apoptosis of each group was detected by flow cytometry. We detected JAK2 and STAT-3 gene expressions of difference groups by RT-PCR. WB assay was used to detect the expression of JAK2, p-JAK2, STAT-3 and p-STAT3 protein in the cells of each group. In animal experiment, SD rats were divided into normal group, model control group, aloe polysaccharide group and positive drug group. A rat model of colitis was established with 2,4,6- three nitrobenzene sulfonic acid (TNBS). IL-6 concentrations of difference groups were measured by Elisa test, and compared the colon length of difference groups, H&E staining observation of colon tissue changes in each group. We observed JAK2, p-JAK2, STAT-3 and p-STAT3 protein expression in colon tissues by immuno histochemistry and measured JAK2 and STAT-3 gene expression of difference groups by RT-PCR. We found IL-6 concentration and cell apoptosis rate of Model group were significantly up-regulation compared with normal group (P<0.05, respectively) in the cell experiment. Compared with Model group, The IL-6 concentration and apoptosis rate of aloe polysaccharide group and positive drug group were significantly down-regulation (P<0.05, respectively). In the gene expression, JAK2 and STAT-3 expression of aloe polysaccharide group and positive drug group were higher than model group (P<0.05, respectively). JAK2, p-JAK2, STAT-3 and p-STAT3 protein expression of Aloe polysaccharide group and positive drug group were lower than model group. In animal experiment, compared with model group, The serum IL-6 concentration of aloe polysaccharide group and positive drug group were significantly decreased (P<0.05, respectively), colon length was improved by drug treated, The HE stain of aloe polysaccharide and positive drug group were significantly improved. In immuno histochemistry, The JAK2, p-JAK2, STAT-3 and p-STAT3 protein expression of aloe polysaccharide and positive drug group was significantly improved, The JAK2 and STAT-3 gene expression of aloe polysaccharide group and positive drug group were signivicantly lower than those of model group (P<0.05, respectively). Depending on the results, We supposed Aloe polysaccharide could effectively control the apoptosis of colonic tissues by inhibiting the JAK2/STAT-3 signaling pathway in vovo and vitro. 10.1016/j.biopha.2016.11.138