Shenling Baizhusan Alleviates Intestinal Inflammation in Rat Model of Crohn's Disease via p38 MAPK Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo observe the effect of Shenling Baizhusan on the intestinal inflammatory reaction in the rat model of Crohn's disease （CD） and study its relationship with p38 mitogen-activated protein kinase （MAPK） signaling pathway， so as to provide an experimental and theoretical basis for the clinical application of this prescription. MethodA total of 72 SD rats （36 males and 36 females） were randomized into a normal group （n=12） and a modeling group （n=60）. The rats in the modeling group were treated with 2，4，6-trinitrobenzene sulfonic acid （TNBS， 3 mL·kg-1） and then randomized into model， mesalazine （0.21 g·kg-1·d-1）， and low-， medium-， and high-dose （5.88， 11.76， 23.59 g·kg-1·d-1， respectively） Shenling Baizhusan groups. The rats in the drug intervention groups were administrated with corresponding agents by gavage for 14 days， and those in the normal and model groups with an equal volume of distilled water. The disease activity index （DAI） score of inflammatory bowel disease （IBD） and the colon mucosal damage index （CMDI） score of rats in each group were assessed after gavage. Hematoxylin-eosin （HE） staining was used to observe the histopathological changes in the colon， and enzyme-linked immunosorbent assay （ELISA） to measure the levels of tumor necrosis factor alpha （TNF-α）， interleukin-1 （IL-1）， and interleukin-6 （IL-6） in the serum. Western blotting was employed to determine the protein levels of p38 MAPK， phosphorylated p38 MAPK （p-p38 MAPK）， p65 nuclear factor （NF）-κB， and phosphorylated-p65 NF-κB （p-NF-κB p65） in the colon tissue. Quantitative real-time polymerase chain reaction was conducted to determine the miRNA levels of p38 MAPK and NF-κB p65 in the colon tissue. ResultThe model group had higher DAI and CMDI scores than the normal group （P<0.01） and showed damaged epithelial cells in the colon mucosa， disarrangement of glands， damaged simple tubular glands， local necrosis， infiltration of a large number of inflammatory cells and lymphocytes in each layer， and presence of ulceration. Compared with the normal group， the model group showed elevated levels of TNF-α， IL-1， and IL-6 in the serum （P<0.01） and up-regulated protein levels of p-p38 MAPK and p-NF-κB p65 and miRNA level of p38 MAPK in the colon tissue （P<0.01）. Compared with the model group， mesalazine and high- and medium-dose Shenling Baizhusan decreased the DAI and CMDI scores （P<0.05， P<0.01）， repaired the mucosal epithelium of the colon tissue， increased the glands and goblet cells， lowered the levels of TNF-α， IL-1， and IL-6 in the serum （P<0.05， P<0.01）， and down-regulated the protein levels of p-p38 MAPK and p-NF-κB p65 and the miRNA level of p38 MAP in the colon mucosa （P<0.01， P<0.05）. ConclusionShenling Baizhusan can reduce intestinal inflammation of CD rats and promote the repair of colon mucosa by down-regulating the protein levels of p-p38 MAPK and pNF-κB p65 and the miRNA level of p38 MAPK to inhibit the p38 MAPK pathway.