Traditional Chinese medicine has been used for treating diseases for thousands of years. It has not been widely used in the world because of its complex composition and obscure pharmacological mechanisms. With the development of science and network pharmacology, the mechanism of traditional Chinese medicine is now becoming more clear.On the basis of previous studies, the immune-TNBS-ethanol rat model was established. The intervention mechanism of Traditional Chinese medicine in UC rats was explored by observing the expression of related factors in rats. We found that Sodium Houttuyniae, Matrine and HQHLD could reduce the intestinal ulcer formation and tissue necrosis and decrease the intestinal inflammatory response of UC, so as to laterally verify the the effectiveness of traditional Chinese medicine against ulcerative colitis.
TGF - β and IL − 10 are both negative regulators of the inflammatory response. TGF - β1 is not only a multi-effect cytokine, but also an important anti-inflammatory factor of UC. Normal expression can inhibit inflammatory reaction and cell proliferation, regulate cell growth, cell differentiation and immune function, while overexpression can promote the process of intestinal fibrosis[13, 14]. Rezaie et al. found that there was a lot of TGF - β1 in the saliva of UC patients, which was mainly expressed in the inflammatory cells of the lamina propria near the oral surface, suggesting that TGF - β1 may play an important role in promoting epithelial healing after mucosal injury. Babyatsky[15, 16] found that the expression of TGF - β was significantly increased in the mucosa of UC and CD patients. The expression of TGF - β1 mRNA was mainly located in the lamina propria cells on the surface of the intestinal mucosa with a large number of inflammatory cells in UC and CD patients and the TGF - β1 regulated the remodeling and functional characteristics of epithelial cells in the lamina propria of mucosa, which could be the key cytokine in the inflammatory phase. Monteleone first revealed that the defect of the TGF - β1 cascade amplification signal was related to the pathogenesis of IBD. Therefore, TGF - β1 induction played an important role in the regulation of the intestinal immune system. The increase of TGF - β1 and its receptor TGF β RI in the active phase of UC could be the protective response of the body, which had the role of remodeling and maintaining the remission of UC pathological intestinal mucosa. IL − 10 was mainly produced by Th2 cells, monocytes, and macrophages. It can down-regulate the production of pro-inflammatory cytokines and Th1 cytokines, inhibit the activation of monocytes, macrophages, granulocytes and T cells, and play an important role in a stable mucosal environment. The anti-inflammatory cytokine IL − 10 dampens intestinal inflammation and is therefore a good candidate gene for IBD[18, 19]. In animal experiments, it was found that IL − 10 knockout mice could spontaneously lead to chronic non-infectious intestinal inflammation in the general environment without specific pathogenic bacteria. Clinical studies had found that the expression of IL − 10 mRNA in the intestinal mucosa of UC patients was reduced, and so was the production of IL − 10 mRNA by monocytes in the lamina propria of the inflammatory colon mucosa. The over-expression of IL − 10 in different animal models of ulcerative colitis had proved beneficial. It was found that IL − 10 modified by Lactococcus had a positive effect on the improvement of experimental colitis[22, 23]. Bifidobacterium modified IL − 10 expanded the bacterial species of IL-10 intestinal delivery.
The results of this study showed that the expression of anti-inflammatory factor TGF - β1 in intestinal tissue decreased after 4 weeks of administration, which indicated that the synthesis of TGF - β1 in the body decreased and could not play the role of inhibiting the of Traditional Chinese medicine inflammatory reaction. After treatment, TGF - β1 levels in each group had an upward trend, and the expression of TGF - β1 in all Traditional Chinese medicine group (Sodium Houttuyniae group, Matrine group and HQHLD group) increased significantly, and the most significant increase was found in the HQHLD group. The above results showed that the traditional Chinese medicine worked better in increasing the anti-inflammatory factors in the intestine, and it also showed that the anti-inflammatory effect of Traditional Chinese medicine compound was higher than that of a single monomer. After 4 weeks of administration, the level of TGF - β1 in the serum of the model group increased significantly, which could be owing to the activation of anti-inflammatory and repair mechanisms. The expression levels of TGF - β1 in all treatment groups were higher than in the normal group, especially in the Sodium Houttuyniae group and the HQHLD group, which indicated that Sodium Houttuyniae and HQHLD had stronger anti-inflammatory and repair functions, and also showed that the Sodium Houttuyniae and HQHLD were strengthened the body and removed pathogenic factors. The expression of IL − 10 in the model group was significantly lower than that of normal group. The expression of IL − 10 in all treatment groups was significantly higher than that in the model group. The increase of IL − 10 in Traditional Chinese medicine treatment groups were particularly significant, which indicated that the UC model inhibited the expression of anti-inflammatory factor IL − 10. The Sodium Houttuyniae, Matrine and HQHLD could increase IL − 10 and play an anti-inflammatory role.
Adhesion molecule is a kind of transmembrane glycoprotein which can mediate cell adhesion, chemotaxis and homing of lymphocytes. It is a kind of adhesion molecule selectively expressed on the surface of vascular endothelial cells of the intestinal mucosa and its related lymphoid tissues, which mainly mediates the selective homing of lymphocytes to normal mucosa and participates in the immune response and inflammatory response in the gastrointestinal tract. The integrin family member α4β7 is the receptor of MadCAM-1. After CD45RB high CD4 + T cell reconstruction, the colitis model of SCID mice were treated with Anti-MadCAM-1 or α4β7 specific antibody, the number of lymphocytes in the colon was significantly reduced, suggesting that MadCAM-1 /α4β7 participated in the infiltration of lymphocytes into the inflammatory bowel. Battat found that the inhibition of α4β7-mediated lymphocyte trafficking was effective in ulcerative colitis. Clinical and animal experimental studies had confirmed that UC was related to the abnormal expression of MadCAM-1, and the expression of MadCAM-1 in vascular endothelial cells in the inflammatory colon of UC patients was up-regulated. The expression level of MadCAM-1 in the venules of the lamina propria of colon in mice with hapten induced colitis or IL-2 gene knockout mice was significantly increased. The expressions of MadCAM-1 in the lamina propria and submucosa of the mouse colitis model induced by Oxazolidone, TNBS and DSS were also increased. Shigematsu applied anti-MadCAM-1 monoclonal antibodies to pretreat colitis in mice, which significantly reduced the adhesion of lymphocytes on endothelial cells of the intestinal mucosa. Inhibition of MAdCAM-1 and leukocyte recruitment can improve DSS induced colitis.
The results of the PCR experiments showed that the expression of MadCAM-1 mRNA in the intestinal tissue increased significantly after 4 weeks of drug administration, suggesting that the pathogenesis of intestinal injuries in this UC model was related to the directional homing of lymphocytes to the intestinal mucosa mediated by MadCAM-1. Sodium Houttuyniae, Matrine and HQHLD could reduce the expression of MadCAM-1 mRNA in intestinal tissues, the effect of HQHLD was particularly significant. After 4 weeks of drug administration, the expressions of MadCAM-1 in the serum of all treatment group were up-regulated, while the expressions of MadCAM-1 in intestinal tissue were down-regulated, which could be due to the increase of lymphocyte homing to the peripheral blood and other tissues, and the decrease of lymphocyte homing to the intestinal tissue in treatment groups, so as to reduce intestinal inflammatory reactions. The changes after administering HQHLD were the most significant, which indicates that the effect of Chinese medicine compound HQHLD on UC was the best.