Effect of Tongxie Yaofang on Expressions of Colon SERT and Liver 5-HT2AR Proteins in Rats with Ulcerative Colitis Model of Liver Stagnation and Spleen Deficiency / 中国实验方剂学杂志

Objective:To observe the effect of Tongxie Yaofang on the expressions of colon serotonin transporter （SERT）， liver 5-hydroxytryptamine_2A receptor （5-HT_2AR） protein， serum 5-HT and inflammatory factors in ulcerative colitis （UC） model rats of liver stagnation and spleen deficiency， in order to explore the basis of syndrome of liver stagnation and spleen deficiency and the intervention mechanism of Tongxie Yaofang. Method:Fifty male SD rats were randomly divided into blank control group， model group， high， medium and low-dose Tongxie Yaofang group （10，5，2.5 g·kg^-1）， and salazosulacil group （0.3 g·kg^-1）. The ulcerative colitis model of liver depression and spleen deficiency was established by 2，4，6-trinitrobenzene sulfonic acid （TNBS）/ethanol solution enema + restraint stress + diet loss. After successful modeling， the samples were collected after 21 days of drug intervention. Htoxylin eosin （HE） staining and oil red staining were used to observe the pathological changes of colon and liver in each group. Serum interleukin-6 （IL-6）， IL-9， 5-HT and superoxide dismutase （SOD） were detected by enzyme linked immunosorbent assay （ELISA）. Protein expressions of SERT in the colons and 5-HT_2AR in liver of rats were detected by Western blot. Result:Compared with the normal group， obvious ulcers were formed in the colon and lipid droplets in the liver increased in the model group， serum levels of IL-6， IL-9 and 5-HT in the model group increased， while the level of SOD decreased （<italic>P</italic><0.05）. The protein expression of SERT in colon decreased， whereas the protein expression of 5-HT_2AR in liver increased （<italic>P</italic><0.05）. Compare with model group， the pathological damage of colon was improved， and the formation of lipid droplets in liver was reduced in high， medium-dose Tongxie Yaofang groups and sulfasalazine group. The serum levels of IL-6， IL-9 and 5-HT decreased， while the level of SOD increased in Tongxie Yaofang group and sulfasalazine group （<italic>P</italic><0.05）. The protein expression of SERT in colon increased in high，low-dose Tongxie Yaofang groups and sulfasalazine group， and the protein expression of 5-HT_2AR in liver decreased in medium， low dose Tongxie Yaofang groups and sulfasalazine group （<italic>P</italic><0.05）. Conclusion:Tongxie Yaofang may reduce the content of 5-HT， and regulate the intestinal motility and sensory system by up-regulating the expression of SERT in the colon， inhibit the expressions of IL-6，IL-9 and other inflammatory factors， and play an anti-inflammatory role， reduce the content of 5-HT and the expression of 5-HT_2AR in the liver， increase the level of SOD， regulate emotion and lipid metabolism in the liver， and then exert the intervention effect on ulcerative colitis with liver depression and spleen deficiency on the whole.