ObjectiveTo explore the role of interleukin-6 （IL-6）/signal transducer and activator of transcription 3 （STAT3） pathway in the balance of T helper 17 （Th17）/regulatory T （Treg） cells in ulcerative colitis （UC） with internal dampness-heat accumulation syndrome and the intervention mechanism of Shaoyaotang. MethodA total of 60 SD rats were randomized into blank group （equivalent volume of normal saline）， model group （equivalent volume of normal saline）， western medicine control group （0.42 g·kg^-1 mesalazine）， and low-dose （11.1 g·kg^-1）， medium-dose （22.2 g·kg^-1）， and high-dose （44.4 g·kg^-1） Shaoyaotang groups. UC with internal dampness-heat accumulation syndrome was induced in rats with the compound method except for the blank group. The administration lasted 14 days for each group. At 24 h after the last administration， rats were killed and the spleen and colon tissues were separated. The histopathological changes of colon were observed based on hematoxylin and eosin （HE） staining and the levels of interleukin-17 （IL-17） and transforming growth factor-β₁ （TGF-β₁） in colon tissue were detected by immunohistochemistry （IHC）. Flow cytometry was employed to determine the levels of Th17/Treg cells in the spleen， and Western blot to measure the levels of IL-6 and STAT3 proteins in colon tissue. ResultCompared with the blank group， the model group had lesions such as congestion and erosion， low percentage of spleen Treg cells （P<0.01）， high percentage of Th17 cells （P<0.01）， and high levels of IL-6 and STAT3 proteins in colon tissue （P<0.01）. Compared with the model group， the administration groups showed alleviation of colon injury， high percentage of spleen Treg cells （P<0.05， P<0.01）， low percentage of Th17 cells （P<0.01）， and low levels of IL-6 and STAT3 proteins in colon tissue （P<0.01）. ConclusionShaoyaotang regulates the balance of Th17/Treg by inhibiting the IL-6/STAT3 pathway， thereby relieving the pathological damage of UC rats with internal dampness-heat accumulation syndrome and affecting their immune function.

ObjectiveTo investigate the role of cyclic adenosine monophosphate （cAMP）/protein kinase A （PKA）/cAMP-response element binding protein （CREB） signaling pathway in water metabolism and intestinal epithelial permeability in ulcerative colitis （UC） and the intervention mechanism of Shaoyaotang based on the theory of large intestine governing fluids. MethodSixty male SD rats were divided into blank group， model group， mesalazine group （0.42 g·kg^-1）， Shaoyaotang low-dose group （11.1 g·kg^-1）， Shaoyaotang medium-dose group （22.2 g·kg^-1） and Shaoyaotang high-dose group （44.4 g·kg^-1）， with 10 in each group. The UC rat model of internal retention of dampness-heat was established by compound factors. The blank group and the model group were given normal saline （ig）. The mesalazine group was given mesalazine （ig）， and Shaoyaotang low-， medium- and high-dose groups were administrated with corresponding doses of Shaoyaotang （ig）. The treatment lasted for 14 days. The diarrhea score and fecal moisture content of rats in each group were observed. The contents of diamine oxidase （DAO） and D-lactic acid in plasma were detected by enzyme-linked immunosorbent assay （ELISA）. The protein expressions of aquaporin （AQP）8， AQP4， ZO-1 and Occludin in colon tissues were detected by immunohistochemistry， while those of cAMP， PKA and CREB in colon tissues were determined by Western blot. ResultCompared with the normal group， the model group had elevated diarrhea score and fecal moisten content （P<0.01）， increased contents of DAO and D-lactic acid in plasma （P<0.01） and decreased protein expressions of ZO-1， Occludin， AQP8， AQP4， cAMP， PKA and CREB in colon （P<0.01）. Compared with the conditions in the model group， the contents of DAO and D-lactic acid in plasma in each administration groups were lower （P<0.01）， while the protein expressions of ZO-1， Occludin， AQP8， AQP4， cAMP， PKA and CREB in colon were higher （P<0.01）. ConclusionShaoyaotang alleviates the diarrhea in UC， probably through activating cAMP/PKA/CREB signaling pathway， up-regulating expressions of AQPs， enhancing tight junctions in intestinal epithelium and thus improving the water metabolism in colon and the intestinal mucosal permeability.

ObjectiveTo investigate the effect of Shaoyaotang on fecal metabolites in rats with ulcerative colitis （UC） induced by 2，4，6-trinitrobenzenesulfonic acid （TNBS） based on liquid chromatography-mass spectrometry （LC-MS）. MethodMale SPF SD rats were randomly divided into normal group， model group and Shaoyaotang group （11.1 g·kg^-1）. Except for normal group， UC rat model was induced by TNBS， and each group was given normal saline except Shaoyaotang group. All groups were treated for 7 days， and the general condition and disease activity index （DAI） were observed. Hematoxylin-eosin （HE） staining was used to observe the histopathological changes of colon， and the protein expressions of interleukin-8 （IL-8） and interleukin-22 （IL-22） in colon tissue were detected by immunohistochemistry （IHC）. Rat fecal samples were detected by LC-MS， and the data were analyzed by principal component analysis （PCA） and partial least squares discriminant analysis （PLS-DA）. Human Metabolome Database （HMDB） and Kyoto Encyclopedia of Genes and Genomes （KEGG） were searched to screen differential metabolites in combination with literature reference. Then， pathway enrichment analysis was conducted using Metabo Analyst 5.0. ResultShaoyaotang （ig） decreased the DAI of UC rats. Compared with the normal group， the model group had damaged colonic mucosa structure， submucosal inflammatory cell infiltration， increased protein expressions of IL-8 （P<0.01） and IL-22 （P<0.05） in colon tissue. Compared with the conditions in the model group， the colonic damage was alleviated in the Shaoyaotang group， and the protein expressions of IL-8 and IL-22 in colon tissue were decreased （P<0.01）. After screening， 15 differential metabolites were identified from the Shaoyaotang group， and the involved pathways mainly included biosynthesis of unsaturated fatty acids， linoleic acid metabolism， terpenoid backbone biosynthesis， porphyrin and chlorophyll metabolism， amino sugar and nucleotide sugar metabolism， pyrimidine metabolism and steroid hormone biosynthesis. ConclusionShaoyaotang has a therapeutic effect on UC， and its anti-inflammatory effect may be related to improving lipid metabolism and regulating the metabolism of cofactors and vitamins as well as the abnormal carbohydrate metabolism.

Shaoyaotang is composed of Cptidis Rhizoma， Scutellariae Radix， Rhei Radix et Rhizoma， Paeoniae Radix Alba， Angelicae Sinensis Radix， Aucklandiae Radix， Arecae Semen， Cinnamomi Cortex and Glycyrrhizae Radix et Rhizoma， with the functions of clearing away heat， eliminating dampness， regulating Qi and activating blood. Thus， it is proposed as the main formula for the treatment of dampness-heat dysentery by later generations of doctors. In modern clinical application， in addition to original Shaoyaotang， its modified formulas are also used for the treatment of ulcerative colitis， and can be used in combination with other prescriptions （such as Tongxie Yaofang， Pulsatilla Soup， Shenling Baizhu San）， western medicine （such as mesalazine， sulfasalazine， Infliximab）， traditional Chinese medicine （TCM） acupuncture or moxibustion and other characteristic therapies. Clinical efficacy results indicate that Shaoyaotang and its modified formulas can significantly lower Mayo Endoscopic Score （MES）， Baron score， TCM syndrome score and other disease scores， and improve patients’ intestinal symptoms， with few side effects. Experimental pharmacological studies reveal that Shaoyaotang can inhibit tumor necrosis factor-α （TNF-α）， nuclear transcription factor-κB （NF-κB）， interleukin-1β （IL-1β） and other pro-inflammatory factors to up regulate the expression of anti-inflammatory factors such as interleukin-10 （IL-10）， thereby reducing the inflammatory response. The formula could also reduce apoptosis by regulating inflammatory signaling pathway and blocking the chain reaction， and repair abnormal immune barrier by balancing immune axis and regulating immune proteins. Additionally， it could adjust the balance of intestinal flora， promote intestinal epithelial cell regeneration and improve mucosal permeability， so as to restore the balance of intestinal environment and thus treat ulcerative colitis. Its monomers baicalin， paeoniflorin， and berberine have anti-inflammatory， antibacterial， metabolism-regulating and other effects. This paper systematically reviewed the clinical and basic research progress of Shaoyaotang in the treatment of ulcerative colitis.