Efficacy And Mechanism Study Of Tiantian Capsule And Aloe Vera In Treating Ulcerative Colitis

In chapter one,Tiantian Capsule(TTC)is a functional food that has been reported to mitigate constipation.Our previous study found that TTC treatment promoted mucus secretion and maintained the thickness of the colonic mucus layer in constipated model rats.Moreover,mucus was potentially important in the remission of ulcerative colitis(UC).Here,this study aimed to explore the therapeutical effects of TTC in UC and further investigate the potential action mechanism.UC rat model was induced by administering 3%dextran sulfate sodium(DSS)solution for 10 days.TTC(18 mg/kg and 36 mg/kg)or 5-ASA(400 mg/kg)was administered orally during the process of model establishment.The severity of UC was assessed by colon length and disease activity index(DAI).Hi stopatho logical assay of colon was evaluated by H&E staining.Myeloperoxidase(MPO)and inflammatory factors were detected in colon tissue by ELISA.We also examined the thickness of colon mucus layer by Alcian blue stain.The expression of MUC2 and signaling pathway proteins such as PI3K,p-PI3K,AKT,p-AKT,mTOR and p-mTOR were explored using western blotting.TTC(18 mg/kg and 36 mg/kg)administration attenuated UC in aspects of disease activity index,the colon length shortening.Further investigations revealed that TTC not only decreased expression of MPO and pro-inflammatory cytokine,such as IL-6,IL-1βand TNF-α,but also up-regulated the expressions of IL-10.Additionally,the expressions of mucin MUC2 and thickness of the mucus layer were elevated,and the PI3K/AKT/mTOR signal pathway was also inhibited after TTC treatment.Our findings demonstrated that the therapeutical effect of TTC in UC rats is probably due to anti-inflammation and the regulation of mucus barrier.In chapter two,Aloe vera(L.)Burm.f.(Aloe vera)is a medicinal herb that used in Traditional Chinese Medicine practice for the treatment of gastrointestinal diseases such as constipation and colitis.Recent studies also reported its beneficial effect in mitigating UC.Nevertheless,the underlying mechanisms of Aloe vera against UC remain largely unknown.This study aimed to explore a relation between the therapeutical effects of Aloe vera in UC and colonic mucus secretion,and further investigate the underlying pathways through which Aloe vera regulates colon mucus as well as preliminarily studied the main active constitute of Aloe vera to alleviate UC.UPLC-MS/MS were employed to analyze the Aloe vera.The rat models of UC were induced by free subjected to fresh 3%DSS solution for 8 days and then accessed to tap water for 2 days.Aloe vera(18 mg/kg and 72 mg/kg)or 5-ASA(400 mg/kg)was administered orally from day 1 to 10.At the end of experiment,rats were sacrificed and the colon tissues were harvested for analysis.UC symptoms was evaluated by DAI,colon length and H&E staining.The Alcian blue stain were determined colon mucus layer.MPO,mucin and cytokines in colon tissues were determined by ELISA.The expression of PI3K/AKT and PKC/ERK pathway-associated proteins was detected by Western blot.We then evaluated the effects of three main components of Aloe vera(Aloe-emodin,aloin A and B)on mucin secretion and cytokine expression in vitro by ELISA.Oral supplement with Aloe vera resulted in a significantly decreased DSS-induced UC symptoms,including decreased DAI,prevention of the colon length shortening,and alleviation of the pathological changes occurring in colon.The expression of colonic pro-inflammatory mediators,including IL-6,IL-1β and TNF-α were suppressed,yet the expression of IL-10 was up-regulated by Aloe vera treatment.Moreover,Aloe vera significantly up-regulated the expressions of mucin proteins(e.g.,MUC2 and MUC5AC)and increased the thickness of mucus layer in the colon.Further,we revealed that Aloe vera significantly upregulated p-PKC and p-ERK expression and downregulated p-PI3K and p-AKT expression.Finally,we discovered that treatment with aloin A markedly decreased IL-6 levels and increased MUC2 expression in LPS-stimulated LS174T cell.These results support that Aloe vera improved UC by enhancing colon mucus barrier functions in addition to reducing inflammation.Moreover,aloin A might be a main active components of Aloe vera to ameliorate UC.