Therapeutic Effect Of Paeonol On Ulcerative Colitis And Its Mechanism

Objectives:Ulcerative colitis(UC)is a common clinical disease with an increasing incidence in recent years,which still lacks of efficient treatment strategies.Our previous clinical studies have shown that paeonol injection has a therapeutic potential to patients with UC.This study aims to determine the protective effect of paeonolon UC and elucidate the possible underlying mechanisms.Methods:Clinic trials and animal experiments were adopted to investigate the effect of paeonol on UC and its mechanism.Including the following five parts:(1)80 patients with UC were recruited in the digestive department at the Second Affiliated Hospital of Zhengzhou University from January 2015 to September 2016,were divided into control group(treated with mesalazine or prednisone)and treatment group(basictreatments with intramuscular injection of paeonol).The level of platelet,hemoglobin,albumin,C-reactive protein,erythrocyte sedimentation rate,oxidative stress,inflammatory factor,ICAM-1 and MMP-9 in the serum were determined on the day 14 after treatment,and the clinical efficacy of paeonol was analyzed;(2)Protective effect of paeonol on rats with DSS-induced UC.After the induction of UC in rats by DSS,rats were randomly divided into control group,model group,paeonol low dose group,paeonol high dose group and positive control group.The changes of body weight and DAI score were recorded,the concentration of inflammatory cytokine in serum and MDA,SOD in plasma were determinedby ELISA,m RNA expression level of inflammatory cytokines in colon tissue were quantified with RT-PCR,the expression level of ICAM-1 and MMP-9 in colonic mucosa were detected with Western Blot,the damage degree of colorectal mucosa was also assessed;(3)Anti-inflammatory effect and mechanism of paeonol on UC induced by DSS.UC rats were randomly divided into control group,model group,paeonol low dose group,paeonol middle dose group,paeonol high dose group and positive control group,the concentration of inflammatory cytokine in serum were detected by ELISA,the expression level of inflammatory m RNA in serum were detected with RT-PCR,the expression of p-IκB,p-p65,p-IKKα/β,p-Erk1/2,p-JNK and p-p38 of the NF-κB and MAPK signaling pathways were detected by Western Blot;(4)The influence of paeonol on CD4+T cell subsets and relating cytokines.UC rats were prepared by DSS,and the proportion of CD4+T cell subsets(Th1,Th2,Thl7 and Treg cells)was detected by flow cytometry and the expression level of transcription factors of CD4+T cells was measured by RT-PCR,CD4+T cytokines was analyzed by antibody microarray.Th1,Th2,Thl7 and Treg cells in colonic mucosa were detected by immunohistochemical staining,IL-23R/Jak2/tat3 signaling pathway was detected by Western Blot;(5)Effects of paeonol on intestinal growth factors in UC rats.UC rats were randomly divided into control group,model group,paeonol low dose group,paeonol high dose group and positive control group,SABC immunohistochemical staining method was used to observe the mean vascular density,MASSON staining was used to observe the microvascular thrombosis.The levels of VEGF,b FGF and PDGF in plasma and colonic were measured by ELISA,levels of NO in plasma and colonic tissues were measured by radioimmunoassay,expression levels of HIF-1 in plasma and colon were measured by Western Blot.Results:(1)Paeonol can significantly improve the clinical symptoms and intestinal mucosal lesions,eliminate complications effectively,and reduce the concentration of platelet,C-reactive protein,erythrocyte sedimentation rate,expression levels of ICAM-1 and MMP-9 in UC patients.The level of hemoglobin,albumin increased after the treatment of paeonol without serious adverse reactions;(2)Paeonol inhibits the loss of body weight and improves the DAI index effectively.Compared with control group,paeonol treatment reduces the expression levels of IL-1,IL-4,INF-γ,TNF-α and oxidative stress,but increases IL-10 in UC rats,in addition,the expression of ICAM-1,MMP-9 protein and the formation of micro-thrombosis were reduced,the average vascular density and the formation of micro-thrombosis were improved;(3)Paeonol can significantly inhibits the expressionof proinflammatory cytokines such as IL-1β,IL-4,IL-6,IFN-γ,TNF-α and MCP-1 protein and m RNA levels in UC rats.It also reduces the levels of p-IκB,p-p65,p-IKKα/β,p-Erk1/2,p-JNK and p-p38 in NF-κB and MAPK signaling pathways,thus results in an inhibition of the activity of NF-κB and MAPK pathway;(4)Paeonol increases the proportion of Treg,downregulates the ratio of Thl,Th2 and Thl7 cells,Elevated Fox P3 level and reduced GATA3,RORc,T-bet,IL-2,IL-4,IL-21,IL-17 expression levels.Paeonol also inbibits the expression level of IL-23 R,JAK-2 and the phosphorylation of STAT3,enhances the phosphorylation of smad,then has an inhibition on IL-23R/Jak2/Stat3 signaling pathway;(5)Paeonol could improve the average vascular density and microthrombosis effectively in UC rats,decrease the levels of VEGF,NO,b FGF and HIF-1 in plasma and colonic tissues.Conclusions:(1)Paeonol injection exerts a good therapeutic effect on UC possibly through reducing the level of oxidative stress,inhibiting the expression of inflammatory factor and vascular cytokines;(2)Paeonol can alleviate oxidative stress and the m RNA expression of inflammatory factors,eliminate inflammatory response,and inhibit the expression of ICAM-1,MMPx cadvdd-9 protein,efficiently improve the intestinal and vascular function;(3)Paeonol protects against chronic ulcerative colitis by restoration of the imbalance of CD+T cells through inhibiting the activity of IL-23R/Jak2/Stat3 signaling and NF-κB and MAPK pathway;(4)Paeonol improves intestinal mucosal-associated growth factor expression and affects the relevant metabolic pathways.