Inhibition Effects Of IL-1?,IL-6,TNF-? Expression By Triptolide On Experinmental Ulcerative Colitis In Mice

Part one: The Expression and Significance of Chemokine IL-1? and IL-6 in Ulcerative ColitisPurpose: To investigate the expression and significance of chemokine IL-1? and IL-6in ulcerative colitis(UC).Methods: Forty–two in-patients with active UC in Affiliated Hospital of Nantong University from Dec.2012 to Dec.2015 were consecutively recruited in our study and twenty healthy volunteers were served as control group.Expression of IL-1? and IL-6 in the inflamed mucosa of UC group and normal colonic mucosa of control group was determined respectively by immunohistochemistry(IH),and association of IL-1? and IL-6with disease severity was evaluated in UC patients.Twenty Balb/c female mice were randomly divided into normal control(NC)group(n=10)and Dextran sulfate sodium(DSS)-induced UC group(n=10).NC group received distilled water for 7 days.UC group received solution of 5% DSS for 7 days.The mice were observed daily with respect to body weight,mental condition,activity,diet,and defecation.On day 8,all the mice were sacrificed by luxation vertebrae.DAI,macroscopic colon injury scores and microscopic histopathology scores were evaluated.To testify the role of IL-1? and IL-6 in the pathogenesis of UC,Serum IL-1? and IL-6 concentrations were determined by enzyme-linked immunosorbent assay(ELISA)while mRNA expressions in the inflamed colonic mucosa specimen were examined by reverse transcription polymerase chain reaction(RT-PCR).Result: There was no or minimal expression of IL-1? and IL-6 in the normal colonic mucosa of healthy volunteers.The expression of IL-1? and IL-6 in UC group was significantly higher than that in healthy volunteers(4.03±0.62 vs.0.46±0.10,4.32±0.86 vs.0.62±0.15,P<0.05).The expression level of IL-1? and IL-6 was positively associated with disease activity in UC group.In the DSS-induced mice colitis group,DAI,macroscopic colon injury scores and microscopic histopathology scores were remarkablyincreased and clinical manifestation was significantly exacerbated as compared with NC group(P<0.05).Meanwhile,serum concentrations and gene expression of IL-1? and IL-6 in the DSS group were significantly higher than that in NC group(P<0.05).Conclusion: The expression level of IL-1? and IL-6 was remarkably upregulated in the inflamed colonic mucosa of UC patients and experimental colitis.IL-1? and IL-6 might be involved in the development of UC via inflammatory response.Part two:Triptolide Ameliorates Intestinal Inflammation in Experimental Colitis by Mechanisms Involving Inhibition of IL-1?,IL-6 and TNF-? OverexpressionPurpose: The study was to explore whether triptolide(TL)could attenuate DSS-induced colitis in mice by repressing the overexpression of IL-1?,IL-6 and TNF-?.Methods To set up mice colitis model,80 Balb/c female mice were randomly classified into 8 groups,normal control group were given distilled water freely for 7 days,the others were given the same solution of 5% DSS to drink for 7 days.Group A(normal control group): untreated,Group B(NS group): treated with intraperitoneal injection of 0.2ml physiological saline once per day.Group C(propanediol group): treated with intraperitoneal injection of 0.2 ml propanediol once a day.Group D(dexamethasone group): treated with intraperitoneal injection of dexamethasone(0.1mg/kg/d)once per day.Group E(mesalazine group): treated with water dissolved mesalazine(20~30mg/kg/d)via nasogastric tube three times a day.Group F(TL low-dose treatment group): treated with intraperitoneal injection of TL(0.20mg/kg dissolved in 20% propanediol).Group G(TL moderate-dose treatment group): treated with intraperitoneal injection of TL(0.40mg/kg dissolved in 20% propanediol).Group H(TL high-dose treatment group): treated with intraperitoneal injection of TL(0.60mg/kg dissolved in 20% propanediol).The mice were observed daily with respect to body weight,mental condition,activity,diet,and defecation.On day 8,all the mice were sacrificed by luxation vertebrae.DAI,macroscopic colon injury scores and microscopic histopathology scores were evaluated.Serum IL-1?,IL-6and TNF-? concentrations were determined by ELISA.mRNA expressions in the inflamed colonic mucosa specimen were examined by RT-PCR while protein expressions were detected by IH and Western Blot.Results In the moderate-dose and high-dose treatment groups,DAI,macroscopic colon injury scores and microscopic histopathology scores was remarkably inhibited and clinical manifestation was significantly improved as compared with that in NS group and propanediol group(P<0.05).Serum levels of IL-1?,IL-6and TNF-? were significantly decreased,and the protein expression of IL-1?,IL-6 and TNF-? in colon tissue was also downregulated in TL moderate-dose and high-dose groups,compared with normal saline treatment or propylene glycol treatment(P < 0.05).No statistical difference was found among TL moderate-dose group,TL high-dose treatment group,mesalazine group and dexamethasone group.Our findings indicated that TL treatment had similar therapeutic effect as dexamethasone and mesalazine,which might be through inhibition of the overexpression of IL-1?,IL-6 and TNF-? in UC.Conclusions Triptolide ameliorates the intestinal inflammation in the experimental colitis by the mechanism involving downregulation of overexpression of IL-1?,IL-6 and TNF-?.Triptolide as a novel therapeutic strategy in UC deserves further investigation.