Anti-inflammatory And Analgesic Effects And Mechanism Of Xiaojianzhong Tang On Intestinal Inflammation Induced By High-fat Diet

Background:The theory of "High Fat Diet Injures Spleen " is derived from Li Dongyuan’s Pi Wei Lun,and the function of spleen in TCM includes that of the almost whole digestive system such as stomach and intestine.The current study found that high-fat diet induced intestinal inflammation,consistent with this theory.Xiaojianzhong tang is composed of Jiaoyi,Paeonia lactiflora,Guizhi,Glycyrrhiza uralensis,Jujube and Ginger,with the effect of warming and tonifying Medium Jiao and relieving pain,and it is effective in treating intestinal inflammatory diseases such as ulcerative colitis and irritable bowel syndrome,but its molecular mechanism is not completely clear.TRPV1 plays a key role in mediating high-fat diet-induced intestinal inflammation.Fatty acids cause CGRP、SP release through activation TRPV1,leading to neurogenic inflammation.Existing evidence shows that many compounds that activate TRPV1 can be isolated from the constituent herbs of XiaoJianzhong tang,such as the spicy ingredients of ginger 6-gingerol,10-gingerol,6-shogaol,ginger ketone and so on.TRPV1 is closely related to the pain mechanisms.Earlier,our group found that the main components of licorice exert TRPV1 inhibitory effect.Therefore,we propose the hypothesis that Xiaojianzhong tang alleviates the intestinal inflammation induced by high fat diet by the mechanism of regulating TRPV1 and downstream CGRP,SP.In this study,we use behavioral,histopathology,molecular biology and other techniques.The rat model of intestinal inflammation induced by high fat diet was used of studying the molecular mechanism of Xiaojianzhong tang in the treatment of intestinal inflammatory diseases,and to expand the modern molecular biological connotation of the theory of "High Fat Diet Injures Spleen ".Objective:To study the anti-inflammatory and analgesic mechanism of Xiaojianzhong tang on intestinal inflammation induced by high fat diet.Methods:1 High-fat diet for 8 weeks induced intestinal inflammation model in rats,Xiaojianzhong granule intervention with different doses during 7～8 weeks,to observe the general situation of rats,to detect the effect of Xiaojianzhong tang on pain behavior in rats through cold plate experiment,hot plate experiment,and Von Frey experiment.2 On the rat model of intestinal inflammation induced by high fat diet,the serum inflammatory factor IL-10、IL-22、TNF-α concentration was detected by ELISA method,and the histopathological changes were observed by HE staining in colon and ileum of rats.3 The expression of TRPV1、NK1R、CGRP in rat ileal and colon tissues was detected by immunohistochemistry in rat model of intestinal inflammation induced by high fat diet.Results:1 General Situation of RatsHigh fat diet caused diarrhea,weight loss,mental malaise,decreased activity,burnout,decreased reactivity,dull hair color and fur loss.2 Rats’ Pain Behavior Results2.1 Cold plate experiment:Compared with the normal group,the threshold value of cold pain in the model group was significantly shortened(P<0.05);compared with the model group,the threshold value of cold pain in the positive drug group and Xiaojianzhong groups increased(P<0.01).2.2 Hot plate experiment:Compared with the normal group,the threshold value of heat pain in the model group was significantly shortened(P<0.01);and compared with the model group,the threshold value of heat pain in the three dose groups of Xiao Jianzhong could be prolonged(P<0.01 or P<0.05).2.3 Von Frey experiment:Compared with the normal group,the number of pain responses in the model group increased significantly(P<0.01);and compared with the model group,the number of pain responses in the positive drug group and three Xiao Jianzhong groups decreased(P<0.01).compared with the Xiaojianzhong low dose group,XiaoJianzhong high and medium dose groups increased the number of pain responses(P<0.01).3 Serum Inflammatory Factor Results3.1 Serum IL-10 concentration:Compared with normal group,model group has no significant difference in serum IL-10 concentration(P>0.05).The serum IL-10 concentration in Xiaojianzhong high dose group increased compared with the model group(P<0.01).3.2 Serum IL-22 concentration:Compared with normal group,there was no significant difference in serum IL-22 concentration in model group(P>0.05).Compared with the model group,the serum IL-22 concentration in Xiaojianzhong medium and low dose and positive drug group increased significantly(P<0.01 or P<0.05).3.3 Serum TNF-α concentration:Compared with normal group,serum TNF-α concentration in model group increased(P<0.05).The serum TNF-α concentration in Xiaojianzhong high,medium and low dose groups decreased significantly compared with model group(P<0.01 or P<0.05).Compared with the positive drug group,serum TNF-α concentration in Xiaojianzhong high dose group decreased(P<0.05).The serum TNF-α concentration in high dose group was significantly lower than that in medium and low dose groups(P<0.01).4 Pathological Results4.1 Colon:Compared with normal group,the pathological score of colon tissue in model group increased significantly(P<0.01).The pathological scores of treatment groups except for the low-dose group decreased compared with the model group(P<0.01).Compared with the positive drug group,the pathological score of Xiaojianzhong high dose group decreased significantly(P<0.01).The pathological score of Xiaojianzhong high dose group was significantly lower than medium and low dose group(P<0.05).4.2 Ileum:Compared with normal group,the pathological score of ileum tissue in model group increased(P<0.01).The pathological score of ileum in positive group,Xiaojianzhong high dose and medium dose group decreased significantly(P<0.01).Compared with the positive drug group,the ileal pathological score was significantly reduced in Xiaojianzhong high dose group(P<0.05).Compared with the Xiaojianzhong low dose group,high and medium dose groups decreased the pathological score.5 Immunohistochemical Results5.1 Comparison of TRPV1 Positive Expressions5.1.1 Colon:Compared with normal group,the expression of TRPV1 in model group was significantly up-regulated(P<0.01).The expression of colon TRPV1 in rats in each treatment group was down-regulated compared with the model group(P<0.01),Compared with the positive drug group,the expression of TRPV1 in Xiaojianzhong high dose group increased significantly(P<0.01).5.1.2 Ileum;Compared with normal group,the TRPV1 expression of ileum tissue in model group was significantly up-regulated(P<0.01).Compared with the model group,the expression of ileal TRPV1 in rats was significantly downregulated in each treatment group(P<0.01).The expression of TRPV1 in Xiaojianzhong high dose group decreased significantly compared with the positive drug group(P<0.01).5.2 Comparison of NK1R Positive Expressions5.2.1 Colon:Compared with normal group,the expression of NK1R in colon tissue in model group was significantly up-regulated(P<0.01).The expression of colonic NK1R in each treatment group was significantly down-regulated compared with the model group(P<0.05 or P<0.01).5.2.2 Ileum:Compared with normal group,the expression NK1R in ileum tissue in the model group increased significantly(P<0.01).Compared with the model group,the expression of ileal NK1R in each treatment group was significantly down-regulated(P<0.05 or P<0.01).5.3 Comparison of CGRP Positive Expressions5.3.1 Colon:Compared with normal group,the expression of colon CGRP in model group increased significantly(P<0.01).The positive expression of colon CGRP in rats in each treatment group was significantly decreased compared with the model group(P<0.01).5.3.2 Ileum:Compared with normal group,the CGRP expression of ileum in model group increased significantly(P<0.01).The positive expression of ileal CGRP decreased in Xiaojianzhong medium and low dose groups compared with the model group(P<0.01).Conclusion and significance:Xiaojianzhong tang can alleviate the pain and inflammatory reaction of intestinal inflammation induced by high fat diet and improve histopathological manifestations.The mechanism may be related to the down-regulation of TRPV1,in intestinal tissue and the reduction of SP,CGRP release.This study is helpful to clarify the theory of " High Fat Diet Injures Spleen " and to reveal the molecular mechanism of TCM prescription treatment.