Investigate The Intervention Mechanism Of Shaoyao Gancao Decoction On Abdominal Pain In Post Inflammatoryirritable Bowel Syndrome Rats Based On 5-HT And TRPV1 Pathways

Objective:Post-inflammatory irritable bowel syndrome(PI-IBS)is a functional gastrointestinal tract disease,which has an increasing incidence.PI-IBS seriously reduces the quality of life of patients and occupies a lot of medical resources.At present,western medicine are used to improve symptoms and prevent seizures,however,it has poor theraputic effects and many side effects.Traditional Chinese medicine has achieved significant effect in the treatment of PI-IBS.Shaoyao Gancao Decoction(SGD)is a classic prescription,which has the function of soothing muscles,relieving the liver,slowing down pain and analgesics.Recent years,the properties of analgesia and anti-inflammatory of SGD have received widespread attention.However,whether PI-IBS can relieve abdominal pain symptoms has not been reported.The purpose of this thesis was to investigate the interventional effect and potential mechanism of SGD on abdominal pain in PI-IBS rats.Methods:Rat model of post inflammatory-irritable bowel syndrome(PI-IBS)was prepared by using 2,4,6-trinitrobenzenesulfonic acid(TNBS).To identify the effect of SGD on the symptoms of abdominal pain in PI-IBS rats,disease activity index(DAI),abdominal withdrawal reflex(AWR),and pathological changes in the colon were regarded as indicators.Serum and colon tissue were used to determine the enterochromaffin cells(EC)cell number.To analyze the effect of SGD on 5-HT signal pathway,UHPLC-QTRAP-MS / MS method was used to determine the level of 5-HT in rat plasma,and immunohistochemistry was performed to determine the number of chromaffin cells(EC)in colon tissue.At last,the gene and protein level were analyzed by RT-qPCR and western blotting.In addition,we clarified the role of TRPV1 signaling pathway in SGD improving PI-IBS abdominal pain from two dimensions of animal and cell,gene and protein.Results:1.Compared with the control group,PI-IBS model rats had significantly higher DAI,increased visceral nociceptive sensitivity(P <0.05),and pathological changes in colonic morphology,all of which suggested that the PI-IBS model was successfully prepared.After SGD treatment for 14 days,the above conditions were all relieved in different degrees and showed a dose-dependent on SGD,indicating that SGD could dose-dependently reduce the symptoms of abdominal pain and diarrhea in PI-IBS rats.2.After building the PI-IBS model rats,the number of EC cells in colon tissue,5-HT levels in serum and the mRNA levels of 5-HT synthase TPH were increased significantly(P <0.01),but there was no difference in the mRNA level of the 5-HT transporter SERT;SGD treatment could reverse the above phenomenon in a dose-dependent manner,suggesting that the 5-HT signaling pathway plays an important role in the efficacy of SGD.3.In PI-IBS model rats,the mRNA levels of TRPV1 and calcineurin in the colon tissue were significantly increased.At the same time,the protein expression of TRPV1 and p-CaMKII were also increased,suggesting that SGD can reverse the enhanced expression and function of TRPV1 in PI-IBS rats in a dose-dependent manner.In cell lines,SGD can significantly inhibit the mRNA level of over-activated TRPV1,but has no inhibitory effect on TRPV1 in normal HEK293 cells.Conclusion:The results of this experiment indicate that SGD can significantly reduce the symptoms of abdominal pain in PI-IBS rats,and its mechanism may be related to the regulation of 5-HT signaling pathway and the inhibition of TRPV1 expression and function.