Hewei Jiangni granule alleviates visceral hypersensitivity in a rat model of non-erosive reflux disease via transient receptor potential channel signaling

Objective:To uncover the underlying mechanism of Hewei Jiangni granule(HWJNG)on non-erosive reflux disease(NERD)treatment by examining histological changes,gastrointestinal neurochemicals release and visceral hypersensitivity-related receptor expression in NERD model rats.Methods:A NERD rat model was established via a combination of basal sensitization and acid perfusion.HWJNG treatments at different doses were then administered.Pathological changes to tissues,mast cell(MC)activation,serum levels of esophageal visceral hypersensitivity-related neurochemicals,and transient receptor potential(TRP)receptor mRNA and protein levels were investigated.Results:Compared with the control group,the expression of tryptase in MCs,the changes of intercellular space,and the serum levels of substance P(SP),calcitonin gene-related peptides(CGRP)and proteinaseactivated receptor 2(PAR2)increased in the model group(all P<.05).The expression of TRP vanilloid 1(Trpv1)mRNA decreased in esophagus and dorsal root ganglia(DRG)of the model group(P=.030&P=.013),and the expression of TRP melastatin channel subfamily member 8(Trpm8)mRNA decreased in the esophagus of model group(P<.01).The level of esophageal TRPV1 protein increased in the model group(P<.01)and the level of TRPM8 protein decreased in esophagus and DRG of the model group(both P<.05).Compared with the model group,the serum levels of SP,CGRP,and PAR2 in the mediumdose HWJNG group showed significant decreases(all P<.05).The expression of Trpv1 mRNA in esophagus and DRG of the HWJNG groups and the Omeprazole group remarkably decreased(all P<.05),as was the expression of Trpm8 mRNA in esophagus of the HWJNG groups(all P<.05).Conclusion:HWJNG alleviated visceral hypersensitivity in NERD model rats by regulating TRP-mediated signaling.Our results indicate that HWJNG has potential as a therapeutic agent for NERD.