Pitongshu Alleviates the Adverse Symptoms in Rats with Functional Dyspepsia Through Regulating Visceral Hypersensitivity Caused by 5-HT Overexpression

Abstract

Aim: The aim of the study was to explore the efficacy as well as the mechanism of action of Pitongshu (PTS) on rats with functional dyspepsia (FD) induced by iodoacetamide gavage and tail clamping.

Methods: The bioactive components of PTS were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), whereas the potential targets of PTS were obtained from the Similarity Ensemble Approach (SEA), TCMSP, and Swiss Target Prediction Database. The disease targets were obtained from the DisGeNET database, whereas Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed using the R Software. The method of iodoacetamide gavage combined with tail clamping was used to establish the FD rat model in this study. Body weight, food intake, gastrointestinal motility, gastric acidity and secretion, and the mechanical pain threshold of rats were measured. The open-field test was also performed. The stomach and duodenum were histologically observed. The levels of serotonin (5-HT), Calcitonin Gene-Related Peptide (CGRP), Motilin (MTL), and Gastrin (GAS) in gastric tissues were detected by ELISA.

Results: A total of 139 bioactive components and 17 potential targets of PTS were identified through a network pharmacology approach. The results of GO and KEGG enrichment analyses indicated that PTS could reduce the 5-HT secretion of gastric tissues through the serotonergic synaptic pathway and alleviate the symptoms of FD, indicating that PTS plays a therapeutic role. The results of animal experiments showed that PTS could increase body weight and food intake, improve autonomous activity, and decrease gastric acidity and secretion in FD rats. Furthermore, gastric sensitivity increased in FD rats, and PTS treatment could significantly decrease it. The results of ELISA showed that the overexpression of 5-HT and CGRP was decreased after PTS treatment in FD rats. Lastly, PTS could significantly improve gastrointestinal motility, as well as the levels of GAS and MTL in FD rats.

Conclusion: PTS may reduce 5-HT secretion by regulating the serotonergic synaptic pathway, thereby reducing visceral sensitivity and alleviating the symptoms of FD.

Keywords: 5-HT; CGRP; Pitongshu; functional dyspepsia; serotonin synapse; visceral hypersensitivity.