Electroacupuncture and Moxibustion Modulate the BDNF and TrkB Expression in the Colon and Dorsal Root Ganglia of IBS Rats with Visceral Hypersensitivity.

Duiyin Jin,Siyi Lv,Yanan Liu,Yuanyuan Wang,Xiaomei Wang,Mi Liu,Mei Li,Huangan Wu,Qin Qi

doi:10.1155/2021/8137244

Abstract

Objective To evaluate the effects of electroacupuncture and moxibustion on brain-derived neurotrophic factor (BDNF) and its receptor tyrosine kinase receptor B (TrkB) protein and mRNA expressions in the colon and dorsal root ganglia of IBS rats with visceral hypersensitivity and to explore their underlying therapeutic mechanisms. Method Forty Sprague Dawley rats were randomly divided into normal, model, model + mild moxibustion (MM), model + electroacupuncture (EA), and model + pinaverium bromide (PB) groups, with eight rats in each group. Chronic visceral hypersensitive IBS rat models were established by colorectal distension (CRD) with mustard oil clyster. Rats in the MM and EA groups, respectively, received moxibustion and electroacupuncture treatments on the Tianshu (ST25) and Shangjuxu (ST37) acupoints once daily for 7 days, and rats in the PB group received pinaverium bromide by oral gavage once daily for 7 consecutive days. After treatment, rats underwent abdominal withdrawal reflex (AWR) scoring under CRD and colon histopathological examination. Immunohistochemistry and real-time quantitative PCR (RT-qPCR) were used to study the protein and mRNA expressions of BDNF and TrkB in the rat colon and dorsal root ganglia. Results Compared with the normal group, AWR scores and body weight were clearly increased in the model group rats (both P < 0.01). The body weights were significantly elevated (P < 0.01, P < 0.05), but the AWR scores were reduced (P < 0.05, P < 0.01), after electroacupuncture and mild moxibustion treatment. Compared with levels in normal rats, BDNF and TrkB protein and mRNA expressions were significantly elevated in the IBS model rats (P < 0.01) but were downregulated after mild moxibustion, electroacupuncture, and Western medicine treatment (P < 0.01). Conclusion Electroacupuncture and moxibustion improved visceral hypersensitivity of IBS rats possibly by reducing BDNF and TrkB protein and mRNA expressions in the colon and dorsal root ganglia.

Highlights

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder with a syndrome of persistent or recurrent episodes of intestinal disorder
All IBS rats in different groups had lower body weight than rats in the normal group (P < 0.01) (Figure 1(a)). e abdominal withdrawal reflex (AWR) scores of rats in the model group were significantly elevated under all colorectal distension (CRD) pressures (20, 40, 60, and 80 mmHg) compared with the normal group
0 NC MC mild moxibustion (MM) EA pinaverium bromide (PB) (b) visceral hypersensitivity and the possible therapeutic mechanism based on Brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB)

Summary

Introduction

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder with a syndrome of persistent or recurrent episodes of intestinal disorder. It is characterized by abdominal pain, abdominal distension, altered bowel habits, and/or character of stool that severely affect the quality of patients’ life. BDNF interacts with substance P (SP), nerve growth factor, and calcitonin gene-related peptide (CGRP) to regulate intestinal sensation and affect colon sensitivity [10]. Studies found that moderate amounts of BDNF can maintain the normal function of sensory nerves; abnormal elevation of BDNF can lead to a variety of pain-related sensations, such as chronic pain, inflammatory pain, and visceral pain [11]

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Conclusion