Moxibustion Eases Chronic Inflammatory Visceral Pain In Rats Via MAPK Signaling Pathway In The Spinal Cord

Yan Huang; Dan Zhang; Zhi-Yuan Li; Yan-Ting Yang; Li-Jie Wu; Ji Zhang; Fang-Yuan Zhi; Xi-Ying Li; Zheng Shi; Jue Hong; Xiao-Peng Ma

doi:10.2147/JPR.S218588

Moxibustion Eases Chronic Inflammatory Visceral Pain In Rats Via MAPK Signaling Pathway In The Spinal Cord

J Pain Res. 2019 Nov 7:12:2999-3012. doi: 10.2147/JPR.S218588. eCollection 2019.

Authors

Yan Huang^#^{1

2}, Dan Zhang^#^{1

3}, Zhi-Yuan Li^#⁴, Yan-Ting Yang³, Li-Jie Wu¹, Ji Zhang¹, Fang-Yuan Zhi¹, Xi-Ying Li¹, Zheng Shi³, Jue Hong³, Xiao-Peng Ma^{1

3}

Affiliations

¹ Yueyang Clinical Medical School, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, People's Republic of China.
² Acupuncture and Moxibustion Department, Huangpu District Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai 200010, People's Republic of China.
³ Laboratory of Acupuncture, Moxibustion, and Immunology, Shanghai Research Institute of Acupuncture and Meridian, Shanghai 200030, People's Republic of China.
⁴ Acupuncture and Moxibustion Department, Zhejiang Provincial Hospital of TCM, Hangzhou, Zhejiang 310006, People's Republic of China.

^# Contributed equally.

Abstract

Purpose: The purpose of this study was to explore the central analgesia mechanism of moxibustion for chronic inflammatory visceral pain (CIVP).

Methods: A CIVP rat model was established by 2,4,6-trinitrobenzene sulfonic acid (TNBS) plus 50% ethanol via enema. The analgesic effect of moxibustion was evaluated using the abdominal withdrawal reflex (AWR), mechanical withdrawal threshold (MWT), and thermal withdrawal latency (TWL). The expression profile of phosphorylated proteins of the mitogen-activated protein kinase (MAPK) signaling pathway in the spinal cord was assayed by protein microarray. The differentially expressed proteins were examined by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) for functional clusters and corresponding signaling pathways.

Results: Moxibustion exerted a significant analgesic effect for CIVP rats, mainly presenting as a decrease in the AWR score (all P<0.01) under different levels of distending pressure and an increase in MWT and TWL thresholds (all P<0.05). Compared with the normal group, 76 proteins were upregulated while 15 were downregulated, and MAPK signaling pathway was activated in the model group. Compared with the model group, there were 53 downregulated and 38 upregulated proteins in the moxibustion group, and MAPK signaling pathway was inhibited. Fold change (FC)>1.3 or <0.77 was taken as the screening standard to define the differentially expressed proteins. Fifteen differentially expressed proteins upregulated in the model group were downregulated in the moxibustion group. GO analysis showed that the differentially expressed proteins mainly controlled cellular metabolism regulation, transportation, and stress reactions. KEGG analysis revealed that these differentially expressed proteins were mostly involved in the ERK, JNK, and p38 pathways, and the ERK pathway was predominant.

Conclusion: Moxibustion mitigates CIVP in rats and inhibits the phosphorylation of proteins in the spinal MAPK signaling pathway. The analgesic effect of moxibustion may be associated with the regulation of the spinal MAPK signaling pathway.

Keywords: MAPK signaling pathway; analgesia; chronic inflammatory visceral pain; moxibustion; spinal cord.