Acupoint catgut embedding attenuates fibromyalgia pain through attenuation of TRPV1 signaling pathway in mouse

Chronic pain is considered as pain lasting for more than three months and has emerged as a global health problem affecting individuals and society. Chronic extensive pain is the main syndrome upsetting individuals with fibromyalgia (FM), accompanied by anxiety, obesity, sleep disturbances, and depression, Transient receptor potential vanilloid 1 (TRPV1) has been reported to transduce inflammatory and pain signals to the brain.

Acupoint catgut embedding (ACE) is a novel acupuncture technique that provides continuous effects and convenience. ACE was performed at the bilateral ST36 acupoint. 

We demonstrated similar pain levels among all groups at baseline. After cold stress, chronic mechanical or thermal nociception was induced (D14: mechanical: 1.85 ± 0.13 g; thermal: 4.85 ± 0.26 s) and reversed in ACE-treated mice (D14: mechanical: 3.99 ± 0.16 g; thermal: 7.42 ± 0.45 s) as well as Trpv1-/- group (Day 14, mechanical: 4.25 ± 0.2 g; thermal: 7.91 ± 0.21 s) mice. Inflammatory mediators were augmented in FM individuals and were abridged after ACE management and TRPV1 gene loss. TRPV1 and its linked mediators were increased in the thalamus (THA), somatosensory cortex (SSC), medial prefrontal cortex (mPFC), and anterior cingulate cortex (ACC) in FM mice. The up-regulation of these mediators was diminished in ACE and Trpv1-/- groups. 

We suggest that chronic pain can be modulated by ACE or Trpv1-/-. ACE-induced analgesia via TRPV1 signaling pathways may be beneficial targets for FM treatment.