Effect of pestle needle therapy on the posterior cervical muscle in a rabbit model of cervical spondylosis.

Objective: To investigate the effect of pestle needle therapy (PNT) on the posterior cervical muscle (PCM) in a rabbit model of cervical spondylosis (CS) and explore the underlying mechanisms.

Methods: Rabbits were divided into control, CS models I and II (CS1 and CS2), electroacupuncture (EA), PNT I and II (PN1 and PN2), activator (AVT), and PNT combined with activator (C-AVT) groups. A long-term neck immobilization technique was used to establish a rabbit model of CS. Following completion of modeling, the EA group received electroacupuncture intervention, whereas the CS1, CS2, and C-AVT groups received PNT intervention. The AVT and C-AVT groups received local 740 Y-P injections into the PCM daily. The inflammatory injury to PCM was evaluated based on pain threshold, morphological changes, and interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α levels. PCM fibrosis was evaluated by measuring the positive area (PA) of collagen fibrils (CFs) and collagen type 1 alpha 1 (Col1α1) using Masson's and immunohistochemical staining. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay and transmission electron microscopy were used to identify apoptotic cells and assess autophagy, respectively. Western blotting was used to determine B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), cysteine aspartate-specific protease (caspase)-3, sequestosome-1 (P62), microtubule-associated protein light chain 3 (LC3-I/II), phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), and mammalian target of rapamycin (mTOR) levels. Real-time quantitative polymerase chain reaction was used to determine mRNA expression levels of PI3K, AKT, mTOR, autophagy protein (ATG), and ATG7.

Results: PNT alleviated PCM cell degeneration and necrosis, inhibited inflammatory cell infiltration, decreased IL-1β, IL-6, and TNF-α levels, and decreased the PA of CFs and Col1α1. In the PN1 group, cell apoptosis in the PCM decreased, autophagy increased, Bcl-2 and LC3-II/I levels increased, Bax, Caspase-3, and P62 levels decreased, and the mRNA expression of ATG5 and ATG7 increased. PNT inhibits protein and mRNA expression of PI3K, AKT, and mTOR. Finally, the trend in the results of the rescue experiment was consistent with previous results.

Conclusion: PNT inhibited apoptosis and promoted autophagy of PCM cells in CS rabbits and alleviated inflammation and fibrosis injury of PCM by inhibiting the PI3K/AKT/mTOR pathway.