Modulatory mechanisms of electroacupuncture in fascial tissue repair: a pilot study using a rat model of thoracolumbar fasciitis

Introduction: Myofasciitis, a prevalent cause of musculoskeletal pain, is associated with thoracolumbar fascial changes. Acupuncture is effective for pain relief, but its role in fascial repair remains unclear. This study examined the effects of electroacupuncture (EA) at BL23 ( Shenshu ) and BL40 ( Weizhong ) on fascial tissue repair in a rat model of thoracolumbar fasciitis (TLF). Methods: The study involved 42 six-week-old Sprague–Dawley rats divided into control ( n = 15) and modeling ( n = 27) groups. TLF was induced by injecting complete Freund’s adjuvant into the thoracolumbar fascia. Three rats in the control and modeling groups were used for model validation. The remaining 24 modeled rats were split into model and EA groups ( n = 12 each). EA was administered at BL23 and BL40 to rats in the EA group for 20 min daily for 9 days. Assessments included skin pain sensitivity, musculoskeletal ultrasound, histological evaluation of fascial thickness, and measurement of inflammatory markers and fibroblast activity. Results: EA-treated rats showed significant improvements, including reduced mechanical pain sensitivity, decreased fascial thickness and lower expression of pro-inflammatory markers (tumor necrosis factor-α, interleukin 1β) and fibroblast activity markers (proliferating cell nuclear antigen, α-smooth muscle actin, and vimentin). There was also a favorable balance in extracellular matrix components (increased type I/III collagen and matrix metalloproteinase (MMP)-1/tissue inhibitor of MMP (TIMP)-1 ratios), which was linked to reduced activity of the transforming growth factor (TGF)-β1/suppressor of mother against decapentaplegic (Smad)2 pathway. Conclusion: EA at BL23 and BL40 reduces inflammation, inhibits fibroblast proliferation and activation, and promotes fascial repair, likely via modulation of the TGF-β1/Smad2 pathway. These findings support the therapeutic potential of EA for the treatment of myofasciitis, potentially aiding in chronic musculoskeletal pain management and fascial tissue repair.