Articular cartilage damage related to irreversible physical disability affects most patients with chronic rheumatoid arthritis (RA). Strategies targeting the preservation of cartilage function are needed. Laser acupuncture (LA) can be an emerging alternative therapy for RA; however, its molecular mechanism underlying the beneficial effect on cartilage has not been elucidated. This study aimed to examine the potential chondroprotective effects of LA on extracellular matrix (ECM) macromolecules and proinflammatory cytokines in the articular cartilage of adjuvant-induced arthritis (AIA) rats and explore its related mechanisms.
Monoarthritis was induced in adult male Sprague-Dawley rats (250-300 g) via intraarticular injection of complete Freund's adjuvant (CFA) into the tibiotarsal joint. Animals were treated with LA at BL60 and KI3 acupoints three days after CFA administration with a 780 nm GaAlAs laser at 15 J/cm2 daily for ten days. The main outcome measures including paw circumference, paw withdrawal threshold, histopathology and immunoassays of tumor necrosis factor-α (TNF-α), collagen type II (CoII), cartilage oligomeric matrix protein (COMP) were analyzed.
LA significantly reduced ankle edema and inflammation-induced hyperalgesia in AIA rats (P < 0.05). Moreover, the TNF-α levels were significantly decreased while CoII, COMP and proteoglycans proteins were significantly enhanced following LA stimulation of the AIA cartilage compared to those treated with sham-LA (P < 0.05).
LA attenuates cartilage degradation in AIA rat by suppressing TNF-α activation and up-regulating ECM macromolecules, suggesting LA might be of potential clinical interest in RA treatment.