Abstract: BACKGROUND: It has been found that Shutiao Jingjin Massage can effectively improve the clinical symptoms of knee osteoarthritis in the early stage, but its treatment mechanism needs to be verified.
OBJECTIVE: To explore the effect of Shutiao Jingjin Massage on knee osteoarthritis and its possible mechanism
METHODS: Thirty-four male New Zealand rabbits were randomly divided into blank group (n=9) and model group (n=25). Rabbit models of knee osteoarthritis were established by injecting 4% papain solution into the knee joint cavity. Six weeks after modeling, one rabbit in each group was randomly selected for cartilage hematoxylin-eosin staining and Mankin’s scoring. After the model evaluation, the model group was randomly divided into model control group (n=8), massage group (n=8) and glucosamine group (n=8). The massage group was treated with Shutiao Jingjin Massage, once every other day; the glucosamine group was given aqueous solution of glucosamine sulfate capsules by gavage, once a day. Interventions in each group lasted 4 weeks. At 1 week after intervention, the pathological morphology of cartilage was observed by safranin O-fast green staining. The expression of extracellular signal-regulated kinases 1 and 2, nuclear factor-kappa B p65, Bcl-2, Bax, and cysteine-aspartic acid protease-3 in cartilage tissue was detected by western blot assay and immunohistochemistry. The levels of interleukin-1β in peripheral blood and joint fluid were determined by enzyme-linked immunosorbent assay.
RESULTS AND CONCLUSION: Cartilage section microscopic observation: the model control group had cartilage surface defect and damage, cartilage layer thinning, abnormal cluster aggregation of chondrocytes, and tidal line damage; in the massage group, there was no obvious damage on the cartilage surface, chondrocyte arrangement was basically normal, no obvious abnormal aggregation occurred, and the tidal line was regular; compared with the model control group, the glucosamine group did not show significant improvement. Compared with the blank group, the expression of extracellular signal-regulated kinases 1 and 2, nuclear factor-kappa B p65, Bax, and cysteine-aspartic acid protease-3 protein in the model control group was increased (P < 0.01), while the Bcl-2 expression decreased (P < 0.01). The expression levels of extracellular signal-regulated kinases 1 and 2, nuclear factor-kappa B p65, Bax, and cysteine-aspartic acid protease-3 protein in the massage group were significantly lower than those in the model control group (P < 0.01) and slightly lower than those in the glucosamine group (P < 0.05), while the expression of Bcl-2 was significantly higher than that in the model control group (P < 0.01) and slightly higher than that in the glucosamine group (P < 0.05). Compared with the blank group, the mass concentrations of interleukin-1β in the joint fluid and peripheral blood were significantly increased in the model control group (P < 0.01). Compared with the model control group, the mass concentrations of interleukin-1β in the joint fluid and peripheral blood were significantly decreased in the massage group (P < 0.01). The mass concentrations of interleukin-1β in the joint fluid and peripheral blood were significantly higher in the glucosamine group than the massage group (P < 0.01). To conclude, Shutiao Jingjin Massage can inhibit cartilage degeneration and slow down the progression of knee osteoarthritis, probably by regulating the secretion and release of interleukin-1β, interacting with the extracellular signal-regulated kinase 1/2-nuclear transcription factor κB signaling pathway, inhibiting excessive apoptosis of chondrocytes, maintaining the stability of intracellular environment in chondrocytes and repairing damaged cartilage.

Key words: knee osteoarthritis, Shutiao Jingjin, cartilage injury, extracellular signal-regulated kinase 1/2, nuclear transcription factor κB, cartilage internal environment