[Effect of acupuncture on expression of matrix metalloproteinase and tissue inhibitor in cartilage of rats with knee osteoarthritis].

OBJECTIVE: To explore the curative mechanism of acupuncture treatment on osteoarthritis (OA). METHODS: Forty cases of female SD rats were randomly divided into a normal group, a model group, an acupuncture group and a medication group, 10 cases in each group. OA animal model was established by using the method of heel tendon resection for unilateral hind limb. The acupuncture group was treated with electroacupuncture at "Xiqian"(ST 35) and "Housanli"(ST 36), and the medication group with inunction of Diclofenac cream, and the normal group and the model group without any treatment. The expression of matrix metalloproteinase-1, 3 (MMP-1, MMP-3) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the cartilage were observed by immunohistochemistry. RESULTS: There were significant differences among four groups. The expressions of MMP-1, MMP-3 and TIMP-1 in the model, acupuncture and medication groups were all significantly stronger than those in the normal group (all P < 0.01). The expressions of MMP-1 and MMP-3 in the acupuncture and medication groups were down regulated and TIMP-1 expression up-regulated with significant differences as compared with the model group (all P < 0.01), and the expressions of MMP-1 and MMP-3 in acupuncture group were significantly lower, while TIMP-1 expression significantly higher than that in the medication group (all P < 0.01). CONCLUSION: Acupuncture can down-regulate the expression of MMP-1 and MMP-3 and up-regulate the expression of TIMP1, which is superior to that of Diclofenac cream, showing that acupuncture has a certain protective effect on cartilage from OA.