“Eucommia Ulmoides-Angelica Sinensis” Ameliorate Osteoarthritis Through the Regulation of MMP-13 Via Wnt/β-catenin Signaling

OBJECTIVE To study the mechanism of “Eucommia ulmoides(EU)-Angelica sinensis(AS)” mediated Wnt/β-catenin signal in regulating the expression of MMP13 in the prevention and treatment of osteoarthritis(OA). METHODS SD rats were randomly divided into six groups: sham group, OA group, OA+kidney tonifying group(EU 40 mg·kg^-1), OA+blood activating group(AS 40 mg·kg^-1), OA+kidney tonifying and blood activating group(EU-AS solution 40 mg·kg^-1), OA+positive conrol group(celebrex 10 mg·kg^-1+otailin 1.2 mg·kg^-1), after inducing of OA model, rats in each group were administrated for 8 weeks. Safranin O(SO) staining was then used to evaluate the injury of cartilage, expression of MMP-13 in cartilage was detected by immunohistochemical levels of IL-6 and IL-8 in rats serum were detected by ELISA, the expression of MMP-3, MMP-9, MMP-13 and β-catenin in cartilage was analyzed by Western blotting. The chondrocyte isolated from normal SD rats were incubated with IL-1β(10 ng·mL^-1) to induce inflammation model of OA. SO staining was used to detect the phenotype of chondrocytes, levels of IL-6 and IL-8 in chondrocytes were detected by ELISA, β-catenin expression in chondrocytes was detected by using immunofluorescence staining, mRNA expression of IL-6, IL-8, MMP-3, MMP-9 and MMP-13 in chondrocytes was analyzed by qRT-PCR, protein expression of MMP-3, MMP-9, MMP-13 and β-catenin in chondrocytes was analyzed by Western blotting. RESULTS There were different degrees of repair of cartilage injury in the administration groups, the levels of IL-6 and IL-8 in serum, the expression of MMP-3, MMP-9, MMP-13 and β-catenin in cartilage tissues were also down-regulated. Compared with IL-1β group, EU-AS could improve chondrocyte cell survival rate, improve cell morphology, reduce the levels of IL-6 and IL-8 in chondrocytes, reduce the fluorescence intensity of β-catenin in chondrocytes, down regulate the mRNA expression of IL-6, IL-8, MMP-3, MMP-9 and MMP-13 in chondrocytes and the protein expression of MMP-3, MMP-9, MMP-13 and β-catenin. CONCLUSION EU-AS, a traditional Chinese medicine for invigorating the kidney and promoting blood circulation, can ameliorate OA by promoting the chondrocyte proliferation, regulating the level of inflammatory factors, inhibiting cartilage matrix degradation and cartilage pathological damage, and the mechanism may be related to the regulation of MMP-13 expression by Wnt/β-catenin signal transduction.