Synovitis Ointment Improved Knee Osteoarthritis by Suppressing SDF-1/CXCR4 Signaling Pathway

OBJECTIVE: Knee osteoarthritis (KOA) remains a challenge for clinicians worldwide and lacks major advancements in treatment. In this study, we investigated the mechanism of synovitis ointment interference on KOA. METHODS: SD rats were used to establish KOA models and were randomly divided into five groups: the control group, the KOA group, the KOA + synovitis ointment group, the KOA + Western medicine group, and the KOA + Chinese medicine group. Detection of pathological injury of the joint was observed through HE staining. Enzyme-linked immunosorbent assay (ELISA) was used to measure the expression of SDF-1, CXCR4, MMP-9, and MMP-13. Effects of synovitis ointment on bone cell fibrosis were detected through Masson staining, and the relative mRNA expression of PLOD2, COL1A1, TIMP1, and TGF-β was observed using the real-time quantitative (RT-PCR) method. RESULTS: Mankin's score and the knee diameters showed that the KOA model has been successfully established; compared with the OA group, the synovitis ointment group improved the pathological injury of the knee joint. Compared with the KOA group, the synovitis ointment group, the KOA + Western medicine group, and the KOA + Chinese medicine group significantly decreased the expression of SDF-1, CXCR4, MMP-9, and MMP-13. Synovitis ointment reduced the relative content of bone cell fiber compared to that in the KOA group. While, the relative mRNA expression of PLOD2, COL1A1, TIMP1, and TGF-β was significantly decreased in the synovitis ointment group. CONCLUSION: Synovitis ointment inhibited the inflammation and bone cell fibrosis of KOA, and the mechanism was related to the SDF-1/CXCR4 singling pathway.