Polydatin inhibits IL-1β-mediated chondrocyte inflammation and ameliorates cartilage degradation: Involvement of the NF-κB and Wnt/β-catenin pathways.

Osteoarthritis (OA) is a highly prevalent chronic joint disease that involves extracellular matrix (ECM) degradation and articular cartilage inflammation. Polydatin (PD) can alleviate inflammatory reactions in numerous diseases. The present study aimed to investigate the chondroprotective and anti-inflammatory effects of PD on interleukin (IL)- 1β-treated chondrocytes in vitro and anterior cruciate ligament transection-induced rat OA models in vivo. Primary chondrocytes were isolated from SD rats and cultured. Only second-passage cells were used for subsequent experiments. Counting kit-8, quantitative real-time polymerase chain reaction, western blotting, enzyme-linked immunosorbent assay, and immunofluorescence were used to detect relevant indices. Rat OA models were established to obtain in vivo data. PD treatment decreased the production of nitric oxide (NO), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and IL-6 during IL-1β-stimulated chondrocyte inflammation. Moreover, PD upregulated aggrecan and collagen II expression, whereas downregulated a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) and matrix metalloproteinase-13 (MMP-13) expression on IL-1β-mediated chondrocytes. Additionally, PD reduced IL-1β-stimulated NF-κB and Wnt/β-catenin activation and nuclear translocation. The results of histological analysis and scoring revealed that OA in the rat models was effectively ameliorated by the intra-articular injection of PD. PD suppressed IL-1β-stimulated iNOS, COX-2, NO, and PGE2 production, TNF-α, IL-6, collagen X, MMP-13, and ADAMTS-5 expression, collagen II and aggrecan degeneration by inhibiting NF-κB and Wnt/β-catenin signaling in vitro. PD also mitigated OA progression in the rat models, thereby providing reliable data that PD could serve as a promising candidate for OA therapy.