Study on the mechanism of pycnogenol in improving the cellular microenvironment in osteoarthritis progression

WANG Feng; LI Zhi-bin; SUN Zhi-ping; LI Wen-xiong; XIAO Zhen

doi:10.13820/j.cnki.gdyx.20241943

Abstract：Objective To investigate the effects of Pycnogenol on the cellular microenvironment in osteoarthritis(OA)rats,providing theoretical and pharmacological evidence for OA treatment.Methods An OA rat model was estab-lished via intra-articular injection of iodoacetic acid.OA rats were treated with varying doses of Pycnogenol.Synovial flu-id,synovial tissue,subchondral bone,and fibroblast-like synoviocytes were isolated.Levels of inflammatory cytokines in knee joint fluid were assessed using enzyme-linked immunosorbent assays(ELISA).The proportion of immune cells and the expression of M1/M2 macrophage markers in synovial fluid were measured by flow cytometry,real-time PCR,and Western blotting.Subchondral bone parameters were evaluated using magnetic resonance imaging(MRI).Results Pyc-nogenol significantly suppressed the upregulation of interleukin-1 β,interleukin-6,and tumor necrosis factor-α in OA rats in a dose-dependent manner(P＜0.05).It inhibited the increase in reactive oxygen species and the decrease in su-peroxide dismutase in the knee joint fluid of OA rats(P＜0.05).Pycnogenol also increased the expression of M2 macro-phage markers in the synovial fluid(P＜0.05).In cell experiments,Pycnogenol inhibited fibroblast-like synoviocyte proliferation,migration,and invasion while promoting apoptosis(P＜0.05).Additionally,Pycnogenol reversed changes in subchondral bone metrics in OA rats in a dose-dependent manner(P＜0.05)and inhibited osteoblast formation in-duced by OA(P＜0.05).Conclusion Pycnogenol ameliorates OA progression by promoting M2 macrophage polariza-tion,inhibiting fibroblast-like synoviocyte function,and mitigating subchondral bone remodeling.