| Abstract: | It has been reported that vitexin has anti‐inflammatory effects in osteoarthritis (OA) rats. However, the effects of vitexin on interleukins‐1β (IL‐1β)‐stimulated OA patient‐derived chondrocytes have not been reported. The purpose of this study was to investigate the anti‐inflammatory effects of vitexin on IL‐1β‐stimulated human osteoarthritis chondrocytes and to reveal the involvement of hypoxia‐inducible factor 1α (HIF‐1α) pathway. Enzyme‐linked immunosorbent assay, quantitative real‐time PCR and Western blotting assays were employed. ELISA results demonstrated that the proinflammatory cytokine levels of interleukins‐6 (IL‐6) and tumour necrosis factor α (TNF‐α) in the serum and synovial fluid and HIF‐1α level in the synovial fluid were significantly elevated in OA patients compared to normal healthy subjects. Moreover, the Western blotting results indicated that the protein expression of HIF‐1α was significantly higher in the cartilage tissues of OA patients. OA patient‐derived chondrocytes were stimulated by IL‐1β and treated with different concentration of vitexin for 24 hours. Vitexin showed no cytotoxicity and increased the survival of chondrocytes under IL‐1β stimulation. Vitexin suppressed IL‐1β‐induced production of NO and prostaglandin E2 (PGE2) in chondrocytes culture. The treatment of vitexin significantly inhibited IL‐1β‐induced expressions of proinflammatory cytokine levels of IL‐6, TNF‐α, matrix metalloproteinase (MMP)‐1, MMP‐3 and MMP‐13. Furthermore, Western blotting results demonstrated that HIF‐1α is involved in vitexin's protective effects on IL‐1β‐stimulated injuries in OA patient‐derived chondrocytes. Our study demonstrates that vitexin alleviates IL‐1β‐induced inflammatory responses in chondrocytes from osteoarthritis patients, which may be attributed partly to the inhibition of HIF‐1α pathway. |
