Resveratrol inhibits the IL-1β-induced expression of MMP-13 and IL-6 in human articular chondrocytes via TLR4/MyD88-dependent and -independent signaling cascades

The natural polyphenolic compound, resveratrol, has been shown to exhibit anti-osteoarthritic activity. Therefore it is hypothesized that resveratrol may serve as a nutritional supplement to counteract osteoarthritis (OA). However, the mechanisms responsible for these anti-osteoarthritic effects have not yet been fully elucidated. The aim of this study was to determine whether the biological effects of resveratrol against interleukin (IL)-1β‑induced inflammation in human articular chondrocytes involved both Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)-dependent and -independent signaling pathways. Human articular chondrocytes derived from patients with OA were stimulated with IL-1β, and then co-treated with resveratrol. Cell viability was subsequently evaluated by MTS assays, and the concentrations of matrix metalloproteinase (MMP)-13 and the pro-inflammatory factor, IL-6, were detected in culture supernatants using ELISA. The mRNA and protein levels of downstream mediators of TLR4/MyD88-dependent and -independent signaling pathways were also assayed by RT-qPCR and western blot analysis, respectively. Our results revealed that resveratrol prevented the IL-1β-induced reduction in cell viability. Furthermore, stimulation of the chondrocytes with IL-1β resulted in a significant upregulation of TLR4 and downstream targets of both TLR4/MyD88-dependent and -independent signaling pathways that are associated with the synthesis of MMP-13 and IL-6. Correspondingly, IL-1β-induced catabolic and inflammatory responses were effectively reversed by resveratrol. Taken together, these data suggest that resveratrol exerted protective effects against matrix degradation and inflammation in OA-affected chondrocytes by inhibiting both TLR4/MyD88-dependent and -independent signaling pathways. Thus, resveratrol represents a potential treatment for OA and warrants further investigation.