Neferine Inhibits Expression of Inflammatory Mediators and Matrix Degrading Enzymes in IL-1 β-Treated Rat Chondrocytes via Suppressing MAPK and NF-κB Signaling Pathways

AbstractOsteoarthritis (OA), in which inflammation plays a crucial role, is the most common joint disease characterized by cartilage degradation. Neferine (Nef), a dibenzyl isoquinoline alkaloid, has shown its anti-inflammatory effects on other inflammatory diseases. Therefore, we hypothesized that Nef might also have an anti-inflammatory effect on OA and explored its effect on IL-1 β-treated rat chondrocytes. Sprague Dawley (SD) rat chondrocytes were stimulated with IL-1β (10 ng/ml) and Nef (1, 5, and 10 μM) or IL-1β (10 ng/ml) alone for 24 h. Expression of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), matrix metalloproteinases (MMPs), and thrombosp ondin motifs-5 (ADAMTS5) was determined by quantitative real-time PCR and Western blotting. Expression of collagen II and aggrecan was examined by Western blotting, immunofluorescence, and safranin O staining. In addition, activation of MAPK and NF-κB signaling pathway was examined by Western blott ing, and p65 nuclear translocation was evaluated by immunofluorescence. Nef reduced expression of inflammatory regulators (iNOS and COX-2) in IL-1β-treated chondrocytes. Expression of IL-1β-induced major catabolic enzymes (MMP3, MMP13, and ADAMTS5) was inhibited by Nef. Meanwhile, downregulation o f collagen II and aggrecan expression was also ameliorated. Furthermore, Nef dampened abnormal activation of MAPK and NF-κB signaling pathway triggered by IL-1β. Overall, the results above showed that Nef inhi...
Source: Inflammation - Category: Allergy & Immunology Source Type: research