Inhibition effect of Caragana sinica root extracts on Osteoarthritis through MAPKs, NF-κB signaling pathway
Abstract
Osteoarthritis (OA) is a common joint disease characterized by degradation and inflammation of cartilage
extracellular matrix. We aimed to evaluate the protective effect of Caragana sinica root (CSR) on
interleukin (IL)-1β-stimulated rat chondrocytes and a monosodium iodoacetate (MIA)-induced model of
OA. In vitro, cell viability of CSR-treated chondrocytes was measured by MTT assay. The mRNA
expression of Matrix metallopeptidases (MMPs), a disintegrin and metalloproteinase with
thrombospondin motifs (ADAMTSs) and extracellular matrix (ECM) were analyzed by quantitative
real-time PCR (qRT-PCR). Moreover, the protein expression of MAPK (phosphorylation of EKR, JNK,
p38), inhibitory kappa B (IκBα) and nuclear factor-kappa B (NF-κB p65) was detected by western blot
analysis. In vivo, the production of nitric oxide (NO) was detected by Griess reagent, while those of
inflammatory mediators, MMPs and ECM were detected by ELISA. The degree of OA was evaluated by
histopathological analyses, Osteoarthritis Research Society International (OARSI) score and micro-CT
analysis. CSR significantly inhibited the expression of MMPs, ADAMTSs and the degradation of ECM in
IL-1β-stimulated chondrocytes. Furthermore, CSR significantly suppressed IL-1β-stimulated of MAPKs,
NF-κB signaling pathway. In vivo, CSR and Indomethacin inhibited the production of inflammatory
mediators, MMPs and degradation of ECM in MIA-induced model of OA. In addition, CSR improved the
severity of OA. Taken together, these results suggest CSR is a potential therapeutic active agent in the
treatment of OA