Chicago Sky Blue 6B modulates MAPK/NF-kB pathway in rat knee osteoarthritis

Knee osteoarthritis (OA) has emerged as a growing public health concern in recent years. We aimed to investigate the impact of Chicago Sky Blue 6B (CSB) on OA progression in rats. In this study, we established a rat OA model using DMM surgery and conducted histological staining to assess the overall morphology of rat knee joints, as well as the content of proteoglycans and collagen upon CSB treatment. Additionally, in vitro experiments were performed using qPCR and WB to detect the expression of matrix molecules and matrix-degrading enzymes. The expression of relevant proteins in the MAPK/NF-kB pathway was also examined. Our in vitro experiments show that IL-1β decreased Aggrecan and COL2A1 gene expression and increased MMP3, MMP13 and ADAMTS5 gene expression. CSB treatment alleviated the IL-1β-induced inflammatory response. Further experiments indicated that CSB inhibited downstream inflammatory responses by suppressing the MAPK/NF-kB pathway. In vivo experiments confirmed the therapeutic effect of CSB in alleviating OA induced by DMM surgery in rats. We demonstrated that CSB could alleviate OA in rats through the MAPK/NF-kB pathway, highlighting its potential as a therapeutic agent.