Bajijiasu protects articular cartilage and reduces inflammation by regulating akt/mtor/nf-b signaling pathway in osteoarthritis

Purpose: Osteoarthritis (OA) is a very common chronic disease characterized by degenerative articular cartilage, which also can affect tissues such as subchondral bone, meniscus and synovium. This project aims to study the protective effect and mechanism of bajijiasu(BJ)extracted from Chinese herbal medicine on osteoarthritis. Methods: The experimental mice were divided into drug treatment group and control group by constructing mouse knee joint OA model, and then the effects of drugs on OA process were detected by histological staining, immunohistochemistry and immunofluorescence. Primary chondrocytes from ribs of newborn mice were co-cultured with IL-1β and BJ, and primary chondrocytes cultured with IL-1β alone were used as controls. After extracting proteins and RNA, metabolic and inflammatory related factors were detected by western blot and real-time quantitative PCR. Results: The OARSI score of the drug-treated group was significantly lower than that of the OA group (P<0.05). Immunohistochemistry and immunofluorescence showed that compared with the OA group,matrix metalloproteinase-13(MMP-13),matrix metalloproteinase-3(MMP-3)and iNOS were lowly expressed in the drug-treated group(P<0.05). In vitro results showed that BJ significantly reduced the expression of MMP3, MMP9, MMP13, iNOS and COX-2,and also significantly increased the expression of aggrecan and collagen II .Moreover, BJ regulated the AKT/mTOR/NF-κBsignaling pathway and increased the expression of autophagy-related factors,such as LC3 and beclin1. Conclusions: BJ alleviates the metabolic breakdown and inflammatory expression of OA in vivo and in vitro, which were possibly due to the regulation of AKT/mTOR/NF-κB signaling pathway to promote autophagy.View Large Image Figure ViewerDownload Hi-res image Download (PPT)