Psoralen Protects Chondrocytes, Exhibits Anti-Inflammatory Effects on Synoviocytes, and Attenuates Monosodium Iodoacetate-Induced Osteoarthritis

Current study examined whether psoralen (PSO) exhibits anti-inflammatory responses, protection and activation of chondrocytes, and relieve osteoarthritis (OA). Rats chondrocytes and human synoviocytes were cultured in tumor necrosis factor-α (TNF-α) conditioned culture medium with/without PSO to test the cell morphologies and cytotoxicities in vitro. Cartilaginous extracellular matrix (ECM) and proliferative gene/protein expression levels were evaluated in chondrocytes. Meanwhile, matrix metalloproteinases (MMPs) and interleukins (ILs) gene/protein expression were analyzed in synoviocytes. SD rats of monosodium iodoacetate (MIA) induced OA model were used in order to assess the effects of PSO on attenuating degeneration of the articular cartilage in vivo. Results showed TNF-α conditioned culturing with/without PSO (1-100 µM) had no any toxicity on both the cell lines. PSO (10 µM) activated cartilaginous specific ECM expression along with up-regulation of proliferative genes at transcriptional levels. Interestingly, PSO significantly reversed TNF-α induced up-regulation of MMP13 and ILs synoviocytes in a dose-dependent manner (1 to 20 µM), while down-regulated cartilaginous ECM production. Following six weeks of PSO treatments to articular cartilage osteoarthritis, compared to MIA-induced group, the appearance and physiological structure of articular cartilage was more integrated with greatly organized chondrocytes and abundant cartilage matrix. In conclusion, PSO protects and activates chondrocytes, antagonizing the expression of MMPs and ILs secreted by synovial cells, and effectively attenuates MIA-induced OA.