Stichopus chloronotus aqueous extract as a chondroprotective agent for human chondrocytes isolated from osteoarthitis articular cartilage in vitro.

The proinflammatory cytokines, metalloproteinases family (MMPs), inflammatory mediators PGE2, COX-2 and NO are the most important group of compounds responsible for the loss of metabolic homeostasis of articular cartilage by promoting catabolic and destructive processes in the pathogenesis of osteoarthritis (OA). Stichopus chloronotus, a marine sea cucumber which is rich in n-3 PUFAs and phenolic compound, may exert a favorable influence on the course of the disease. The objective of this study was to investigate the regeneration and anti-inflammatory potential of S. chloronotus aqueous extract (SCAE) on human OA articular chondrocytes (HOC). The HOC isolated from knee joint cartilage removed during surgery were cultured with SCAE for 7 days. The effect of SCAE on anabolic and catabolic gene expression was verified by real-time PCR. Monolayer chondrocytes were stained with toluidine blue whereas sGAG, NO and PGE2 production in medium were analyzed by ELISA. The HOC cultured in various SCAE have polygonal morphology maintaining their chondrocytes characteristic. SAE supplementation tested was found to be effective pro-chondrogenic, anti-inflammatory and anti-oxidative agents, as evidenced by upregulation of cartilage specific markers collagen type II, aggrecan core protein and sox-9 expression and downregulation of collagen type 1, IL-1, IL-6, IL-8, MMP-1, MMP-3, MMP-13, COX-2, iNOS and PAR-2 expression. The presence of SCAE in the culture was able to increase sGAG and reduce NO and PGE2 production significantly. These results suggested that SCAE demonstrated chondroprotective ability by suppressing catabolic activities, oxidative damage and effectively promoting chondrocytes growth.