Fig. 9

Schematic diagram of the protective effects of Dio on OA. IL-1β is an inflammatory cytokine which is excessive released in the joints of OA patients. The cytokine can induce the expression of pro-inflammatory factors (iNOS, COX2, MMPs and ADAMTS5) and downregulate the synthesis of Collagen II and Aggrecan in chondrocytes. Moreover, IL-1β functions by activating the MAPK and NF-κB signaling pathways. Dio can block IL-1β-induced MAPK and NF-κB signaling pathway activation, resulting in the inhibition of IL-1β-induced overexpression of MMPs and ADAMTS-5 and the improvement of the production of Collagen II and Aggrecan, which contribute to the maintenance of chondrocyte matrix homeostasis