Chondroprotective effects and multi-target mechanisms of Icariin in IL-1 beta-induced human SW 1353 chondrosarcoma cells and a rat osteoarthritis model

Cartilage degradation is the most predominant pathological change during osteoarthritis (OA). Furthermore, accumulating evidence suggests that an excess of matrix metalloproteinase-13 (MMP-13) plays a critical role in the breakdown of cartilage. Here, the effects of Icariin on the expression of MMP-13 in IL-1 beta-induced SW 1353 chondrosarcoma cells were investigated. In addition, the in vivo effects of Icariin on an experimental rat model of OA induced by anterior cruciate ligament transection (ACLT) was examined. SW1353 chondrosarcoma cells were pretreated with or without Icariin and MAPK and Wnt/beta-catenin signaling pathway inhibitors, then were stimulated with IL-1 beta. In rats, experimental OA was induced by ACLT. These rats then received intra-articular injections of vehicle, signaling pathway inhibitors, and/or Icariin. Expression of MMP-13, phosphorylated p38, phosphorylated JNK, and beta-catenin were verified by western blotting. In addition, levels of MMP-13 mRNA were detected using quantitative real-time PCR. In histological analyses, treatment with Icariin reduced the number of cartilage lesions present. In addition, treatment with Icariin was associated with lower levels of phosphorylated p38, phosphorylated JNK, and beta-catenin in both IL-1 beta-induced SW1353 chondrosarcoma cells and in the rat OA model. Furthermore, the suppressive effect of Icariin on MMP-13 was greater than that exhibited by other signaling pathway inhibitors. Overall, these data suggest that Icariin has therapeutic potential for the treatment of OA. (C) 2013 Elsevier B.V. All rights reserved.