Anti-arthritic effects of chlorogenic acid in interleukin-1 beta-induced rabbit chondrocytes and a rabbit osteoarthritis model

Cartilage degradation is one of the pathological changes of osteoarthritis (OA), and accumulating evidence suggests an excess of matrix metalloproteinases (MMPs) plays a role in this cartilage breakdown. Here, we investigated the effects of chlorogenic acid (CGA) on the mRNA and protein expression of MMPs in interleukin (IL)-1 beta-induced rabbit chondrocytes and evaluated the in vivo effects of CGA in experimental OA induced by anterior cruciate ligament transection (ACLT) in rabbits. Using quantitative real-time PCR and ELISA to investigate the expression levels of MMP-1, MMP-3, MMP-13, and tissue inhibitors of metalloproteinase-1 (TIMP-1) in IL-1 beta-induced rabbit chondrocytes, we showed that CGA inhibits the expression of these MMPs while increasing TIMP-1 expression, at both the mRNA and protein levels. In addition, IL-1 beta-induced activation of nuclear factor kappa B (NF-kappa B) and the degradation of inhibitor of kappa B (I kappa B)-alpha were suppressed by CGA. In rabbits, CGA decreased cartilage degradation as assessed by morphological and histological analyses. The down-regulation of MMP-1, MMP-3, and MMP-13 expression and up-regulation of TIMP-1 expression were also detected in CGA-treated cartilage compared with vehicle-treated cartilage, confirming these findings in an in vivo model. Taken together, these findings indicate that CGA may be considered as a possible candidate agent in the treatment of OA. (C) 2010 Elsevier B.V. All rights reserved.