title: Shikonin inhibits inflammatory responses in rabbit chondrocytes and shows chondroprotection in osteoarthritic rabbit knee.
abstract: Shikonin, a natural product from Lithospermum erythrorhizon, exerts a wide range of anti-inflammatory actions both in vitro and in vivo. Matrix metalloproteinases (MMPs) have long been considered as the major catabolic enzymes involved in osteoarthritis (OA) cartilage erosion. Here, we investigated the anti-inflammatory and effects of shikonin on MMPs in both IL-1β induced rabbit chondrocytes and the experimental rabbit OA model induced by anterior cruciate ligament (ACL) transection and evaluated the potential involvement of nuclear factor kappa B (NF-κB) in the processes. In vitro, rabbit chondrocytes were cultured and pretreated with shikonin (0, 1, 5, 10μM) for 1h (h) with or without IL-1β (10ng/ml) for 24h. The expression of MMPs (MMP-1, MMP-3 and MMP-13) and tissue inhibitors of metalloproteinase-1 (TIMP-1) at mRNA and protein levels were determined by quantitative real-time PCR and ELISA respectively. NF-κB related signaling molecules were investigated by Western blotting. In vivo study, the effects of shikonin on MMPs and TIMP-1 were determined at the gene level and the cartilage damage was evaluated at the histological level after the rabbits sacrificed. We found that shikonin significantly reversed the elevated expression of MMP-1, MMP-3 and MMP-13 and the reduced expression of TIMP-1 at both gene and protein levels in IL-1β induced chondrocytes. Additionally, the reduction of IκBα and the activation of NF-κB p65 induced by IL-1β were subsided by shikonin in rabbit chondrocytes. In vivo, both the cartilage damage and the elevated expression of MMP-1, MMP-3 and MMP-13 and the decreased expression of TIMP-1 were ameliorated in shikonin intra-articular injection knees compared to vehicle knees. Our findings indicated that shikonin have anti-inflammatory and chondro-protective effects and may be a potential therapeutic agent for the treatment of OA.
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061 Shaanxi, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061 Shaanxi, PR China.
authors.forename: Zhanhai
authors.initials: Z
authors.lastname: Yin
authors.affiliation: Key Laboratory of Environment and Gene Related Diseases, Xi'an Jiaotong University, Ministry Education, Xi'an 710061 Shaanxi, PR China.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061 Shaanxi, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Xue
authors.affiliation: School of Pharmacy, Xi'an Jiaotong University, Xi'an 710061 Shaanxi, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.affiliation: School of Pharmacy, Xi'an Jiaotong University, Xi'an 710061 Shaanxi, PR China.
authors.forename: Ruimiao
authors.initials: R
authors.lastname: Chang
authors.affiliation: Department of Human Anatomy, Histology and Embryology, Xi'an Jiaotong University, Xi'an 710061 Shaanxi, PR China.
authors.forename: Kaige
authors.initials: K
authors.lastname: Ma
authors.affiliation: Department of Orthopaedics, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061 Shaanxi, PR China. Electronic address: yushengqiu@yeah.net.
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Qiu
mesh_terms: D000818:Animals; D002356:Cartilage / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D019902:Chondrocytes / Q000187:drug effects*; D005786:Gene Expression Regulation / Q000187:drug effects; D051550:I-kappa B Kinase / Q000235:genetics / Q000378:metabolism; D007249:Inflammation / Q000188:drug therapy*; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism; D008297:Male; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D009285:Naphthoquinones / Q000494:pharmacology*; D010003:Osteoarthritis / Q000188:drug therapy*; D011817:Rabbits; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism
chemical_list: D053583:Interleukin-1beta; D016328:NF-kappa B; D009285:Naphthoquinones; D019715:Tissue Inhibitor of Metalloproteinase-1; C016101:shikonin; D051550:I-kappa B Kinase; D020782:Matrix Metalloproteinases
keywords: Chondrocytes; Interleukin-1β; Matrix metallopeptidases; NF-κB; Osteoarthritis; Shikonin