title: [Mechanisms of icariin in regulating bone formation of osteoblasts and bone resorption of osteoclasts].
abstract: OBJECTIVE
  To investigate the molecular mechanisms of icariin (ICA) in regulating the bone formation of osteoblasts and the bone resorption of osteoclasts.
  
  
  METHODS
  Primary osteoblast cell cultures were obtained from newborn rat calvarial. Calcified nodules were stained by alizarin red. The mRNA levels of osterix (OSX), runt-related transcription factor 2 (Runx-2), alkaline phosphatase (ALP), Collagen1, osteoprotegerin (OPG), and receptor activator of nuclear factor-ΚB ligand (RANKL) were analyzed by quantitative real-time RT-PCR, the protein levels of OPG, RANKL, and Collagen1 were examined by Western blotting, and the intracellular Ca(2+) concentration of osteoblasts was measured on a flow cytometer using the Cellquest program.
  
  
  RESULTS
  Compared with control group, ICA markedly promoted bone formation by significant up-regulating the gene expressions of OSX, Runx-2,ALP, and Collagen1, the protein expression of Collagen1(all P<0.01), and the Ca(2+) concentration. Furthermore, ICA remarkably inhibited bone resorption by significant up-regulating the mRNA and protein expressions of OPG as well as the OPG/RANKL ratio.
  
  
  CONCLUSIONS
  ICA could promote bone formation of osteoblasts through inducting the gene expressions of OSX,Runx-2, ALP and Collagen1, and the protein expressions of Collagen1, and by increasing the Ca (2+) concentration. Moreover, ICA could inhibit bone resorption of osteoclasts through regulating OPG/RANKL signal pathway.
authors.affiliation: Institute of Orthopaedics, Lanzhou General Hospital, Lanzhou Command of PLA, Lanzhou,China.
authors.forename: Xiao-ni
authors.initials: XN
authors.lastname: Ma
authors.forename: Bao-feng
authors.initials: BF
authors.lastname: Ge
authors.forename: Ke-ming
authors.initials: KM
authors.lastname: Chen
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.forename: Wen-gui
authors.initials: WG
authors.lastname: Shi
authors.forename: Yan-fang
authors.initials: YF
authors.lastname: Xie
authors.forename: Xiao-yu
authors.initials: XY
authors.lastname: Guo
authors.forename: Xiang
authors.initials: X
authors.lastname: Lv
authors.forename: Kui
authors.initials: K
authors.lastname: Cheng
authors.forename: Yu-hai
authors.initials: YH
authors.lastname: Gao
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001862:Bone Resorption; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology*; D015870:Gene Expression; D010006:Osteoblasts / Q000187:drug effects*; D010010:Osteoclasts / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects*; D053244:Osteoprotegerin / Q000378:metabolism; D053245:RANK Ligand / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D024042:Collagen Type I; D050659:Core Binding Factor Alpha 1 Subunit; D005419:Flavonoids; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; C493717:Runx2 protein, rat; C495181:Sp7 protein, rat; C506032:Tnfrsf11b protein, rat; D014157:Transcription Factors; D000469:Alkaline Phosphatase; C056599:icariin