title: [Inhibitory effect of diacerein on osteoclastic bone destruction and its possible mechanism of action].
abstract: OBJECTIVE
  To study the inhibitory action of diacerein on the formation of osteoclasts (OCLs) and their activity in bone resorption as well as the relationship between this action and the expression of osteoprotegerin (OPG) and receptor activator of NF-kappaB ligand (RANKL) in MC3T3-E1 cells.
  
  
  METHODS
  A coculture system constituted with MC3T3-E1 cells and bone marrow cells for osteoclasts formation was established in vitro. TRAP-positive and multinucleated cells with three or more nuclei in each cell were counted as osteoclasts and the number of pits formed on the dentine slices was determined to judge the activity of osteoclasts. Western blotting, RT-PCR and flow cytometer were used to detect the expression of OPG and RANKL in MC3T3-E1 cells.
  
  
  RESULTS
  Diacerein significantly inhibited the formation and function of the cultured osteoclasts stimulated by IL-1beta. sRANKL could reverse the effect of diacerein. Diacerein inhibited protein and mRNA expression of RANKL but enhanced those of OPG in MC3T3-E1 cells.
  
  
  CONCLUSIONS
  Diacerein may inhibit osteoclastic bone destruction through the inhibition of RANKL expression and the increase of OPG expression in MC3T3-E1 cells.
authors.affiliation: Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union, Medical College, Beijing 100050, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Yu-Jia
authors.initials: YJ
authors.lastname: Mao
authors.forename: Wen-Jie
authors.initials: WJ
authors.lastname: Wang
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000880:Anthraquinones / Q000494:pharmacology*; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D001854:Bone Marrow Cells / Q000502:physiology; D001862:Bone Resorption; D002460:Cell Line; D018920:Coculture Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D010010:Osteoclasts / Q000502:physiology*; D053244:Osteoprotegerin / Q000096:biosynthesis* / Q000235:genetics; D053245:RANK Ligand / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics
chemical_list: D000880:Anthraquinones; D000893:Anti-Inflammatory Agents; D053244:Osteoprotegerin; D053245:RANK Ligand; D012333:RNA, Messenger; C025292:diacerein