title: Effect of Rehmannia glutinosa Libosch extracts on bone metabolism.
abstract: BACKGROUND
  Rehmannia glutinosa Libosch extracts (RGX) were investigated to determine if they play roles in bone metabolism.
  
  
  METHODS
  The effects on osteoblasts were determined by measuring (1) cell proliferation, (2) alkaline phosphatase (ALP) activity, (3) mRNA expression of bone-related proteins, (4) transcriptional activity of Runx2, and (5) osteoprotegerin (OPG) secretion. The effects on the osteoclasts were investigated by measuring (1) tartrate-resistant acid phosphatase-positive [TRAP(+)] multinucleated cell (MNC) formation and (2) resorption areas after culturing osteoclast precursors. Bone mineral density (BMD) measurements and histological observations on rats were also carried out.
  
  
  RESULTS
  RGX treatment showed a significant increase in both the proliferation and ALP activity of osteoblasts. RGX increased the expression of the bone-related genes. OPG secretion was markedly increased after RGX treatment. In addition, RGX treatment decreased the number of TRAP(+) MNCs and the resorption areas. In vivo studies using ovariectomy-induced osteoporotic rats revealed that RGX alleviated the decrease in the trabecular BMD, and increased the cortical bone thickness and trabeculation of the bone marrow spaces.
  
  
  CONCLUSIONS
  RGX stimulates the proliferation and activities of osteoblasts, while inhibiting the generation and resorptive activities of osteoclasts. It also shows preventive effects on osteoporotic bone loss induced by an ovariectomy. Although the active substances have not yet been identified, it is believed that the RGX seems to contain active components that have a potential to enhance the bone metabolism in osteoporosis.
authors.affiliation: OCT Inc., 2-17, Omok-ri, Seonggeo-eup, Choongnam 330-831, Chonan, South Korea. rnd@oscotec.com
authors.forename: Kwi Ok
authors.initials: KO
authors.lastname: Oh
authors.forename: Se Won
authors.initials: SW
authors.lastname: Kim
authors.forename: Jong Yeo
authors.initials: JY
authors.lastname: Kim
authors.forename: Seon Yle
authors.initials: SY
authors.lastname: Ko
authors.forename: Hyun Man
authors.initials: HM
authors.lastname: Kim
authors.forename: Jeong Hwa
authors.initials: JH
authors.lastname: Baek
authors.forename: Hyun Mo
authors.initials: HM
authors.lastname: Ryoo
authors.forename: Jung Keun
authors.initials: JK
authors.lastname: Kim
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D015519:Bone Density / Q000187:drug effects; D001854:Bone Marrow Cells / Q000378:metabolism; D001862:Bone Resorption / Q000378:metabolism; D001842:Bone and Bones / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D024042:Collagen Type I / Q000378:metabolism; D050659:Core Binding Factor Alpha 1 Subunit; D005260:Female; D006801:Humans; D051379:Mice; D009363:Neoplasm Proteins; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism; D010010:Osteoclasts / Q000187:drug effects / Q000378:metabolism; D053495:Osteopontin; D010024:Osteoporosis / Q000188:drug therapy; D010052:Ovariectomy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D012333:RNA, Messenger / Q000096:biosynthesis; D016601:RNA-Binding Proteins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D032267:Rehmannia / Q000737:chemistry*; D012795:Sialoglycoproteins / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D024042:Collagen Type I; D050659:Core Binding Factor Alpha 1 Subunit; C079092:MtrB protein, Bacteria; D009363:Neoplasm Proteins; D010936:Plant Extracts; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; C506896:Spp1 protein, mouse; C506897:Spp1 protein, rat; D014157:Transcription Factors; D053495:Osteopontin; D000469:Alkaline Phosphatase