Effect of Rehmannia glutinosa Libosch extracts on bone metabolism.
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.
Oh
Kwi Ok
KO
OCT Inc., 2-17, Omok-ri, Seonggeo-eup, Choongnam 330-831, Chonan, South Korea. rnd@oscotec.com
Kim
Se Won
SW
Kim
Jong Yeo
JY
Ko
Seon Yle
SY
Kim
Hyun Man
HM
Baek
Jeong Hwa
JH
Ryoo
Hyun Mo
HM
Kim
Jung Keun
JK
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
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