title: Stimulatory effect of menaquinone-7 (vitamin K2) on osteoblastic bone formation in vitro.
abstract: Menaquinone-7, which is vitamin K2 (menatetrenone) with seven isoprene units, is highly contained in the fermented soybean. The effect of menaquinone-7 (MK-7) on osteoblastic bone formation was investigated. Femoral-diaphyseal and metaphyseal tissues of young male rats (4 weeks old) were cultured for 48 h in a medium containing either vehicle or MK-7 (10(-7)-10(-5) M). Calcium content, alkaline phosphatase activity, and deoxyribonuclic acid (DNA) content in the diaphyseal and metaphyseal tissues was significantly increased in the presence of MK-7 (10(-6) and 10(-5) M). The effect of MK-7 in increasing the diaphyseal and metaphyseal calcium content and alkaline phosphatase activity was completely prevented in the presence of cycloheximide (10(-6) M), an inhibitor of protein synthesis. Moreover, osteoblastic MC3T3-E1 cells after subculture were cultured for 24 h in a serum-free medium containing MK-7 (10(-7)-10(-5) M). Protein content, alkaline phophatase activity, osteocalcin and DNA content in the cells was significantly increased in the presence of MK-7 (10(-6) and 10(-5) M). The effect of MK-7 in increasing protein content, alkaline phosphatase activity, and osteocalcin production in the cells was completely blocked by cycloheximide. This study demonstrates that MK-7 has an anabolic effect on bone tissue and osteoblastic MC3T3-E1 cells in vitro, suggesting that the compound can stimulate osteoblastic bone formation.
authors.affiliation: Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: E
authors.initials: E
authors.lastname: Sugimoto
authors.forename: S
authors.initials: S
authors.lastname: Hachiya
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D016895:Culture Media, Serum-Free; D046508:Culture Techniques; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000378:metabolism; D008297:Male; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects* / Q000502:physiology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D024482:Vitamin K 2 / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D016895:Culture Media, Serum-Free; D011500:Protein Synthesis Inhibitors; D011506:Proteins; D024482:Vitamin K 2; C062629:menaquinone 7; D004247:DNA; D003513:Cycloheximide; D000469:Alkaline Phosphatase; D002118:Calcium