title: Epigallocatechin-3-gallate increases the formation of mineralized bone nodules by human osteoblast-like cells.
abstract: Consumption of green tea, a rich source of epigallocatechin-3-gallate (EGCG), is associated with increased bone mineral density. However, the direct effects of this flavonoid on bone mineralization are not known. The present study demonstrates the effects of EGCG on the formation of mineralized bone nodules by SaOS-2 human osteoblast (HOB)-like cells. EGCG at concentrations of 1-5 microM caused a dose-dependent increase in the number and area of mineralized bone nodules as assessed by both von Kossa and alizarin red staining. EGCG also increased alkaline phosphatase activity, an early marker of osteoblastic differentiation. After 48 h of treatment, EGCG decreased protein levels of Runx2, a transcription factor that regulates osteoblast maturation by inhibiting late-stage differentiation. The observed effects of EGCG on bone formation by HOB-like cells suggest that EGCG may have beneficial effects on bone health.
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada M5S 3E2.
authors.forename: Bahareh
authors.initials: B
authors.lastname: Vali
authors.forename: Leticia G
authors.initials: LG
authors.lastname: Rao
authors.forename: Ahmed
authors.initials: A
authors.lastname: El-Sohemy
mesh_terms: D000469:Alkaline Phosphatase / Q000187:drug effects / Q000378:metabolism; D002113:Calcification, Physiologic / Q000187:drug effects*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006801:Humans; D010006:Osteoblasts / Q000187:drug effects*
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; C493709:RUNX2 protein, human; D002392:Catechin; C045651:epigallocatechin gallate; D000469:Alkaline Phosphatase