title: Pro-bone and antifat effects of green tea and its polyphenol, epigallocatechin, in rat mesenchymal stem cells in vitro.
abstract: Green tea has been demonstrated recently as a potent bone supportive agent. Our previous studies showed that green tea and its polyphenolic constituents can promote bone-forming osteoblast activities and inhibit the bone-resorpting osteoclast formation. The objective of the present study was to investigate whether green tea and its components can regulate the osteogenic and adipogenic differentiation in pluripotent rat mesenchymal stem cells (MSCs). The rat MSCs were isolated from the bone marrow of tibiae and femora. The cells were treated with decaffeinated green tea extract (GTE) and six tea polyphenols under osteogenic induction. The alkaline phosphatase (ALP) activities and matrix calcium (Ca) deposition were assessed after 7 and 14 days of treatment. Our results demonstrated that GTE could significantly increase ALP dose dependently in the concentrations without cytotoxicity (0-100 μg/mL). Among six tested tea polyphenols, epigallocatechin (EGC) was shown to be the most effective in promoting osteogenic differentiation. At 20 μM, EGC increased ALP levels and Ca deposition significantly by 2.3- and 1.7-fold, respectively, when compared with the control group. EGC also increased the mRNA expression of bone formation markers runt-related transcription factor 2, ALP, osteonectin, and osteopontin. Furthermore, EGC demonstrated its antiadipogenicity by decreasing the adipocyte formation and inhibiting the mRNA expression levels of the adipogenic markers peroxisome proliferator-activated receptor γ, ccaat/enhancer-binding protein β, and fatty acid binding protein 4. In conclusion, this is the first report of the dual action of green tea polyphenol EGC in promoting osteogenesis and inhibiting adipocyte formation in MSCs. Our results provide scientific evidence to support the potential use of green tea in supporting the bone against degenerative diseases such as osteoporosis.
authors: Institute of Chinese Medicine, State Key Laboratory of Phytochemistry and Plant Resources in West China, Department of Orthopaedics and Traumatology, Jockey Club Centre for Osteoporosis Care and Control and School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
authors: Chun Hay
authors: CH
authors: Ko
authors: Wing Sum
authors: WS
authors: Siu
authors: Hing Lok
authors: HL
authors: Wong
authors: Wai Ting
authors: WT
authors: Shum
authors: Kwok Pui
authors: KP
authors: Fung
authors: Clara Bik
authors: CB
authors: San Lau
authors: Ping Chung
authors: PC
authors: Leung
mesh_terms: D050156:Adipogenesis / Q000187:drug effects*; D000818:Animals; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology; D059808:Polyphenols / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013662:Tea / Q000737:chemistry
chemical_list: D010936:Plant Extracts; D059808:Polyphenols; D013662:Tea; D002392:Catechin; C057580:gallocatechol