title: Quercetin, a bioflavonoid, accelerates TNF-alpha-induced growth inhibition and apoptosis in MC3T3-E1 osteoblastic cells.
abstract: The bioflavonoid quercetin is believed to play an important role in preventing bone loss by affecting osteoclastogenesis and regulating many systemic and local factors including hormones and cytokines. This study examined how quercetin acts on tumor necrosis factor-alpha (TNF-alpha)-mediated growth inhibition and apoptosis in MC3T3-E1 osteoblastic cells. Tritium uptake assay showed that a quercetin treatment accelerated TNF-alpha-induced inhibition of DNA synthesis in the cells in a dose-dependent manner. Both the 3-(4,5-dimethylthiazol-2yl-)-2,5-diphenyl tetrazolium bromide and trypan blue staining assays also showed the quercetin-mediated facilitation of TNF-alpha-induced cytotoxicity in the cells. Apoptosis assays revealed an accelerating effect of quercetin on TNF-alpha-induced apoptosis in MC3T3-E1 cells. In addition, Fas activation and poly (ADP ribose) polymerase cleavage are thought to be closely associated with the TNF-alpha-induced apoptosis and its acceleration by the quercetin treatment in the cells. Collectively, this study showed that quercetin accelerates the TNF-alpha-induced growth inhibition and apoptosis in MC3T3-E1 osteoblastic cells.
authors.affiliation: Research Center of Bioactive Materials, Chonbuk National University, Chonju 561-756, South Korea.
authors.forename: Young-Ok
authors.initials: YO
authors.lastname: Son
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Kook
authors.forename: Ki-Choon
authors.initials: KC
authors.lastname: Choi
authors.forename: Yong-Suk
authors.initials: YS
authors.lastname: Jang
authors.forename: Young-Mi
authors.initials: YM
authors.lastname: Jeon
authors.forename: Jong-Ghee
authors.initials: JG
authors.lastname: Kim
authors.forename: Kyung-Yeol
authors.initials: KY
authors.lastname: Lee
authors.forename: Ju
authors.initials: J
authors.lastname: Kim
authors.forename: Mi-Sun
authors.initials: MS
authors.lastname: Chung
authors.forename: Gook-Hyun
authors.initials: GH
authors.lastname: Chung
authors.forename: Jeong-Chae
authors.initials: JC
authors.lastname: Lee
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011794:Quercetin / Q000494:pharmacology*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D014409:Tumor Necrosis Factor-alpha; D011794:Quercetin