title: Apigenin isolated from Daphne genkwa Siebold et Zucc. inhibits 3T3-L1 preadipocyte differentiation through a modulation of mitotic clonal expansion.
abstract: OBJECTIVE
  Obesity develops when energy intake chronically exceeds total energy expenditure. We sought to assess whether the flavonoid-rich fraction of crude extracts from Daphne genkwa Siebold et Zuccarini (GFF) might inhibit adipogenesis of 3T3-L1 cells.
  
  
  METHODS
  Cell viability of 3T3-L1 preadipocytes was assessed by MTT assays, and lipid accumulation was measured by Oil Red O. Adipogenesis related factors were checked by Western blot analysis. Flow cytometry was used to analyze the mitotic cell cycle during the mitotic clonal expansion phase.
  
  
  RESULTS
  Among five flavonoids isolated from GFF, only apigenin potently inhibited the differentiation of 3T3-L1 cells. Apigenin reduced CCAAT/enhancer binding protein (C/EBP) α and peroxisome proliferator-activated receptor γ levels. Apigenin-treated 3T3-L1 cells failed to undergo clonal expansion during the early phase of adipocyte differentiation. Apigenin arrested cell cycle progression at the G0/G1 phase. This effect was associated with a marked decrease in cyclin D1 and cyclin-dependent kinase 4 expression, with the concomitant and sustained expression of p27(Kip1). In addition, apigenin inhibited the DNA-binding activity of C/EBPβ in differentiating 3T3-L1 cells by down-regulating the 35kDa isoform of C/EBPβ (liver-enriched activating protein) and up-regulating the expression of two different sets of C/EBP inhibitors: C/EBP homologous protein and the phospho-liver-enriched inhibitory protein isoform of C/EBPβ.
  
  
  CONCLUSIONS
  These findings suggest that apigenin can prevent 3T3-L1 preadipocyte differentiation by the inhibition of the mitotic clonal expansion and the adipogenesis related factors and upregulation of the expression of multiple C/EBPβ inhibitors.
authors.affiliation: Functional Food Center, Korea Institute of Science and Technology, Gangneung, Gangwon-do 210-340, Republic of Korea.
authors.forename: Mi-Ae
authors.initials: MA
authors.lastname: Kim
authors.affiliation: Functional Food Center, Korea Institute of Science and Technology, Gangneung, Gangwon-do 210-340, Republic of Korea.
authors.forename: Kyungsu
authors.initials: K
authors.lastname: Kang
authors.affiliation: Functional Food Center, Korea Institute of Science and Technology, Gangneung, Gangwon-do 210-340, Republic of Korea.
authors.forename: Hee-Ju
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Functional Food Center, Korea Institute of Science and Technology, Gangneung, Gangwon-do 210-340, Republic of Korea.
authors.forename: Myungsuk
authors.initials: M
authors.lastname: Kim
authors.affiliation: Functional Food Center, Korea Institute of Science and Technology, Gangneung, Gangwon-do 210-340, Republic of Korea.
authors.forename: Chul Young
authors.initials: CY
authors.lastname: Kim
authors.affiliation: Functional Food Center, Korea Institute of Science and Technology, Gangneung, Gangwon-do 210-340, Republic of Korea. Electronic address: cwnho@kist.re.kr.
authors.forename: Chu Won
authors.initials: CW
authors.lastname: Nho
mesh_terms: D041721:3T3-L1 Cells / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D017667:Adipocytes / Q000166:cytology* / Q000187:drug effects*; D050156:Adipogenesis / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D047310:Apigenin / Q000302:isolation & purification / Q000494:pharmacology*; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000378:metabolism; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D019938:Cyclin D1 / Q000378:metabolism; D051358:Cyclin-Dependent Kinase 4 / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism; D032364:Daphne / Q000737:chemistry*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D051379:Mice; D047495:PPAR gamma / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology
chemical_list: C083058:C-EPB transcription factor; D022763:CCAAT-Enhancer-Binding Protein-alpha; D022762:CCAAT-Enhancer-Binding Proteins; C493961:Cdkn1b protein, mouse; D047495:PPAR gamma; D010936:Plant Extracts; D019938:Cyclin D1; D050760:Cyclin-Dependent Kinase Inhibitor p27; D047310:Apigenin; C495902:Cdk4 protein, mouse; D051358:Cyclin-Dependent Kinase 4
keywords: 3T3-L1; Apigenin; CCAAT/enhancer binding protein; Daphne genkwa Sieboldet et Zuccarini; Mitotic clonal expansion; Preadipocyte differentiation