title: Green tea extracts reduce adipogenesis by decreasing expression of transcription factors C/EBPα and PPARγ.
abstract: OBJECTIVE
  This study is to determine if green tea (Camellia sinensis) extracts (GTE) affects adipogenesis and further investigate the related molecular mechanisms.
  
  
  METHODS
  Patients with metabolic syndrome were recruited in this study. Of them, 70 patients received GTE and 64 received water to serve as the control group. The human serum adiponectin, visfatin, and leptin concentrations were determined by enzyme-linked immunosorbent assay. Adipogenesis of 3T3-L1 preadipocytes was induced with reagents and then the cells were treated with GTE. The lipids were stained with Oil Red O for analysis of adipogenesis of 3T3-L1 preadipocytes. The 3T3-L1 preadipocytes were treated with increasing concentrations (0.2-0.5%, w/v) of GTE for 2 days and the cell viability was determined by MTT assay. Reverse transcription real-time PCR and immunoblotting assays were performed to determine RNA and protein levels of relative molecules.
  
  
  RESULTS
  GTE increases the serum concentrations of adiponectin but decreases visfatin levels in patients received GTE. The leptin concentrations in serum were not significantly affected. The GTE reduces the adipogenesis-induced lipid accumulation in 3T3-L1 preadipocytes. GTE decreases the mRNA and protein expression of adipogenic transcription factors C/EBPα and PPARγ in 3T3-L1 cells. Expression levels of the adipocyte-specific genes encoding adipocyte protein 2, lipoprotein lipase, and glucose transporter 4 were also decreased by GTE. Furthermore, it was found that GTE reduces phosphorylation of Akt during adipocyte differentiation.
  
  
  CONCLUSIONS
  GTE reduces adipogenesis by decreasing expression of transcription factors C/EBPα and PPARγ by reduction of phosphorylation of Akt during adipocyte differentiation.
authors: School of Nursing, Qingdao University Qingdao 266021, China.
authors: Xiuling
authors: X
authors: Yang
authors: Department of Emergency, The Affiliated Hospital, Qingdao University Qingdao 266003, China.
authors: Lei
authors: L
authors: Yin
authors: Department of Pediatrics, The Affiliated Hospital, Qingdao University Qingdao 266003, China.
authors: Tang
authors: T
authors: Li
authors: Department of Pediatrics, The Affiliated Hospital, Qingdao University Qingdao 266003, China.
authors: Zhihong
authors: Z
authors: Chen
keywords: C/EBPα; Green tea extracts; PPARγ; adipogenesis; transcription factor