title: Kefir inhibits 3T3-L1 adipocyte differentiation through down-regulation of adipogenic transcription factor expression.
abstract: BACKGROUND
  Kefir, a traditional fermented milk composed of microbial symbionts, is reported to have various health benefits such as anti-tumour, anti-inflammatory, anti-neoplastic and pro-digestive effects. In this study, to elucidate the effects of kefir on adipocyte differentiation and lipid accumulation, three fractions were prepared from kefir culture broth. The inhibitory effects of kefir liquid culture broth fraction (Fr-1), soluble fraction (Fr-2) and insoluble fraction (Fr-3), prepared by sonication of kefir solid culture broth, on adipocyte differentiation in 3T3-L1 preadipocytes were examined.
  
  
  RESULTS
  Fr-3 (0.1 mg mL(-1)) significantly decreased lipid accumulation and glycerol-3-phosphate dehydrogenase (GPDH) activity by 60 and 68% respectively without affecting cell viability. In addition, Fr-3 treatment down-regulated the mRNA expression of adipogenic transcription factors including C/EBPα (32%), PPARγ (46%) and SREBP-1c (34%) during adipocyte differentiation compared with untreated control cells. The mRNA expression of adipocyte-specific genes (aP2, FAS and ACC) was also clearly decreased.
  
  
  CONCLUSIONS
  The results suggest that the insoluble fraction of kefir (Fr-3) mediates anti-adipogenic effects through the inhibition of adipocyte differentiation, partly via suppression of the C/EBPα-, SREBP-1c- and PPARγ-dependent pathways.
authors: Department of Medical Nutrition, Kyung Hee University, Yongin 446-701, Korea.
authors: Jin-Nyoung
authors: JN
authors: Ho
authors: Jae-Woo
authors: JW
authors: Choi
authors: Won-Chul
authors: WC
authors: Lim
authors: Mi-Kyoung
authors: MK
authors: Kim
authors: In-Young
authors: IY
authors: Lee
authors: Hong-Yon
authors: HY
authors: Cho
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology*; D050156:Adipogenesis / Q000235:genetics*; D000818:Animals; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000037:antagonists & inhibitors / Q000235:genetics; D002454:Cell Differentiation / Q000502:physiology*; D043302:Cultured Milk Products / Q000737:chemistry / Q000502:physiology*; D015536:Down-Regulation; D005993:Glycerolphosphate Dehydrogenase / Q000037:antagonists & inhibitors; D051379:Mice; D047495:PPAR gamma / Q000037:antagonists & inhibitors / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D012995:Solubility; D051780:Sterol Regulatory Element Binding Protein 1 / Q000037:antagonists & inhibitors / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D022763:CCAAT-Enhancer-Binding Protein-alpha; D047495:PPAR gamma; D012333:RNA, Messenger; D051780:Sterol Regulatory Element Binding Protein 1; D014157:Transcription Factors; D005993:Glycerolphosphate Dehydrogenase