title: Bioconversion of Citrus unshiu peel extracts with cytolase suppresses adipogenic activity in 3T3-L1 cells.
abstract: OBJECTIVE
  Citrus flavonoids have a variety of physiological properties such as anti-oxidant, anti-inflammation, anti-cancer, and anti-obesity. We investigated whether bioconversion of Citrus unshiu with cytolase (CU-C) ameliorates the anti-adipogenic effects by modulation of adipocyte differentiation and lipid metabolism in 3T3-L1 cells.
  
  
  METHODS
  Glycoside forms of Citrus unshiu (CU) were converted into aglycoside forms with cytolase treatment. Cell viability of CU and CU-C was measured at various concentrations in 3T3L-1 cells. The anti-adipogenic and lipolytic effects were examined using Oil red O staining and free glycerol assay, respectively. We performed real time-polymerase chain reaction and western immunoblotting assay to detect mRNA and protein expression of adipogenic transcription factors, respectively.
  
  
  RESULTS
  Treatment with cytolase decreased flavanone rutinoside forms (narirutin and hesperidin) and instead, increased flavanone aglycoside forms (naringenin and hesperetin). During adipocyte differentiation, 3T3-L1 cells were treated with CU or CU-C at a dose of 0.5 mg/ml. Adipocyte differentiation was inhibited in CU-C group, but not in CU group. CU-C markedly suppressed the insulin-induced protein expression of CCAAT/enhancer-binding protein α (C/EBPα) and peroxisome proliferator-activated receptor gamma (PPARγ) as well as the mRNA levels of CEBPα, PPARγ, and sterol regulatory element binding protein 1c (SREBP1c). Both CU and CU-C groups significantly increased the adipolytic activity with the higher release of free glycerol than those of control group in differentiated 3T3-L1 adipocytes. CU-C is particularly superior in suppression of adipogenesis, whereas CU-C has similar effect to CU on stimulation of lipolysis.
  
  
  CONCLUSIONS
  These results suggest that bioconversion of Citrus unshiu peel extracts with cytolase enhances aglycoside flavonoids and improves the anti-adipogenic metabolism via both inhibition of key adipogenic transcription factors and induction of adipolytic activity.
authors.affiliation: Department of Food and Nutrition, College of Natural Sciences, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi 449-728, Korea.
authors.forename: Heejin
authors.initials: H
authors.lastname: Lim
authors.affiliation: Department of Food and Nutrition, College of Natural Sciences, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi 449-728, Korea.
authors.forename: Eunju
authors.initials: E
authors.lastname: Yeo
authors.affiliation: Department of Food and Nutrition, College of Natural Sciences, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi 449-728, Korea.
authors.forename: Eunju
authors.initials: E
authors.lastname: Song
authors.affiliation: Department of Food and Nutrition, College of Natural Sciences, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi 449-728, Korea.
authors.forename: Yun-Hee
authors.initials: YH
authors.lastname: Chang
authors.affiliation: BK Bio Co. Ltd., Gyeonggi 462-819, Korea.
authors.forename: Bok-Kyung
authors.initials: BK
authors.lastname: Han
authors.affiliation: BK Bio Co. Ltd., Gyeonggi 462-819, Korea.
authors.forename: Hyuk-Joon
authors.initials: HJ
authors.lastname: Choi
authors.affiliation: Department of Food and Nutrition, College of Natural Sciences, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggi 449-728, Korea.
authors.forename: Jinah
authors.initials: J
authors.lastname: Hwang
keywords: 3T3-L1 adipocyte; Adipocyte differentiation; Citrus unshiu; anti-adipogenesis; bioconversion