title: Quercetin-rich onion peel extract suppresses adipogenesis by down-regulating adipogenic transcription factors and gene expression in 3T3-L1 adipocytes.
abstract: BACKGROUND
  Onion peel contains a high amount of quercetin, which has been reported to have anti-cholesterol, antithrombotic and insulin-sensitizing properties. This study aimed to elucidate the anti-adipogenic effects of quercetin-rich onion peel extract (OPE) and to compare it with commercially available quercetin using 3T3-L1 preadipocytes.
  
  
  RESULTS
  Without affecting cell viability, both OPE and quercetin averted adipogenesis, as characterized by dose-dependent decreases in intracellular triglyceride content and glycerol 3-phosphate dehydrogenase activity, but the effect was more pronounced with OPE than with quercetin. The mRNA expression levels of key adipogenic genes such as PPARγ, C/EBPα, FABP4, aP2 and LPL were decreased in a dose-dependent manner by both OPE and quercetin.
  
  
  CONCLUSIONS
  The results indicate that OPE treatment significantly prevents intracellular lipid accumulation via hyperactivation of genes regulating lipolysis as compared with quercetin alone.
authors.affiliation: Department of Food Science and Human Nutrition, and Research Institute of Humans Ecology, Chonbuk National University, 567 Baekje-daero, deokjin-gu, Jeonju-si, Jeollabuk-do, 561-756, Republic of Korea.
authors.forename: Cho-Rong
authors.initials: CR
authors.lastname: Bae
authors.forename: Yun-Kyung
authors.initials: YK
authors.lastname: Park
authors.forename: Youn-Soo
authors.initials: YS
authors.lastname: Cha
mesh_terms: D041721:3T3-L1 Cells; D052438:Adipocytes, White / Q000166:cytology / Q000378:metabolism; D050156:Adipogenesis; D000818:Animals; D019440:Anti-Obesity Agents / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism*; D022762:CCAAT-Enhancer-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D002470:Cell Survival; D019587:Dietary Supplements; D015536:Down-Regulation; D005786:Gene Expression Regulation; D008066:Lipolysis; D051379:Mice; D019697:Onions / Q000737:chemistry*; D047495:PPAR gamma / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D019441:Plant Epidermis / Q000737:chemistry*; D010936:Plant Extracts / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism*; D018517:Plant Roots / Q000737:chemistry*; D011794:Quercetin / Q000009:adverse effects / Q000032:analysis / Q000378:metabolism*; D056910:Republic of Korea; D014280:Triglycerides / Q000378:metabolism
chemical_list: D019440:Anti-Obesity Agents; D022762:CCAAT-Enhancer-Binding Proteins; C530718:CEBPA protein, mouse; D047495:PPAR gamma; D010936:Plant Extracts; D014280:Triglycerides; D011794:Quercetin
keywords: 3T3-L1 cells; adipogenesis; glycerol 3-phosphate dehydrogenase (GPDH); onion peel extract (OPE); quercetin