title: β-cryptoxanthin suppresses the adipogenesis of 3T3-L1 cells via RAR activation.
abstract: We recently reported that the oral intake of β-cryptoxanthin exerted anti-obesity effects by lowering visceral fat levels. In the present study, we characterized the molecular mechanisms underlying the lipid-lowering effects of β-cryptoxanthin on 3T3-L1 cells. Consistent with our previous findings, β-cryptoxanthin rapidly reduced the level of intracellular lipids in 3T3-L1 cells as assessed by Oil red O staining. Using an in vitro nuclear receptor binding assay, we demonstrated the ability of β-cryptoxanthin to bind to and activate members of the retinoic acid receptor (RAR) family. Accordingly, treatment of cells with LE540, an RAR antagonist, abolished the β-cryptoxanthin-dependent suppression of 3T3-L1 adipogenesis, suggesting that β-cryptoxanthin mediates its effects on 3T3-L1 cells via RAR activation. In addition, real-time RT-PCR analysis revealed that β-cryptoxanthin down-regulates mRNA expression of PPARγ, a key regulator of adipocyte differentiation, and that this inhibition was blocked by LE540 treatment. Taken together, these data indicate that RAR activation contributes to the molecular mechanism by which β-cryptoxanthin prevents obesity.
authors.affiliation: Research and Development Center, Unitika Ltd, Uji, Kyoto, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Shirakura
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Takayanagi
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Mukai
authors.forename: Hiroki
authors.initials: H
authors.lastname: Tanabe
authors.forename: Makoto
authors.initials: M
authors.lastname: Inoue
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects* / Q000502:physiology; D050156:Adipogenesis / Q000187:drug effects*; D000818:Animals; D019440:Anti-Obesity Agents / Q000494:pharmacology* / Q000627:therapeutic use; D065366:Cryptoxanthins; D003984:Dibenzazepines / Q000494:pharmacology; D015536:Down-Regulation; D050356:Lipid Metabolism / Q000187:drug effects*; D051379:Mice; D009765:Obesity / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control*; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000378:metabolism*; D024341:Xanthophylls / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D019440:Anti-Obesity Agents; D065366:Cryptoxanthins; D003984:Dibenzazepines; C104183:LE 540; D047495:PPAR gamma; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; D024341:Xanthophylls