title: Vitamin E and adiponectin: proposed mechanism for vitamin E-induced improvement in insulin sensitivity.
abstract: Insulin resistance and type 2 diabetes have been treated with the PPARγ agonists thiazolidinediones, or TZDs, since the 1990s. One mechanism by which these drugs may work is through PPARγ-mediated upregulation of adiponectin, an endogenous adipokine that has been shown to increase insulin sensitivity. Interestingly, α- and γ-tocopherol, two vitamin E vitamers, have structural similarities to the TZDs and have also been linked to enhanced insulin sensitivity. A recent study identified a novel function of α- and γ-tocopherol in 3T3-L1 preadipocytes: upregulation of an endogenous ligand involved in activating PPARγ. This study also found that tocopherols dramatically enhanced adiponectin expression and that this effect was mediated through a PPARγ-dependent process. These findings illustrate a possible mechanistic link between vitamin E and insulin sensitivity.
authors.affiliation: Department of Nutrition, University of Massachusetts, Amherst, Massachusetts 01003, USA.
authors.forename: Brianna
authors.initials: B
authors.lastname: Gray
authors.forename: Jennifer
authors.initials: J
authors.lastname: Swick
authors.forename: Alayne G
authors.initials: AG
authors.lastname: Ronnenberg
mesh_terms: D052242:Adiponectin / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D047495:PPAR gamma / Q000378:metabolism*; D015854:Up-Regulation; D014810:Vitamin E / Q000031:analogs & derivatives / Q000494:pharmacology*
chemical_list: D052242:Adiponectin; D007328:Insulin; D047495:PPAR gamma; D014810:Vitamin E