TY - JOUR

T1 - Quercetin enhances adiponectin secretion by a PPAR-gamma independent mechanism

AU - Wein, Silvia

AU - Behm, Norma

AU - Petersen, Rasmus Koefoed

AU - Kristiansen, Karsten

AU - Wolffram, Siegfried

N1 - Copyright (c) 2010 Elsevier B.V. All rights reserved.

PY - 2010/9/11

Y1 - 2010/9/11

N2 - To study possible insulin sensitizing, anti-inflammatory and anti-oxidative effects of the flavonol quercetin, rats were fed a high-fat diet (19%, w/w) with (HFQ) or without (HF) 0.03% quercetin or a flavonoid-poor low-fat (5%, w/w) maintenance diet (LF) over 4 weeks. Body weight was measured weekly, and plasma concentrations of adiponectin, leptin, insulin, glucose, triacylglycerols, total cholesterol, as well as of markers of inflammation and oxidative stress were measured (12h fasted) at the end of the feeding period. Adiponectin and peroxisome-proliferator-activated-receptor (PPAR)-gamma mRNA were measured in adipose tissue (WAT) by real-time RT-PCR. PPAR-gamma transactivation was investigated by means of a reporter gene assay. HF feeding resulted in elevated fasted plasma glucose concentrations, while HFQ did not differ from LF feeding. In the HFQ group plasma concentrations and WAT mRNA levels of adiponectin were elevated compared with the HF group, however, PPAR-gamma mRNA concentration in WAT was decreased (HFQ vs. HF). Compared to both other groups quercetin feeding significantly reduced oxidative stress, measured by plasma 8-iso-PGF(2alpha), while body weight gain, body composition and plasma leptin levels were not affected. Neither quercetin nor its metabolites induced PPAR-gamma-mediated transactivation in vitro. Adiponectin stimulating effects of quercetin are PPAR-gamma-independent and prevent impairment of insulin sensitivity without affecting body weight and composition.

AB - To study possible insulin sensitizing, anti-inflammatory and anti-oxidative effects of the flavonol quercetin, rats were fed a high-fat diet (19%, w/w) with (HFQ) or without (HF) 0.03% quercetin or a flavonoid-poor low-fat (5%, w/w) maintenance diet (LF) over 4 weeks. Body weight was measured weekly, and plasma concentrations of adiponectin, leptin, insulin, glucose, triacylglycerols, total cholesterol, as well as of markers of inflammation and oxidative stress were measured (12h fasted) at the end of the feeding period. Adiponectin and peroxisome-proliferator-activated-receptor (PPAR)-gamma mRNA were measured in adipose tissue (WAT) by real-time RT-PCR. PPAR-gamma transactivation was investigated by means of a reporter gene assay. HF feeding resulted in elevated fasted plasma glucose concentrations, while HFQ did not differ from LF feeding. In the HFQ group plasma concentrations and WAT mRNA levels of adiponectin were elevated compared with the HF group, however, PPAR-gamma mRNA concentration in WAT was decreased (HFQ vs. HF). Compared to both other groups quercetin feeding significantly reduced oxidative stress, measured by plasma 8-iso-PGF(2alpha), while body weight gain, body composition and plasma leptin levels were not affected. Neither quercetin nor its metabolites induced PPAR-gamma-mediated transactivation in vitro. Adiponectin stimulating effects of quercetin are PPAR-gamma-independent and prevent impairment of insulin sensitivity without affecting body weight and composition.

KW - Adiponectin

KW - Animals

KW - Blood Glucose

KW - Cells, Cultured

KW - Cholesterol

KW - Chromatography, High Pressure Liquid

KW - Insulin

KW - Leptin

KW - Male

KW - Mice

KW - Oxidative Stress

KW - PPAR gamma

KW - Quercetin

KW - RNA, Messenger

KW - Rats

KW - Rats, Wistar

KW - Reverse Transcriptase Polymerase Chain Reaction

KW - Triglycerides

U2 - 10.1016/j.ejps.2010.05.004

DO - 10.1016/j.ejps.2010.05.004

M3 - Journal article

C2 - 20580672

VL - 41

SP - 16

EP - 22

JO - Norvegica Pharmaceutica Acta

JF - Norvegica Pharmaceutica Acta

SN - 0928-0987

IS - 1

ER -