Changes in white adipose tissue metabolism induced by resveratrol in rats
Goiuri Alberdi
0
2
3
Vctor M Rodrguez
0
2
3
Jonatan Miranda
0
2
3
Mara T Macarulla
0
2
3
Noem Arias
0
2
3
Cristina Andrs-Lacueva
1
4
Mara P Portillo
0
2
3
0
Department of Nutrition and Food Science, Faculty of Pharmacy, University of Pais Vasco, Paseo de la Universidad 7
,
01006 Vitoria
,
Spain
1
Department of Nutrition and Food Science
,
XaRTA, INSA
,
Faculty of Pharmacy, University of Barcelona
,
Barcelona
,
Spain
2
RETICS RD06/ 0045/0003, Instituto de Salud Carlos III
,
Madrid
,
Spain
3
Department of Nutrition and Food Science, Faculty of Pharmacy, University of Pais Vasco, Paseo de la Universidad 7
,
01006 Vitoria
,
Spain
4
INGENIO-CONSOLIDER Program
,
Fun-c-food (CSD2007-063)
,
Ministry of Science and Innovation
,
Barcelona
,
Spain
Background: A remarkable range of biological functions have been ascribed to resveratrol. Recently, this polyphenol has been shown to have body fat lowering effects. The aim of the present study was to assess some of the potential underlying mechanisms of action which take place in adipose tissue. Methods: Sixteen male Sprague-Dawley rats were randomly divided into two groups: control and treated with 30 mg resveratrol/kg body weight/d. All rats were fed an obesogenic diet and after six weeks of treatment white adipose tissues were dissected. Lipoprotein lipase activity was assessed by fluorimetry, acetyl-CoA carboxylase by radiometry, and malic enzyme, glucose-6P-dehydrogenase and fatty acid synthase by spectrophotometry. Gene expression levels of acetyl-CoA carboxylase, fatty acid synthase, lipoprotein lipase, hormone-sensitive lipase, adipose triglyceride lipase, PPAR-gamma, SREBP-1c and perilipin were assessed by Real time RT-PCR. The amount of resveratrol metabolites in adipose tissue was measured by chromatography. Results: There was no difference in the final body weight of the rats; however, adipose tissues were significantly decreased in the resveratrol-treated group. Resveratrol reduced the activity of lipogenic enzymes, as well as that of heparin-releasable lipoprotein lipase. Moreover, a significant reduction was induced by this polyphenol in hormone-sensitive lipase mRNA levels. No significant changes were observed in other genes. Total amount of resveratrol metabolites in adipose tissue was 2.66 0.55 nmol/g tissue. Conclusions: It can be proposed that the body fat-lowering effect of resveratrol is mediated, at least in part, by a reduction in fatty acid uptake from circulating triacylglycerols and also in de novo lipogenesis.
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Background
Overweight and obesity are a major public health
concern because they are spreading throughout the world
across all age barriers, afflicting not only adults but also
many children and adolescents. Moreover, obesity is
associated with several chronic diseases, such as
diabetes, stroke and hypertension [1]. Considerable efforts
are being made to identify and characterize novel
naturally-occurring molecules which are orally active and
safe and can be employed for obesity prevention, using
a broad range of in vivo and in vitro methodologies. In
this context, polyphenols make up one of the molecule
groups most frequently studied in recent years.
Resveratrol (trans-3,5,4-trihydroxystilbene) is a
phytolaexin polyphenolic compound occurring naturally in
various plants, including grapes, berries and peanuts, in
response to stress, as a defence mechanism against
fungal, viral, bacterial infections and damage from exposure
to ultraviolet radiation [2]. Moreover, this compound is
now available in tablets on the market.
A remarkable range of biological functions have been
ascribed to this molecule. For example, it acts as a
cancer chemoprevention agent, a powerful
anti-inflammatory factor and an antioxidant [3,4]. Its cardiovascular
properties, including inhibition of platelet aggregation
and promotion of vasodilation, by enhancing the
production of nitric oxide, have also been described [5].
More recently, resveratrol has been proposed as a
potential anti-obesity compound. It seems to mimic the
effects of energy restriction, thus leading to reduced
body fat and improved insulin sensitivity [6-13].
Several mechanisms have been proposed to explain
the body fat-lowering effect of resveratrol. It should be
emphasized that a great deal of work has been
developed in isolated adipocytes, thus limiting the
extrapolation of the results to the in vivo situation. In this
context, results coming from in vitro studies, performed
in adipocyte types (3T3-L1 cells, pig adipocytes and
human adipocytes) have shown that resveratrol
increases apoptosis [14,15], decreases proliferation and
differentiation of pre-adipocytes [16-18] and reduces
lipogenesis [18]. Moreover, in in vivo and ex vivo
experiments resveratrol has been shown to increase
mitochondrial biogenesis, thus increasing fatty acid
oxidation, and to enhance epinephrine-induced lipolysis
[8,10,19].
Taking that into consideration, in the present study
we aimed to gain more insight on mecha (...truncated)