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Oxidative Medicine and Cellular Longevity
Volume 2012 (2012), Article ID 185867, 14 pages
Research Article

The Antioxidant Effects of a Polyphenol-Rich Grape Pomace Extract In Vitro Do Not Correspond In Vivo Using Exercise as an Oxidant Stimulus

1Department of Biochemistry and Biotechnology, University of Thessaly, 41221 Larissa, Greece
2Department of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, Agios Ioannis, 62110 Serres, Greece
3Division of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece

Received 22 January 2012; Accepted 26 March 2012

Academic Editor: Chad M. Kerksick

Copyright © 2012 Aristidis S. Veskoukis et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Fruits, such as grapes, are essential food of the Mediterranean diet. Grape extracts have potent antioxidant and chemopreventive properties in vitro. Numerous studies have examined the effects of plant extract administration on redox status at rest in animals and humans but their results are controversial. However, there are no studies comparing the in vitro and in vivo effects of plant extracts on oxidative stress using exercise as an oxidant stimulus. Thus, the aim of this study was to investigate whether a polyphenol-rich grape pomace extract of the Vitis vinifera species possesses in vitro antioxidant properties and to examine whether these properties apply in an in vivo model at rest and during exercise. Our findings indicate that the tested extract exhibits potent in vitro antioxidant properties because it scavenges the DPPH and ABTS•+ radicals and inhibits DNA damage induced by peroxyl and hydroxyl radicals. Administration of the extract in rats generally induced oxidative stress at rest and after exercise whereas exercise performance was not affected. Our findings suggest that the grape pomace extract does not behave with the same way in vitro and in vivo.