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The antioxidant effects of a polyphenol-rich grape pomace extract in vitro do not correspond in vivo using exercise as an oxidant stimulus.

Veskoukis AS, Kyparos A, Nikolaidis MG, Stagos D, Aligiannis N, Halabalaki M, Chronis K, Goutzourelas N, Skaltsounis L, Kouretas D - Oxid Med Cell Longev (2012)

Bottom Line: Numerous studies have examined the effects of plant extract administration on redox status at rest in animals and humans but their results are controversial.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.Our findings suggest that the grape pomace extract does not behave with the same way in vitro and in vivo.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Biotechnology, University of Thessaly, 41221 Larissa, Greece.

ABSTRACT
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.

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Effects of the grape pomace extract on oxidative stress markers in gastrocnemius muscle at rest and postexercise. *Significantly different from the rest value within either the saline or the extract group (P < 0.05). #Significantly different between the saline- and the extract-treated groups at the same time point (P < 0.05).
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fig5: Effects of the grape pomace extract on oxidative stress markers in gastrocnemius muscle at rest and postexercise. *Significantly different from the rest value within either the saline or the extract group (P < 0.05). #Significantly different between the saline- and the extract-treated groups at the same time point (P < 0.05).

Mentions: In xanthine oxidase (Figure 5(a)), significant main effect of time and interaction of treatment × time was found. In post hoc within-group comparisons, xanthine oxidase activity significantly decreased at postexercise in the saline-treated group only. In post hoc between-group comparisons, xanthine oxidase activity decreased in the extract-treated group at rest and increased in the same group compared to the saline-treated group at postexercise. In TAC (Figure 5(b)), protein carbonyls (Figure 5(c)) and GSH (Figure 5(e)), neither significant main effects nor interaction were found. In TBARS (Figure 5(d)), an interaction of treatment × time was found. In within-group and between-group comparisons, TBARS concentration increased at postexercise in the saline-treated group only. In catalase (Figure 5(f)), significant main effects of treatment and time were found. In within-group and between-group comparisons, catalase activity increased at postexercise in the extract-treated group only.


The antioxidant effects of a polyphenol-rich grape pomace extract in vitro do not correspond in vivo using exercise as an oxidant stimulus.

Veskoukis AS, Kyparos A, Nikolaidis MG, Stagos D, Aligiannis N, Halabalaki M, Chronis K, Goutzourelas N, Skaltsounis L, Kouretas D - Oxid Med Cell Longev (2012)

Effects of the grape pomace extract on oxidative stress markers in gastrocnemius muscle at rest and postexercise. *Significantly different from the rest value within either the saline or the extract group (P < 0.05). #Significantly different between the saline- and the extract-treated groups at the same time point (P < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368594&req=5

fig5: Effects of the grape pomace extract on oxidative stress markers in gastrocnemius muscle at rest and postexercise. *Significantly different from the rest value within either the saline or the extract group (P < 0.05). #Significantly different between the saline- and the extract-treated groups at the same time point (P < 0.05).
Mentions: In xanthine oxidase (Figure 5(a)), significant main effect of time and interaction of treatment × time was found. In post hoc within-group comparisons, xanthine oxidase activity significantly decreased at postexercise in the saline-treated group only. In post hoc between-group comparisons, xanthine oxidase activity decreased in the extract-treated group at rest and increased in the same group compared to the saline-treated group at postexercise. In TAC (Figure 5(b)), protein carbonyls (Figure 5(c)) and GSH (Figure 5(e)), neither significant main effects nor interaction were found. In TBARS (Figure 5(d)), an interaction of treatment × time was found. In within-group and between-group comparisons, TBARS concentration increased at postexercise in the saline-treated group only. In catalase (Figure 5(f)), significant main effects of treatment and time were found. In within-group and between-group comparisons, catalase activity increased at postexercise in the extract-treated group only.

Bottom Line: Numerous studies have examined the effects of plant extract administration on redox status at rest in animals and humans but their results are controversial.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.Our findings suggest that the grape pomace extract does not behave with the same way in vitro and in vivo.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Biotechnology, University of Thessaly, 41221 Larissa, Greece.

ABSTRACT
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.

Show MeSH
Related in: MedlinePlus