CIBICI   14215
CENTRO DE INVESTIGACION EN BIOQUIMICA CLINICA E INMUNOLOGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Antioxidant properties of three argentinean red wines varietals determined by in vivo assays.
Autor/es:
BARONI, M.V.; DI PAOLA, R.; GARCÍA, C.; PODIO, N.S.; WUNDERLIN D.A.
Lugar:
Beauné
Reunión:
Conferencia; WAC 2011 (Wine Active Compounds); 2011
Institución organizadora:
UNESCO Chair "Culture & Traditions of Wines" Beauné (Francia)
Resumen:
Recent epidemiological studies support the idea that food, rich in plant bioactive compounds and polyphenols in particular, may exert beneficial health effects.  Red wine is widely distributed in the human diet, being the source of many bioactive compounds, such as: polyphenols, minerals, and vitamins that enable its antioxidant activity. It is known that a wide range of variables such as cultivar, viticultural practices, and vinification techniques can affect the phenolic composition of red wines. Antioxidant property of wine has been extensively studied by analyzing its radical scavenging activity, mainly trough in vitro-chemical assays. However, in vivo assays are also necessary to demonstrate this antioxidant behavior in living systems, looking to elucidate metabolic changes induced by polyphenols when used as chemoprotectors. Saccharomyces cerevisiae is one out of several models to study the response to oxidative stress in eukaryotic cells. So far, it is a useful organism for testing antioxidant agents as well as evaluating changes in metabolism induced by such compounds. The main goal of this study was to determine the antioxidant capacity of three Argentinean wine varietals, using a model in vivo with S. cerevisiae as bioindicator of the chemoprotective activity. Thus, we confronted S. cerevisiae cells with a pro-oxidant (H2O2) in either presence or absence of wine as antioxidant. The set used consisted of 17 red wines: 5 Cabernet Sauvignon, 10 Malbec and 5 Syrah. Yeast cells, grown to the logarithmic phase, were exposed to 0.75 mM H2O2 and/or wine varietals for 1 h. The survival of yeast was expressed relative to control yeast (without H2O2 or wine). The antioxidant activity was evaluated by measuring changes in antioxidant enzymes: Glutathion Reductase (GR) and Glutathion Peroxidase (GPX). Results show that three studied varietals significantly increased the resistance to H2O2 in S. cerevisiae. Yeast survival was significantly higher in presence of H2O2 + Cabernet Sauvignon (70%) than in presence of H2O2 + either Syrah (59%) or Malbec (54%) as well as comparing with cells exposed to H2O2 alone (42%). This protective effect was negatively correlated with GR and GPX activity in exposed cells (r: -0.56; p<0.01), since Malbec and Syrah showed higher enzymatic activity than Cabernet Sauvignon. It could be suggested that phenolics in Cabernet sauvignon may act mainly as radical scavengers, without enhancing the antioxidant enzymatic activity of studied cells. Our current results suggest that the antioxidant capacity of wine is dependent on grape variety, since it largely determines the phenolic profile of wine. Further work is necessary to evaluate the phenolic profile of wine, evaluating the contribution of individual compounds and different mixtures to clarify the antioxidant capacity of wine in living systems.