Efeito antioxidante do vinho tannat produzido em Itaqui (RS) sobre o estresse oxidativo em modelo de hiperglicemia in vitro

Abstract

Hyperglycemia leads a series of biochemical phenomena that are involved in the genesis of oxidative stress. The wine is considered an antioxidant food to contain a large amount of phenolic compounds. The aim of this study was to observe the antioxidant effect of Tannat wine (vintage 2006), produced in Itaqui (RS), on oxidative stress induced by glucose or fructose in erythrocytes in vitro. Erythrocytes were incubated for 24 hours at 37°C with concentrations of 5, 10, 30 and 100 mmol/L glucose or fructose in the presence or absence at different volumes of wine (0.075, 0.15 and 0.225 mL of red wine/mL of erythrocytes). Were determined Thiobarbituric acid reactive species, glucose consumption and osmotic fragility of erythrocytes; in addition total phenolic, anthocyanins, gallic acid, caffeic acid, epicatechin, resveratrol and the DPPH Scavenging Activity of wine. Erythrocytes incubated with glucose and fructose showed a significant increase in lipid peroxidation compared with erythrocytes incubated with 5 mmol/L glucose or fructose, which was prevented by addition of wine. The red wine presented high concentrations of total polyphenols, gallic acid, caffeic acid, epicatechin and resveratrol, further good antioxidant potential. The consumption of glucose by the erythrocytes at concentrations of 5 and 10 mmol/L was significant, this was not observed for the erythrocytes incubated with 30 and 100 mmol/L glucose. The volume of 0.075 ml of wine was able to prevent the inhibition of glucose uptake by erythrocytes incubated with 30 and 100 mmol/L glucose. In the test of osmotic fragility hypotonic concentrations of NaCl induced lysis of erythrocytes progressive, which was significant only for erythrocytes incubated with 30 and 100 mmol/L fructose, this being reversed by treating cells with wine. We conclude that red wine, from the lower volume used, can decrease lipid peroxidation, prevented the inhibition of glucose uptake and decreased osmotic fragility of erythrocytes incubated with fructose. This antioxidant effect of wine is probably due to high concentrations of polyphenols and its good antioxidant capacity.