Ethanol–water extracts from red grape pomace could be used for production of functional foods with anti-platelet properties.

Postprandial oxidative stress has been shown to promote atherosclerosis. Grape pomace (GP) is a source of similar-to-wine bioactive micro-constituents with known antioxidant properties. The aim of the present study was to evaluate metabolic and oxidative stress responses after the intake of grape pomace (GP) extract along with a high-fat meal, in normal and overweight healthy women. In a randomized, double-blind, placebo-controlled crossover study, 18 women were finally included, 11 with BMI < 25 kg/m² and 7 with BMI > 25 kg/m², and consumed a high-fat meal with placebo or GP extract capsules in two separate visits. Blood samples were collected before and 6 h after the consumption. Measurements included basic biochemical markers, uric acid (UA), protein carbonyls (PC), thiobarbituric acid substance (TBARS) levels, as well as superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. At certain time points, the GP extract consumption in normal-weight women reduced UA, TBARS levels, and SOD activity, whereas it increased UA and reduced PC levels in overweight/obese women, compared to the placebo. GP-derived bioactive compounds may exert antioxidant actions during the postprandial state in healthy women, through different mechanisms according to their BMI status.

Evidence from research studies reports that wine consumption is associated with lower cardiovascular disease risk, partly through the amelioration of oxidative stress. The aim of the present study was to examine the effect of regular light to moderate wine consumption from coronary heart disease (CHD) patients compared to the effect induced by alcohol intake without the presence of wine microconstituents, on oxidation-induced macromolecular damage as well as on endogenous antioxidant enzyme activity. A randomized, single-blind, controlled, three-arm parallel intervention was carried out, in which 64 CHD patients were allocated to three intervention groups. Group A consumed no alcohol, and Group B (wine) and Group C (ethanol) consumed 27 g of alcohol/day for 8 weeks. Blood and urine samples were collected at baseline and at 4 and 8 weeks. Urine oxidized guanine species levels, protein carbonyls, thiobarbituric acid substances (TBARS) levels, as well as superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, were measured. Oxidized guanine species and protein carbonyl levels were significantly increased in the ethanol group during the intervention and were significantly decreased in the wine group. These results support the idea that wine’s bioactive compounds may exert antioxidant actions that counteract the macromolecular oxidative damage induced by alcohol in CHD patients.

Excessive oxidative stress may impair bio-molecules and cellular function. Multi antioxidant supplementation is thought to be more effective than a single antioxidant probably through the synergistic or complementary action of natural substances that could enhance the prospective effect. In order to estimate the effect of a plant extract based supplement in apparently healthy volunteers’ oxidative stress markers, a double-blind and placebo controlled intervention was performed. 62 apparently healthy volunteers, overweight with medium adherence to the Mediterranean diet, were recruited and randomly allocated into two intervention groups (supplement or placebo) for 8 weeks. Basic biochemical markers, oxidized LDL (oxLDL), resistance of serum in oxidation, protein carbonyls in serum and 8-isoprostane and DNA/RNA damage in urine were measured. No differentiation was observed in basic biochemical markers, in oxLDL levels as well as in serum resistance against oxidation, during intervention in the examined groups. A significant resistance regarding urine isoprostanes levels in the supplement group compared to the placebo one, was observed. Reduction on DNA/RNA damage and on protein carbonyls levels (almost 30% and 20% respectively, at 8 weeks) was detected in volunteers who consumed the supplement compared to the control group. Consumption of plant extract based supplement seems to reduce DNA/RNA and protein oxidation and in less extent lipids peroxidation. ClinicalTrials.gov Identifier for this study is: NCT02837107.

Inflammation, thrombosis and oxidative stress are rarely studied together when wine’s biological activity is concerned; hence the existing literature lacks a holistic point of view in the biological outcome. The scope of the present study is to parallel evaluate the effect of wine extracts on those mechanisms. Ten wine varieties and two different extraction methods were used leading to five extracts for each wine: total lipids (TL) and fractions with different phenolic compound classes (FI, FII, FIII and FIV). Their effect on oxidative stress, platelet aggregation and the secretion of cytokines from mononuclear cells was measured and a biological score was calculated. FII of white wines is the most potent extract and the extracts FIII and TL are following. Specifically, FII had higher anti-oxidant and anti-inflammatory score while all three fractions had a similar anti-platelet score. Furthermore, FII and FIII extracts were the most potent red wine extracts and revealed the highest anti-oxidant and anti-inflammatory scores. White wine FII extracts were more potent than the red wine ones while FI and FIV extracts of red wine were more potent than the white wine ones. In conclusion, the protective effect of a wine is independent of its color but is strongly associated with its microconstituents profile. FII extract revealed the highest biological score and further examination is needed in order to identify the compounds that are responsible for the aforementioned actions.