Functional Properties of Grape and Wine Polyphenols

Optimized ultrasonic-assisted extraction of phenolic antioxidants from grape (Vitis vinifera L.) skin using response surface methodology

Currently, the analysis of bioactive compounds is easily carried out by modern chromatographic and spectrometric techniques, but the success of the procedure still depends on the efficiency of the extraction methods. This work aimed at finding the optimal conditions for ultrasonic-assisted extraction (UAE) of phenolic antioxidants from grape skin using single-factor experimentation combined with response-surface methodology. Our extraction parameters were ethanol concentration, time and temperature. Total phenolic content (TPC and TPC-280), 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and oxygen radical absorbance capacity (ORAC) were dependent variables. A second-order polynomial model satisfactorily described the experimental data. Optimized extraction conditions for UAE from grape skin were: 59.5% ethanol, 113.6 min and 66.8 °C for TPC extraction; 61.1% ethanol, 99.4 min and 66.1 °C for TPC-280 extraction; 57.1% ethanol, 99.5 min and 66.8 °C for DPPH radical-scavenging activity; 60.2% ethanol, 82.4 min and 66.8 °C for ORAC value. Our work provides detailed and useful information to optimize the extraction of grape skin phenols, which are widely used as dietary supplements and nutraceuticals.

Semirational design and engineering of grapevine glucosyltransferases for enhanced activity and modified product selectivity

Uridine diphosphate-dependent glycosyltransferases (UGTs) catalyze the transfer of a diversity of sugars to several acceptor molecules and often exhibit distinct substrate specificity. Modulation of glycosyltransferases for increased catalytic activity and altered substrate or product specificity are the key manipulations for the biotechnological use of glycosyltransferases in various biosynthetic processes. Here, we have engineered the binding pocket of three previously characterized Vitis vinifera glycosyltransferases, UGT88F12, UGT72B27 and UGT92G6, by structure-guided in silico mutagenesis to facilitate the interactions of active site residues with flavonol glucosides and thus modify substrate specificity and activity. Site-directed mutagenesis at selected sites, followed with liquid chromatography-mass spectrometry based activity assays, exhibited that mutant UGTs were altered in product selectivity and activity as compared to the wild-type enzymes. Mutant UGTs produced larger amounts of flavonol di-monosaccharide glucosides, which imply that the mutations led to structural changes that increased the volume of the binding pocket to accommodate a larger substrate and to release larger products at ease. Mutants showed increased activity and modified product specificity. Thus, structure-based systematic mutations of the amino acid residues in the binding pocket can be explored for the generation of engineered UGTs for diverse biotechnological applications.

Autochthonous Saccharomyces cerevisiae Starter Cultures Enhance Polyphenols Content, Antioxidant Activity, and Anti-Inflammatory Response of Apulian Red Wines

Several biotic and abiotic factors can influence the amount of polyphenols in grape tissues. During vinification, the temperature, presence of grape seeds and peel, and use of enzymes, can influence the extraction of polyphenols. However, little information is available on the effects of yeast strains used in the polyphenolic composition of wine. With this aim, two selected Saccharomyces cerevisiae strains, ITEM 14093 and ITEM 14077 were used to produce wine from two Italian grape cultivars, Primitivo and Negroamaro. At the end of the alcoholic fermentation, the content of total polyphenols and of particular classes of polyphenols (stilbenes, phenolic acids, flavonols, and flavanols) and the antioxidant activity were evaluated and compared in the obtained wines. We also examined the effects of red wine extracts in a culture model of vascular inflammation. The results obtained comparing wine extracts obtained by utilizing commercial or autochthonous yeast showed that wines obtained with selected yeast significantly inhibited vascular inflammation. The results are positively directed towards the healthy properties of wine drinking.

Dietary total antioxidant capacity as a preventive factor against depression in climacteric women

Depression is characterized by physical or psychological distress and in many cases can lead to suicide.

HPLC Analysis of Phenols in Negroamaro and Primitivo Red Wines from Salento

Wine is probably the oldest and still most consumed alcoholic beverage in the world. Nevertheless, it contains several biomolecules with beneficial health effects. Phenols are among them and, in this article, we identified and quantified by HPLC catechin, gallic acid, hydroxytyrosol, quercetin, trans-resveratrol, and syringic acid in Primitivo and Negroamaro red wines from Salento, in Southeast Italy. The concentrations of the analyzed antioxidant molecules were quite high in all varieties. Gallic acid and catechin were the most abundant, but significant concentrations of quercetin, hydroxytyrosol, syringic acid, and trans-resveratrol were also found. Multivariate statistical analysis was also employed to discriminate between Negroamaro and Primitivo wines, suggesting the variables influencing their separation.

Biochemical and Physiological Parameters in Rats Fed with High-Fat Diet: The Protective Effect of Chronic Treatment with Purple Grape Juice (Bordo Variety)

High-fat-diet (HFD) has been related to metabolic and cardiovascular diseases. Consumption of grapes and their byproducts containing phenolic compounds has been reported due to the benefits they produce for human health. The purpose of this study was to investigate the antioxidant and protective effect of chronic intake of purple grape juice on certain biochemical and physiological changes promoted by the consumption of HFD. Forty male rats were randomly divided into four groups to receive standard or HFD diet and/or conventional (CGJ) or organic grape juice (OGJ) for three months. Dietary intake, body weight gain, cardiometabolic parameters, and serum lipoperoxidation were investigated. Results showed that consumption of CGJ and OGJ changed the pattern of food and drink intake of the animals. There was a reduction in the body weight of animals that consumed grape juices and an increase in the weight gain in HFD and OGJ rats. HFD increased abdominal fat and the abdominal fat/weight ratio, and both grape juices prevented these modifications. HFD increased hepatic enzymes levels (aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT)) and reduced urea. Purple grape juices prevented some of these changes. HFD enhanced lipid peroxidation (thiobarbituric acid reactive substances (TBARS)) in serum and CGJ and OGJ prevented this increase. The consumption of purple grape juice has the potential to prevent and ameliorate most of the alterations provoked by HFD, therefore regular intake of grape products could promote beneficial effects.

Phenolic Compounds Determined by LC-MS/MS and In Vitro Antioxidant Capacity of Brazilian Fruits in Two Edible Ripening Stages

The aim of this study was to investigate the free individual phenolics and the in vitro antioxidant capacity of blackberry, acerola, yellow guava, guabiju, jambolan and jabuticaba fruits in two edible stages. Of the thirty-three phenolics investigated by liquid chromatography - tandem mass spectrometry (LC-MS/MS), twenty-five were quantified and the major ones were catechin, isoquercitrin, epicatechin and gallic acid. The highest values for the total phenolic content (in dry matter) were observed for acerola (83.6 to 97.7 mg gallic acid equivalents g^-1 DM) and blackberry (18.9 to 28.3 mg gallic acid equivalents g^-1 DM); however, acerola, jabuticaba, and blackberry showed the highest antioxidant capacities (134.6 to 1120.4 mg Trolox equivalents g^-1 for 2,2-diphenyl-1-picrylhydrazyl and 43.6 to 501.8 μmol Trolox equivalents g^-1 for ferric reducing antioxidant power). For most fruits, the antioxidant capacity decreased during the ripening, possibly due to a decrease in the concentration of most of the phenolics.

In vivo bioavailability of polyphenols from grape by-product extracts, and effect on lipemia of normocholesterolemic Wistar rats

BACKGROUND

The direct use of phenolic extracts from grape by-products can be useful when formulating functional food to improve consumer health. The use of phenolic extracts instead of pure polyphenols as an ingredient is relevant in this context. The present study investigated the bioavailability and absorption of polyphenols from grape by-product extracts and their health effect on cholesterolemia, by adding the extract (GE) to Wistar rats diet (50 g kg^-1 ) in vivo.

RESULTS

GE caused the appearance of (+)-catechin, myricetin and quercetic acid in plasma and liver. (+)-Catechin was the most abundant compound (6 μg mL^-1 in plasma and 0.7 μg mg^-1 protein in liver), whereas no phenolic compounds were detected in plasma or liver in the control group. Similarly, 3,4-hydroxyphenylacetic, a major product of polyphenol digestion, was detected in the plasma, liver and urine of the GE-group only. GE-group had significantly lower cholesterol level and lower total cholesterol/high-density lipoprotein ratio in plasma. Total bile acid content significantly increased in fecal matter after 24 h administration of the GE-enriched diet.

CONCLUSION

Grape extract polyphenols are partially bioavailable and showed improvement in lipid metabolism. Thus, the results suggest that GE is promising as a functional ingredient in the prevention of hypercholesterolemia. © 2018 Society of Chemical Industry.

t-Resveratrol Protects against Acute High Glucose Damage in Endothelial Cells

Postprandial hyperglycemia in diabetic and nondiabetic subjects is associated with endothelial dysfunction. Evidence shows that high glucose generates oxidative stress and a pro-inflammatory state promoting the development of cardiovascular diseases. trans-Resveratrol (t-RV) has been shown to reduce cardiovascular risk. To determine whether t-RV acts as a protector against acute high glucose (AHG)-induced damage, two in vitro models, rat aortic rings (RAR) and human umbilical vein endothelial cells (HUVEC) were used. RAR pretreated with AHG (25 mM D-glucose) for 3 h dramatically decreased the endothelium-dependent relaxation (EDR) induced by acetylcholine in phenylephrine (PE)-precontracted vessels. However, coincubation with t-RV significantly mitigated the damage induced by AHG on EDR. Pretreatment with AHG did not affect the vasodilation induced by sodium nitroprusside. HUVEC treated with t-RV decreased cytotoxicity and reduced radical oxygen species production induced by AHG. Taken together, these results suggest that t-RV can mitigate the AHG-induced EDR damage through a mechanism involving ROS scavenging and probably an increase in the bioavailability of NO.

Antioxidant Activity of Selected Polyphenolics in Yeast Cells: The Case Study of Montenegrin Merlot Wine

Screens of antioxidant activity (AA) of various natural products have been a focus of the research community worldwide. This work aimed to differentiate selected samples of Merlot wines originated from Montenegro, with regard to phenolic profile and antioxidant capacity studied by survival rate, total sulfhydryl groups and activities of glutathione peroxidase (GPx), glutathione reductase and catalase in H₂O₂⁻stressed Saccharomyces cerevisiae cells. In this study, DPPH assay was also performed. Higher total phenolic content leads to an enhanced AA under both conditions. The same trend was observed for catechin and gallic acid, the most abundant phenolics in the examined wine samples. Finally, the findings of an Artificial Neural Network (ANN) model were in a good agreement (r² = 0.978) with the experimental data. All tested samples exhibited a protective effect in H₂O₂⁻stressed yeast cells. Pre-treatment with examined wines increased survival in H₂O₂⁻stressed cells and shifted antioxidative defense towards GPx⁻mediated defense. Finally, sensitivity analysis of obtained ANN model highlights the complexity of the impact that variations in the concentrations of specific phenolic components have on the antioxidant defense system.

Effect of postharvest UV-B or UV-C irradiation on phenolic compounds and their transcription of phenolic biosynthetic genes of table grapes

Ultraviolet (UV) irradiation has been related to the extension shelf-life and maintenance of postharvest quality in fruits. However, the comparison of UV-B and UV-C treatment on the biosynthesis of phenolic compounds of grape remain unclear. This study provides a comparison on the mechanism of phenolic secondary metabolism at the same dose of 3.6 kJ m^-2 UV treatment. Total phenolic compounds, total flavonoid, total flavanol, and total anthocyanin content and antioxidant activities of grapes after UV-C treatments were higher than those of the control and UV-B treatment. Among the evaluated parameters of individual phenolic compounds, the content of trans-resveratrol showed the highest percentage increase after the UV application. The transcriptions of PAL, CHS, F3H, LAR, ANS and STS were higher in grapes treated by UV-C than in those treated by UV-B. The CHS, LAR, ANS and STS genes were more induced in UV-B treatment than in control group. The same applied dose of UV-B or UV-C irradiation have different impact on gene expression and phenolic metabolites synthesis. The UV-C irradiation stimulated a higher gene expression of the phenolic compounds biosynthesis and also induced a greater accumulation of these metabolites at the same applied dose.

What's in wine? A clinician's perspective<sup/>

Alcoholic beverages, specifically wine, have been consumed for many years. Wine is postulated to play an important role in the improvement of cardiovascular risk factors. Most epidemiological studies have found sustained consumption at light-to-moderate amounts to increase HDL cholesterol, reduce platelet aggregation, and promote fibrinolysis. Wine consumption has been inversely associated with ischemic heart disease, and the alcohol-blood pressure association, in most studies, follows a J-shaped curve. These outcomes have been attributed to the molecular constituents of wine, namely ethanol and polyphenols. Due to the continued interest in wine as a biological beverage, we review the chemistry of wine as clinicians, including its chemical composition, viticulture and enological practices, and other chemical factors that influence the bioactive components of wine. We also outline the biological effects of wine components and directions for future research.

Preparation and Antioxidant Activity of Ethyl-Linked Anthocyanin-Flavanol Pigments from Model Wine Solutions

Anthocyanin-flavanol pigments, formed during red wine fermentation and storage by condensation reactions between anthocyanins and flavanols (monomers, oligomers, and polymers), are one of the major groups of polyphenols in aged red wine. However, knowledge of their biological activities is lacking. This is probably due to the structural diversity and complexity of these molecules, which makes the large-scale separation and isolation of the individual compounds very difficult, thus restricting their further study. In this study, anthocyanins (i.e., malvidin-3-glucoside, cyanidin-3-glucoside, and peonidin-3-glucoside) and (–)-epicatechin were first isolated at a preparative scale by high-speed counter-current chromatography. The condensation reaction between each of the isolated anthocyanins and (–)-epicatechin, mediated by acetaldehyde, was conducted in model wine solutions to obtain ethyl-linked anthocyanin-flavanol pigments. The effects of pH, molar ratio, and temperature on the reaction rate were investigated, and the reaction conditions of pH 1.7, molar ratio 1:6:10 (anthocyanin/(–)-epicatechin/acetaldehyde), and reaction temperature of 35 °C were identified as optimal for conversion of anthocyanins to ethyl-linked anthocyanin-flavanol pigments. Six ethyl-linked anthocyanin-flavanol pigments were isolated in larger quantities and collected under optimal reaction conditions, and their chemical structures were identified by HPLC-QTOF-MS and ECD analyses. Furthermore, DPPH, ABTS, and FRAP assays indicate that ethyl-linked anthocyanin-flavanol pigments show stronger antioxidant activities than their precursor anthocyanins.

Chemical Characterization of an Encapsulated Red Wine Powder and Its Effects on Neuronal Cells

Red wine polyphenols are known for their implications for human health protection, although they suffer from high instability. For this reason, a red wine powder was prepared by freeze-drying encapsulation in maltodextrin/arabic gum matrix, and its composition was determined by means of high-performance liquid chromatography coupled quadrupole time-of-flight mass spectrometry (HPLC-MS-QTOF). More than thirty polyphenols, including anthocyanins, flavanols, flavonols, phenolic acids and stilbenoids, were identified. Some of the main quantified polyphenols were: malvidin-3-O-glucoside, malvidin 3-O-(6″-acetyl-glucose), petunidin-3-O-glucoside, quercetin-3-O-glucuronide, syringenin-3-O-glucoside, epicatechin, gallic acid and syringic acid. The biological activity of this de-alcoholized and encapsulated red wine on human neuroblastoma SH-SY5Y cells was studied. The results showed that the encapsulated red wine powder has active redox properties, as verified by performing reactive oxygen species (ROS) analysis utilizing a neuronal model. This could help explain its action against the neurotoxicity induced by 6-hydroxydopamine (6-OHDA).

Dietary Supplementation of Almond Prevents Oxidative Stress by Advocating Antioxidants and Attenuates Impaired Aversive Memory in Male Rats

Scopolamine, an anti-muscarinic agent, has been shown to induce amnesia and oxidative stress similar to that observed in the older age. The present study was designed to determine the relationship between the oxidative status and memory improvement in scopolamine injected rats pre-administered with almonds. Rats (n = 8) in the almond group were administered orally with 400 mg/kg almond suspension for 28 days daily before the intraperitoneal injection of scopolamine (0.5 mg/kg). Passive avoidance task (PAT) was used to assess memory function at the end of treatment. The present study revealed that scopolamine injection significantly impaired the memory function in rats pre-treated with saline which was accompanied by increased oxidative stress as evident by increased brain malondialdehyde (MDA) levels and reduced activities of antioxidant enzymes as compared to healthy controls. Pre-treatment with almond significantly ameliorated scopolamine-induced oxidative stress and memory dysfunction. These findings suggest that dietary supplementation with almonds may have a beneficial effect in reducing the risk of oxidative stress-induced memory loss and delaying or preventing the onset of age-related memory impairment.

Anthocyanin Management in Fruits by Fertilization

Anthocyanins are water-soluble vacuolar plant pigments that are mainly synthesized in epidermal layers and the flesh of fruits such as apples, cherries, grapes, and other berries. Because of their attractive red to purple coloration and their health-promoting potential, anthocyanins are significant determinants for the quality and market value of fruits and fruit-derived products. In crops, anthocyanin accumulation in leaves can be caused by nutrient deficiency which is usually ascribed to insufficient nitrogen or phosphorus fertilization. However, it is a little-known fact that the plant's nutrient status also impacts anthocyanin synthesis in fruits. Hence, strategic nutrient supply can be a powerful tool to modify the anthocyanin content and consequently the quality and market value of important agricultural commodities. Here we summarize the current knowledge of the influence of plant nutrients on anthocyanin synthesis in fruits of major global market value and discuss the underlying cellular processes that integrate nutrient signaling with fruit anthocyanin formation. It is highlighted that fertilization that is finely tuned in amount and timing has the potential to positively influence the fruit quality by regulating anthocyanin levels. We outline new approaches to enrich plant based foods with health-promoting anthocyanins.

Effects of low sulfur dioxide concentrations on bioactive compounds and antioxidant properties of Aglianico red wine

This study analyzed the effect of low sulfur dioxide concentrations on the chromatic properties, phytochemical composition and antioxidant activity of Aglianico red wines with respect to wines produced from conventional winemaking. We determined the phytochemical composition by spectrophotometric methods and HPLC-DAD analysis and the in vitro antioxidant activity of different wine samples by the ORAC assay. The main important classes of fluorophore molecules in red wine were identified by Front-Face fluorescence spectroscopy, and the emission intensity trend was investigated at various sulfur dioxide concentrations. Lastly, we tested the effects of both conventional and low sulfite wines on ex vivo human erythrocytes under oxidative stimulus by the cellular antioxidant activity (CAA) assay and the hemolysis test. The addition of sulfur dioxide, which has well-known side effects, increased the content of certain bioactive components but did not raise the erythrocyte antioxidant capacity.

The impact of cultivar on polyphenol and biogenic amine profiles in Calabrian red grapes during winemaking

In this study, during winemaking, was evaluated the influence of cultivar on bioactive compounds (organic acids, d-(+)-glucose, d-(-)-fructose, biogenic amines (BAs), anthocyanins, polyphenols and flavonoids) and antioxidant activity of Calabrian (Southern Italy) autochthonous grapes (Arvino, Gaglioppo, Greco Nero, Magliocco Canino, Magliocco Dolce and Nocera). Phenolic compounds increased from grapes to wine for all varieties. Arvino grapevine showed the highest DPPH radical scavenging activity, while a promising inhibition of the lipid peroxidation was observed with Greco Nero grapes. BAs were mostly formed during alcoholic fermentation and Arvino always showed the lowest BAs amounts, while Magliocco Canino generally exhibited the highest. Collectively, the results demonstrated that Calabrian autochthonous grapevines were rich in sugars, organic acids and phenolic compounds thus allowing the production of high quality wines.

Targeting Aging with Functional Food: Pasta with Opuntia Single-Arm Pilot Study

Interventions to extend life span represent the new perspective in aging investigation. Healthy dietary habits are important modifiable factors that can favor a healthy aging phenotype. Many studies have demonstrated benefits for metabolic syndrome and type 2 diabetes mellitus resulting from the traditional Mediterranean foods. Opuntia Ficus Indica (OFI), widespread in the Mediterranean basin, belongs to the Cactaceae family. It is known for its antioxidant and anti-inflammatory properties. Moreover, products containing extracts from OFI fruits or cladodes have been used to control obesity and other metabolic parameters, such as glycemia and lipid profile. The aim of this study was to analyze the antioxidant and anti-inflammatory effect of pasta with 3% of OFI cladode extracts added to show its beneficial effect in human health. We performed a single arm longitudinal intervention study in 42 healthy volunteers, administrating 500 g/week of this functional pasta for 30 days. Our pasta had antioxidant and anti-inflammatory properties with putative effect on the aging process and related metabolic diseases. We also demonstrated a hypoglycemic effect. The results are preliminary, but it is possible to speculate that our pasta could be considered an effective food for the prevention of age-related metabolic disorders.

Color, anthocyanin, and antioxidant characteristics of young wines produced from spine grapes (Vitis davidii Foex) in China

Background: Spine grape has gained attention in the field of wine science due to its good growth characteristics. Spine grape wine has been made by local residents for a long time. However, the scientific evaluation of spine wine has not been systemically documented compared to Vitis vinifera grape wines

Methods: We compared 11 spine wines from south China (W1–W11) with 7 high-quality international wines (W12–W18). The total phenolic content, the total anothcyanin content and the antioxidant activity of these wines were analyzed and compared. Meanwhile, anthocyanin profiles of these wines were also documented.

Results: Compared with other wines most of the spine wines had a strong red intensity with a blue hue. Malvidin-3,5-O-diglucoside and malvidin-3-O-(6-O-coumaroyl)-glucoside-5-glucoside appeared to be the major anthocyanins in these wines. The scavenging capacity analyses of these wines using ABTS, DPPH, and CUPRAC assays indicated that spine wines possessed high antioxidant properties, especially spine wine W3, W4, W6 and W8. Their high antioxidant properties were mainly related to the high levels of the total phenolic content and anthocyanins.

Conclusion: These results suggested that spine wine might be considered a good wine source for the Chinese wine industry and provided useful information on the knowledge of spine grape.

Antioxidant and Cytoprotective Activities of Grapevine Stilbenes

Grapevine stem extracts are viticulture byproducts rich in stilbenes that are increasingly studied for their potential biological activities. This study aimed to investigate some biological activities of a grape byproduct with high stilbenoid content and to point out the molecules responsible of these beneficial activities. As a consequence, the extract was subjected to a bioguided fractionation and separation by centrifugal partition chromatography. The obtained fractions were characterized by liquid chromatography coupled to mass spectrometry and nuclear magnetic resonance. Fractions were purified further by column chromatography and resulted in the purification of the main constituents. Thirteen stilbenes have been quantified. The most abundant compounds were ε-viniferin, resveratrol, and, in lesser amounts, isohopeaphenol and ampelopsin A. The extract, fractions, and major stilbenes were tested for their antioxidant activity by oxygen radical absorbance capacity and their cyprotective effects against β-amyloid on rat pheochromocytoma cells. Among them, fraction 5 showed significant antioxidant activity and fraction 2 had a significant cytoprotective effect against β-amyloid-induced toxicity. Two putative inhibitors of β-amyloid toxicity have been identified: ampelopsin A and piceatannol.

LC-MS as a Tool to Overcome the Limitations of Self-Reported Dietary Assessments in the Determination of Wine Intake

The nutritional assessment of individuals is usually performed using highly subjective data collecting tools such as food frequency questionnaires, dietary recalls and food records. However, people are not always capable of recalling all foods (and ingredients) consumed, and in some cases, the intake of specific foods is intentionally omitted. Even though wine is considered positive for cardiovascular status, and is an essential part of Mediterranean culture, individuals may not always report its consumption accurately due to the existence of social preconceptions about alcoholic beverages. In this study, the presence of free resveratrol has been determined in human plasma from 25 Spanish volunteers using liquid chromatography coupled to mass spectrometry (LC-MS). This phenolic compound proved to be useful as a dietary biomarker for wine intake in a known population, and the results were compared with those obtained by self-reported dietary assessments. However, certain limitations must also be taken into account such as inter-individual variations and the type of wine consumed. The LC-MS method was validated for trans-resveratrol determination in human plasma, with an LOD (limit of detection) of 50 ng·mL−1 and an LOQ (limit of quantification) of 150 ng·mL−1, respectively.

A Comparative Study of Phenols in Apulian Italian Wines

Nutraceutics is a growing research field in which researchers study and attempt to improve the biological properties of metabolites in food. Wine is one of the most consumed products in the world and contains a plethora of molecules biologically relevant to human health. In this article, several polyphenols with potential antioxidant activity were measured in wines from Apulia, in Southeast Italy. Hydroxytyrosol, gallic and syringic acids, luteolin, quercetin, and trans-resveratrol were identified and quantified by HPLC. The amount of the analyzed metabolites in wines were largely dependent on their color, with red ones being the richest compared to white and rose wines. Gallic acid was the most abundant polyphenol, followed by syringic acid and luteolin. Nevertheless, significant amounts of hydroxytyrosol, quercetin, and trans-resveratrol were also found. The average concentration of polyphenols found in these wines could have potential health-promoting effects, especially if consumed in moderate quantities on a regular basis.

Polyphenols from Wine Lees as a Novel Functional Bioactive Compound in the Protection Against Oxidative Stress and Hyperlipidaemia

The study examines the potential of wine industry by-product, the lees, as a rich mixture of natural polyphenols, and its physiological potential to reduce postprandial metabolic and oxidative stress caused by a cholesterol-rich diet in in vivo model. Chemical analysis of wine lees showed that their total solid content was 94.2%. Wine lees contained total phenols, total nonflavonoids and total flavonoids expressed in mg of gallic acid equivalents per 100 g of dry mass: 2316.6±37.9, 1332.5±51.1 and 984.1±28.2, respectively. The content of total anthocyanins expressed in mg of cyanidin-3-glucoside equivalents per 100 g of dry mass was 383.1±21.6. Antioxidant capacity of wine lees determined by the DPPH and FRAP methods and expressed in mM of Trolox equivalents per 100 g was 259.8±1.8 and 45.7±1.05, respectively. The experiment lasted 60 days using C57BL/6 mice divided in four groups: group 1 was fed normal diet and used as control, group 2 was fed normal diet with added wine lees, group 3 was fed high-cholesterol diet (HCD), i.e. normal diet with the addition of sunflower oil, and group 4 was fed HCD with wine lees. HCD increased serum total cholesterol (TC) by 2.3-fold, triacylglycerol (TAG) by 1.5-fold, low-density lipoprotein (LDL) by 3.5-fold and liver malondialdehyde (MDA) by 50%, and reduced liver superoxide dismutase (SOD) by 50%, catalase (CAT) by 30% and glutathione (GSH) by 17.5% compared to control. Conversely, treatment with HCD and wine lees reduced TC and LDL up to 1.4 times more than with HCD only, with depletion of lipid peroxidation (MDA) and restoration of SOD and CAT activities in liver, approximating values of the control. HDL levels were unaffected in any group. Serum transaminase activity showed no hepatotoxic properties in the treatment with lees alone. In the proposed model, wine lees as a rich polyphenol source could be a basis for functional food products without alcohol.

Evaluation of the Ability of Polyphenol Extracts of Cocoa and Red Grape to Promote the Antioxidant Response in Yeast Using a Rapid Multiwell Assay

Saccharomyces cerevisiae has been used as a model organism to study the capacity of cocoa and red grape extracts to trigger an antioxidant response. A methodology adapted to microtiter plates has been developed to monitor yeast growth after culture preincubation with food ingredients and exposure to oxidative stress by hydrogen peroxide and menadione. This methodology proved effective in measuring the ability of cocoa and red grape extracts to promote an antioxidant response in yeast, and also the prospect of conducting dose-response studies. Additionally, the method has proven useful to perform studies with mutant strains lacking genes that may be related to the mechanism of action underlying the antioxidant properties. Thus, in a single assay, it is possible to elucidate the sensitivity of strains to oxidative stress, the ability of an ingredient to promote an antioxidant response, and the possible implication of certain genes. Results of assays using strain hst3Δ showed that the antioxidant protection provided by exposure to cocoa and red grape extracts was not present in the strain lacking gene HST3 when H₂ O₂ and menadione were used as oxidizing agents. This effect was previously reported for cocoa extract only, with H₂ O₂ as stressor. Moreover, the results showed that the mutant strain hst3Δ is more resistant to menadione and H₂ O₂ in the absence of preincubation with cocoa and red grape extract, hinting at the possible implication of sirtuin Hst3 in the antioxidant cellular response.

Phytochemicals, Monosaccharides and Elemental Composition of the Non-Pomace Constituent of Organic and Conventional Grape Juices (Vitis labrusca L.): Effect of Drying on the Bioactive Content

Grape and grape derivatives contain a variety of antioxidants that have gain increasing interest for functional foods applications. The chemical composition of grapes is mainly related to grape variety and cultivation factors, and each grape constituent exhib its unique characteristics regarding its bioactive properties. This study investigated the chemical composition and the effect of drying on the bioactive content of the non-pomace constituent obtained in the processing of organic and conventional grape juices from V. labrusca L. The non-pomace samples were analyzed for polyphenols, monosaccharides, antioxidant activity and elemental composition and the effect of drying on the bioactive composition was evaluated in samples subjected to lyophilization and drying with air circulation. The analyses revealed high concentrations of proanthocyanidins, flavanols and anthocyanins, and high antioxidant capacity of the organic and conventional samples. The drying processes reduced significantly (P < 0.05) the total phenolic content that ranged from 13.23 to 36.36 g/kg. Glucose, xylose, and mannose were the predominant monosaccharides, whereas K, Ca and Mg were the most abundant minerals. Variations in the chemical composition of organic and conventional samples were associated with cultivation factors. Nevertheless, this non-pomace constituent is a promising source of nutrients and polyphenols with bioactive potential.

Combination of grape extract-silver nanoparticles and liposomes: A totally green approach

In the present work, silver nanoparticles were prepared using a totally green procedure combining silver nitrate and an extract of grape pomace as a green source. Additionally, nanoparticles were stabilized using phospholipid and water and/or a mixture of water and propylene glycol (PG). To the best of our knowledge, grape-silver nanoparticle stabilized liposomes or PG-liposomes were formulated, for the first time, combining the residual products of wine-made industry, silver nitrate and phospholipids, avoiding the addition of hazardous substances to human health and the environment, in an easy, scalable and reproducible method. The structure and morphology of grape-silver nanoparticle stabilized vesicles were evaluated by transmission electron microscopy (TEM), UV-vis spectroscopy and photon correlation spectroscopy. Samples were designed as possible carrier for skin protection because of their double function: the grape extract acts as antioxidant and the colloidal silver as antimicrobial agent, which might be helpful in eliminating dangerous free radicals and many pathogenic microorganisms. Obtained nanoparticles were small in size and their combination with phospholipids did not hamper the vesicle formation, which were multilamellar and sized ~100nm. TEM images shows a heterogeneous distribution of nanoparticles, which were located both in the intervesicular medium and in the vesicular structure. Further, grape-silver nanoparticles, when stabilized by liposomes, were able to inhibit the proliferation of both Staphylococcus aureus and Pseudomonas aeruginosa and provided a great protection of keratinocytes and fibroblasts against oxidative stress avoiding their damage and death.

Red Grape Skin Polyphenols Blunt Matrix Metalloproteinase-2 and -9 Activity and Expression in Cell Models of Vascular Inflammation: Protective Role in Degenerative and Inflammatory Diseases

Matrix metalloproteinases (MMPs) are endopeptidases responsible for the hydrolysis of various components of extracellular matrix. MMPs, namely gelatinases MMP-2 and MMP-9, contribute to the progression of chronic and degenerative diseases. Since gelatinases' activity and expression are regulated by oxidative stress, we sought to evaluate whether supplementation with polyphenol-rich red grape skin extracts modulated the matrix-degrading capacity in cell models of vascular inflammation. Human endothelial and monocytic cells were incubated with increasing concentrations (0.5-25 μg/mL) of Negroamaro and Primitivo red grape skin polyphenolic extracts (NSPE and PSPE, respectively) or their specific components (0.5-25 μmol/L), before stimulation with inflammatory challenge. NSPE and PSPE inhibited, in a concentration-dependent manner, endothelial invasion as well as the MMP-9 and MMP-2 release in stimulated endothelial cells, and MMP-9 production in inflamed monocytes, without affecting tissue inhibitor of metalloproteinases (TIMP)-1 and TIMP-2. The matrix degrading inhibitory capacity was the same for both NSPE and PSPE, despite their different polyphenolic profiles. Among the main polyphenols of grape skin extracts, trans-resveratrol, trans-piceid, kaempferol and quercetin exhibited the most significant inhibitory effects on matrix-degrading enzyme activities. Our findings appreciate the grape skins as rich source of polyphenols able to prevent the dysregulation of vascular remodelling affecting degenerative and inflammatory diseases.

Putative Role of Red Wine Polyphenols against Brain Pathology in Alzheimer's and Parkinson's Disease

Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common age-related neurodegenerative disorders and hence pose remarkable socio-economical burdens to both families and state. Although AD and PD have different clinical and neuropathological features, they share common molecular mechanisms that appear to be triggered by multi-factorial events, such as protein aggregation, mitochondrial dysfunction, oxidative stress (OS), and neuroinflammation, ultimately leading to neuronal cell death. Currently, there are no established and validated disease-modifying strategies for either AD or PD. Among the various lifestyle factors that may prevent or slow age-related neurodegenerative diseases, epidemiological studies on moderate consumption of red wine, especially as part of a holistic Mediterranean diet, have attracted increasing interest. Red wine is particularly rich in specific polyphenolic compounds that appear to affect the biological processes of AD and PD, such as quercetin, myricetin, catechins, tannins, anthocyanidins, resveratrol, and ferulic acid. Indeed, there is now a consistent body of in vitro and in vivo data on the neuroprotective effects of red wine polyphenols (RWP) showing that they do not merely possess antioxidant properties, but may additionally act upon, in a multi-target manner, the underlying key mechanisms featuring in both AD and PD. Furthermore, it is important that bioavailability issues are addressed in order for neuroprotection to be relevant in a clinical study scenario. This review summarizes the current knowledge about the major classes of RWP and places into perspective their potential to be considered as nutraceuticals to target neuropathology in AD and PD.

Intracellular Antioxidant Activity of Grape Skin Polyphenolic Extracts in Rat Superficial Colonocytes: In situ Detection by Confocal Fluorescence Microscopy

Colon is exposed to a number of prooxidant conditions and several colon diseases are associated with increased levels of reactive species. Polyphenols are the most abundant antioxidants in the diet, but to date no information is available about their absorption and potential intracellular antioxidant activity on colon epithelial cells. The work was addressed to study the intracellular antioxidant activity of red grape polyphenolic extracts on rat colon epithelium experimentally exposed to prooxidant conditions. The experimental model chosen was represented by freshly isolated colon explants, which closely resemble the functional, and morphological characteristics of the epithelium in vivo. The study was carried out by in situ confocal microscopy observation on CM-H2DCFDA charged explants exposed to H₂O₂ (5, 10, and 15 min). The qualitative and quantitative polyphenolic composition of the extracts as well as their in vitro oxygen radical absorbing capacity (ORAC) was determined. The incubation of the explants with the polyphenolic extracts for 1 h produced a significant decrease of the H₂O₂ induced fluorescence. This effect was more pronounced following 15 min H₂O₂ exposure with respect to 5 min and it was also more evident for extracts obtained from mature grapes, which showed an increased ORAC value and qualitative peculiarities in the polyphenolic composition. The results demonstrated the ability of red grape polyphenols to cross the plasma membrane and exert a direct intracellular antioxidant activity in surface colonocytes, inducing a protection against pro-oxidant conditions. The changes in the polyphenol composition due to ripening process was reflected in a more effective antioxidant protection.

Effect of Winemaking on the Composition of Red Wine as a Source of Polyphenols for Anti-Infective Biomaterials

Biomaterials releasing bactericides have currently become tools for thwarting medical device-associated infections. The ideal anti-infective biomaterial must counteract infection while safeguarding eukaryotic cell integrity. Red wine is a widely consumed beverage to which many biological properties are ascribed, including protective effects against oral infections and related bone (osteoarthritis, osteomyelitis, periprosthetic joint infections) and cardiovascular diseases. In this study, fifteen red wine samples derived from grapes native to the Oltrepò Pavese region (Italy), obtained from the winemaking processes of “Bonarda dell’Oltrepò Pavese” red wine, were analyzed alongside three samples obtained from marc pressing. Total polyphenol and monomeric anthocyanin contents were determined and metabolite profiling was conducted by means of a chromatographic analysis. Antibacterial activity of wine samples was evaluated against Streptococcus mutans, responsible for dental caries, Streptococcus salivarius, and Streptococcus pyogenes, two oral bacterial pathogens. Results highlighted the winemaking stages in which samples exhibit the highest content of polyphenols and the greatest antibacterial activity. Considering the global need for new weapons against bacterial infections and alternatives to conventional antibiotics, as well as the favorable bioactivities of polyphenols, results point to red wine as a source of antibacterial substances for developing new anti-infective biomaterials and coatings for biomedical devices.

Resveratrol Supplementation Did Not Improve Cognition in Patients with Schizophrenia: Results from a Randomized Clinical Trial

BACKGROUND

Schizophrenia (SZ) is associated with psychotic experiences and cognitive deficits. Therefore, cognitive function is one of the most critical determinants of quality of life in this pathology. Resveratrol has been related to neuroprotective action, but there are no studies evaluating resveratrol in SZ. The objective of this study was to determine the efficacy of resveratrol supplementation on cognition in individuals with SZ.

METHODS

This is a 1-month randomized, double-blind, and controlled trial (NCT 02062190), in which 19 men with diagnosis of SZ, aged 18-65 years, were assigned to a resveratrol supplementation group (200 mg) or placebo group (200 mg), with a 1-month follow-up. Applying a series of cognitive tests assessed neuropsychology performance (Hopkins Verbal Learning Test, Stroop Color and Word Test, and Weschler Adult Intelligence Scale) and Brief Psychiatric Rating Scale assessed psychopathology severity.

RESULTS

There were no significant improvement in neuropsychology performance (episodic memory, working memory, attention and concentration capacity, inhibitory control, interference measures, selective attention, and mental flexibility) and psychopathology severity after 1 month of resveratrol supplementation (P > 0.05).

CONCLUSION

In conclusion, we have shown that 1 month of a resveratrol supplementation (200 mg/day) did not improve episodic memory, working memory, attention and concentration capacity, inhibitory control, interference measures, selective attention, and mental flexibility as compared with placebo in patients with SZ.