Acute Consumption of Bordo Grape Juice and Wine Improves Serum Antioxidant Status in Healthy Individuals and Inhibits Reactive Oxygen Species Production in Human Neuron-Like Cells

The multiple actions of grape and its polyphenols on female reproductive processes with an emphasis on cell signalling

Grapes are an economically important fruit crop, and their polyphenols (mainly phenolic acids, flavanols, flavonols, anthocyanins, proanthocyanidins, and stilbenes) can exert a wide range of health benefits as an interesting and valuable dietary supplement for natural complementary therapy. However, their potential physiological and therapeutic actions on reproductive processes have not been sufficiently elucidated. This evidence-based study presents current knowledge of grape extracts and polyphenols, as well as their properties and therapeutical actions in relation to female reproduction in a nutshell. Grape extract, and its polyphenols such as resveratrol, proanthocyanidin B2 or delphinidin may influence female reproductive physiology and pathology, as well as regulate multiple signaling pathways related to reproductive hormones, steroid hormones receptors, intracellular regulators of oxidative stress and subsequent inflammation, apoptosis, and proliferation. Their role in the management of ovarian cancer, age-related reproductive insufficiency, ovarian ischemia, PCOS, or menopausal syndrome has been indicated. In particular, the potential involvement of grapeseed extracts and/or proanthocyanidin B2 and delphinidin on ovarian steroidogenesis, oocyte maturation, and developmental capacity has been implicated, albeit at different regulatory levels. Grape polyphenols exert a wide range of health benefits posing grape extract as an interesting and valuable dietary supplement for natural complementary therapy. This evidence-based study focuses on the actions of grapeseed extract and grape polyphenols on female reproductive processes at various regulatory levels and multiple signalling pathways by regulating reproductive hormones (GnRH, gonadotropins, prolactin, steroid hormones, IGFBP), steroid receptors, markers of proliferation and apoptosis. However, lack of knowledge of standardized dosages so far limits their clinical application despite the wide range of their biological and therapeutic potentials.

Chemometrics-assisted excitation-emission matrix fluorescence spectroscopy for rapid identification of commercial reconstituted and sweetened grape juices

As a common fruit juice, grape juice is delicious and nutritious, making it very popular among consumers. However, some illegal manufacturers used shoddy products to lower costs and obtain high profits, which seriously threatens the health and interests of consumers. Hence, this paper proposed excitation-emission matrix (EEM) fluorescence spectroscopy combined with chemometric methods for the rapid identification and classification of commercial grape juices. Spectral characterization of different samples was achieved using the alternating trilinear decomposition (ATLD) algorithm, and chemically meaningful information was obtained and analyzed. Although both reconstituted and sweetened grape juices contain methyl anthranilate (MA) and 2'-aminoacetophenone (o-AAP), the content of MA in sweetened grape juice far exceeds that in reconstituted grape juice, and the MA in sweetened grape juice mainly comes from artificially added grape essence. Then two chemometric methods of hierarchical cluster analysis (HCA) and partial least squares discriminant analysis (PLS-DA) were used for the classification of reconstituted and sweetened grape juices. The results showed that the supervised classification model had a higher correct classification rate (CCR) than the unsupervised classification model, with PLS-DA obtaining 100% CCRs in both training and prediction sets. Therefore, the proposed strategy can be used as a powerful analytical method for the identification and classification of reconstituted and sweetened grape juices and provides a reliable scientific means for ensuring the authenticity and safety of the juice market.

Effect of Acute Intake of Fermented Orange Juice on Fasting and Postprandial Glucose Metabolism, Plasma Lipids and Antioxidant Status in Healthy Human

Higher postprandial plasma glucose and lipemia, and oxidative and inflammatory responses, are considered important cardiovascular risk factors. Fermentation of fruits has generated products with high concentrations of bioactive compounds. The aim of this study was to evaluate the potential acute effects that fermented orange juice (FOJ) can exert in healthy humans by modulating postprandial response, and inflammatory/antioxidant status, compared with orange juice (OJ). Nine volunteers were recruited for a randomized, controlled, and crossover study. Participants ingested 500 mL of FOJ. At 4 h post intake, subjects consumed a standardized mixed meal. Blood samples were collected at 0-8 h hours post intake. The subjects repeated the protocol with OJ following a 2-week washout period. Glucose and lipid metabolism, plasma antioxidant capacity (ORAC, FRAP), endogenous antioxidants (albumin, bilirubin, uric acid), C-reactive protein and fibrinogen were measured in plasma samples. There was a trend of a smaller increase in LDL-C after FOJ intake compared with OJ, a significant decrease in apo-B and significant increase in ORAC. The glycemic and triglyceride response of meal was attenuated with FOJ. No differences were obtained in endogenous antioxidants and inflammation status between the treatments. The acute consumption of FOJ could play a protective role against cardiovascular risk factors.

Bioaccessibility, gut microbial metabolism and intestinal transport of phenolics from 100% Concord grape juice and whole grapes are similar in a simulated digestion and fecal fermentation model

Phenolic rich 100% grape juice has been associated with many health benefits, but its place in dietary guidance is controversial relative to whole fruit. Direct comparisons of phenolic profiles and bioavailability between these food forms are needed. Phenolic bioaccessibility and metabolism from Concord (CG) and Niagara (NG) grapes and corresponding 100% juices were investigated using an in vitro digestion coupled with anaerobic gut fermentation model. Intestinal transport of resulting bioaccessible phenolics and microbial metabolites was estimated using a Caco-2 cell model. Total bioaccessible phenolics from both upper and lower digestion were similar (P > 0.05) between NG (400.9 ± 26.3 μmol per 100 g) and NGJ (349.5 ± 8.3 μmol per 100 g) and significantly different (P < 0.05) between CG (417.2 ± 24.4 μmol per 100 g) and CGJ (294.3 ± 45.4 μmol per 100 g) total cellular transport of phenolics was similar (P > 0.05) between whole grapes (89.4 ± 5.3 μmol per 100 g for CG, and 71.8 ± 2.4 μmol per 100 g for NG) and 100% juices (88.0 ± 5.6 μmol per 100 g for CGJ, and 85.3 ± 9.4 μmol per 100 g for NGJ). Differences were observed between the location of phenolic metabolism, bioaccessibility and subsequent cellular transport of individual phenolics between grapes and juice matrices. Specifically, greater amounts of phenolics were transported from grape juices than whole grapes from the upper tract. However, cumulative bioaccessibility and transport from upper and lower GI digestion/fermentation together indicates that the absorbable phenolics from 100% grape juice is similar to that of whole grapes, suggesting that phenolic-mediated health benefits from consumption of whole fruit and juice may be similar.

Inhibitory activities of grape bioactive compounds against enzymes linked with human diseases

A quest for identification of novel, safe and efficient natural compounds, as additives in the modern food and cosmetic industries, has been prompted by concerns about toxicity and side effects of synthetic products. Plant phenolic compounds are one of the most documented natural products due to their multifarious biological applications. Grape (Vitis vinifera) is an important source of phenolic compounds such as phenolic acids, tannins, quinones, coumarins and, most importantly, flavonoids/flavones. This review crisply encapsulates enzyme inhibitory activities of various grape polyphenols towards different key human-ailment-associated enzymes: xanthine oxidase (gout), tyrosinase (hyperpigmentation), α-amylase and α-glucosidase (diabetes mellitus), pancreatic lipase (obesity), cholinesterase (Alzheimer's disease), angiotensin i-converting enzymes (hypertension), α-synuclein (Parkinson's disease) and histone deacetylase (various diseases). The review also depicts the enzyme inhibitory mechanism of various grape polyphenols and briefly discusses their stature as potential therapeutic and drug development candidates. KEY POINTS: • Nineteen major bioactive polyphenols from the grape/grape products and their disease targets are presented • Sixty-two important polyphenols as enzyme inhibitors from grape/grape products are presented • A thorough description and graphical presentation of biological significance of polyphenols against various diseases.

Utilization of Oenococcus oeni strains to ferment grape juice: Metabolic activities and beneficial health potential

This study aimed to investigate the behavior of Oenococcus oeni MS9 and MS46 strains in sterile grape juice (SGJ, pH 4.0) incubated at 30 °C, in terms of growth and glucose, organic acids and total phenolic compounds utilization. In addition, their antimicrobial activity and the changes in antioxidant properties of fermented juice with selected strain were evaluated. Both strains grew without lag period by ~1.40 log CFU/mL at 12 days with maximum growth rates of about 0.019 h^-1. After this time the MS9 and MS46 strains counts declined by 0.6 log units and remained unchanged respectively. O. oeni MS46 was evaluated in SGJ for low inoculum size (~10⁴ CFU/mL). In this condition it also grew without lag period by 3.11 ± 0.01 log CFU/mL with a μmax of 0.05 h^-1. Glucose and L-malic and citric acids were simultaneously utilized but at different rates and extents, yielding mainly lactic acid with concomitant pH reduction. Acetic acid ranged between 11 and 19 mmol/L. Total phenolic compounds significantly decreased in fermented SGJ with strain MS9 but not MS46. In this last condition, the antioxidant activity increased by 21%. In addition, both O. oeni strains showed antibacterial properties against Escherichia coli 700, Salmonella Typhimurium and Listeria monocytogenes. O. oeni strains, especially MS46, with the ability to growth in SGJ, high malolactic potential and adequate sugars and organic acids profiles from the sensorial viewpoint may be used to ferment grape juice with safer and healthier properties than fresh juice.

The High Content of Quercetin and Catechin in Airen Grape Juice Supports Its Application in Functional Food Production

Ensuring healthy lives and well-being constitutes one of the Sustainable Development Goals of the UN 2030 agenda. Consequently, research into how natural products may promote health is essential for the new generation of nutraceuticals and functional foods that are in high demand today. Grape juice is a natural foodstuff composed of water, sugars, minerals, vitamins and a wide array of polyphenols. Polyphenols are bioactive compounds of great interest due to their antioxidant properties and benefits to health, supporting antimicrobial, anti-aging, and anticarcinogenic activity. The majority of grape juice produced in the world is used for the production of wine, although a small part is used in the food industry, mainly in baby food and sports drinks. The aim of this work is to determine the polyphenol content in the natural and concentrated juice of Airen grapes, the main white grape variety produced in Spain. For this, fresh juices from five grape varietals (Airen, Sauvignon Blanc, Gewürztraminer, Verdejo and Tempranillo) and concentrated Airen juice were analyzed and compared. Results showed similar contents of phenolic acids and stilbenes in all grape varietals studied, although the Airen variety demonstrated a higher concentration of two flavonoids: quercetin and catechin. It can be concluded that the grape juice concentration process negatively affects the stability of these compounds, causing a reduction in the polyphenol content that ranges between 54–71%, with the exception of quercetin and catechin.

The effect of grape products containing polyphenols on oxidative stress: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

The literature showed that Grape Products Containing Polyphenols (GPCP) had anti-oxidant activity. However, the effects of GPCP on different biomarkers of oxidative stress are still controversial. In this regard, this systematic review and meta-analysis aimed to evaluate the effect of Grape Products Containing Polyphenols (GPCP) intake on oxidative stress markers.

METHODS

PubMed, Scopus, Web of Science, and Google Scholar data bases were searched up to August 20, 2020. A random-effects model, weighted mean difference (WMD), and 95% confidence interval (CI) were applied for data analysis. Meta-analysis was conducted over 17 eligible RCTs with a total of 633 participants. The study registration number is CRD42019116696.

RESULTS

A significant increase was observed in Total Antioxidant Capacity (TAC) (weighted mean difference (WMD) = 1.524 mmol/L, 95% confidence interval (CI): 0.83, 2.21). Intake of GPCP enhanced Superoxide Dismutase (SOD) (WMD = 0.450 mmol/L, 95% CI: 0.23, 0.66), TAC (WMD = 2.829 mmol/L, 95% CI: 0.13, 5.52), and Oxygen Radical Absorbance Capacity (ORAC) (WMD = 0.524 μmol/L, 95% CI: 0.42, 0.62) among healthy participants. Higher GPCP doses increased SOD (WMD = 0.539 U/mgHb, 95% CI: 0.24, 0.82) and ORAC (WMD = 0.377 μmol/L, 95% CI: 0.08, 0.67), whereas longer intervention periods enhanced ORAC (WMD = 0.543 μmol/L, 95% CI: 0.43, 0.64).

CONCLUSION

GPCP intake may partly improve status of oxidative stress, but further well-designed trials are required to confirm these results.

Natural Nrf2 Activators from Juices, Wines, Coffee, and Cocoa

Juices, wine, coffee, and cocoa are rich sources of natural polyphenolic compounds that have potent antioxidant activities proven by in vitro and in vivo studies. These polyphenolic compounds quench reactive oxygen and nitrogen species (RONS) or reactive free radicals and act as natural antioxidants which are also able to protect against reactive oxygen species (ROS)-mediated oxidative damage, which elevates cellular antioxidant capacity to induce antioxidant defense mechanisms by modulating transcription factors. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a transcription factor encoded in humans. It is activated as a result of oxidative stress and induces the expression of its target genes. This is one of the most important cellular defense mechanisms against oxidative stress. However, the oxidative stress alone is not enough to activate Nrf2. Hence phytochemicals, especially polyphenolics, act as natural Nrf2 activators. Herein, this review discusses the natural products identified in juices, coffee, cocoa and wines that modulate Nrf2 activity in cellular systems.

Effects of grape juice consumption on muscle fatigue and oxidative stress in judo athletes: a randomized clinical trial

Physiological levels of reactive oxygen species (ROS) are important for intracellular and extracellular redox regulation in signaling and defense processes. Strenuous exercise can also contribute to this imbalance, and the muscle fatigue, evidenced by impaired strength or power generation, can be caused by various reasons, including oxidative stress. Antioxidants can prevent the formation of ROS by intercepting free radicals. Twenty judo athletes were included in this randomized, double-blind clinical trial into grape juice and placebo groups, and they consumed grape juice or placebo daily for 14 days in a crossover model. The outcomes were analyzed before and after combat simulations. The upper limb strength was higher in the grape juice group than in the placebo (p [group] = 0.003). The lipid damage levels were 10% higher in the placebo group (p [interaction] = 0.048). During the pre-exercise, the placebo group showed 19% more DNA damage than the grape juice group. The superoxide dismutase activity was 80% lower in the grape juice group (p [interaction] < 0.001). The consumption of grape juice can improve parameters of oxidative stress by reducing the lipid and DNA damage.

Adding value to polyvinylpolypyrrolidone winery residue: A resource of polyphenols with neuroprotective effects and ability to modulate type 2 diabetes-relevant enzymes

A polyphenols-rich extract was obtained from polyvinylpolypyrrolidone (PVPP) winery residue, and its neuroprotective effects and ability to modulate the kinetics of type 2 diabetes-relevant enzymes were characterized. The PVPP-white wine extract is a mixture of polyphenols (840.08 ± 161.25 µg/mg, dry weight) dominated by proanthocyanidins and hydroxycinnamic acids, affording strong antioxidant activity, as detected by the protection of membrane lipids against oxidation and superoxide radical anion scavenging activity. Regarding type 2 diabetes framework, the extract inhibits α-glucosidase (K_i = 166.9 µg/mL) and aldose reductase (K_i = 127.5 µg/mL) through non-competitive mechanisms. Despite the modest ability to inhibit rat brain acetylcholinesterase, it protects neuronal SH-SY5Y cells against oxidative damage promoted by glutamate, decreasing reactive oxygen species generation and preserving cell redox state. Thus, PVPP-white wine extract has potential to support the development of functional foods and/or nutraceuticals aiming neuroprotection and glucose homeostasis regulation, with high relevance in Alzheimeŕs disease and type 2 diabetes interlink.

Grapes and their derivatives in modulation of cognitive decline: a critical review of epidemiological and randomized-controlled trials in humans

With an increase in life expectancy, the incidence of chronic degenerative pathologies such as dementia has progressively risen. Cognitive impairment leads to the gradual loss of skills, which results in substantial personal and financial cost at the individual and societal levels. Grapes and wines are rich in healthy compounds, which may help to maintain homeostasis and reduce the risk of several chronic illnesses, including dementia. This review analyzed papers that were systematically searched in PubMed, MEDLINE, Embase, and CAB-Abstract, using the association between grapes (or their derivatives) and their effects on cognitive functions in humans. Analysis was restricted to epidemiological and randomized-controlled studies. Consumption of grape juice (200-500 mL/day) and/or light-to-moderate wine (one to four glasses/day) was generally associated with improved cognitive performance, while the results for other alcoholic beverages were controversial and inconclusive. Bioactive molecules contained in grapes and wine were also considered, with particular attention paid to resveratrol. Due to the relatively high doses required (150-1000 mg/day) for bioactivity coupled with its low bioavailability, resveratrol is only one of the possible grape-derived compounds that may partly underpin the beneficial effects of grapes on the central nervous system.