Antioxidant Properties Of Polyphenols Research Articles

Microencapsulation of peanut skin polyphenols for shelf life improvement of sunflower seeds.

Derived from industrial processing waste, peanut skins contain polyphenols that delay oxidative food spoilage. However, these compounds are susceptible to light, heat, and oxygen exposure. Microencapsulation provides a solution by offering protection from these factors. The aim of this study was to evaluate the protective effect of peanut skin extract microcapsules on the chemical, microbiological, and sensory property and shelf life of sunflower seeds during storage. Five roasted sunflower seed samples were prepared: control (S-C); added with butylhydroxytoluene (S-BHT); coated with carboxymethyl cellulose (S-CMC); coated with CMC and the addition of peanut skin crude extract (S-CMC-CE); coated with CMC and the addition of microcapsules (S-CMC-M20). Sensory acceptability was determined using hedonic testing. Chemical (peroxide value, conjugated dienes, hexanal and nonanal content, and fatty acid profile), microbiological, and descriptive analyses were carried out on samples stored for 45 days at room temperature. Shelf life was calculated using a simple linear regression. All samples were microbiologically fit for human consumption and accepted by consumer panelists, scoring above five points on the nine-point hedonic scale. S-CMC-M20 exhibited the lowest peroxide value (6.59meqO2/kg) and hexanal content (0.4µg/g) at the end of the storage. Estimated shelf life showed that S-MC-M20 (76.3 days) extended its duration nearly ninefold compared to S-C (8.3 days) and doubled that of S-CMC-CE (37.5 days). This indicates a superior efficacy of microencapsulated extract compared to its unencapsulated form, presenting a promising natural strategy for improving the shelf life of analogous food items. PRACTICAL APPLICATION: Incorporating peanut skin extract microcapsules in coating sunflower seeds presents a promising strategy to extend the shelf life of lipid-rich foods, capitalizing on the antioxidant properties of polyphenols. This innovative approach not only enhances nutritional quality but also addresses sustainability concerns by repurposing agro-industrial byproducts, such as peanut skins. By meeting consumer demand for functional foods with added health benefits, this technique offers potential opportunities for the development of novel, value-added food products while contributing to circular economy principles and waste management efforts.

Intracellular Redox Behavior of Quercetin and Resveratrol Singly and in Mixtures.

Polyphenols have attracted great interest as potent antioxidant compounds and nutraceuticals; however, their antioxidant properties represent a multifaceted phenomenon, including pro-oxidant effects under particular conditions and complex behavior when multiple polyphenols are simultaneously present. Moreover, their intracellular behavior cannot always be predicted from their ability to counteract the production of ROS in acellular assays. The present work aimed to study the direct intracellular redox activity of two polyphenols, resveratrol and quercetin, singly and in mixture in a cellular short-term bioassay under both basal and pro-oxidant conditions. The study was carried out by spectrofluorimetric assessment of the intracellular fluorescence of CM-H2DCFDA-charged HeLa cells under either basal conditions, due to the reactive species associated with the normal cellular oxidative metabolism, or pro-oxidant conditions induced by H2O2 exposure. Under basal conditions, the obtained results showed a significant antioxidant effect of quercetin and a weaker antioxidant effect of resveratrol when used singly, while antagonism of their effect was detected in their equimolar mixtures at all the concentrations used. Under exposure of the cells to H2O2, quercetin exhibited a dose-dependent intracellular antioxidant activity whereas resveratrol manifested a pro-oxidant intracellular activity, while their equimolar mixtures showed an intracellular interaction between the 2 polyphenols, with additive effects at 5 µM and synergic at 25 µM and 50 µM. Thus, the results clarified the direct intracellular antioxidant/pro-oxidant activity of quercetin and resveratrol alone and in their equimolar mixtures in the cell model HeLa cells and highlighted that the antioxidant properties of polyphenols in mixtures at the cellular level depend not only on the nature of the compounds themselves but also on the type of interactions in the cellular system, which in turn are influenced by the concentration and the oxidative status of the cell.

Ingestion of taxifolin-rich foods affects brain activity, mental fatigue, and the whole blood transcriptome in healthy young adults: a randomized, double-blind, placebo-controlled, crossover study.

The antioxidant properties of polyphenols, which are found in most plants, have been shown to be useful for maintaining health, including enhancing brain function and alleviating stress. We aimed to investigate the effect of a single intake of taxifolin-containing foods on cognitive task performance and whole blood gene expression in healthy young adults. This study was a randomized, placebo-controlled, double-blind, crossover trial in which healthy young adults were administered a single dose of either a placebo or food containing taxifolin. Cognitive tests (serial 3s, serial 7s, and rapid visual information processing) to examine brain activity and visual analog scale questionnaires to analyze mental fatigue were applied. The set of tests was repeated four times. The findings showed that taxifolin intake improved calculation abilities and reduced mental fatigue. An analysis of whole blood gene expression before and after the test revealed that the expression of foreign substance removal-related genes increased following the ingestion of taxifolin and that most differentially expressed genes were enriched in granulocytes. Taxifolin intake was shown to affect the brain activity of healthy young adults and demonstrated an antifatigue effect, thereby reducing subjective fatigue. A single intake of taxifolin may enhance the removal of foreign substances by strengthening the innate immune system and suppressing the occurrence of injury.

Quercetin improves lacrimal gland function through its anti-oxidant actions: Evidence from animal studies, and a pilot study in healthy human volunteers

Anti-oxidant properties of polyphenols have been gaining medical attention as a preventive factor against aging and/or lifestyle diseases. In this study, we examined the anti-oxidant activity of quercetin improved tear function through its effects on the lacrimal gland in mice and humans. Six week-old diabetic mice, a model for decreased tear production, were fed for 12 weeks ad libitum with an experimental diet containing 0.5% quercetin. As a result, the tear volume was significantly improved compared to the control, despite no changes in body weight, food intake, lacrimal gland morphology or biochemical serum parameters. Moreover, significantly higher SOD-1 and SOD-2 protein levels were detected in the lacrimal glands of quercetin-treated mice by western blot. In addition, quercetin treatment of mouse corneal cell lines exposed to oxidative stress resulted in dose-dependent inhibition of ROS production and enhanced cell survival. Finally, we examined quercetin pharmacokinetics, specifically its presence in serum and tears subsequent to onion consumption in healthy volunteers, and found that the distribution of quercetin and its metabolite shifted from serum to tear following onion intake. An improvement in tear film stability also resulted following the intake by these healthy volunteers of a new, quercetin-rich onion cultivar (”Quergold”) in powder form. These results suggested that quercetin improved tear function through its effects on the lacrimal gland in mice and humans.

In Vitro and In Vivo Digestive Fate and Antioxidant Activities of Polyphenols from Hulless Barley: Impact of Various Thermal Processing Methods and β-Glucan.

The unfavorable bioaccessibility of polyphenols in cereal-based food limits their physiological functions as most polyphenols bind spontaneously to the cell-wall polysaccharides. Effects of β-glucan and various thermal processing methods including flaking and roasting, stir-frying, steam-flash explosion, and popping expansion on the bioaccessibility and antioxidant properties of polyphenols from hulless barley in vitro and in vivo were investigated in this study. The bioaccessibility and antioxidant capacity (via DPPH, ·OH, and ·O2- free radical scavenging, TAC, and FRAP assays) of polyphenol extracts from hulless barley treated by steam-flash explosion and popping expansion increased significantly before and after in vitro digestion compared to those from raw and other processed hulless barley. Further, the total polyphenol content of hulless barley elevated dramatically following hydrolyzing with β-glucanase, which was positively correlated with the antioxidant activity. Additionally, the hulless barley treated with steam-flash explosion exhibited potent antidiabetic effects and antioxidant capacity (via TAC, SOD, GSH-Px, CAT, and MDA assays) in type 2 diabetic rats. The absorption of individual phenolic compounds in the alimentary canal of rats was impacted obviously by thermal processing. This study provides new insights into enhancing the bioaccessibility of the polyphenols and suggests that β-glucans interact with polyphenols and proteins in the hulless barley matrix.

Biological Actions and Molecular Mechanisms of Sambucus nigra L. in Neurodegeneration: A Cell Culture Approach.

Sambucus nigra flowers (elderflower) have been widely used in traditional medicine for the relief of early symptoms of common cold. Its chemical composition mainly consists of polyphenolic compounds such as flavonoids, hydroxycinnamic acids, and triterpenes. Although the antioxidant properties of polyphenols are well known, the aim of this study is to assess the antioxidant and protective potentials of Sambucus nigra flowers in the human neuroblastoma (SH-SY5Y) cell line using different in vitro approaches. The antioxidant capacity is first evaluated by the oxygen radical absorbance capacity (ORAC) and the free radical scavenging activity (DPPH) methods. Cell viability is assessed by the crystal violet method; furthermore, the intracellular ROS formation (DCFH-DA method) is determined, together with the effect on the cell antioxidant defenses: reduced glutathione (GSH) and antioxidant enzyme activities (GPx, GR). On the other hand, mTORC1 hyperactivation and autophagy blockage have been associated with an increase in the formation of protein aggregates, this promoting the transference and expansion of neurodegenerative diseases. Then, the ability of Sambucus nigra flowers in the regulation of mTORC1 signaling activity and the reduction in oxidative stress through the activation of autophagy/mitophagy flux is also examined. In this regard, search for different molecules with a potential inhibitory effect on mTORC1 activation could have multiple positive effects either in the molecular pathogenic events and/or in the progression of several diseases including neurodegenerative ones.

Antioxidant properties of plant polyphenols in the counteraction of alcohol-abuse induced damage: Impact on the Mediterranean diet

Polyphenols are antioxidants contained in plants as olive and grape. As part of the Mediterranean diet, they may decrease the risk of cancer, of chronic and neurodegenerative diseases. Alcohol consumption plays a detrimental effect on health, causing tissue damage and disrupting the metabolism of Neurotrophins (NTs). NTs are crucial proteins for the life cycle of neuronal and non-neuronal cells. Alcohol abuse elicits changes in NTs levels in the brain and in other target organs, however, it was observed minor damage in animals early exposed to red wine, probably due to the antioxidant effects of polyphenols. Indeed, data show that resveratrol or other polyphenols extracted from the olive can effectively counteract serum free radicals’ formation caused by chronic alcohol intake, contrasting also alcohol-induced NTs liver elevation. The aim of the present review is to update pieces of evidences about the antioxidant properties of polyphenols and their role in counteracting alcohol-induced damage.

The Efficacy of Administering Fruit-Derived Polyphenols to Improve Health Biomarkers, Exercise Performance and Related Physiological Responses.

Polyphenols are secondary metabolites involved in a myriad of critical processes in plants. Over recent decades, special attention has been paid to the anti-oxidative role of fruit-derived polyphenols in the human diet, with evidence supporting the contribution of polyphenols in the prevention of numerous non-communicable disease outcomes. However, due to the low concentration in biological fluids in vivo, the antioxidant properties of polyphenols seem to be related to an enhanced endogenous antioxidant capacity induced via signaling through the nuclear respiratory factor 2 pathway. Polyphenols also seem to possess anti-inflammatory and antioxidant properties and have been shown to enhance vascular function via nitric oxide mediated mechanisms. Consequently, there is rationale to support fruit-derived polyphenol supplementation to enhance exercise performance, possibly via improved muscle perfusion. Fruit-derived polyphenol supplementation in exercise studies have included a variety of fruits, e.g., New Zealand blackcurrant, pomegranate, and cherry, in the form of extracts (multicomponent or purified), juices and infusions to varying degrees of benefit. For example, research has yet to link the health-related benefits of black elderberry (Sambucus nigra L.) ingestion to exercise performance in spite of the purported health benefits associated with black elderberry provision in vitro and in vivo models, which has been attributed to their high antioxidant capacity and polyphenol content. This review summarizes the existing evidence supporting a beneficial effect of fruit-derived polyphenols on various biological processes and outlines the potential for black elderberry ingestion to improve nitric oxide production, exercise performance, and the associated physiological responses before-, during- and post-exercise.

二次正交旋转优化橄榄多酚提取及其抗氧化性研究

二次正交旋转优化橄榄多酚提取及其抗氧化性研究

Antioxidant Properties of Polyphenols and Their Potential Use in Improvement of Male Fertility: A Review

Antioxidant Properties of Polyphenols and Their Potential Use in Improvement of Male Fertility: A Review

Identification and antioxidant properties of polyphenols in lotus seed epicarp at different ripening stages

In this study, polyphenols from lotus seed epicarp (PLSE) at three different ripening stages were purified by column chromatography and identified by RP-HPLC and HPLC–ESI-MS2. The antioxidant activities of PLSE were also investigated. We found that the contents of PLSE at the green ripening stage, half ripening stage and full ripening stage are 13.08%, 10.95% and 6.73% respectively. The levels of catechin, epicatechin, hyperoside, and isoquercitrin in PLSE at the three different ripening stages were different. Moreover, the amounts of catechin and epicatechin decreased, while the contents of hyperoside and isoquercitrin increased as the seed ripened. We found that PLSE at three different ripening stages had good scavenging abilities on DPPH and ABTS+ radicals. However, the scavenging ability decreased with maturation. Our results may be valuable with regard to the utilization of lotus seed epicarp as a functional food material.

Dietary polyphenols increase fecal mucin and immunoglobulin A and ameliorate the disturbance in gut microbiota caused by a high fat diet.

The effects of dietary polyphenols on human health have mainly been discussed in the context of preventing degenerative diseases, particularly cardiovascular diseases and cancer. The antioxidant properties of polyphenols have been widely studied, but it has become clear that the mechanism of action of polyphenols extends beyond the modulation of oxidative stress, as they are poorly absorbed from the digestive tract. The purpose of this study was to clarify the effects of polyphenols on the colonic environment, intestinal barrier function, and gut microbiota. We demonstrated that dietary polyphenols derived from aronia, haskap, and bilberry, markedly elevated the amount of fecal mucin and immunoglobulin A (IgA) as an intestinal barrier function and ameliorated the disturbance in gut microbiota caused by a high fat diet in rats. These results suggest that dietary polyphenols play a significant role in the prevention of degenerative diseases through improvement of the colonic environment without any absorption from the digestive tract.

Editorial (Thematic Issue: “Dietary Polyphenols: Well beyond the Antioxidant Capacity”)

In the last decades epidemiological studies and associated meta-analyses have strongly suggested that long term consumption of plant foods (fruits, vegetables, cereals, dry legumes, and beverages like wine, coffee and tea) offers protection against development of oxidative stress related pathologies, such as cancers, cardiovascular diseases, diabetes, osteoporosis and neurodegenerative diseases [1, 2]. These results have prompted research to study polyphenols, following the discovery of their antioxidant and radical scavenger activities [3]. So, the antioxidant properties of polyphenols have been widely studied from the mid- 1990s, but the latest research indicates that the mechanisms of action of polyphenols go beyond the modulation of oxidative stress [3]. Polyphenols protective activity can be ascribed to their capacity of interact with cellular functions at different levels, such as affecting gene expression, protein synthesis and enzyme activities, binding to membrane or nuclear receptors as either an elective ligand or a ligand mimic. Recently, it has been also demonstrated the antibacterial activity of some polyphenols against multidrug-resistant bacteria [4]. The goal of this special issue is to present novel results about dietary polyphenols healthy properties, with particular attention to their mechanisms of action. On behalf of all authors, we hope that this issue of Current Pharmaceutical Biotechnology will promote novel ideas and provide prospects for theirs scientific activity. Finally, we would like to thanks all the contributors and reviewer for their precious and valuable contribution in this issue.

Purification of polyphenols from Sabina vulgaris antoine and its antioxidant properties

To purify polyphenols from Sabina vulgaris and to investigate its antioxidant properties. Polyphenols were purified from Sabina vulgaris Antoine with macroporous resin HPD-700, and the quantity of polyphenols was determined by Folin-Ciocalteu colorimetry. The antioxidant properties of polyphenols were evaluated by total antioxidant capacity (T-AOC) and its activities of scavenging DPPH (1,1 diphenyl-2-picry-hydrazyl) radicals, superoxide anion (O2·-), hydroxyl free radicals (OH·) and ferric reducing antioxidant power (FRAP). After purification, the purity of polyphenols increased from 0.053% to 0.995%.The antioxidant properties study showed that its inhibition rate of scavenging DPPH radicals and FRAP was 151.83 U/ml and 204.59 U/ml. Its scavenging capacity for superoxide anion (O2·-) and hydroxyl free radicals (OH·) was 151.83 U/ml and 204.59 U/ml. The total antioxidant capacity was 72.68 U/ml. Polyphenols from Sabina vulgaris Antoine have high antioxidant properties, suggesting that it worth further study of its pharmacological effects.

Influence of Polyphenol-plasma Protein Interaction on the Antioxidant Properties of Polyphenols

Polyphenols are the most abundant antioxidants. Polyphenols are known to non-covalent interact with plasma proteins in blood through hydrophobic or hydrophilic interactions. It was found that the effect of polyphenol-plasma protein interaction (PpPI) on the bioavailability of polyphenols is not equivocal. Because the conclusion of individual reports are contradictory to each other; therefore, it is very difficult to give a univocal comment on the influence of PpPI on antioxidant property of polyphenols. The influence of PpPI on the antioxidant activity of polyphenols is decided by the antioxidant assay, the structure characteristics of polyphenols, as well as the proteins. This mini review mainly focused on the influence of PpPI on the antioxidant properties of polyphenols.

Cardioprotective effects of red wine and vodka in a model of endothelial dysfunction

BackgroundModerate alcohol consumption is largely believed to be cardioprotective, while red wine is hypothesized to offer benefit in part due to the proangiogenic and antioxidant properties of polyphenols. We investigated the cardiovascular effects of both red wine and vodka in a swine model of endothelial dysfunction. MethodsTwenty-seven male Yorkshire swine fed a high-fat/cholesterol diet were divided into three groups and received either no alcohol (Control), red wine, or vodka. After 7 wk, myocardial perfusion was measured, and ventricular tissue was analyzed for microvascular reactivity and immunohistochemical studies. ResultsThere were no differences in myocardial perfusion, in arteriolar or capillary density, or in VEGF expression among groups. Total protein oxidation as well as expression of superoxide dismutase-1 and -2 and NADPH oxidase was decreased in both treatment groups compared to controls. Endothelium-dependent microvessel relaxation, however, was significantly improved only in the red wine–supplemented group. ConclusionsSupplementation with both red wine and vodka decreased oxidative stress by several measures, implicating the effects of ethanol in reducing oxidative stress in the myocardium. However, it was only in the red wine–supplemented group that an improvement in microvessel function was observed. This suggests that a component of red wine, independent of ethanol, possibly a polyphenol such as resveratrol, may confer cardioprotection by normalizing endothelial dysfunction induced by an atherogenic diet.

Acid mine drainage attenuation by inhibition of pyrite bioleaching using limestone and olive pomace

The control and inhibition of pyrite bioleaching involved in the generation of acid mine drainage was studied. Inhibition of pyrite bioleaching was performed by varying the pyrite concentration in the medium (substrate inhibition) and/or by addition of limestone (inhibition by pH increase) and olive pomace (inhibition by organic compounds). Inhibition tests of pyrite bioleaching were performed according to a full factorial design with three factors (pyrite, limestone and olive pomace) taken at two levels. Preliminary pyrite bioleaching tests showed the ability of the available inoculum to oxidise the mineral. Subsequently, experimental data for total soluble iron denoted strong inhibition under all the different operating conditions of the factorial design, except when larger pyrite concentrations were used. In particular, inhibition by limestone was due to the increase in pH which negatively affects microorganisms, while inhibition by olive pomace may be related to the antioxidant properties of polyphenols. Interactions among operating conditions were specifically assessed by analysis of variance. Only limestone and/or pomace addition resulted in a significant (95%) diminution of iron extraction.

Inhibition of Iron Oxidizing Bacteria Involved in the Generation of Acid Mine Drainage

Obligate autotrophic and acidophilic characteristics of iron oxidizing bacteria were exploited to prevent or attenuate the generation of AMD. Inhibition of iron oxidizing bacteria growth was performed by variation of growth medium by increasing pyrite concentration (substrate inhibition), by addition of limestone (inhibition by pH increase) and olive pomace (inhibition by organic compounds). Preliminary pyrite bioleaching tests showed the ability of the available inoculum to oxidize the mineral. Inhibition tests of batch growth were performed according to full factorial design with three factors (pyrite, limestone and olive pomace). Experimental data denoted a strong inhibition in all the operating conditions, except the case when larger pyrite concentrations were used. In particular, limestone is a strong inhibitor and inhibition by olive pomace may be related to the antioxidant properties of polyphenols. Interactions among operating conditions were specifically assessed by analysis of variance.

No acute effects of grape juice on appetite, implicit memory and mood

Background: Animal experiments document effects of grape juice on cognitive performance and motor skills, and observational studies in humans suggest an inverse association between flavonoid intake and cognitive decline. These effects may be related to the antioxidant properties of polyphenols. Juice consumption and flavonoid intake may also affect appetite.Objective: To study the acute effects of grape juice consumption on appetite, mood and implicit memory during a time of increased lethargy – the post-lunch dip.Design: Thirty-five participants with a mean age of 26 years who smoked a mean of 11 cigarettes/day for 8 years were included in the study. It included a practice session and two treatment sessions. All sessions involved consumption of grape juice or an energy-matched placebo with lunch followed by assessments of mood, implicit memory, appetite and food intake.Results: Mood decreased over time for both treatments, but there were no differences after lunch between grape juice and placebo for any measure.Conclusion: This study did not document any acute effects of grape juice consumption on mood, implicit memory, appetite or food intake in smokers.

The inhibitory effects of isoflavonoids and resveratrol on oxdized low-density lipoprotein uptake in macrophage cell line J774.1

The interaction between oxidized low-density lipoprotein (LDL) and macrophages are known to be important in the development of arteriosclerosis. Macrophages take up oxidized LDL, becoming foam cells, which contribute to the thickening of the blood vessel wall. The antioxidant properties of polyphenols found in vegetables and other foods have been shown to have a protective effect against arteriosclerosis. To elucidate the effect of flavonoids from fruits, vegetables and cereals on oxidized LDL uptake in macrophages, the inhibitory activity of various flavonoids on DiI-ac-LDL uptake reaction in mouse macrophage cell line J774.1 was measured. We found significant uptake of DiI-ac-LDL, but not DiI-LDL, into the J774.1 cells. In addition, polyinosin and dextran sulphate inhibited uptake, but apigenin, kaempferol, and naringenin, did not. Isoflavones and resveratrol significantly inhibit uptake of DiI-ac-LDL into macrophages, and have a protective effect against arteriosclerosis.