Red wine mitigates the postprandial increase of LDL susceptibility to oxidation

Production of fermented tea petal decoction with insights into in vitro biochemical tests, antioxidant assay and GC-MS analysis

Abstract

This research work was designed to attempt and propose the first report on production and biochemical characterization of fermented tea flower petal decoction or simply tea petal wine. The tea petal decoction and brewer’s yeast or Saccharomyces cerevisiae were co-cultured for fermentation. Antioxidant activity and chromatographic separation of potential candidates were assessed. Primary investigations for qualitative characters on this fermented broth revealed the presence of steroids, tannin, flavonoids, phenol, cardiac glycosides, coumarin, caffeine etc. Our manufactured fermented broth showed high free radical scavenging activity after 2 months of aging. High DPPH scavenging activities were also observed in solvent fractions of acetone, ethanol and methanol. The antioxidant activity, alcohol percentage and other qualities were seen to be gradually increased during aging. Gas chromatography-mass spectrometry analysis revealed the presence of 44 compounds including many potential antioxidant molecules and other bioactive agents. Hopefully, presence of alcohol with medicinally active compounds and antioxidant activity will make it as acceptable as a good wine and tea flower as economically functional.

Graphical abstract

Pecan-enriched diets decrease postprandial lipid peroxidation and increase total antioxidant capacity in adults at-risk for cardiovascular disease

Pecans are a rich source of antioxidants, but the effect of regular consumption on post-meal responses is unknown. The objective of this study was to examine the impact of daily pecan consumption for 8 weeks on fasting and postprandial lipid peroxidation, total antioxidant capacity (TAC), and tocopherols in adults at higher risk for cardiovascular disease (CVD) (hypercholesterolemia or elevated adiposity). We hypothesized that daily pecan consumption would result in increased fasting γ-tocopherol, increased fasting and postprandial TAC, and decreased fasting and postprandial lipid peroxidation. This was a randomized, parallel, controlled trial with 3 treatments: two pecan groups and a nut free control (n = 16). The ADD group (n = 15) consumed pecans as part of a free-living diet, and the SUB group (n = 16) substituted the pecans for isocaloric foods from their habitual diet. At the pre- and post-intervention, a high saturated fat breakfast shake was consumed with postprandial blood draws over 2h. In the ADD and SUB groups, postprandial lipid peroxidation was suppressed (iAUC: 0.9 ± 1.3 to -2.9 ± 2.0 and 4.5 ± 1.7 to 0.7 ± 1.1 µM/2h, respectively; P <0.05) and TAC was elevated (iAUC: -240.8 ± 110.2 to 130.9 ± 131.7 and -227.6 ± 131.2 to 208.7 ± 145.7 µM Trolox Equivalents/2h, respectively; P <0.01) from pre- to post-intervention. Furthermore, there was an increase in γ-tocopherol from pre- to post-intervention within the ADD (1.4 ± 0.1 to 1.8 ± 0.1 µg/mL; P <0.001) and SUB groups (1.8 ± 0.2 to 2.1 ± 0.2 µg/mL; P <0.05). There were no changes in any variable within the control group. These findings suggest that daily pecan consumption protects against oxidative stress that occurs following a high-fat meal in adults at risk for CVD.

Proanthocyanidins and Where to Find Them: A Meta-Analytic Approach to Investigate Their Chemistry, Biosynthesis, Distribution, and Effect on Human Health

Proanthocyanidins (PACs) are a class of polyphenolic compounds that are attracting considerable interest in the nutraceutical field due to their potential health benefits. However, knowledge about the chemistry, biosynthesis, and distribution of PACs is limited. This review summarizes the main chemical characteristics and biosynthetic pathways and the main analytical methods aimed at their identification and quantification in raw plant matrices. Furthermore, meta-analytic approaches were used to identify the main plant sources in which PACs were contained and to investigate their potential effect on human health. In particular, a cluster analysis identified PACs in 35 different plant families and 60 different plant parts normally consumed in the human diet. On the other hand, a literature search, coupled with forest plot analyses, highlighted how PACs can be actively involved in both local and systemic effects. Finally, the potential mechanisms of action through which PACs may impact human health were investigated, focusing on their systemic hypoglycemic and lipid-lowering effects and their local anti-inflammatory actions on the intestinal epithelium. Overall, this review may be considered a complete report in which chemical, biosynthetic, ecological, and pharmacological aspects of PACs are discussed.

Wine's Phenolic Compounds and Health: A Pythagorean View

In support of the J curve that describes the association between wine consumption and all-cause mortality, researchers and the lay press often advocate the health benefits of (poly)phenol consumption via red wine intake and cite the vast amount of in vitro literature that would corroborate the hypothesis. Other researchers dismiss such evidence and call for total abstention. In this review, we take a skeptical, Pythagorean stance and we critically try to move the debate forward by pointing the readers to the many pitfalls of red wine (poly)phenol research, which we arbitrarily treat as if they were pharmacological agents. We conclude that, after 30 years of dedicated research and despite the considerable expenditure, we still lack solid, "pharmacological", human evidence to confirm wine (poly)phenols' biological actions. Future research will eventually clarify their activities and will back the current recommendations of responsibly drinking moderate amounts of wine with meals.

Glycaemic regulation, appetite and ex vivo oxidative stress in young adults following consumption of high-carbohydrate cereal bars fortified with polyphenol-rich berries

Consumption of certain berries appears to slow postprandial glucose absorption, attributable to polyphenols, which may benefit exercise and cognition, reduce appetite and/or oxidative stress. This randomised, crossover, placebo-controlled study determined whether polyphenol-rich fruits added to carbohydrate-based foods produce a dose-dependent moderation of postprandial glycaemic, glucoregulatory hormone, appetite and ex vivo oxidative stress responses. Twenty participants (eighteen males/two females; 24 (sd 5) years; BMI: 27 (sd 3) kg/m2) consumed one of five cereal bars (approximately 88 % carbohydrate) containing no fruit ingredients (reference), freeze-dried black raspberries (10 or 20 % total weight; LOW-Rasp and HIGH-Rasp, respectively) and cranberry extract (0·5 or 1 % total weight; LOW-Cran and HIGH-Cran), on trials separated by ≥5 d. Postprandial peak/nadir from baseline (Δmax) and incremental postprandial AUC over 60 and 180 min for glucose and other biochemistries were measured to examine the dose-dependent effects. Glucose AUC0-180 min trended towards being higher (43 %) after HIGH-Rasp v. LOW-Rasp (P=0·06), with no glucose differences between the raspberry and reference bars. Relative to reference, HIGH-Rasp resulted in a 17 % lower Δmax insulin, 3 % lower C-peptide (AUC0-60 min and 3 % lower glucose-dependent insulinotropic polypeptide (AUC0-180 min) P&lt;0·05. No treatment effects were observed for the cranberry bars regarding glucose and glucoregulatory hormones, nor were there any treatment effects for either berry type regarding ex vivo oxidation, appetite-mediating hormones or appetite. Fortification with freeze-dried black raspberries (approximately 25 g, containing 1·2 g of polyphenols) seems to slightly improve the glucoregulatory hormone and glycaemic responses to a high-carbohydrate food item in young adults but did not affect appetite or oxidative stress responses at doses or with methods studied herein.

Interaction between Mediterranean diet and statins on mortality risk in patients with cardiovascular disease: Findings from the Moli-sani Study

BACKGROUND

Statins are prescribed for patients with cardiovascular disease (CVD), along with the recommendation of adopting healthy diets. We evaluated the independent and the combined effect of statins and Mediterranean diet (MD) towards mortality risk in patients with previous CVD by using real-life data from a population-based prospective cohort.

METHODS

Longitudinal analysis on 1180 subjects (mean age 67.7 ± 10) with prior CVD at enrollment in the Moli-sani Study and followed up for 7.9 y (median). Adherence to MD was appraised by a Mediterranean diet score. Hazard ratios (HR) with 95% confidence intervals (95% CI) were calculated by multivariable Cox regression and competing risk models.

RESULTS

Multivariable risk estimates associated with a 2-point increase in MD score were 0.84 (95% CI 0.70-1.00), 0.77 (0.61-0.97) and 0.70 (0.52-0.93) for overall, cardiovascular and coronary artery disease (CAD)/cerebrovascular deaths, respectively. Statins were not associated with death risk. Subjects combining statins and average-high adherence to MD had much lower than expected risk of cardiovascular and CAD/cerebrovascular mortality (p for interaction = 0.045 and 0.0015, respectively) as compared to those neither using statins nor having average-high MD. The combination of average-high MD and statins was associated in a likely synergistic way with reduced low-grade inflammation, but not with blood cholesterol.

CONCLUSIONS

MD lowered the risk of all-cause, cardiovascular and CAD/cerebrovascular mortality CVD patients, net of statins. In the same population, statins reduced CVD death risk only in combination with MD. Low-grade inflammation, rather than lipids, is likely to be on the pathway of the interaction between MD and statins towards mortality risk.

Fatty Acid Profile Is Modulated by Dietary Resveratrol in Rainbow Trout (Oncorhynchus mykiss)

To produce fish of a high quality that are rich in omega-3 fatty acids (n-3 FA) and simultaneously generate more sustainable aquaculture, the combined use of phytochemicals and vegetable oils in fish feed seems to be a promising approach. Resveratrol (RV) potentially induces endogenous fatty acid synthesis, resulting in elevated n-3 FA levels in fish. RV putatively influences ∆6-desaturase, the key enzyme in FA metabolism, and serves as a ligand for PPARα, a transcription factor regulating β-oxidation. Rainbow trout (36.35 ± 0.03 g) were randomly allocated into six groups and fed diets with reduced fish oil levels (F4 = 4%, F2 = 2% and F0 = 0% of dry matter) supplemented with 0.3% (w/w) RV (F4 + RV, F2 + RV and F0 + RV). RV significantly affected FA composition in liver tissue and whole fish homogenates. 20:5n-3 (EPA) and 22:6n-3 (DHA) were significantly increased whereas precursor FA were diminished in fish fed the F2 + RV and F0 + RV diets when compared to F4 + RV and F0. RV significantly elevated ∆6-desaturase protein levels in the livers of F0 + RV fed animals. Hepatic mRNA expression of ∆6-desaturase, PPARα, and its target genes were affected by the dietary fish oil level and not by dietary RV. The results of this study indicated a potential benefit of supplementing RV in fish oil deprived diets elevating n-3 FA levels in rainbow trout.

A review of plant-based compounds and medicinal plants effective on atherosclerosis

Atherosclerosis is one of the most important cardiovascular diseases that involve vessels through the development of fatty streaks and plaques. Plant-based compounds can help treat or prevent atherosclerosis through affecting the involved factors. The main purpose of this review article is to investigate and introduce medicinal plants and their potential activities regarding antioxidant properties, effective on lipids level and development of plaque, atherosclerosis, and progression of atherosclerosis as well as the development of cardiovascular disease and ischemia. To search for the relevant articles indexed in Information Sciences Institute, PubMed, Scientific Information Database, IranMedex, and Scopus between 1980 and 2013, with further emphasis on those indexed from 2004 to 2015, we used these search terms: atherosclerosis, antioxidant, cholesterol, inflammation, and the medicinal plants below. Then, the articles with inclusion criteria were used in the final analysis of the findings. Plant-based active compounds, including phenols, flavonoids, and antioxidants, can be effective on atherosclerosis predisposing factors and hence in preventing this disease and associated harmful complications, especially through reducing cholesterol, preventing increase in free radicals, and ultimately decreasing vascular plaque and vascular resistance. Hence, medicinal plants can contribute to treating atherosclerosis and preventing its progression through reducing cholesterolemia, free radicals, inflammation, vascular resistance, and certain enzymes. They, alone or in combination with hypocholesterolemic drugs, can therefore be useful for patients with hyperlipidemia and its complications.

Ocular promoting activity of grape polyphenols-A review

The eye is a sensitive organ with complex optical system involves in the perception of light. Although it has several protective mechanisms by itself, various physiological and metabolic disorders are detrimental to the proper functioning of the visual system. Grape juice has long been used worldwide for its potent medicinal values including ocular promotion. Bioactivities of grape products are highly attributed to the presence of health promoting phytochemicals in them. Some phytochemicals present in the grape juice have been involved in the maintenance of intra-ocular pressure, regulation of glucose metabolisms and suppression of pro-inflammatory cytokines in the system. Particularly, the grape derived phytochemicals involve in minimizing various eye defects such as macular degradation, uvea, cataract formation, red eye, diabetic retinopathy and so on. However, only limited number of studies has been conducted so far focusing the ocular promoting activity of grape polyphenols. In this review, we discuss the role of grape polyphenols in ocular promotion relating their anti-oxidant, anti-microbial, anti-aging, anti-hypertensive and anti-inflammatory properties.

A Chilean Berry Concentrate Protects against Postprandial Oxidative Stress and Increases Plasma Antioxidant Activity in Healthy Humans

This study formulated and characterized an antioxidant-rich concentrate of berries (BPC-350) produced in Chile, which was used to perform a crossover study aimed at determining the effect of the berries on the modulation of plasma postprandial oxidative stress and antioxidant status. Healthy male volunteers (N = 11) were randomly assigned to three experimental meals: (1) 250 g of ground turkey burger (GTB) + 500 mL of water; (2) 250 g of GTB + 500 mL of 5% BPC-350; (3) 250 g of GTB prepared with 6% BPC-350 + 500 mL of 5% BPC-350. Venous blood samples were collected prior to meal intake and every hour for six hours after intake. Malondialdehyde (MDA), carbonyls in proteins, and DPPH (2,2-diphenyl-1-picrylhydrazyl) antioxidant capacity were quantified in plasma. Significant differences indicated that BPC-350 decreases MDA plasma concentration and protein carbonyls (p < 0.05). Additionally, a significant increase in the DPPH antioxidant capacity was observed in Meals 2 and 3 when compared to Meal 1 (p < 0.05). The results are discussed in terms of oxidative reactions that occur during digestion at the stomach level and the important effect of oxidative reactions that occur during the thermal processing of red meat.

[Wine consumption and prevention of coronary artery disease]

There is a J-shaped correlation between the amount of alcohol consumed per day and overall mortality risk and an inverse correlation between the amount of alcohol consumed per day and cardiovascular mortality. The evidence is stronger for men than for women. The correlations are independent of the type of alcoholic beverage predominantly consumed. Possible mechanisms explaining the cardioprotective, antiatherosclerotic effects of moderate alcohol consumption are inhibition of platelet aggregation, increase in serum high density lipoprotein (HDL) levels and prevention of diabetes mellitus. The two latter mechanisms can also explain a delayed progression of atherosclerosis due to alcohol consumption. The beneficial effects are counteracted by detrimental effects of alcohol on the incidence of cancer diseases, liver cirrhosis, violence and accidents; therefore, alcohol consumption in general cannot be recommended for prevention of cardiovascular diseases.

Effects of red wine on postprandial stress: potential implication in non-alcoholic fatty liver disease development

INTRODUCTION

Red wine consumption is considered to be protective against oxidative stress. Diet strongly influences non-alcoholic fatty liver disease, which is associated with oxidative stress and is considered the hepatic manifestation of the metabolic syndrome.

METHODS

We reviewed the available evidence that investigated the effects of red wine on the postprandial-induced metabolic and oxidative stress in humans.

RESULTS

After red wine consumption with meal, despite the improvement in non-enzymatic antioxidant capacity and lipoperoxidation markers, the influence of confounding factors such as uric acid should be taken into account. Both uric acid and triglycerides increases, induced by ethanol, could cause liver damage. On the other hand, further researches are required in order to understand the meaning of the induction of antioxidant enzymes by red wine and red wine polyphenols in the context of non-alcoholic fatty liver disease.

CONCLUSION

In conclusion, inconsistent and contrasting findings exist regarding the potential benefits of red wine consumption against postprandial stress.

Effects of functional olive oil enriched with its own phenolic compounds on endothelial function in hypertensive patients. A randomised controlled trial

The additional health-promoting properties of functional virgin olive oil (FVOO) enriched with its own phenolic compounds (OOPC) versus the parental virgin olive oil (VOO) must be tested in appropriate human clinical trials. Our aim was to assess the effects of FVOO on endothelial function in hypertensive patients. Thirteen pre- and stage-1 hypertensive patients received a single dose of 30 mL of FVOO (OOPC=961 mg/kg) or VOO (OOPC=289 mg/kg) in a postprandial randomised, double blind, crossover trial. Endothelial function, measured as ischemic reactive hyperemia (IRH) and related biomarkers, were followed for 5h after consumption. Compared with VOO, FVOO increased IRH (P<0.05) and plasma Cmax of hydroxytyrosol sulphate, a metabolite of OOPC 2h postprandial (P=0.05). After FVOO ingestion, oxidised LDL decreased (P=0.010) in an inverse relationship with IRH AUC values (P=0.01). FVOO provided more benefits on endothelial function than a standard natural virgin olive oil in pre- and hypertensive patients.

TRIAL REGISTRATION

isrctn.org. Identifier ISRCTN03450153.

Resveratrol protects SR-B1 levels in keratinocytes exposed to cigarette smoke

Cigarette smoking (CS) has been strongly linked to several health conditions including heart disease, lung cancer, and other respiratory and circulatory ailments. Deleterious effects of cigarette smoking on skin have also been well documented, but unlike effects on other organs, damage does not depend upon inhalation. The upper layer of the skin, the stratum corneum (rich in cholesterol fatty acids and ceramide), is very susceptible to damage induced by exposure to environmental stressors that can modify its lipid composition and thereby affect its function of protecting skin from dehydration. Scavenger receptor B1 (SR-B1) is involved in the uptake of cholesterol in several tissues including skin. We previously demonstrated that CS exposure induces formation of aldehyde (HNE) adducts that decrease SR-B1 expression. As topical resveratrol, a well-known polyphenolic stilbene, has been demonstrated to show benefits against skin disorders, we investigated its possible role as a protective agent against CS-induced reduction of SR-B1 expression in cutaneous tissue. In this study, we demonstrate that resveratrol at doses ranging from 0.5 to 10 μM is not toxic and is able to increase SR-B1 protein levels in a dose-dependent manner in human keratinocytes. Moreover, when the cells that were pretreated with various doses of resveratrol were exposed to CS, the loss of SR-B1 was prevented in a dose-dependent manner. In addition, in keratinocytes, resveratrol was also able to prevent an increase in HNE-protein adducts induced by CS. In particular resveratrol was able to prevent HNE-SR-B1 adduct formation. Thus, resveratrol seems to be a natural compound that could provide skin with a defense against exogenous stressors by protecting the essential cholesterol receptor, SR-B1.

Wine by-products: phenolic characterization and antioxidant activity evaluation of grapes and grape pomaces from six different French grape varieties

Grenache, Syrah, Carignan Noir, Mourvèdre, Counoise and Alicante Bouchet grape seeds and skins, harvested in 2009 and 2010 in the Rhône valley area of France, and their respective pomaces remaining after vinification, were analyzed for their phenolic composition and antioxidant activity. The polyphenol content was quantified by HPLC and the Folin-Ciocalteu assay. The antioxidant potential was measured with four different assays: ORAC, FRAP, ABTS and DPPH. Seeds contained higher amounts of total polyphenols, up to 44.5 mg of gallic acid equivalent [GAE]/g dry weight in Alicante pomace, than skin extracts. The maximum total phenolic in skins was 31.6 mg GAE/g dry weight detected in 2010 Alicante pomace. Seeds also had the highest antioxidant capacity. HPLC analysis revealed that, despite the vinification process, pomaces still contained an appreciable amount of proanthocyanidins as well as several anthocyanin glycosides. Alicante and Syrah proved to be the varieties of most interest in terms of their potential development for nutraceutical purposes.

Biosynthesis, natural sources, dietary intake, pharmacokinetic properties, and biological activities of hydroxycinnamic acids

Hydroxycinnamic acids are the most widely distributed phenolic acids in plants. Broadly speaking, they can be defined as compounds derived from cinnamic acid. They are present at high concentrations in many food products, including fruits, vegetables, tea, cocoa, and wine. A diet rich in hydroxycinnamic acids is thought to be associated with beneficial health effects such as a reduced risk of cardiovascular disease. The impact of hydroxycinnamic acids on health depends on their intake and pharmacokinetic properties. This review discusses their chemistry, biosynthesis, natural sources, dietary intake, and pharmacokinetic properties.

Dietary iron-initiated lipid oxidation and its inhibition by polyphenols in gastric conditions

The gastric tract may be the first site where food is exposed to postprandial oxidative stress and antioxidant activity by plant micronutrients. After food intake, dietary iron, dioxygen, and emulsified lipids come into close contact and lipid oxidation may take place. This study investigated lipid oxidation and its inhibition by dietary polyphenols in gastric-like conditions. Lipid oxidation induced by heme and nonheme iron was studied in acidic sunflower oil-in-water emulsions. The emulsifier type (bovine serum albumin, phospholipids), pH, and iron form were found to be factors governing the oxidation rates. Quercetin, rutin, and chlorogenic acid highly inhibited the metmyoglobin-initiated lipid oxidation in both emulsified systems at pH 5.8. Additionally, quercetin inhibited nonheme iron-initiated processes, while it was inefficient with hematin as an initiator. The presence of human gastric juice did not influence lipid oxidation, although it diminished the antioxidant activity of phenolics. Model emulsions may thus be valuable tools to study the gastric stability of polyunsaturated lipids.

Effect of red wine consumption on biomarkers of oxidative stress

AIMS

To evaluate the effect of acute and chronic consumption of red wine or de-alcoholized red wine with a similar antioxidant capacity on plasma total antioxidant capacity (TEAC), nuclear factor-κB (NF-κB) activity and F2-isoprostanes (8-iso-PGF(2α)) in healthy men.

METHODS

Nineteen healthy men with an increased waist circumference (≥94 cm) and a body mass index above 25 kg/m(2) participated in a randomized, controlled crossover design trial. They daily consumed 450 ml of red wine (four drinks; 41.4 g alcohol) or 450 ml of de-alcoholized red wine during dinner for 4 weeks each. On the last day of each treatment period, blood was collected before and 1 h after a standardized dinner with red wine or de-alcoholized red wine and also 24-h urine was collected.

RESULTS

Absolute TEAC levels were higher 1 h after dinner with red wine compared with dinner with de-alcoholized red wine (1.3 versus 1.1 mmol Trolox equivalents/l; P = 0.03). Consumption of dinner together with de-alcoholized red wine acutely stimulated NF-κB activity in peripheral blood mononuclear cells (0.4-0.7 HeLa equivalents/2.5 μg protein; P = 0.006), whereas this increase was completely suppressed when the dinner was combined with red wine. A chronic increase in urinary 8-iso-PGF(2α) after 4 weeks of red wine consumption compared with de-alcoholized red wine consumption (157 pg/mg creatinine and 141 pg/mg creatinine, respectively, P = 0.006) was also observed.

CONCLUSIONS

Consumption of a moderate dose of red wine can acutely increase plasma TEAC and suppress NF-κB activation induced by a meal. Controversially, 4 weeks of red wine consumption compared with de-alcoholized red wine consumption increases the oxidative lipid damage marker 8-iso-PGF(2α).

Resveratrol--pills to replace a healthy diet?

Nutrapharmacology, or the use of bioactive food compounds at pharmacological doses is emerging as a therapeutic approach to target the complex metabolic dysregulations in ageing and obesity-related chronic disease. Resveratrol, a polyphenol found in the skin of grapes, and other edible plants and related food products, has received extensive attention through the link with the French paradox, and later with its chemopreventive activity demonstrated in vitro and in animal cancer models. A plethora of laboratory investigations has provided evidence for the multi-faceted properties of resveratrol and suggests that resveratrol may target ageing and obesity-related chronic disease by regulating inflammation and oxidative stress. A number of obstacles stand in the path to clinical usage however, not least the lack of clinical evidence to date, and the myriad of doses and formulations available. Further, data on the effects of resveratrol consumption in a capsule vs. food form is conflicting, and there are uncertain effects of long term dosing. The review will summarize the human pharmacokinetic and pharmacodynamic published data, and the topics for research if resveratrol is to become a multi-target therapeutic agent addressing chronic disease.

Red wine prevents the postprandial increase in plasma cholesterol oxidation products: a pilot study

Moderate wine consumption has been shown to lower cardiovascular risk. One of the mechanisms could involve the control of postprandial hyperlipaemia, a well-defined risk factor for atherosclerosis, reasonably by reducing the absorption of lipid oxidised species from the meal. The objective of the present study was to investigate whether wine consumption with the meal is able to reduce the postprandial increase in plasma lipid hydroperoxides and cholesterol oxidation products, in human subjects. In two different study sessions, twelve healthy volunteers consumed the same test meal rich in oxidised and oxidisable lipids (a double cheeseburger), with 300 ml of water (control) or with 300 ml of red wine (wine). The postprandial plasma concentration of cholesterol oxidation products was measured by GC–MS. The control meal induced a significant increase in the plasma concentration of lipid hydroperoxides and of two cholesterol oxidation products, 7-β-hydroxycholesterol and 7-ketocholesterol. The postprandial increase in lipid hydroperoxides and cholesterol oxidation products was fully prevented by wine when consumed with the meal. In conclusion, the present study provides evidence that consumption of wine with the meal could prevent the postprandial increase in plasma cholesterol oxidation products.

Non-enzymatic antioxidant capacity assays: Limitations of use in biomedicine

The 'Total antioxidant capacity' (TAC) is a parameter frequently used for characterization of food products and of the antioxidant status of the body. This mini-review shows shortcomings of TAC assays and points of concern that should be considered when performing and interpreting results of such assays. The term TAC is not optimal since the assay measures only part of antioxidant capacity, usually excluding enzymatic activities. Antioxidant and oxidant-regenerating enzymes in blood cells and the blood vessel wall have a profound impact on the antioxidant properties of blood plasma, which is not reflected in the in vitro assays of isolated plasma. The term 'Non-enzymatic antioxidant capacity' (NEAC) is suggested as more relevant than TAC. NEAC is estimated by various methods, which yield different values and results obtained using different methods do not always show satisfactory correlation. One reason for the discrepancy of results is the use of different oxidants in NEAC assays. The use of hydroxyl radical as the oxidant is not recommended in view of the high and non-specific reactivity of this species.

Effect of dietary melanoidins on lipid peroxidation during simulated gastric digestion: their possible role in the prevention of oxidative damage

The ability of high molecular weight melanoidins extracted from coffee, barley coffee, and dark beer to inhibit lipid peroxidation during simulated gastric digestion of turkey meat has been investigated. Results showed that melanoidins decrease the synthesis of lipid hydroperoxides and secondary lipoxidation products. Coffee melanoidins at 3 mg/mL reversed the reaction and broke down hydroperoxides to concentrations lower than the initial value. Barley coffee and dark beer melanoidins were less effective, and even at 12 mg/mL did not reverse the reaction. The proposed mechanism of action involved Fe(2+) chelating capacity, heme-binding ability, and radical-scavenging activity. Melanoidins were characterized for their content in total proteins, carbohydrates, and phenolics, and the relationship between the chemical composition and the antioxidant activity of dietary melanoidins was investigated. Coffee melanoidins, which contain more phenolics and proteins with respect to the other melanoidins, showed greater antioxidant activity with respect to the other melanoidins tested.

Antioxidant activity of wine pigments derived from anthocyanins: hydrogen transfer reactions to the dpph radical and inhibition of the heme-induced peroxidation of linoleic acid

The consumption of red wine can provide substantial concentrations of antioxidant polyphenols, in particular grape anthocyanins (e.g., malvidin-3-O-beta-d-glucoside (1)) and specific red wine pigments formed by reaction between anthocyanins and other wine components such as catechin (3), ethanol, and hydroxycinnamic acids. In this work, the antioxidant properties of red wine pigments (RWPs) are evaluated by the DPPH assay and by inhibition of the heme-induced peroxidation of linoleic acid in acidic conditions (a model of antioxidant action in the gastric compartment). RWPs having a 1 and 3 moieties linked via a CH(3)-CH bridge appear more potent than the pigment with a direct 1-3 linkage. Pyranoanthocyanins derived from 1 reduce more DPPH radicals than 1 irrespective of the substitution of their additional aromatic ring. Pyranoanthocyanins are also efficient inhibitors of the heme-induced lipid peroxidation, although the highly hydrophilic pigment derived from pyruvic acid appears less active.

Wine and oxidative stress: up-to-date evidence of the effects of moderate wine consumption on oxidative damage in humans

Wine and alcohol consumption has been considered to be protective against coronary heart disease development, an oxidative stress associated disease. Wine contains polyphenols displaying antioxidant properties tested in in vitro and in vivo studies. Due to this, a general consensus exists, both among the general public and the scientific community, that wine, particularly red wine, is an antioxidant beverage. Alcohol consumption, however, is associated with oxidative damage. Several studies have been carried out on the antioxidant health benefits of wine and wine polyphenols. However, adequate scientific evidence (Level I or II) is required to be provided before recommendations or statements which can reach the general public can be formulated. Here, we summarize the state of the art of the up-to-date body of knowledge, and the extent to which there exists evidence of the benefits of moderate wine consumption on oxidative damage in humans. From the available data, there is no evidence, at present, that sustained wine consumption provides antioxidant benefits in healthy volunteers other than to counteract a possible pro-oxidative effect of the alcohol. On the contrary, data on the antioxidant protective effect of red wine in oxidative stress situations are promising. In this way, the postprandial oxidative stress after a meal, despite the diversity of biomarkers used for its evaluation, is counteracted by the ingestion of wine. Further studies are warranted.

Alcohol, wine, and cardiovascular health

Studies evaluating the health benefits of alcohol and wine have demonstrated that moderate consumption is associated with a decrease in all-cause and cardiovascular mortality. Various populations and alcoholic beverages exhibit this effect to different degrees. Alcoholic beverages exhibit multiple mechanisms that may favorably influence cardiac risk potential actions on platelets, antioxidants, fibrinolysis, and lipids. However, other data suggest that the perceived benefit of alcoholic beverages in general, and wine in particular, are the result of socioeconomic confounders. In the absence of more rigorous evidence, it is not currently possible to define the role of wine in human health.

Impaired postprandial endothelial function depends on the type of fat consumed by healthy men

Postprandial lipemia impairs endothelial function possibly via an oxidative stress mechanism. A stearic acid-rich triacylglycerol (TAG) (shea butter) results in a blunted postprandial increase in plasma TAG compared with an oleic acid-rich TAG; however, its acute effects on endothelial function and oxidative stress are unknown. A randomized crossover trial (n = 17 men) compared the effects of 50 g fat, rich in stearic acid [shea butter blend (SA)] or oleic acid [high oleic sunflower oil (HO)], on changes in endothelial function [brachial artery flow-mediated dilatation (FMD)], arterial tone [pulse wave analysis (PWA), and carotid-femoral pulse wave velocity (PWV(c-f))], and oxidative stress (plasma 8-isoprostane F2alpha) at fasting and 3 h following the test meals. The postprandial increase in plasma TAG was lower (66% lower incremental area under curve) following the SA meal [28.3 (9.7, 46.9)] than after the HO meal [83.4 (57.0, 109.8); P < 0.001] (geometric means with 95% CI, arbitary units). Following the HO meal, there was a decrease in FMD [-3.0% (-4.4, -1.6); P < 0.001] and an increase in plasma 8-isoprostane F2alpha [10.4ng/L (3.8, 16.9); P = 0.005] compared with fasting values, but no changes followed the SA meal. The changes in 8-isoprostane F2alpha and FMD differed between meals and were 14.0 ng/L (6.4, 21.6; P = 0.001) and 1.75% (0.10, 3.39; P = 0.02), respectively. The reductions in PWA and PWV c-f did not differ between meals. This study demonstrates that a stearic acid-rich fat attenuates the postprandial impairment in endothelial function compared with an oleic acid-rich fat and supports the hypothesis that postprandial lipemia impairs endothelial function via an increase in oxidative stress.

Manipulation of lipid bioaccessibility of almond seeds influences postprandial lipemia in healthy human subjects

BACKGROUND

Plant cell walls are known to influence the rate and extent of lipid release from plant food tissues during digestion; however, the effect of cell wall structure on postprandial lipemia is unknown.

OBJECTIVE

The objective was to investigate the effects of lipid release (bioaccessibility) on postprandial lipemia by comparing lipid encapsulated by cell walls with lipid present as free oil.

DESIGN

A randomized crossover trial (n = 20 men) compared the effects of 3 meals containing 54 g fat provided as whole almond seed macroparticles (WA), almond oil and defatted almond flour (AO), or a sunflower oil blend as control (CO) on postprandial changes in oxidative stress (8-isoprostane F(2)alpha concentrations), vascular tone (peripheral augmentation index), and plasma triacylglycerol, glucose, and insulin concentrations.

RESULTS

The postprandial increase in plasma triacylglycerol was lower [74% and 58% lower incremental area under curve (iAUC)] after the WA meal than after the AO and CO meals (P < 0.001). Increases in plasma glucose concentrations (0-180 min) were significantly higher after the WA meal (iAUC: 114; 95% CI: 76, 153) than after the AO meal (iAUC: 74; 95% CI: 48, 99) (P < 0.05), but no significant differences from the CO meal were observed (iAUC: 88; 95% CI: 66, 109). The peak reductions in peripheral augmentation index after the WA, AO, and CO meals (-9.5%, -10.1%, and -12.6%, respectively, at 2 h) were not significantly different between meals. Plasma 8-isoprostane F(2)alpha and insulin concentrations did not differ significantly between meals.

CONCLUSIONS

The bioaccessibility of lipid in almond seeds, which is regulated by the structure and properties of cell walls, plays a primary role in determining postprandial lipemia.

Effects of anthocyanin-rich purple potato flakes on antioxidant status in F344 rats fed a cholesterol-rich diet

We examined the antioxidant effects of polyphenol/anthocyanin-rich potato (Solanum tuberosumcv. Shadow-Queen) flakes in male rats fed a high-cholesterol diet. The rats were served either a high-cholesterol (0·5 % cholesterol plus 0·125 % sodium cholate) diet, or a high-cholesterol diet containing a mixture of 243 g α-maize starch/kg supplemented with one of the following (per kg diet): 300 g medium purple potato (Shadow-Queen), 300 g white potato (Solanum tuberosumcv. Toyoshiro) or 300 g dark purple sweet potato (Ipomoea batatascv. Ayamurasaki) flakes for 28 d. We analysed thiobarbituric acid reactive substance (TBARS) levels in the serum and liver, and antioxidant enzyme activities in the liver. At this dosage, TBARS levels in the serum and liver of the Shadow-Queen and Ayamurasaki groups were significantly lower than those in the control and Toyoshiro groups. The serum urate levels in all the flake groups were significantly lower than that in the control group. The hepatic glutathione levels in the Shadow-Queen and Ayamurasaki groups were significantly higher than in the control and Toyoshiro groups. The activities of hepatic glutathione reductase and glutathioneS-transferase in the Shadow-Queen and Ayamurasaki groups were significantly greater than those in the control group. These results show that modulation of antioxidant enzymes and oxidative status in the serum and liver by the purple potato flake diet (Shadow-Queen) containing polyphenols/anthocyanins may play an important role in the protection against adverse effects related to oxidative damage in rats fed a high-cholesterol diet.

Selenium supplementation prevents the increase in atherogenic electronegative LDL (LDL minus) in the postprandial phase

Evidence is accumulating that postprandial phenomena play a role in atherogenesis. Dietary lipid hydroperoxides that escape from the gastrointestinal barrier can be incorporated into plasma lipoproteins, leading to a modified form of LDL (LDL minus). The present human study was designed to investigate the effect of selenium supplementation on the formation of LDL minus in the postprandial phase. Fourteen healthy subjects ate the same test meal, high in lipid hydroperoxides, at baseline and after 10-day selenium supplementation (110 microg/day). Plasma selenium, LDL minus, LDL resistance to oxidative modification, plasma antioxidants (ascorbic acid, GSH and GPx activity) and MDA were measured in preprandial (time 0) and postprandial (3h) phases. Supplementation did not induce changes in the concentration of selenium in fasting plasma, but, at the same time, it induced a significant decrease in preprandial plasma GPx activity and inhibited the meal-induced increase in GPx activity. Selenium supplementation fully prevented the meal-induced increase in both LDL minus level and LDL susceptibility to oxidation. This study demonstrated the efficacy of selenium in preventing postprandial oxidative stress. The results, obtained on subjects adequately supplied with selenium, suggest that a non-limiting selenium availability counteracts the postprandial formation of the atherogenic form of LDL and provide a rationale for the epidemiological evidence of the inverse correlation between selenium intake and the incidence of chronic and degenerative diseases.

Dietary antioxidants as inhibitors of the heme-induced peroxidation of linoleic acid: mechanism of action and synergism

In this work, a quantitative kinetic model for investigating the heme-induced peroxidation of linoleic acid and its inhibition by two important dietary antioxidants, quercetin and alpha-tocopherol, is developed. The main conclusions of this work are: (1) The time dependence of the lipid hydroperoxide concentration is critically dependent on the rate constant for lipid hydroperoxide cleavage, initial fraction of lipid hydroperoxides among the pool of conjugated dienes, and rate of heme degradation. (2) The lipophilic antioxidant alpha-tocopherol acts as a chain-breaking antioxidant that quickly reduces 1-2 eq of lipid peroxyl radicals (inhibition of propagation), whereas the more hydrophilic antioxidant quercetin is only marginally chain-breaking but capable of reducing 4-5 eq of iron-oxo initiator (inhibition of initiation). (3) Based on comparisons between experimental peroxidation curves and simulated curves assuming additivity, it can be concluded that combinations of alpha-tocopherol and quercetin are generally synergistic. The kinetic analysis and HPLC titrations of the antioxidants both suggest that synergism mainly arises from a capacity of alpha-tocopherol to regenerate some quercetin oxidation products still endowed with a reducing activity.

Pomegranate Wine Has Greater Protection Capacity Than Red Wine on Low-Density Lipoprotein Oxidation

Although there is a large body of evidence on the main role of red wine in protection of low-density lipoprotein (LDL) against oxidation, there are few data on the role of pomegranate juice, which has high phenolic content. We conducted this study considering the possible importance of pomegranate wine as an antioxidant and in order to make a comparison between red and pomegranate wines. The phenol levels of pomegranate and red wines (4,850 mg/L gallic acid equivalents and 815 mg/L gallic acid equivalents, respectively) were in accordance with their total antioxidant activity (39.5% and 33.7%, respectively). Both wines decreased LDL-diene levels following a 30-minute incubation period compared with controls (145 +/- 3.2 micromol/mg of LDL protein). However, pure pomegranate wine demonstrated a greater antioxidant effect (P < .01) on diene level (110 +/- 4.6 micromol/mg of LDL protein) than pure red wine (124 +/- 3.2 micromol/mg of LDL protein). In conclusion, we suggest that pomegranate wine has potential protective effects toward LDL oxidation, and it may be a dietary choice for people who prefer fruit wines.

Beneficial effects of grape seed extract on malondialdehyde-modified LDL

Following consecutive 12-wk administration of tablets containing 0, 200 or 400 mg grape seed extract (calculated as proanthocyanidin) to 61 healthy subjects with LDL cholesterol (LDL-C) levels of 100 to 180 mg/dL, effects of such treatment compared to administration of placebo tablets on malondialdehyde-modified LDL (MDA-LDL), representing one oxidized type of LDL, were investigated by a single blind method. MDA-LDL level in the 200 mg (calculated as proanthocyanidin) group was significantly (p = 0.008) reduced compared to the basal level, 12 wk after the start of administration. In the 400 mg (calculated as proanthocyanidin) group, a significant decrease in MDA-LDL level compared to the basal level was found 6 and 12 wk after the start of administration (6 wk: p = 0.015, 12 wk: p = 0.009). Subjects with high levels of MDA-LDL/ApoB (MDA-LDL/ApoB > or = 100 mU/mL) in the 200 mg group showed significantly (p = 0.011) reduced MDA-LDL levels at 12 wk after the start of administration. In the 400 mg group, significant decreases in MDA-LDL level compared to the basal level were seen 6 and 12 wk after the start of administration (6 wk: p = 0.001, 12 wk: p < 0.001); and at week 6, significantly (p = 0.048) lower values were observed compared to those in patients who took placebo tablets (0 mg proanthocyanidin). In subjects demonstrating the least body weight changes during the test period (less than +/- 1.0 kg) in the 400 mg group, there was an increasing trend (p = 0.088) in adiponectin levels 12 wk after the start of treatment. These results suggested that tablets containing grape seed extract exerted reducing effects on oxidized LDL, and might be useful in preventing lifestyle-related diseases such as arteriosclerosis.

Concomitant consumption of red wine and polyunsaturated fatty acids in edible oil does not influence the peroxidation status of chylomicron lipids despite increasing plasma catechin concentration

BACKGROUND AND AIMS

Atherosclerosis may be ameliorated by red wine consumption possibly by providing antioxidants. The effects of red wine on the peroxidation status of chylomicrons (CM) are unknown. The aims were to compare the lipid peroxidation status of oil rich in polyunsaturated fatty acids (PUFA) from a standardised high-fat meal with that of the CM at peak concentrations following ingestion of the meal with and without wine, and to examine the contribution of wine to the antioxidant content of the plasma.

METHODS AND RESULTS

Fasted subjects ingested the meal randomly with and without red wine. The peroxidation status was described by conjugated dienes (CD), lipid hydroperoxides (LOOH) and thiobarbituric acid reactive substances (TBARS). CM lag times and the area under the curve (AUC) of CD were determined under oxidative stress. Plasma catechin concentrations and oxygen radical absorbance capacity (ORAC) values were determined. The CM produced with and without wine did not differ in their concentration of CD, LOOH and TBARS. Lag times of CM with and without wine were not significantly different, nor were the AUC. Plasma catechin values increased significantly after consumption of wine with the meal, whereas ORAC values did not.

CONCLUSION

Red wine consumption increases plasma catechins, but does not influence lipid peroxidation in postprandial CM.

Postprandial LDL phenolic content and LDL oxidation are modulated by olive oil phenolic compounds in humans

Olive oil phenolic compounds are potent antioxidants in vitro, but evidence for antioxidant action in vivo is controversial. We examined the role of the phenolic compounds from olive oil on postprandial oxidative stress and LDL antioxidant content. Oral fat loads of 40 mL of similar olive oils, but with high (366 mg/kg), moderate (164 mg/kg), and low (2.7 mg/kg) phenolic content, were administered to 12 healthy male volunteers in a cross-over study design after a washout period in which a strict antioxidant diet was followed. Tyrosol and hydroxytyrosol, phenolic compounds of olive oil, were dose-dependently absorbed (p<0.001). Total phenolic compounds in LDL increased at postprandial state in a direct relationship with the phenolic compounds content of the olive oil ingested (p<0.05). Plasma concentrations of tyrosol, hydroxytyrosol, and 3-O-methyl-hydroxytyrosol directly correlated with changes in the total phenolic compounds content of the LDL after the high phenolic compounds content olive oil ingestion. A 40 mL dose of olive oil promoted a postprandial oxidative stress, the degree of LDL oxidation being lower as the phenolic content of the olive oil administered increases. In conclusion, olive oil phenolic content seems to modulate the LDL phenolic content and the postprandial oxidative stress promoted by 40 mL olive oil ingestion in humans.

Single and repeated moderate consumption of native or dealcoholized red wine show different effects on antioxidant parameters in blood and DNA strand breaks in peripheral leukocytes in healthy volunteers: a randomized controlled trial (ISRCTN68505294)

BACKGROUND

Red wine (RW) is rich in antioxidant polyphenols that might protect from oxidative stress related diseases, such as cardiovascular disease and cancer. Antioxidant effects after single ingestion of RW or dealcoholized RW (DRW) have been observed in several studies, but results after regular consumption are contradictory. Thus, we examined if single or repeated consumption of moderate amounts of RW or DRW exert antioxidant activity in vivo.

METHODS

Total phenolic content and concentration of other antioxidants in plasma/serum, total antioxidant capacity (TEAC) in plasma as well as DNA strand breaks in peripheral leukocytes were measured in healthy non-smokers A) before, 90 and 360 min after ingestion of one glass of RW, DRW or water; B) before and after consumption of one glass of RW or DRW daily for 6 weeks. DNA strand breaks (SB) were determined by single cell gel electrophoresis (Comet Assay) in untreated cells and after induction of oxidative stress ex vivo with H2O2 (300 microM, 20 min).

RESULTS

Both RW and DRW transiently increased total phenolic content in plasma after single consumption, but only RW lead to a sustained increase if consumed regularly. Plasma antioxidant capacity was not affected by single or regular consumption of RW or DRW. Effects of RW and DRW on DNA SB were conflicting. DNA strand breaks in untreated cells increased after a single dose of RW and DRW, whereas H2O2 induced SB were reduced after DRW. In contrast, regular RW consumption reduced SB in untreated cells but did not affect H2O2 induced SB.

CONCLUSION

The results suggest that consumption of both RW and DRW leads to an accumulation of phenolic compounds in plasma without increasing plasma antioxidant capacity. Red wine and DRW seem to affect the occurrence of DNA strand breaks, but this cannot be referred to antioxidant effects.