[Validation of self-applicable questionnaire for a Mediterranean dietary index in Chile]. / Validación de cuestionario autoaplicable para un índice de alimentación mediterránea en Chile.

BACKGROUND: Availability of brief dietary indexes that can effectively evaluate dietary patterns and their association with health is critical for prevention and management of several chronic disease conditions. AIM: To adapt a self-applicable Mediterranean Dietary Index in Chile (Chilean-MDI). MATERIAL AND METHODS: The Chilean-MDI was developed based on a previous Mediterranean eating score that was adapted to Chilean dietary habits. This index was further validated in a sample of 153 adults by comparing the concordance between the results obtained by self-application of the Chilean-MDI with those obtained by a trained nutritionist. Additionally, the index was applied in a sample of 53,366 Chilean adults in order to describe the diet quality of our population. RESULTS: There was an adequate concordance between findings obtained by self-application of the Chilean-MDI and those achieved by the nutritionist. The application of the index in Chilean adult population showed a better diet quality (high Mediterranean diet adherence) among women, with advanced age and among people with higher educational levels. CONCLUSIONS: The Chilean-MDI can be successfully self-applied to portray the overall diet quality in the Chilean adult population. Additionally, this dietary index describes overall food intake in Chilean adults, showing demographic trends that are comparable to those obtained with similar indexes applied in other populations.

Wine grape pomace flour improves blood pressure, fasting glucose and protein damage in humans: a randomized controlled trial.

BACKGROUND: The Mediterranean diet is a healthy diet with positive scientific evidence of preventing chronic diseases. Bioactive components support the healthy properties of the Mediterranean diet. Antioxidants and fiber, two components of the Mediterranean diet, are key functional nutrients for healthy eating and nutrition. Wine grape pomace is a rich source of these dietary constituents and may be beneficial for human health. Our hypothesis was that the intake of red wine grape pomace flour (WGPF) prepared from red wine grapes (Cabernet Sauvignon variety) reduced the metabolic syndrome in humans. To evaluate the effect of WGPF on components of metabolic syndrome we design a 16-week longitudinal intervention study. Thirty-eight males, 30-65 years of age, with at least one component of metabolic syndrome, were randomly assigned to either the intervention group (n = 25) or the control group (n = 13). At lunch, the intervention group was given 20 g of WGPF per day, which contained 10 g of dietary fiber, 822 mg of polyphenols and an antioxidant capacity of 7258 ORAC units. Both groups were asked to maintain their regular eating habits and lifestyles. Clinical evaluation, anthropometric measurements and biochemical blood analyses were done at the beginning and the end of the study. RESULTS: WGPF intake significantly decreased systolic and diastolic blood pressure as well as fasting glucose levels. Plasma γ-tocopherol and δ-tocopherol increased and carbonyl group in plasma protein decreased in WGPT group, significantly. No significant effect was observed for waist circumference, HDL cholesterol, triglycerides, total antioxidant capacity and vitamin C in and between groups. The group-dependent magnitude of the differences between the baseline and final postprandial insulin values and γ-tocopherol concentrations was statistically significant. CONCLUSIONS: The consumption of WGPF-rich in fiber and polyphenol antioxidants, as a food supplement in a regular diet improves blood pressure, glycaemia and postprandial insulin. In addition, increased antioxidant defenses and decreased oxidative protein damage indicating attenuation of oxidative stress. WGPF might be a useful food ingredient for health promotion and chronic disease prevention.

[Assessment of the reliability of food labeling in Chile]. / ¿Podemos confiar en el etiquetado nutricional de los alimentos en Chile?

BACKGROUND: Nutrition labeling is a tool that helps people to make healthy choices when choosing foods and drinks for consumption. Easy to understand information promotes rational choices. However the implementation of this information by industry and their proper use by consumers is complex. A key aspect is the existence of appropriate laws and regulations. Fortunately, Chile has a mandatory guideline for labeling packed food products. Though, the correctness of the information appearing in the label is essential. AIM: To evaluate the veracity of nutritional information appearing on food labels in our country. MATERIAL AND METHODS: We tabulated the information on the labels of over 1,000 packed products and analyzed it using globally accepted tables as reference. We included cereals, vegetables, fruits and juices, nuts, legumes, dairy, fish and shellfish, meat, oils and fats and sweets. RESULTS: Ninety percent of the information appearing in the labels of analyzed products was presumably correct. However, there were great variations among food groups. CONCLUSIONS: This information allowed evaluate the application of the Food Health Regulations reform implemented in 2006, specifically Article 115. The possible improvements to achieve the original aims of the initiative are discussed.

Lysosomal vitamin E accumulation in Niemann-Pick type C disease.

Niemann-Pick C disease (NPC) is a neuro-visceral lysosomal storage disorder mainly caused by genetic defects in the NPC1 gene. As a result of loss of NPC1 function large quantities of free cholesterol and other lipids accumulate within late endosomes and lysosomes. In NPC livers and brains, the buildup of lipids correlates with oxidative damage; however the molecular mechanisms that trigger it remain unknown. Here we study potential alterations in vitamin E (α-tocopherol, α-TOH), the most potent endogenous antioxidant, in liver tissue and neurons from NPC1 mice. We found increased levels of α-TOH in NPC cells. We observed accumulation and entrapment of α-TOH in NPC neurons, mainly in the late endocytic pathway. Accordingly, α-TOH levels were increased in cerebellum of NPC1 mice. Also, we found decreased mRNA levels of the α-TOH transporter, α-Tocopherol Transfer Protein (α-TTP), in the cerebellum of NPC1 mice. Finally, by subcellular fractionation studies we detected a significant increase in the hepatic α-TOH content in purified lysosomes from NPC1 mice. In conclusion, these results suggest that NPC cells cannot transport vitamin E correctly leading to α-TOH buildup in the endosomal/lysosomal system. This may result in a decreased bioavailability and impaired antioxidant function of vitamin E in NPC, contributing to the disease pathogenesis.

Modification of fatty acid composition in broiler chickens fed canola oil.

This article describes the possibility of modifying the composition of fat tissue in broiler chickens fed canola oil, which is high in monounsaturated fatty acids. 128 one-day old broiler chickens, randomly assigned into 4 groups of 32 chicks each, received one of four diets containing 15% oil with different percentages of canola oil (diet 1: 0% canola oil, diet 2: 5% canola oil, diet 3: 10% canola oil and diet 4: 15% canola oil), for 31 days. Each group was divided into 4 subgroups of 8 chicks. The birds were sacrificed at day 45 to obtain tissue samples. The fatty acid composition was measured in meat (legs and breasts), fat (abdominal and subcutaneous) and plasma. An increase in oleic acid (p<0.01) was detected, as well as a decrease in linoleic acid (p<0.01), together with a slight increase in α-linolenic acid (p<0.05) with a higher percentage of canola oil. The composition of fat tissue was more representative of the dietary fatty acids than muscle tissue. In conclusion, canola oil increased the content of omega 9 and omega 3 fatty acids and decreased the content of omega 6 fatty acids in meat, fat and plasma in broiler chickens.

Diagnosis of mild platelet function disorders. Reliability and usefulness of light transmission platelet aggregation and serotonin secretion assays.

Light transmission platelet aggregation (PA), adapted to measure platelet secretion (PS), is the reference test for diagnosing platelet functional disorders (PFD). Problems with these assays include lack of standardisation, unknown reproducibility and lack of universally accepted diagnostic criteria. We addressed these issues in patients with inherited mucocutaneous bleeding (MCB). Normal and abnormal PA tests in 213 patients were reproducible in 93.3% and 90.4% of the cases, respectively. Mean intra-subject coefficient of variation for PA with strong agonists were <9% and mean intra-class correlation coefficient for weak agonists were >0.86 (P < 0.0001). Concomitant impaired PA with 10 micromol/l-adrenaline and 4 micromol/l-ADP was observed in 13.7% of the controls. This combination was not considered per se a criterion for PFD. PA with adrenaline > or = 42% or irreversible aggregation with 4 micromol/l ADP had 93% and 95% Negative Predictive Value for diagnosing PFD, respectively. PA defects were consistently associated with abnormal PS. In contrast, 14.3% of patients with MCB had isolated PS. Thus, standardized PA/PS assays are highly reproducible and concordant in normal and patient populations. Normal PA with adrenaline and low ADP concentration robustly predict a normal PA. Simultaneous PA/PS assays enable the diagnosis of isolated PS defects. This study confirmed that hereditary PA-PS defects are highly prevalent.

Health impact of Mediterranean diets in food at work.

OBJECTIVE: To evaluate the feasibility of diet mediterranisation, in a food-at-work context, and its consequence on metabolic syndrome in a mid-age unselected healthy male population group. DESIGN: One-year longitudinal intervention study. Physical exercise was not modified. SETTING: All workers of the Santiago division of 'Maestranza Diesel', a metal-mechanic company servicing the mining industry, were invited to participate. SUBJECTS: Initially, 145 workers of a total of 171, of average age 39 years, accepted to participate (sixteen women and 129 men). A subgroup of ninety-six men fully completed the controls programmed for the intervention study. Losses from the original group correspond to missing one control (sixteen), leaving the company (eleven) or blood sampling discomfort (six). The women and sixteen male workers, hired post study initiation, did participate but were excluded from this 12-month analysis. RESULTS: Diet mediterranisation was successful, reflected in the daily food consumption at the canteen and the evolution of the Mediterranean diet score (MDS) from 4.8 +/- 1.4 to 7.4 +/- 1.5 (limits 0-14). Some metabolic syndrome components showed statistically significant improvement and also statistically significant correlation with the MDS: waist circumference, HDL-cholesterol, systolic and diastolic blood pressure. After 12 months, the reversion rate for metabolic syndrome was 48 % (12/23) with an incidence rate of 4.1 % for new cases (3/73). In total, metabolic syndrome decreased from 24.0 % to 15.6 % (23/96 to 15/96) (P = 0.029). CONCLUSIONS: Diet mediterranisation is feasible in a food-at-work intervention, affecting lunch consumption at the workers canteen and overall consumption evaluated with MDS, together with a significant reduction in metabolic syndrome.

Lipoperoxidation and protein oxidative damage exhibit different kinetics during septic shock.

Septic shock (SS)-related multiorgan dysfunction has been associated with oxidative damage, but little is known about the temporal damage profile and its relationship to severity. The present work investigated prospectively 21 SS patients. Blood samples were obtained at diagnosis, 24, 72 hours, day 7, and at 3 months. At admission, thiobarbituric acid reactive substances (TBARSs), plasma protein carbonyls, plasma protein methionine sulfoxide (MS), ferric/reducing antioxidant power (FRAP), total red blood cell glutathione (RBCG), uric acid (UA), and bilirrubin levels were increased (P < .05). Total radical-trapping antioxidant potential (TRAP) and vitamin-E were similar to controls, and vitamin-C was decreased (P < .05). During evolution, TBARS and RBCG increased (P < .001), vitamin-E levels remained stable, whereas plasma protein carbonyls and MS, TRAP, vitamin-C, reduced glutathione, and UA levels decreased (P < .006). After 3 months, plasma protein carbonyls and MS persisted elevated. More severe patients exhibited higher TBARS, TRAP, FRAP, vitamin-C, UA, and bilirrubin levels. Our results suggest early and persistent oxidative stress during septic shock and a correlation between increasing levels of lipoperoxidation and sepsis severity.

Nox1-based NADPH oxidase-derived superoxide is required for VSMC activation by advanced glycation end-products.

Vascular diseases are important clinical complications of diabetes. Advanced glycation end-products (AGE) are mediators of vascular dysfunction, but their effects on vascular smooth muscle cell (VSMC) ROS production are unclear. We studied the source and downstream targets of AGE-mediated ROS and reactive nitrogen species production in these cells. Significant increases in superoxide production in AGE-treated VSMC were measured using lucigenin (7650+/-433 vs 4485+/-424 LU/10(6) cells, p<0.001) or coelenterazine (277,907+/-71,295 vs 120,456+/-4140 LU/10(6) cells, p<0.05) and confirmed by ESR spectroscopy. These signals were blocked by the flavin-containing oxidase inhibitor diphenylene iodonium (DPI). AGE-stimulated NF-kappaB activity was abolished by DPI and the superoxide scavenger MnTBAP. AGE differentially regulated VSMC NADPH oxidase catalytic subunits, stimulating the transcription of Nox1 (201+/-12.7%, p<0.0001), while having no effect on Nox4. AGE also increased 3-nitrotyrosine formation, which was inhibited by MnTBAP, DPI, or the NOS inhibitor L-NAME. Regarding the source of NO, AGE stimulated inducible nitric oxide synthase mRNA (1 vs 9.7+/-3.0, p=0.046), which was abolished by a NF-kappaB inhibitor, SOD, catalase, or siRNA against Nox1. This study establishes that AGE activate iNOS in VSMC through a ROS-sensitive, NF-kappaB-dependent mechanism involving ROS generation by a Nox1-based oxidase.

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.

Oxidative Stress in Acute Hypobaric Hypoxia.

Irarrázaval, Sebastián, Claudio Allard, Juan Campodónico, Druso Pérez, Pablo Strobel, Luis Vásquez, Inés Urquiaga, Guadalupe Echeverría, and Federico Leighton. Oxidative stress in acute hypobaric hypoxia. High Alt Med Biol. 18:128-134, 2017.-The effects of acute hypobaric hypoxia endured by mountaineers were studied, specifically as evidenced by acute mountain sickness (AMS) and oxidative stress damage. Ten male volunteers were exposed to acute hypobaric hypoxia, and AMS was evaluated through arterial oxygen saturation (SaO2), cardiac rate, and the Lake Louise Score (LLS). Oxidative stress was determined through blood profile tests performed 24 hours before and after high-altitude exposure, assessing the oxidative damage and antioxidant profiles. Dietary habits were assessed using the Chilean Mediterranean Diet Index. During ascent (i.e., first 8 hours), all volunteers presented AMS (LLS ≥3 points), as manifested by a median LLS increment of four points, a 15 bpm cardiac rate, and 17% decrease in SaO2. Additionally, plasma lipid oxidative damage increased after the expedition, as evaluated through malondialdehyde, which was directly correlated with the LLS (R2 = 0.720, p = 0.003) and inversely correlated with SaO2 (R2 = 0.436; p = 0.035) at a high altitude. Preascent carbonyl levels were inversely correlated to SaO2 (R2 = 0.490; p = 0.008) and directly correlated to cardiac rate (R2 = 0.225, p = 0.016) at a high altitude. Moreover, dietary habits were inversely correlated with increased carbonyls during the expedition (R2 = 0.436; p = 0.047). In conclusion, acute hypobaric hypoxia induced AMS and an increment in oxidative stress markers 24 hours after altitude exposure in the volunteers. Furthermore, oxidative stress damage was related to AMS severity. Finally, volunteers with closer adherence to a Mediterranean diet presented a lower increase in oxidative damage during ascent, reflecting the potential preventive role of diet against AMS.

Inverse Associations between a Locally Validated Mediterranean Diet Index, Overweight/Obesity, and Metabolic Syndrome in Chilean Adults.

Obesity and metabolic syndrome (MetS) are key risk factors for chronic disease. Dietary patterns are critical in the incidence and persistence of obesity and MetS, yet there is few data linking diet to obesity and MetS in Chile. Our objective was to use a locally validated diet index to evaluate adherence to a Mediterranean dietary pattern and its correlations with overweight/obesity (OW/O) and MetS prevalence in Chilean adults. We conducted a nationwide, cross-sectional online survey of Chilean adults with complete self-reported diet and body mass index data (n = 24,882). A subsample of 4348 users (17.5%) had valid MetS data. An inverse association was observed between adherence to Mediterranean diet and OW/O and MetS prevalence. As diet quality decreased from healthy, to moderately-healthy, to unhealthy, prevalence increased from 44.8, 51.1, to 60.9% for OW/O and from 13.4, 18.5, to 28.9% for MetS (p-values < 0.001). Adjusted odds ratios for OW/O and MetS were significantly higher in moderately-healthy (OR = 1.58 and 1.54) and unhealthy (OR = 2.20 and 2.49, respectively) diet groups in comparison to the healthy diet group. This study represents the first report on the relationship between Mediterranean diet and chronic disease risk in Chile. It suggests that the Mediterranean diet may be applied to manage chronic disease risk beyond the Mediterranean basin.

Myricetin, quercetin and catechin-gallate inhibit glucose uptake in isolated rat adipocytes.

The facilitative glucose transporter, GLUT4, mediates insulin-stimulated glucose uptake in adipocytes and muscles, and the participation of GLUT4 in the pathogenesis of various clinical conditions associated with obesity, visceral fat accumulation and insulin resistance has been proposed. Glucose uptake by some members of the GLUT family, mainly GLUT1, is inhibited by flavonoids, the natural polyphenols present in fruits, vegetables and wine. Therefore it is of interest to establish if these polyphenolic compounds present in the diet, known to be effective antioxidants but also endowed with several other biological activities such as protein-tyrosine kinase inhibition, interfere with GLUT4 function. In the present study, we show that three flavonoids, quercetin, myricetin and catechin-gallate, inhibit the uptake of methylglucose by adipocytes over the concentration range of 10-100 microM. These three flavonoids show a competitive pattern of inhibition, with K(i)=16, 33.5 and 90 microM respectively. In contrast, neither catechin nor gallic acid inhibit methylglucose uptake. To obtain a better understanding of the interaction among GLUT4 and flavonoids, we have derived a GLUT4 three-dimensional molecular comparative model, using structural co-ordinates from a GLUT3 comparative model and a mechanosensitive ion channel [PDB (Protein Data Bank) code 1MSL] solved by X-ray diffraction. On the whole, the experimental evidence and computer simulation data favour a transport inhibition mechanism in which flavonoids and GLUT4 interact directly, rather than by a mechanism related to protein-tyrosine kinase and insulin signalling inhibition. Furthermore, the results suggest that GLUT transporters are involved in flavonoid incorporation into cells.

Antioxidant and pro-oxidant effects of red wine and its fractions on Cu(II) induced LDL oxidation evaluated by absorbance and chemiluminescence measurements.

Cu(II) mediated low density lipoprotein (LDL) oxidation has been followed by the changes in absorbance at 234 nm and the emitted low level chemiluminescence (CL). The similarity of the time profiles allows us to conclude that the emitted CL is due to the decomposition of a transient product, most likely a hydroperoxide. Red wine, as well as its fractions, afford a noticeable protection when added prior to the start of the LDL oxidation process. On the other hand, when they are added after the onset of the autocatalytic oxidation phase, red wine and its fractions behave as pro-oxidants. This is particularly evidenced by a strong burst of CL (enhancement of the light by a factor approximately 20). This burst is reduced by metal chelators (EDTA and DFO) and can be associated to a sequence of reactions such as XOH + Cu(II) --> X* + H(+) + Cu(I), Cu(I) + LOOH --> chemiluminescence where XOH is a phenolic compound and LOOH is a peroxide-like compound produced in the LDL oxidation.

Red wine reduces oxidative stress in patients with acute coronary syndrome.

BACKGROUND: Moderate red wine consumption improved endothelial function in normal volunteers. Herein we explored the effects of moderate red wine consumption in endothelial function and in oxidative stress in patients with an acute coronary syndrome. METHODS: 20 patients treated with percutaneous coronary interventions after an acute coronary syndrome were randomized to a red-wine group (n=9, 250 ml daily, Cabernet Sauvignon) or to a control group (n=11, abstinence from alcoholic beverages). Studies were performed at baseline and after 2 months. Endothelial function was estimated by flow-mediated vasodilatation of the brachial artery. Plasma antioxidant capacity was measured by total antioxidant reactivity and ferric reducing antioxidant power. Oxidative damage was evaluated by measurements of 8-OH deoxyguanosine content in leukocyte deoxyribonucleic acid. RESULTS: The endothelium dependent/independent dilatation ratio significantly improved compared to baseline in both groups. The 8-OH deoxyguanosine content decreased significantly in both groups; this effect was more pronounced with wine (p<0.002 vs. control). Oxidative deoxyribonucleic acid damage in controls decreased from 13.1+/-1.1 to 10.0+/-1.0 (p<0.003); with wine from 13+/-0.8 to 5.6+/-0.7 per 10(5) guanosines (p<0.001; p<0.002 vs. control). Total antioxidant reactivity increased from 240+/-18 to 268+/-18 microM in the control group and from 273+/-20 to 330+/-15 microM in the wine group (p<0.03 vs. control). Ferric reducing antioxidant power increased from 1106+/-60 to 1235+/-42 microM in the control group and from 1219+/-82 to 1450+/-63 microM in the wine group (p<0.001 vs. control). CONCLUSIONS: The addition of moderate amounts of red wine did not improve endothelial function beyond conventional therapy, whereas it showed benefits in parameters of oxidative stress in these patients.

Serum Ferritin Is Associated with Metabolic Syndrome and Red Meat Consumption.

BACKGROUND AND AIMS: Hyperferritinemia has been related with a wide spectrum of pathologies, including diabetes, cardiovascular disease, neurodegenerative disorders, and metabolic syndrome. The aim of this study was to investigate the association between hyperferritinemia and iron consumption. METHODS AND RESULTS: Serum ferritin concentration was evaluated in 66 presumed healthy men, along with other clinical and biochemical markers of chronic diseases. A three-day food questionnaire was applied for nutrition information. Hyperferritinemia was a condition found in 13.4% of the volunteers analyzed. Significant correlations were found between serum ferritin concentration and metabolic syndrome parameters (HDL cholesterol, triglycerides, and fasting glucose) as well as an increase of the serum ferritin mean value with the number of risk factors of metabolic syndrome. Also, oxidative stress markers (carbonyl groups, AOPP, and glycated hemoglobin), hepatic damage markers (GGT, SGOT), and parameters related to insulin resistance (HOMA, blood insulin, and blood glucose) correlate significantly with serum ferritin. Volunteers had an excessive iron intake, principally by bread consumption. Analyses of food intake showed that red meat consumption correlates significantly with serum ferritin. CONCLUSION: Red meat consumption, metabolic syndrome, and chronic disease markers are associated with hyperferritinemia in a population of Chilean men.

Cytochemical and biochemical demonstration of an ATPase in membranes of human peroxisomes.

We demonstrated a neutral Mg-ATPase activity in human peroxisomal membranes. To establish the precise experimental conditions for detection of this ATPase, both cytochemical and biochemical characterizations were first carried out in liver peroxisomes from control and cipofibrate-treated rats. The results demonstrated an Mg-ATPase reaction in both normal and proliferated peroxisomes. The nucleotidase activity, with marked preference for ATP, was sensitive to the inhibitors N-ethylmaleimide and 7-chloro-4-nitro-benzo-2-oxadiazole (NBDCl). An ultrastructural cytochemical analysis was developed to evaluate the peroxisomal localization, which localized the reaction product to the peroxisomal membrane. These characteristics can help to differentiate the peroxisomal ATPase from the activity found in mitochondria and endoplasmic reticulum. The conditions established for detecting the rat peroxisomal ATPase were then applied to human peroxisomes isolated from liver and skin fibroblasts in culture. A similar Mg-ATPase activity was readily shown, both cytochemically and biochemically, in the membranes of human peroxisomes. These results, together with previous evidence, strongly support the presence of a specific ATPase in the human peroxisomal membrane. This ATPase may play a crucial role in peroxisome biogenesis.

Wine, diet, antioxidant defenses, and oxidative damage.

Oxidative stress is a central mechanism for the pathogenesis of ischemic heart disease and atherogenesis, for cancer and other chronic diseases in general, and it also plays a major role in the aging process. Dietary antioxidants constitute a large group of compounds that differ in mechanism of action, bioavailability and side effects. A systematic analysis of the role of the various antioxidants in chronic diseases is hampered by the difficulty of employing death or clinical events as end points in intervention studies. Therefore, valid markers for oxidative stress, which show dose response and are sensitive to changes in dietary supply of antioxidants, are potentially of great value when trying to establish healthy dietary patterns, or when one component, like red wine, is evaluated specifically. To evaluate potential oxidative stress markers we have studied the effect of different diets plus wine supplementation on antioxidant defenses and oxidative damage. In three experimental series, four groups of young male university students, one of older men and other of older women, 20-24 volunteers each, received Mediterranean or occidental (high-fat) diets alone or supplemented with red wine, white wine, or fruits and vegetables. Measurements included, leukocyte DNA 8-OH-deoxyguanosine (8OHdG), plasma 7 beta-hydroxycholesterol, TBARS and well-characterized antioxidants, and plasma and urine polyphenol antioxidants. In all experimental groups that received red wine, consumption resulted in marked decrease in 8OHdG. The changes observed in 8OHdG correlate positively with the other markers of oxidative damage, and shows a clear inverse correlation with the plasma level of well established antioxidants and with measurements of total antioxidant capacity. Urinary total polyphenol content as well as the sum of some specific plasma species also correlate inversely with 8OHdG. In conclusion, the results identify 8OHdG as a very promising general marker of oxidative stress in nutrition intervention studies in humans, and red wine shows a remarkable protective effect.

Cytoprotection by neutral fraction of tannat red wine against oxidative stress-induced cell death.

Some of the beneficial effects of the Mediterranean diet on human pathologies have been attributed to red wine polyphenols. It has been postulated that the antioxidant activity of the latter would be also responsible for the cytoprotective capacity of red wine that has been reported in a few papers. Nevertheless, red wine shows a complex composition, and the active fraction is not known yet. In this context, the protective capacity of total lyophilized extracts of red wine and anthocyanin, neutral, or acidic fractions, was explored in PC12 cells in culture after a hydrogen peroxide insult. Although all fractions showed high antioxidant activity, only the neutral fraction was cytoprotective. The analysis of this active fraction showed that it was rich in the aglycons quercetin and myricetin as well as the glycosides of kaempferol, isorhamnetin, epicatechin, and catechin, some of which are known to be cytoprotective. This is the first paper to reveal the active fraction of total wine responsible of its cytoprotection.

Juice and phenolic fractions of the berry Aristotelia chilensis inhibit LDL oxidation in vitro and protect human endothelial cells against oxidative stress.

Oxidative modification of low-density lipoprotein (LDL) particles is a key event in the development of atherosclerosis. Oxidized LDL induces oxidative stress and modifies gene expression in endothelial cells. Berries constitute a rich dietary source of phenolic antioxidants. We found that the endemic Chilean berry Aristotelia chilensis (ach) has higher phenol content and scores better for total radical-trapping potential and total antioxidant reactivity in in vitro antioxidant capacity tests, when compared to different commercial berries. The juice of ach is also effective in inhibiting copper-induced LDL oxidation. In human endothelial cell cultures, the addition of ach juice significantly protects from hydrogen peroxide-induced intracellular oxidative stress and is dose-dependent. The aqueous, anthocyanin-rich fraction of ach juice accounts for most of ach's antioxidant properties. These results show that ach is a rich source of phenolics with high antioxidant capacity and suggest that it may have antiatherogenic properties.