Scielo RSS <![CDATA[Biological Research]]> vol. 37 num. 2 lang. en <![CDATA[SciELO Logo]]> <![CDATA[<b>Alcohol and Mortality from All Causes </b>]]> A large number of prospective studies have observed an inverse relationship between a moderate intake of alcohol and coronary heart disease morbidity and mortality. Concerning death from all-causes, results are not unanimous. Alcohol intake was associated with a protection of all-cause mortality in England and USA physicians and the large study of the American Cancer Society. None of these studies separated the effects of different alcoholic beverages. In our prospective studies in France on 35 000 middle-aged men, we observed that only wine at moderate intake, was associated with a protective effect on all-cause mortality. The reason was that in addition to the known effect on cardiovascular diseases, a very moderate intake of wine, protected also from cancer and other causes as confirmed by Gronbaek in Denmark. Our recent results also indicate that the protective effect of a moderate intake of wine on all-cause mortality is observed at all levels of blood pressure and serum cholesterol. <![CDATA[<b>Risk of Dementia and Alcohol and Wine Consumption</b>: <b>a Review of Recent Results</b>]]> The term dementia refers to a clinical syndrome of acquired intellectual disturbances produced by brain dysfunction. Dementia may result from a wide variety of disorders, including degenerative (e.g. Alzheimer's disease, AD), vascular (e.g. multi-infarct dementia), and traumatic (e.g. head injury). Long-term abuse of alcohol is related to the development of the Wernicke-Korsakoff's syndrome or alcohol dementia. However, light to moderate alcohol intake might also reduce the risk of dementia and AD. In Bordeaux (France), a population-based prospective study found that subjects drinking 3 to 4 standard glasses of wine per day (> 250 and up to 500 ml), categorized as moderate drinkers, the crude odds ratio (OR) was 0.18 for incident dementia (p < 0.01) and 0.25 for Alzheimer's disease (p < 0.03), as compared to the non-drinkers. After adjusting for age, sex, education, occupation, baseline cognitive performances and other possible confounders, the ORs were respectively 0.19 (p < 0.01) and 0.28 (p < 0.05). In the 922 mild drinkers (< 1 to 2 glasses per day) there was a negative association only with AD, after adjustment (OR = 0.55; p < 0.05). The inverse relationship between moderate wine drinking and incident dementia was explained neither by known predictors of dementia nor by medical, psychological or socio-familial factors. These results were confirmed from data of the Rotterdam study. Light-to-moderate drinking (one to three drinks per day) was significantly associated with a lower risk of any dementia (hazard ratio 0.58 [95 % CI 0.38-0.90]) and vascular dementia (hazard ratio 0.29 [0.09-0.93]). No evidence that the relation between alcohol and dementia varied by type of alcoholic beverage was found. Stroke constitutes one of the most common causes of serious functional impairment in developed countries. Ischaemic strokes represent about 80% of all strokes. Several studies have been published and the overall conclusion is that heavy drinking is a risk factor for most stroke subtypes. Regular light to moderate drinking seemed to be associated with a decreased risk for ischaemic stroke. <![CDATA[<b>Intake of Beer, Wine and Spirits and Risk of Heavy Drinking and Alcoholic Cirrhosis</b>]]> Studies have suggested that wine drinkers are at lower risk of death than beer or spirit drinkers. The aim of this study is to examine whether the risk of becoming a heavy drinker or developing alcoholic cirrhosis differs among individuals who prefer different types of alcoholic beverages. In a longitudinal setting we found that both the risk of becoming a heavy or excessive drinker (above 14 and 21 drinks per week for women and above 21 and 35 drinks per week for men) and the risk of developing alcoholic cirrhosis depended on the individuals preference of wine, beer or spirits. We conclude that moderate wine drinkers appear to be at lower risk of becoming heavy and excessive drinkers and that this may add to the explanation of the reported beverage-specific differences in morbidity and mortality. <![CDATA[<b>Moderation in Australia-Policy and Achievements</b>]]> Alcohol has been consumed in Australia since European settlement in 1788. In 1998, approximately 60 % of Australians consumed an alcoholic beverage at least once per week. The effects of alcohol on the human body are dose dependent, where the harmful effects of alcohol are generally observed only when alcohol consumption exceeds moderate consumption levels of 30 to 40 g of alcohol per day. The discovery that a J-shaped curve described the relationship between level of alcohol consumption and risk of cardiovascular disease was, however, only made in 1990_cardiovascular disease is the leading cause of death in the western world. Thus prior to 1990, Australian public health policy focused primarily on the harmful effects of alcohol consumption and the health benefits of a moderate level of alcohol consumption have only recently been recognized in public policy. This paper chronicles changes in Australian Federal government policy on alcohol since the initial draft National health policy on alcohol in Australia was presented to the Ministerial Council on Drug Strategy in 1987 to the National Drug Strategic plan for action 2001 to 2003-2004 which was launched in July last year <![CDATA[<b>Alcohol, Wine and Platelet Function</b>]]> Epidemiological studies have demonstrated an inverse correlation between moderate wine and alcohol consumption and morbidity and mortality from coronary heart disease. The protective effect has been associated with an increase in the plasma level of HDL cholesterol, as it is well recognized that plasma HDL is inversely correlated with CHD. In addition, it has become evident that blood platelets contribute to the rate of development of atherosclerosis and CHD through several mechanisms. In recent studies it has been shown that the level of HDL cholesterol can explain only 50 % of the protective effect of alcoholic beverages; the other 50 % may be partly related to a decrease in platelet activity. This anti-platelet activity of wine is explained by ethanol but also by the polyphenolic components with which red wines are richly endowed. Several studies carried out on humans and animals have shown that wine phenolics could exert their effects by reducing prostanoid synthesis from arachidonate. In addition, it has been suggested that wine phenolics could reduce platelet activity mediated by nitric oxide. Moreover, wine phenolics increase vitamin E levels while decreasing the oxidation of platelets submitted to oxidative stress. However, a rebound phenomenon of hyperaggregability is observed after an acute alcohol consumption which is not observed with wine consumption. This protection afforded by wine has been duplicated in animals with grape phenolics added to alcohol. The rebound phenomenon may explain ischemic strokes or sudden deaths known to occur after episodes of drunkenness. It appears that wine, and wine phenolics in particular, could have a more significant inhibitory effect on platelet aggregation and could explain, in part, the hypothesis that red wine is more protective against atherosclerosis and coronary heart disease. <![CDATA[<b>Distinctive Effects of Red Wine and Diet on Haemostatic Cardiovascular Risk Factors</b>]]> The aim of this study was to compare the effects of Mediterranean-type diet (MD), high-fat diet (HFD), and red wine supplementation on plasma concentration of emergent haemostatic cardiovascular risk factors (HCVRF) and on variables of primary haemostasis (bleeding time, plasma von Willebrand factor and platelet aggregation/secretion). In a controlled prospective intervention study, two groups (21 healthy males each) received either MD or HFD during 90 days. Between days 30-60, both diets were supplemented with 240 ml/day of red wine. After adjusting by baseline values, MD was associated with: lower plasma fibrinogen (p =0.03), factor VIIc (p=0.034) and factor VIIIc (p=0.0057); higher levels of protein S (p=0.013); longer bleeding time (p=0.017); and marginal increases in platelet serotonin aggregation and secretion after stimulation with epinephrine. Red wine supplementation, in both diets, resulted in decreased plasma fibrinogen (p=0.001) and factor VIIc (p=0.05), and in increased t-PA (p=0.01) and PAI-1 (p=0.0003). The effects of wine on antithrombin III (p=0.01) were divergent: there was a decrease in the HFD group but it increased slightly in the MD group. No effects of diet or wine were detected in plasma protein C, C-reactive protein or von Willebrand factor. BT did not change significantly with wine supplementation. Wine intake resulted in a significant increase in ex vivo platelet aggregation and secretion after stimulation with collagen (1 and 2 µg/ml, p 0.01). MD and moderate consumption of red wine have complementary, mostly beneficial effects on haemostatic CV risk factors. The longer BT in individuals on MD, obtained independently of red wine, denotes less interaction of platelets with the vascular wall, which could be beneficial from the point of view of CV risk <![CDATA[<B>Diet and Endothelial Function</B>]]> Endothelial dysfunction is one of the earliest events in atherogenesis. A consequence of endothelial damage is a lower availability of nitric oxide (NO), the most potent endogenous vasodilator. NO inhibits platelet aggregation, smooth muscle cell proliferation and adhesion of monocytes to endothelial cells. Endothelial dysfunction is present in patients with cardiovascular disease and/or coronary risk factors, such as hypertension, dyslipidemia, diabetes, smoking or hyperhomocysteinemia. At present, soluble markers and high resolution ultrasound of the brachial artery, have provided simple tools for the study of endothelial function and the effects of several interventions. It has been demonstrated that dietary factors may induce significant changes on vascular reactivity. Nutrients, such as fish oil, antioxidants, L-arginine, folic acid and soy protein have shown an improvement in endothelial function that can mediate, at least partially, the cardioprotective effects of these substances. Attention has been focused on dietary patterns in populations with lower prevalence of cardiovascular disease. There is some evidence suggesting that Mediterranean diet characterized by high consumption of vegetables, fish, olive oil and moderate wine consumption may have a positive effect on endothelial function. These results give us evidence on the significant role of diet on endothelial function and its impact on the pathogenesis of atherosclerosis <![CDATA[<B>Inhibitory Effects of Red Wine Extracts on Endothelial-Dependent Adhesive Interactions with Monocytes Induced by Oxysterols</B>]]> Red wine polyphenolic compounds have been demonstrated to possess antioxidant properties, and several studies have suggested that they might constitute a relevant dietary factor in the protection from coronary heart disease. The aim of the present study is to examine whether red wine extracts (RWE) can ameliorate oxysterol-induced endothelial response, and whether inhibition of adhesion molecule expression is involved in monocyte adhesion to endothelial cells. Surface expression and mRNA levels of adhesion molecules (intercellular adhesion molecule 1 and vascular cell adhesion molecule 1) were determined by ELISA and RT-PCR performed on human aortic endothelial cells (HAEC) monolayers stimulated with 7b-hydroxycholesterol or 25-hydroxycholesterol. Incubation of HAEC with oxysterols (10 muM) increased expression of adhesion molecules in a time-dependent manner. Pretreatment of HAEC with RWE at final concentrations of 1, 10, and 100 ng/ml significantly inhibited the increase of surface protein expression and mRNA levels. Adherence of monocytes to oxysterol-stimulated HAEC was increased compared to that of unstimulated cells. Treatment of HAEC with RWE significantly inhibited adherence of monocytes. These results suggest that RWE works as an anti-atherogenic agent through the inhibition of endothelial-dependent adhesive interactions with monocytes induced by oxysterols <![CDATA[<b>Red Wine administration to Apolipoprotein E-deficient Mice reduces their Macrophage-derived Extracellular Matrix Atherogenic Properties </b>]]> Proteoglycans (PGs) from the arterial extracellular matrix (ECM) contribute to the trapping of LDL and oxidized LDL (Ox-LDL) in the arterial wall, a phenomenon called "lipoprotein retention". Moreover, we have shown that subsequent to their binding to the matrix, LDL and Ox-LDL are taken up by macrophages. Oxidative stress significantly increases macrophage secretion of ECM-PGs, lipoprotein binding to the ECM and the uptake of ECM-retained lipoproteins by macrophages. The aim of the present study was to determine whether red wine administration to atherosclerotic mice would affect their peritoneal macrophage-derived extracellular matrix properties, such as the glycosaminoglycan content and the ability to bind LDL. In addition, we questioned the ability of LDL bound to the mice peritoneal macrophages-derived ECM to be taken up by macrophages. Red wine administration to atherosclerotic mice did not affect the mice peritoneal macrophages-derived ECM glycosaminoglycan content but it significantly reduced the mice peritoneal macrophages-derived ECM ability to bind LDL and the subsequent uptake of ECM-retained LDL by the macrophages. The present study thus clearly demonstrated the inhibitory effect of red wine consumption by E0 mice on their peritoneal macrophage-derived extracellular matrix atherogenic properties. <![CDATA[<b>Interaction of Olive Oil Phenol Antioxidant Components with Low-density Lipoprotein </b>]]> Phenolic compounds have shown to inhibit LDL oxidation in vitro and ex vivo; however, they are hydrosoluble compounds while LDL is a lipoprotein. Analysis of phenolic compounds in LDLs by HPLC is necessary to demonstrate their binding capacity to lipoproteins. We developed and validated a solid phase extraction method (SPE) that allowed us the purification of LDL samples and their analysis by HPLC. This methodology allowed us to demonstrate the in vitro binding capacity of tyrosol, one of the main phenolic compounds in olive oil, to LDL. In the intervention dietary study with volunteers, food rich in phenolic compounds affected LDL composition. Changes in LDL phenolics composition are not observed after the short-term ingestion of food rich in phenolic compounds. However, after one week of olive oil consumption and Mediterranean diet there was an increase in phenolics (p=0.021). An accumulative effect seems necessary to observe significative differences in LDL phenolic composition. <![CDATA[<b>Effect of Mediterranean and Occidental Diets, and Red Wine, on Plasma Fatty Acids in Humans</b>: <b>An Intervention Study</b>]]> The type of diet consumed by individuals has been associated with the development of some chronic diseases, including cardiovascular disease (CVD), cancer, diabetes, and others. Populations that consume diets rich in fruits and vegetables and drink wine in moderation, as the Mediterranean, have a higher life expectancy and less chronic diseases than other occidental populations. We carried out an intervention study in humans to evaluate the effect of a Mediterranean diet (MD), an Occidental diet (OD) and their supplementation with red wine, on biochemical, physiological and clinical parameters related to atherosclerosis and other chronic diseases. For 3 months, two groups of 21 male volunteers each, received either a MD or an OD; during the second month, red wine was added isocalorically, 240 ml/day. At days 0, 30, 60 and 90, clinical, physiological and biochemical evaluations were made. In this article we report on the results obtained in plasma fatty acids profile that includes saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), w-6 fatty acids, w-3 fatty acids and w-6/w-3 ratio. Other results have been published previously. Plasma fatty acid percentages in the OD group, compared to the MD group, did not show differences in SFA, but the OD group showed lower levels of MUFA and w-3 fatty acids, and higher levels of PUFA and w-6 fatty acids, with a higher w-6/w-3 ratio than the MD group. Wine supplementation reduced MUFA and increased PUFA in both dietary groups, suggesting that wine could improve a diet with a good w-6/w-3 ratio. Volunteers on MD showed a better fatty acid profile than those on OD, suggesting a lower cardiovascular risk. Moderate consumption of wine improves this profile in the MD group. <![CDATA[<b>Omega-3 Fatty Acids and Antioxidants in Edible Wild Plants </b>]]> Human beings evolved on a diet that was balanced in the omega-6 and omega-3 polyunsaturated fatty acids (PUFA), and was high in antioxidants. Edible wild plants provide alpha-linolenic acid (ALA) and higher amounts of vitamin E and vitamin C than cultivated plants. In addition to the antioxidant vitamins, edible wild plants are rich in phenols and other compounds that increase their antioxidant capacity. It is therefore important to systematically analyze the total antioxidant capacity of wild plants and promote their commercialization in both developed and developing countries. The diets of Western countries have contained increasingly larger amounts of linoleic acid (LA), which has been promoted for its cholesterol-lowering effect. It is now recognized that dietary LA favors oxidative modification of low density lipoprotein (LDL) cholesterol and increases platelet response to aggregation. In contrast, ALA intake is associated with inhibitory effects on the clotting activity of platelets, on their response to thrombin, and on the regulation of arachidonic acid (AA) metabolism. In clinical studies, ALA contributed to lowering of blood pressure, and a prospective epidemiological study showed that ALA is inversely related to the risk of coronary heart disease in men. Dietary amounts of LA as well as the ratio of LA to ALA appear to be important for the metabolism of ALA to longer-chain omega-3 PUFAs. Relatively large reserves of LA in body fat, as are found in vegans or in the diet of omnivores in Western societies, would tend to slow down the formation of long-chain omega-3 fatty acids from ALA. Therefore, the role of ALA in human nutrition becomes important in terms of long-term dietary intake. One advantage of the consumption of ALA over omega-3 fatty acids from fish is that the problem of insufficient vitamin E intake does not exist with high intake of ALA from plant sources. <![CDATA[<b>Polyphenols and Red Wine as Antioxidants against Peroxynitrite and other Oxidants </b>]]> The antioxidant capacity of polyphenols (+)-catechin, (-)-epicatechin and myricetin, and of different types of red wines (Cabernet Sauvignon, Malbec and blended wine) was evaluated by three assays. (a) NADH oxidation by peroxynitrite (ONOO-): the ONOO- scavenging activity was higher for myricetin (IC50=35 µM) than for (+)-catechin (IC50=275 µM) and (-)-epicatechin (IC50=313 µM). (b) Peroxynitrite initiated chemiluminescence in rat liver homogenate: (-)-epicatechin (IC50=7.0 µM) and (+)-catechin (IC50=13 µM) were more potent than myricetin (IC50=20 µM) in inhibiting the chemiluminescence signal. (c) Lucigenin chemiluminescence in aortic rings: (-)-epicatechin (IC50=15 µM) and (+)-catechin (IC50=18 µM) showed higher antioxidant capacity than myricetin (IC50=32 µM). All the assayed red wines were able to scavenge the oxidants and free radical species that generate the signal in each assay. Cabernet Sauvignon was the red wine with the highest antioxidant capacity in comparison with Malbec and blended wine. It is concluded that the use of sensitive biological systems (as the aortic ring chemiluminescence) provides important information in addition to the results from chemical (NADH oxidation by peroxynitrite) and biochemical (homogenate chemiluminescence) assays and offers advances in the physiological role of polyphenols <![CDATA[<B>A Pyranine based Procedure for Evaluation of the Total Antioxidant Potential (TRAP) of Polyphenols</B>: <B>A Comparison with closely related Methodologies</B>]]> A novel procedure for the evaluation of total reactive antioxidant potentials (TRAP) is described. The method is based on the measurement of the bleaching of pyranine by peroxyl radicals. The addition of the antioxidants produces a clear induction time whose magnitude is directly related to the antioxidant concentration. A comparison of the values obtained with those reported employing closely related methodologies shows that the results are significantly affected by the substrate employed to monitor the steady state free radical concentration. Possible sources of this dependence are discussed <![CDATA[<B>Membrane effects of Cocoa Procyanidins in Liposomes and Jurkat T Cells</B>]]> We investigated the effects of the interaction between flavanols and related procyanidins (dimer to hexamer) with both cell and synthetic membranes, on bilayer fluidity and susceptibility to oxidation. Cocoa derived dimers (0.05 to 1 µg/ml) protected Jurkat T cells from AMVN-mediated oxidation and increased plasma membrane fluidity. These effects occurred in a concentration- and chain length-dependent manner. In liposomes, procyanidins prevented the Fe2+-induced permeabilization of the membrane. Together, these results support the hypothesis that procyanidins could interact with the polar headgroup of lipids, increasing membrane fluidity and also, preventing the access of molecules that could affect membrane integrity <![CDATA[<B>Antioxidant Mechanisms of Polyphenolic Caffeic Acid Oligomers, Constituents of <I>Salvia officinalis</B></I>]]> Caffeic acid, rosmarinic acid and oligomers of caffeic acid with multiple catechol groups are all constituents of Salvia officinalis. Their antioxidant potential was investigated with regard to their radical scavenging activity and the stability and structure of the intermediate radicals. Pulse-radiolytic studies revealed very high rate constants with hydroxyl radicals. Evidence from kinetic modeling calculations suggested an unusual complex behavior due to the presence of both O4- and O3-semiquinones and formation and decay of a hydroxyl radical adduct at the vinyl side chain. The radical structures observed by EPR spectroscopy after autoxidation in slightly alkaline solutions were only partially identified due to their instability and generally represented dissociated O4-semiquinones. Hybrid density-functional calculations of the potential radical structures showed distinct differences between the resonance stabilization of the O4- and O3-semiquinones of caffeic and dihydrocaffeic acids, reflected also in the considerably faster decay of the O3-semiquinone observed by pulse radiolysis. No evidence was found for dimerization reactions via Cb radicals typical for lignin biosynthesis <![CDATA[<B>Is the Chilean Diet a Mediterranean-type Diet?</B>]]> Food intake in Chile has changed markedly in the last decades, showing an increase in fat consumption and presently a small fruit and vegetables intake. A parallel is made between the Chilean and Mediterranean diet (mainly the one from Spain, Italy, and Greece), both currently and from 50 years ago. The main differences and similarities are based on food availability. Although Chilean diet seems to be approaching the traditional Mediterranean diet of the 60's, there is concern about changes that are moving away from Chilean traditional diet and towards a western one. A new food pyramid for Chile is proposed based on the traditional Mediterranean-type diet <![CDATA[<B>ABSTRACTS OF THE SPEAKERS' PRESENTATIONS</B>]]> Food intake in Chile has changed markedly in the last decades, showing an increase in fat consumption and presently a small fruit and vegetables intake. A parallel is made between the Chilean and Mediterranean diet (mainly the one from Spain, Italy, and Greece), both currently and from 50 years ago. The main differences and similarities are based on food availability. Although Chilean diet seems to be approaching the traditional Mediterranean diet of the 60's, there is concern about changes that are moving away from Chilean traditional diet and towards a western one. A new food pyramid for Chile is proposed based on the traditional Mediterranean-type diet <![CDATA[<B>ABSTRACTS OF THE POSTER PRESENTANTIONS </B>]]> Food intake in Chile has changed markedly in the last decades, showing an increase in fat consumption and presently a small fruit and vegetables intake. A parallel is made between the Chilean and Mediterranean diet (mainly the one from Spain, Italy, and Greece), both currently and from 50 years ago. The main differences and similarities are based on food availability. Although Chilean diet seems to be approaching the traditional Mediterranean diet of the 60's, there is concern about changes that are moving away from Chilean traditional diet and towards a western one. A new food pyramid for Chile is proposed based on the traditional Mediterranean-type diet