214,432 research outputs found

    Antioxidant Supplementation in the Treatment of Aging-Associated Diseases

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    Oxidative stress is generally considered as the consequence of an imbalance between pro- and antioxidants species, which often results into indiscriminate and global damage at the organismal level. Elderly people are more susceptible to oxidative stress and this depends, almost in part, from a decreased performance of their endogenous antioxidant system. As many studies reported an inverse correlation between systemic levels of antioxidants and several diseases, primarily cardiovascular diseases, but also diabetes and neurological disorders, antioxidant supplementation has been foreseen as an effective preventive and therapeutic intervention for aging-associated pathologies. However, the expectations of this therapeutic approach have often been partially disappointed by clinical trials. The interplay of both endogenous and exogenous antioxidants with the systemic redox system is very complex and represents an issue that is still under debate. In this review a selection of recent clinical studies concerning antioxidants supplementation and the evaluation of their influence in aging-related diseases is analyzed. The controversial outcomes of antioxidants supplementation therapies, which might partially depend from an underestimation of the patient specific metabolic demand and genetic background, are presented

    Antioxidants of natural plant origins: from sources to food industry applications

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    ReviewIn recent years, great interest has been focused on using natural antioxidants in food products, due to studies indicating possible adverse effects that may be related to the consumption of synthetic antioxidants. A variety of plant materials are known to be natural sources of antioxidants, such as herbs, spices, seeds, fruits and vegetables. The interest in these natural components is not only due to their biological value, but also to their economic impact, as most of them may be extracted from food by-products and under-exploited plant species. This article provides an overview of current knowledge on natural antioxidants: their sources, extraction methods and stabilization processes. In addition, recent studies on their applications in the food industry are also addressed; namely, as preservatives in different food products and in active films for packaging purposes and edible coatingsinfo:eu-repo/semantics/publishedVersio

    Plasma antioxidants from chocolate

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    There is some speculation that dietary flavonoids from chocolate, in particular (-)epicatechin, may promote cardiovascular health as a result of direct antioxidant effects or through antithrombotic mechanisms. Here we show that consumption of plain, dark chocolate results in an increase in both the total antioxidant capacity and the (-)epicatechin content of blood plasma, but that these effects are markedly reduced when the chocolate is consumed with milk or if milk is incorporated as milk chocolate. Our findings indicate that milk may interfere with the absorption of antioxidants from chocolate in vivo and may therefore negate the potential health benefits that can be derived from eating moderate amounts of dark chocolate

    Electrochemical Study of Antioxidant Regeneration Mechanisms – Application in Dermocosmetics.

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    Oxidative stress is associated to the massive generation of reactive oxygen species inducing fast oxidative reactions in chain. To overcome this problem, reasonable supplementations of antioxidants are widely practiced, mostly based on empirical protocols. An electrochemical process is proposed to choose the best molecules association inducing the greatest antioxidant capacity, by coupling homogeneous or heterogeneous catalytic reactions involving antioxidants with an electrochemical step. Cyclic voltammetry and constant potential electrolysis experiments were used to highlight regeneration reactions induced by specific associations of hydrophilic and lipophilic antioxidants in homogeneous medium or at liquid/liquid interface. Results showed that N-Acetyl-L-Cysteine (NAC) was effectively regenerated by both ascorbic acid (AA) and ascorbyl glucoside (AA-2G) but not by ascorbyl phosphate magnesium (AA-2P). The antioxidant properties of alpha-tocopherol also increased to 40% when associated with AA. The process was successfully applied for the first time to the study of simple emulsions. Formulations involving NAC and AA-2G presented the highest synergic effect, the antioxidant capacity being amplified by more than 35%. On the other hand no catalytic mechanism was observed when introducing three antioxidants in the cream because it induced too low reaction kinetics. This electrochemical process can thus be exploited as a tool for the optimisation of “anti-aging” dermocosmetic formulations

    Protective activity of aromatic amines and imines against oxidative nerve cell death

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    Oxidative stress is a widespread phenomenon in the pathology of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Neuronal cell death due to oxidative stress may causally contribute to the pathogeneses of these diseases. Therefore, neuroprotective antioxidants are considered to be a promising approach to slow down disease progression. We have investigated different aromatic amine and imine compounds for neuroprotective antioxidant functions in cell culture, and found that these compounds possess excellent cytoprotective potential in diverse paradigms of oxidative neuronal cell death, including clonal cell lines, primary cerebellar neurons, and organotypic hippocampal slice cultures. Aromatic amines and imines are effective against oxidative glutamate toxicity, glutathione depletion, and hydrogen peroxide toxicity. Their mode of action as direct antioxidants; was experimentally confirmed by electron spin resonance spectroscopy, cell-free brain lipid peroxidation assays, and intracellular peroxide measurements. With half-maximal effective concentrations of 20-75 nm in different neuroprotection experiments, the aromatic imines phenothiazine, phenoxazine, and iminostilbene proved to be about two orders of magnitude more effective than common phenolic antioxidants. This remarkable efficacy could be directly correlated to calculated properties of the compounds by means of a novel, quantitative structure-activity relationship model. We conclude that bridged bisarylimines with a single free NH-bond, such as iminostilbene, are superior neuroprotective antioxidants, and may be promising lead structures for rational drug development

    Determination of the Chemical Composition of Grape Seed Powders by Gc-ms Analysis

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    Substantiation of the expedience of using of natural antioxidants for inhibiting of oxidative and hydrolytic rancidity in confectionary industry is an urgent direction. The offered way of solving the problem is to use a fat-less grape seed powder, a product, obtained as wastes of vine-making as a source of antioxidants. For this aim, there were realized experimental studies of water-alcohol extracts (ethanol, isopropanol) by the method of gas chromatography with mass-spectroscopic detection (CG-MS) of the chemical composition of grape seed powders under industrial conditions. The obtained data allowed to establish that the studied extracts contain an essential amount of phenol compounds of the different origin: aromatic acids – gallic and egallic acids; resveratrol; flavonoids – quercetin and its derivatives, catechine, epicatechine, campferol and others alongside with esters of fatty acids. These components are strong antioxidants, and their introduction to a grape seed powder must favor inhibition of the oxidizing process of fats in fat-containing confectionary products, so increasing shelf-life of products

    Comparison of stabilization by Vitamin E and 2,6-di-tert-butylphenols during polyethylene radio-thermal-oxidation

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    This paper reports a compilation of data for PE+Vitamin E and 2,6-di-tert-butylphenols oxidation in radio-thermal ageing. Data unambiguously show that Vitamin E reacts with P° and POO° whereas 2,6-di-tert-butyl phenols only react with POO°. Kinetic parameters of the stabilization reactions for both kinds of antioxidants were tentatively extracted from phenol depletion curves, and discussed regarding the structure of the stabilizer. They were also used for completing an existing kinetic model used for predicting the stabilization by antioxidants. This one permits to compare the efficiency of stabilizer with dose rate or sample thickness

    Effect of production system and geographic location on milk quality parameters

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    A main reason for the rapid increase in organic food consumption is the perception that organic foods have a superior nutritional composition and/or convey health benefits. However, there is currently limited scientific knowledge about the effect of production systems on food composition. The study reported here compared fatty acid profiles and levels of fat soluble antioxidants in milk from organic and conventional production systems in 5 geographic regions in Europe (Wales, England, Denmark, Sweden and Italy). Levels of nutritionally desirable mono- and poly-unsaturated fatty acids (vaccenic acid, CLA, α-linolenic acid) and/or a range of fat soluble antioxidants were found to be significantly higher in organic milk

    The effects of berry juice on cognitive decline in older adults : a thesis presented in partial fulfilment of the requirements of Master of Arts in Psychology at Massey University, Palmerston North, New Zealand

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    This study examined the effects of blackcurrant and boysenberry juices on cognitive processes in older adults. Current research suggests that fruits such as these may be able to reverse some of the effects of ageing on cognition. The free radical theory of ageing proposes that individuals age because oxidative damage accumulates in cells and interferes with cell functions. The hardest working tissues such as the brain accumulate the most oxidative damage through respiration. Antioxidants can protect against free radical formation and damage. Anthocyanins can contribute to half of the antioxidant capacity of deeply coloured berry fruit. An increase in dietary antioxidants such as anthocyanins may help to alleviate free radical damage within the brain. Research has shown that oxidative damage within the brain can impair cognitive functioning. Working memory shows age-related decline, along with visuospatial abilities, word retrieval and sustained attention. Some of this decline is thought to be related to oxidative damage of neurotransmitters such as acetylcholine and areas of the brain such as the hippocampus. Past research with humans has shown that some antioxidants can affect cognitive functioning in an older population. Animal studies have also established that diets enriched with anthocyanins can improve memory, motor control and neurotransmitter functioning. The present study involved giving berry juice drinks to 52 older adults that had been assessed as having a mild impairment of cognitive function. The participants were divided into three groups and drank 200mL a day of either blackcurrant juice, boysenberry juice or a placebo for twelve weeks. The participants were assessed at three different times over the course of the experiment using the RBANS. The RBANS is sensitive to small changes in its tests of memory, visuospatial ability, language and attention. The results of this study did not support previous research on antioxidants and cognitive functioning. There were no significant interactions between berry juices and any of the cognitive domains assessed by the RBANS over the course of the experiment. Some of the limitations of the study may be responsible for a lack of effect. The experiment was short with a low dose of antioxidants, and there was little control over the participants altering their own diet after being informed of the reasoning behind the study
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