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Dietary Antioxidants (dietary + antioxidant)
Selected AbstractsDietary antioxidant intake, allergic sensitization and allergic diseases in young childrenALLERGY, Issue 12 2009S. Patel Background:, Allergic diseases have risen in prevalence over recent decades. The aetiology remains unclear but is likely to be a result of changing lifestyle and/or environment. A reduction in antioxidant intake, consequent to reduced intake of fresh fruits and vegetables, has been suggested as a possible cause. Objective:, To investigate whether dietary antioxidant intake at age 5 was related to atopy at 5 and 8 years of age amongst children in an unselected birth cohort. Methods:, Children were followed from birth. Parents completed a validated respiratory questionnaire and children were skin prick tested at 5 and 8 years of age. Serum IgE levels were measured at age 5. At age 5, antioxidant intake was assessed using a semi-quantitative food frequency questionnaire (FFQ). A nutrient analysis program computed nutrient intake, and frequency counts of foods high in the antioxidant vitamins A, C and E were assessed. Results:, Eight hundred and sixty-one children completed both the respiratory and FFQ. Beta-carotene intake was associated with reduced risk of allergic sensitization at age 5 [0.80 (0.68,0.93)] and 8 [0.81 (0.70,0.94)]. In addition, beta-carotene intake was negatively associated with total IgE levels (P = 0.002). Vitamin E intake was associated with an increased risk of allergic sensitization [1.19 (1.02,1.39)], only at age 5. There was no association between antioxidant intakes and wheeze or eczema. Conclusion:, Increased beta-carotene intake was associated with a reduced risk of allergic sensitization and lower IgE levels, in 5- and 8-year-old children. Dietary antioxidants may play a role in the development of allergic sensitization. [source] Ascorbic acid oral treatment modifies lipolytic response and behavioural activity but not glucocorticoid metabolism in cafeteria diet-fed ratsACTA PHYSIOLOGICA, Issue 4 2009D. F. Garcia-Diaz Abstract Aim:, To analyse the effects of vitamin C (VC), a potent dietary antioxidant, oral supplementation on body weight gain, behavioural activity, lipolytic response and glucocorticoid metabolism in the early stages of diet-induced overweight in rats. Methods:, Food intake, locomotive activity and faecal corticosterone were assessed during the 14 day trial period. After 2 weeks, the animals were sacrificed and the body composition, biochemical markers and lipolytic response from isolated adipocytes from retroperitoneal white adipose tissue were examined. Results:, The intake of a high-fat diet by rats induced a significant increase in body weight, adiposity and insulin resistance markers as well as a decrease in faecal corticosterone levels compared with standard diet-fed rats. Interestingly, the animals fed on the cafeteria diet showed a significant increase in the isoproterenol-induced lipolytic response in isolated adipocytes. Furthermore, this cafeteria-fed group showed a reduced locomotive behaviour than the control rats. On the other hand, oral VC supplementation in animals receiving the high-fat diet restored the cafeteria diet effect in some of the analysed variables such as final body weight and plasma insulin to control group levels. Remarkably, increases in locomotive behaviour and a significant decrease in the lipolytic response induced by isoproterenol on isolated adipocytes from animals treated with VC were observed. Conclusion:, This work demonstrates that an oral ascorbic acid supplementation has direct effects on behavioural activity and on adipocyte lipolysis in early obesity stages in rats, which could indicate a protective short-term role of this vitamin against adiposity induced by chronic high-fat diet consumption. [source] Oxidative stress as a mediator of life history trade-offs: mechanisms, measurements and interpretationECOLOGY LETTERS, Issue 1 2009Pat Monaghan Abstract The concept of trade-offs is central to our understanding of life-history evolution. The underlying mechanisms, however, have been little studied. Oxidative stress results from a mismatch between the production of damaging reactive oxygen species (ROS) and the organism's capacity to mitigate their damaging effects. Managing oxidative stress is likely to be a major determinant of life histories, as virtually all activities generate ROS. There is a recent burgeoning of interest in how oxidative stress is related to different components of animal performance. The emphasis to date has been on immediate or short-term effects, but there is an increasing realization that oxidative stress will influence life histories over longer time scales. The concept of oxidative stress is currently used somewhat loosely by many ecologists, and the erroneous assumption often made that dietary antioxidants are necessarily the major line of defence against ROS-induced damage. We summarize current knowledge on how oxidative stress occurs and the different methods for measuring it, and highlight where ecologists can be too simplistic in their approach. We critically review the potential role of oxidative stress in mediating life-history trade-offs, and present a framework for formulating appropriate hypotheses and guiding experimental design. We indicate throughout potentially fruitful areas for further research. [source] Gene expression profiling of aging in multiple mouse strains: identification of aging biomarkers and impact of dietary antioxidantsAGING CELL, Issue 4 2009Sang-Kyu Park Summary We used DNA microarrays to identify panels of transcriptional markers of aging that are differentially expressed in young (5 month) and old (25 month) mice of multiple inbred strains (129sv, BALB/c, CBA, DBA, B6, C3H and B6C3F1). In the heart, age-related changes of five genes were studied throughout the mouse lifespan: complement component 4, chemokine ligand 14, component of Sp100-rs, phenylalanine hydroxylase and src family associated phosphoprotein 2. A similar analysis in the brain (cerebellum) involved complement component 1q (alpha polypeptide), complement component 4, P lysozyme structural, glial fibrillary acidic protein and cathepsin S. Caloric restriction (CR) inhibited age-related expression of these genes in both tissues. Parametric analysis of gene set enrichment identified several biological processes that are induced with aging in multiple mouse strains. We also tested the ability of dietary antioxidants to oppose these transcriptional markers of aging. Lycopene, resveratrol, acetyl- l -carnitine and tempol were as effective as CR in the heart, and ,-lipoic acid and coenzyme Q10 were as effective as CR in the cerebellum. These findings suggest that transcriptional biomarkers of aging in mice can be used to estimate the efficacy of aging interventions on a tissue-specific basis. [source] ANALYSIS OF ANTIOXIDANT POTENTIAL USING A BIOASSAY BASED ON OXIDATION OF 5-(2 AMINOETHYL)BENZENE-1,2,4-TRIOL FOR SCREENING PLANT FOOD EXTRACTSJOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2007YU YAO ABSTRACT Neurotoxic products including reactive quinones and oxygen species such as H2O2 are generated upon oxidation of 4-(2-aminoethyl)-1,2-benzenediol (dopamine) and 5-(2-aminoethyl)benzene-1,2,4-triol (6-OH dopamine). Moreover, neurotoxicity of 6-OH dopamine and related oxidative stress may be increased in the presence of cytochrome c (Cytc) that is released from its normal mitochondrial location. A Cytc-enhanced 6-OH dopamine oxidation reaction is presented as a model bioassay for identifying possible neuroprotective food antioxidants and their metabolites. A concentration-dependent effect was observed for Cytc upon 6-OH dopamine oxidation. Fruit/vegetable extracts, prepared from Fragaria and Pisum, were tested by this assay; a three- to fourfold greater antioxidant potency was observed for Fragaria. The results were discussed in terms of the content for antioxidant phytochemicals. In addition, potencies for these dietary antioxidants were compared to those of a related assay based on N,N,N,,N,-tetramethyl-1,4-phenylene-diamine peroxidation. PRACTICAL APPLICATIONS The bioassay presented herein is intended to be used for screening the antioxidant activities of purified dietary compounds and their in vivo metabolites, as well as crude plant extracts and other food preparations. Examples are provided by the use of fruit and vegetable extracts; and these activities arecompared with those of purified phytochemicals. Because of the potential relevance of this assay to some neurological disorders and mitochondrial dysfunctions, phytochemicals and food extracts with strong protective activities in this initial screen may be good candidates for further analyses (biochemical, cellular and animal experiments) related to such disorders e.g., related to dopaminergic neurodegeneration as discussed below. [source] Effects of Vitamin E and Organic Selenium on Oxidative Stability of ,-3 Enriched Dark Chicken Meat during CookingJOURNAL OF FOOD SCIENCE, Issue 2 2010T.I. Perez ABSTRACT:, The influence of vitamin E and selenomethionine (SeMet) on lipid oxidation in frozen,raw and cooked ,-3 enriched dark chicken meat was evaluated. Feed was supplemented with 2 levels of vitamin E (250 and 50 IU/kg of feed) and selenium (0.1 mg of sodium selenite/kg of feed and 0.3 mg of SeMet/kg of feed). An extruded linseed product was used as the ,-linolenic acid source. Fatty acid (FA) profile, oxysterols, and thiobarbituric reactive acid substances (TBARs) were analyzed in frozen,raw, boiled, pan-fried, and roasted meat. After 6 mo of storage, oxysterols in frozen,raw meat remained stable with either high or low levels of dietary antioxidants. During cooking, high levels of vitamin E reduced oxysterol formation, whereas high levels of SeMet were inconsistent and even increased oxysterols during roasting. TBARs in frozen,raw meat stored for 6 mo were inhibited by high levels of either antioxidant. Conversely, no protective effect during cooking was observed at this time of storage. After 12 mo at ,30 °C no antioxidant protection was observed. [source] Deuteration of dietary antioxidants: ferulic acid derivatives and ,-tocopherol,JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 5-6 2007Kirsti Parikka [source] Single-cell gel electrophoresis: a tool for investigation of DNA protection or damage mediated by dietary antioxidantsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2007Yim Tong Szeto Abstract One method of assessing DNA damage is the comet assay, which was developed in 1988. The comet assay enables the detection of DNA strand breaks in individual cells. This test has also been used to study the in vitro and in vivo genotoxic or genoprotective effects of certain agents such as dietary antioxidants. This paper aims to consolidate the antioxidant and pro-oxidant effects of a series of dietary agents which have been evaluated by comet assay. Copyright © 2007 Society of Chemical Industry [source] Distribution of 127 edible plant species for antioxidant activities by two assaysJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2006Ray-Yu Yang Abstract Epidemiological studies have demonstrated the protective effects of fruit and vegetable consumption on human health. A total of 150 edible plants representing 127 species were evaluated for Trolox equivalent antioxidant capacity (TEAC) and superoxide scavenging (SOS) activity. Distributions of vegetables for TEAC and SOS were not continuous but highly skewed. TEAC values on a dry weight basis ranged from 0 to 2105 µmol TE g,1 and SOS values ranged from 0 to 6206 µmol ascorbate equivalent (AE) g,1. The majority of vegetables clustered within 200 µmol TE g,1 and 400 µmol AE g,1. Vegetable species were grouped into six classes after natural logarithm transformation of TEAC and SOS values. Most highly consumed vegetables fell in the very low to medium classes. Species in the very high class for both TEAC and SOS included leaves of Cedrela sinensis (Chinese cedar), Oroxylum indicum (Damocles tree), Cassia siamea (cassod tree) and Cassia tora (sickle senna). Edible plants high in antioxidant activity (AOA) were mostly perennial and underutilised crops, while commonly consumed vegetables were generally low in AOA. There is great potential to increase dietary antioxidants and improve human health through consumption of diverse vegetable species, especially those high in AOA. Copyright © 2006 Society of Chemical Industry [source] Interaction of Phytochemical-Quercetin with the Other Antioxidant, Ascorbic Acid and their Protective Effect in Tilapia after Ultraviolet IrradiationJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 5 2009Gustavo A. Rodriguez-Montes De Oca Semi-purified, casein-gelatin-based diets were prepared and supplemented with quercetin (Q) and/ or ascorbic acid (AA): control diet C,Q,(100 mg/kg AA), diet C ,Q+ (100 mg/kg AA + quercetin 10 g/kg), diet C +Q, (1000 mg/kg AA), and diet C +Q+ (1000 mg/kg AA + quercetin 10 g/kg). These diets were fed to tilapia for 19 wk and then fish were divided into controls and ultraviolet (UV) treatments. Fish were exposed to UV radiation. Control groups were protected with a MYLAR® polyester film and plexiglass. At week 20, the same fish were re-exposed to UV radiation. Control groups of fish were protected by a double layer of MYLAR® and the UV groups were exposed with no protection. Before UV exposure, 24 h after, and 7 d after the second treatment, fish liver and skin were dissected for Q and AA analyses. The proportion of oxidized ascorbate was significantly increased in fish from treatments C ,Q, and C ,Q+ . Q concentrations in fish after exposures were negligible in skin, whereas liver concentrations were significantly different among control (34 ± 10 ,g/g) and UV-irradiated fish (11 ± 6 ,g/g), respectively. The interaction between these two dietary antioxidants may change after chronic UV irradiation. [source] Evidence for oil-induced oxidative stress to larvae of the lightbrown apple moth, Epiphyas postvittana Walker (Lepidoptera: Tortricidae)PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 4 2002Peter D Taverner Abstract For the purpose of understanding better the mode of action of alkanes on insects, the relationship between mortality, weight loss in oxygen enriched atmospheres and dietary antioxidants was examined using an alkane, C15 Ampol CPD and a spray oil, C23 DC-Tron NR, on lightbrown apple moth, Epiphyas postvittana Walker, (LBAM). The results showed that the surfactant blend used in CPD was an insignificant contributor to the overall toxicity of dilute oil/water emulsions. Higher weight loss occurred in CPD-dipped larvae than C23 DC-Tron NR-dipped larvae, which suggests that alkanes disrupt tracheal waxes and render insects more prone to desiccation. High levels of oxygen increased the toxicity of CPD to LBAM larvae. In addition, dietary supplements of anti-oxidant, ,-tocopherol, fed to LBAM larvae were successful in reducing the toxicity of CPD. These results suggest that the alkane may contribute to oxidative injury. The potential role of oil-induced oxidative stress in acute and chronic toxicity in insects is discussed. © 2002 Society of Chemical Industry [source] Antioxidants modulate the IL-6 induced inhibition of negative acute-phase protein secretion in HepG2 cellsCELL BIOCHEMISTRY AND FUNCTION, Issue 1 2008Mohamed A. El-Saadany Abstract Despite increasing evidence on the potential of dietary antioxidants in modulating the etiology of certain chronic diseases such as cancer and cardiovascular diseases, little is known about their beneficial role in acute-phase responses and inflammatory diseases. From this viewpoint the aim of this study was to investigate the effect of selected dietary antioxidants in modulating the secretion of negative acute-phase proteins caused by interleukin-6 (IL-6) in HepG2 cells. Cells were first stimulated with a fixed dose of IL-6 for 24,h then incubated for a further 8,h with varying concentrations of eight antioxidants, ,-lipoic acid (LA), (,)-epicatechin (EC), (,)-epicatechin gallate (ECG), (,)-epigallocatechin (EGC), (,)-epigallocatechin gallate (EGCG), ,-tocopherol (TOC), ascorbic acid (AA) and N-acetylcysteine (NAC). The culture supernatants were assayed for transthyretin (TTR) and retinol binding protein (RBP) using ELISA. The data revealed that IL-6 significantly reduced TTR and RBP secretion compared with the basal production. All tested antioxidants attenuate the reduction in TTR and RPB levels. The strongest effects were achieved with the highest concentration of each antioxidant. The order of effect were LA,>,EGCG,>,ECG,>,TOC,>,EGC,>,EC,>,NAC,>,AA. In conclusion, these results provide evidence that the dietary antioxidants can play a fundamental role in inflammatory processes. Copyright © 2007 John Wiley & Sons, Ltd. [source] | |||||||||||||