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Antioxidant Potential (antioxidant + potential)
Selected AbstractsANALYSIS 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] Topical ascorbic acid on photoaged skin.EXPERIMENTAL DERMATOLOGY, Issue 3 2003Clinical, topographical, ultrastructural evaluation: double-blind study vs. placebo Abstract:, Vitamin C is known for its antioxidant potential and activity in the collagen biosynthetic pathway. Photoprotective properties of topically applied vitamin C have also been demonstrated, placing this molecule as a potential candidate for use in the prevention and treatment of skin ageing. A topically applied cream containing 5% vitamin C and its excipient were tested on healthy female volunteers presenting with photoaged skin on their low-neck and arms in view to evaluate efficacy and safety of such treatment. A double-blind, randomized trial was performed over a 6-month period, comparing the action of the vitamin C cream vs. excipient on photoaged skin. Clinical assessments included evaluation at the beginning and after 3 and 6 months of daily treatment. They were performed by the investigator and compared with the volunteer self assessment. Skin relief parameters were determined on silicone rubber replicas performed at the same time-points. Cutaneous biopsies were obtained at the end of the trial and investigated using immunohistochemistry and electron microscopy. Clinical examination by a dermatologist as well as self-assessment by the volunteers disclosed a significant improvement, in terms of the ,global score', on the vitamin C-treated side compared with the control. A highly significant increase in the density of skin microrelief and a decrease of the deep furrows were demonstrated. Ultrastructural evidence of the elastic tissue repair was also obtained and well corroborated the favorable results of the clinical and skin surface examinations. Topical application of 5% vitamin C cream was an effective and well-tolerated treatment. It led to a clinically apparent improvement of the photodamaged skin and induced modifications of skin relief and ultrastructure, suggesting a positive influence of topical vitamin C on parameters characteristic for sun-induced skin ageing. [source] Pakistolides A and B, Novel Enzyme Inhibitory and Antioxidant Dimeric 4-(Glucosyloxy)Benzoates from Berchemia pakistanicaHELVETICA CHIMICA ACTA, Issue 2 2004Naveen Mukhtar Pakistolides A and B, novel dimeric , -(glucosyloxy)benzoates were isolated from Berchemia pakistanica and assigned structures 1 and 2 on the basis of extensive NMR studies. In addition, the known compounds 7,5,-dimethoxy-3,5,2,-trihydroxyflavone (=3,5-dihydroxy-2-(2-hydroxy-5-methoxyphenyl)-7-methoxy-4H -1-benzopyran-4-one), 4,,5-dihydroxy-3,6,7-trimethoxyflavone (=5-hydroxy-2-(4-hydroxyphenyl)-3,6,7-trimethoxy-4H -1-benzopyran-4-one), 5,6-dihydroxy-4,7-dimethoxy-2-methylanthracene-9,10-dione, and 1,3,4-trihydroxy-6,7,8-trimethoxy-2-methylanthracene-9,10-dione were reported for the first time from the genus Berchemia. Both 1 and 2 showed significant , -glucosidase and lipoxygenase inhibitory activities, while 2 also showed antioxidant potential. [source] Comparative study on composition and antioxidant properties of mint and black tea extractINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 10 2008Ekambaram Padmini Summary The antioxidant properties of plants could be correlated with oxidative stress defence in different human diseases. The present study was undertaken to evaluate and compare the antioxidant potential and the phytochemical composition in the aqueous extracts of mint leaves, black tea and black tea enriched with mint extract. All the three preparations exhibited free radical-scavenging potential for nitric oxide (NO) radical, superoxide anion radical and hydroxyl radical, and the values were lesser than those of the antioxidants which acted as standards. In comparison, the mint extract exhibited higher free radical and NO scavenging effect. Hydroxyl radical and superoxide scavenging effects were more pronounced in tea with the mint extract, while the reducing power was exhibited more significantly by the black tea extract. The phytochemical compounds were identified and the total phenols and flavonoids were quantified and compared between these extracts. [source] Characterization of blond and Star Ruby (red) Jaffa grapefruits using antioxidant and electrophoretic methodsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2006Shela Gorinstein Summary Antioxidant and electrophoretic methods were used to characterize the quality differences between blond and Star Ruby (red) grapefruits. Dietary fibre, minerals and trace elements, total polyphenols, anthocyanins, flavonoids, phenolic and ascorbic acids were also determined. The antioxidant potential of red grapefruit was significantly higher than that of the blond fruit (P < 0.05) and correlated well with the total polyphenols (R2 from 0.8456 to 0.9711). In both the cultivars studied, thirty-two electrophoretic bands were detected [sodium dodecyl-polyacrylamide gel eletrophoresis (SDS-PAGE)]. The main electrophoretic bands occurred between 20 and 43 kDa in both grapefruits with few minor differences between the varieties. Our findings indicate the following (i) red grapefruit is preferable: it has a higher concentration of bioactive compounds and antioxidant potential than the blond; (ii) 1, 1-diphenyl-2-picrylhydrazyl (DPPH) test is a more sensitive method for the determination of antioxidant potential; (iii) there are some minor differences in electrophoretic patterns; (iv) antioxidant and electrophoretic methods are a good combination for characterization of differences of the same citrus fruits. [source] Is ,-lipoic acid a scavenger of reactive oxygen species in vivo?IUBMB LIFE, Issue 6 2008Evidence for its initiation of stress signaling pathways that promote endogenous antioxidant capacity Abstract The chemical reduction and oxidation (redox) properties of ,-lipoic acid (LA) suggest that it may have potent antioxidant potential. A significant number of studies now show that LA and its reduced form, dihydrolipoic acid (DHLA), directly scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) species and protect cells against a host of insults where oxidative stress is part of the underlying etiology. However, owing to its limited and transient accumulation in tissues following oral intake, the efficacy of nonprotein-bound LA to function as a physiological antioxidant has been questioned. Herein, we review the evidence that the micronutrient functions of LA may be more as an effector of important cellular stress response pathways that ultimately influence endogenous cellular antioxidant levels and reduce proinflammatory mechanisms. This would promote a sustained improvement in cellular resistance to pathologies where oxidative stress is involved, which would not be forthcoming if LA solely acted as a transient ROS scavenger. © 2008 IUBMB IUBMB Life, 60(6): 362,367, 2008 [source] Appearance of biomarkers of in vitro ageing after successive stimulation of WI-38 fibroblasts with IL-1, and TNF-,: senescence associated ,-galactosidase activity and morphotype transitionJOURNAL OF ANATOMY, Issue 4 2000PATRICK DUMONT Sublethal oxidative stresses increase the proportions of human fibroblasts positive for senescence associated ,-galactosidase activity and accelerate the transition in the fibroblast morphotypes characterising fibroblast ageing. Stimulation of fibroblasts with TNF-, or IL-1, transiently increases the production of reactive oxygen species (ROS) in human fibroblasts. Here we propose that repeated stimulation of WI-38 fibroblasts with TNF-, or IL-1, can generate enough ROS to accelerate the transition in the fibroblast morphotypes and increase the proportion of cells positive for senescence associated ,-galactosidase activity. The involvement of ROS is suggested by experiments where the stimulation of fibroblasts with TNF-, or IL-1, are performed in the presence of N-acetylcysteine which increases the intracellular antioxidant potential. It is proposed that the decrease in the proportions of morphotypes I and II, and the increase in the proportions of morphotypes III to VI observed after successive stimulation with TNF-, or IL1-, is attributed to an increased ROS production occurring during the stimulation. [source] The comparison of in vivo antigenotoxic and antioxidative capacity of two propylene glycol extracts of Calendula officinalis (marigold) and vitamin E in young growing pigsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 6 2009T. Franki Summary The objective of the study was to evaluate the protective effect of Calendula officinalis propylene glycol extracts against oxidative DNA damage and lipid peroxidation induced by high polyunsaturated fatty acid (PUFA) intake in young growing pigs. Forty young growing pigs were assigned to five treatment groups: control; oil (linseed oil supplementation); C. officinalis 1 and 2 groups (linseed oil plus 3 ml/day of C. officinalis propylene glycol extracts); and vitamin E group (linseed oil plus 100 mg/kg of vitamin E). Lymphocyte DNA fragmentation and 24-h urinary 8-hydroxy-2,-deoxyguanosine (8-OHdG) excretion were measured to determine DNA damage. Lipid peroxidation was studied by analysing plasma and urine malondialdehyde (MDA), and urine isoprostane concentrations (iPF2,-VI), total antioxidant status of plasma and glutathione peroxidase (GPx) assays. C. officinalis 1 (extract from petals) effectively protected DNA from oxidative damage. It indicated a numerical trend towards the reduction of plasma MDA and urinary iPF2,-VI excretion. Its effect was comparable with that of vitamin E. C. officinalis 2 (extract from flower tops) showed less antioxidant potential than the extract from petals. We can conclude that the amount of C. officinalis extracts proposed for internal use by traditional medicine protects the organism against DNA damage induced by high PUFA intake. [source] The relationship between obesity and markers of oxidative stress in dogsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 2 2009M. G. Cline Obesity, a serious epidemic affecting much of our pet population, increases the risk of developing numerous diseases. It has been demonstrated that obesity increases oxidative stress in obese children, cats and other species. Oxidative stress can result in DNA damage with subsequent alterations in gene expression, cell signaling, mutations, cell death or cell transformation. These effects of oxidative damage predispose animals and humans to numerous disease processes and cancer. The objective of the study was to demonstrate that obese dogs are under oxidative stress resulting in DNA damage and decreased endogenous antioxidant protection measured by serum glutathione levels and the ratio of reduced (GSH) to oxidized (GSSG) glutathione. In this case,control study, 10 obese dogs were compared with aged-matched healthy control dogs. Dogs with BCS of 7 or greater (9 pt scale) were considered obese. Dogs were evaluated by history, physical exam, body condition score, CBC, serum biochemical analysis and total T4, with both groups showing no significant differences in CBC, serum biochemical or T4 analysis. Single-cell gel electrophoresis (Comet assay) was used to measure DNA damage, and high performance liquid chromatography was used to measure serum glutathione. Reduced glutathione levels were significantly higher in the obese group (p = 0.012). The results of this pilot study suggest that obesity is associated with an increase in antioxidant potential, therefore justifying a larger study with antioxidant supplementation to determine how antioxidants in weight loss diets effects endogenous antioxidant capabilities. [source] Penicillium chrysogenum glucose oxidase , a study on its antifungal effectsJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2004É. Leiter Abstract Aims:, Purification and characterization of the high molecular mass Candida albicans -killing protein secreted by Penicillium chrysogenum. Methods and Results:, The protein was purified by a combination of ultrafiltration, chromatofocusing and gel filtration. Enzymological characteristics [relative molecular mass (Mr) = 155 000, subunit structure ,2 with Mr,, = 76 000, isoelectric point (pI) = 5·4] were determined using SDS-PAGE and 2D-electrophoresis. N-terminal amino acid sequencing and homology search demonstrated that the antifungal protein was the glucose oxidase (GOX) of the fungus. The enzyme was cytotoxic for a series of bacteria, yeasts and filamentous fungi. Vitamin C (1·0 mg ml,1) prevented oxidative cell injuries triggered by 0·004 U GOX in Emericella nidulans cultures but bovine liver catalase was ineffective even at a GOX : catalase activity ratio of 0·004 : 200 U. A secondary inhibition of growth in E. nidulans cultures by the oxygen-depleting GOX,catalase system was likely to replace the primary inhibition exerted by H2O2. Conclusions:,Penicillium chrysogenum GOX possesses similar enzymological features to those described earlier for other Penicillium GOXs. Its cytotoxicity was dependent on the inherent antioxidant potential of the test micro-organisms. Significance and Impact of the Study:,Penicillium chrysogenum GOX may find future applications in glucose biosensor production, the disinfection of medical implants or in the food industry as an antimicrobial and/or preservative agent. [source] Effects of ageing on carbonyl stress and antioxidant defense in RBCs of obese Type 2 diabetic patientsJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2005Alina Constantin Abstract In this study we investigated the effects of ageing on the carbonyl stress (protein carbonyls and 4-hydroxy-2-nonenal groups) and glutathione antioxidant defense in red blood cells (RBCs) of obese Type 2 diabetic patients with/without hypertensive complications. To this purpose the following methods were used: spectrophotometry (protein carbonyls, glutathione and glutathione peroxidase assays), immunofluorescence (4-hydroxy-2-nonenal localization), western blotting (immunodetection of carbonylated proteins). The results showed that compared to RBCs of healthy subjects, in obese Type 2 diabetics, ageing is associated with: (i) an increase in the concentration and expression of carbonylated proteins, a marker of oxidative stress; (ii) a decrease of both non-enzymatic and enzymatic endogenous glutathione defenses; (iii) a severely disturbed oxidant/antioxidant balance when obesity was associated with hypertension. The simultaneous insults of high blood pressure, obesity, and diabetes conducted to the highest carbonyl strss, exposure of 4-hydroxy-2-nonenal Michel adducts at the outer leaflet of RBCs plasmalemma, and the lowest glutathione antioxidant potential, particularly in elderly patients. These results can explain the gradual age-dependent diminishment of the detoxification potenital of RBCs that at the old age can not overcome the deleterious effects of the high systemic oxidative stress. [source] HEALTH-RELATED FUNCTIONALITY OF PHENOLIC-ENRICHED PEA SPROUTS IN RELATION TO DIABETES AND HYPERTENSION MANAGEMENTJOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2008ELIZABETH BURGUIERES ABSTRACT The rationale for this investigation is that phenolic content in light-modulated pea seedlings could be enhanced by exogenous elicitors with antioxidant potential such as folic acid and vitamin C. Such phenolic-enriched extracts may have health benefits to consumers. The antioxidant-linked functional attributes of the phenolic-enriched extracts were evaluated for potential health-related benefits. Specifically, effectiveness in inhibiting ,-amylase and ,-glucosidase in relation to hyperglycemia (linked to diabetes management), as well as inhibiting angiotensin-converting enzyme I (ACE I), in relation to hypertension, was evaluated. The results show that phenolic-enriched extracts had the ability to inhibit ,-amylase and ,-glucosidase activity. On the day with the highest total phenolic content, day 8, inhibition of ,-amylase and ,-glucosidase was most prominent. Further, the same extracts showed positive benefits for potential hypertension management reflected in the inhibition of ACE I. These results taken together indicated that light-sprouted pea seedling extracts when incorporated into the diet could contribute to potential management of hyperglycemia linked to diabetes and hypertension related to cardiovascular risk. PRACTICAL APPLICATIONS In this in vitro study results show the positive effect of the different phenolic-enriched pea sprouts on hyperglycemia risk factors. It is clear that phenolic-enriched pea sprouts have high antioxidant activity, ACE 1 inhibitory activity and also good inhibitory activity on carbohydrate-modulating enzyme such as alpha-glucosidase related to glucose absorption in the intestine. The potential for managing both glucose absorption and cellular redox dysfunction for preventing postprandial hyperglycemia linked to type 2 diabetes and hyperglycemia-induced vascular complications leading to hypertension can be designed in part through food systems and therefore provides the rationale basis for further clinical studies. This strategy can be further extended to enhance phenolic-linked health benefits of a wide variety of legumes, fruits and vegetables and therefore can be the basis for food ingredient design for functional food applications. [source] THE EFFECT OF AIR-DRYING, FREEZE-DRYING AND STORAGE ON THE QUALITY AND ANTIOXIDANT ACTIVITY OF SOME SELECTED BERRIESJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2009MAGDALENA MICHALCZYK ABSTRACT The aim of this study was to analyze the effects of air-drying and freeze-drying and subsequent storage of dried products on the content of polyphenols, anthocyanins and the antioxidant properties of selected berry fruits. The material was raspberry (Rubus ideaus L.), strawberry (Fragaria ananassa Duch) and bilberry (Vaccinum myrtillus). Despite exposure to atmospheric oxygen, the stored freeze-dried fruit retained the properties of the raw material better than the air-dried product. In the case of the latter, there were considerable differences in the retention of total polyphenolic and anthocyanin content as well as antioxidant properties in the three fruit species examined. In particular, bilberry maintained a high polyphenol and anthocyanin content and high antioxidant potential despite the greatest losses of these compounds. PRACTICAL APPLICATIONS Consumer demand for food with health-promoting qualities is increasing. The food industry has intensified its efforts to provide high quality, semi-processed products that fulfil this requirement. The results presented in this work indicate that even after long-term storage and despite exposure to atmospheric oxygen, freeze-dried berries retain the antioxidant properties of the raw material to a very high degree. Therefore, lyophilisates can satisfy this particular need. Air-dried berries are much less stable during long-term storage. The dynamics of the changes occurring during the storage of both kinds of product are presented in detail. [source] Influence of Storage Temperature on the Kinetics of the Changes in Anthocyanins, Vitamin C, and Antioxidant Capacity in Fresh-Cut Strawberries Stored under High-Oxygen AtmospheresJOURNAL OF FOOD SCIENCE, Issue 2 2009I. Odriozola-Serrano ABSTRACT:, Changes in the main antioxidant properties of fresh-cut strawberries stored under high-oxygen atmospheres (80 kPa O2) were studied at selected temperatures (5 to 20 °C). The suitability of zero- and 1st-order kinetics as well as a model based on Weibull distribution function to describe changes in experimental data is discussed. A non-Arrhenius approach was used to determine the temperature dependence of the estimated rate constants. A Weibull kinetic model most accurately (R2adj, 0.800) estimated changes in anthocyanins and antioxidant capacity of fresh-cut strawberries throughout the storage period, whereas a 1st-order model adequately fitted (R2adj, 0.982) the variation of vitamin C. The temperature dependency of the kinetic rate constants for each antioxidant property was successfully modeled through the non-Arrhenius approach (R2adj, 0.709). The Tc obtained for anthocyanins, vitamin C, and antioxidant capacity degradation were 290, 284, and 289 K, respectively, indicating the temperature at which a marked acceleration of the losses in the antioxidant potential of strawberry wedges occurs. These findings will help to describe the variation of the antioxidant potential of fresh-cut strawberries upon storage time and temperature. [source] Evidence that 3-hydroxy-3-methylglutaric acid promotes lipid and protein oxidative damage and reduces the nonenzymatic antioxidant defenses in rat cerebral cortexJOURNAL OF NEUROSCIENCE RESEARCH, Issue 3 2008Guilhian Leipnitz Abstract In the present work we investigated the in vitro effect of 3-hydroxy-3-methylglutarate (HMG) that accumulates in 3-hydroxy-3-methylglutaryl-CoA lyase deficiency (HMGLD) on important parameters of oxidative stress in rat cerebral cortex. It was observed that HMG induced lipid peroxidation by significantly increasing chemiluminescence and levels of thiobarbituric acid-reactive substances (TBA-RS). This effect was prevented by the antioxidants ,-tocopherol, melatonin, N-acetylcysteine, and superoxide dismutase plus catalase, suggesting that free radicals were involved in the lipid oxidative damage. On the other hand, HMG did not change TBA-RS levels in intact or disrupted mitochondrial preparations, indicating that generation of oxidants by this organic acid was dependent on cytosolic mechanisms. HMG also induced protein oxidative damage in cortical supernatants, which was reflected by increased carbonyl content and sulfhydryl oxidation. Furthermore, HMG significantly reduced the nonenzymatic antioxidant defenses total-radical trapping antioxidant potential, total antioxidant reactivity, and reduced glutathione (GSH) levels in rat cerebral cortex. HMG-induced GSH reduction was totally blocked by melatonin pretreatment. We also verified that the decrease of GSH levels provoked by HMG in cortical supernatants was not due to a direct oxidative effect of this organic acid, because exposition of commercial GSH and purified membrane protein-bound thiol groups to HMG in the absence of cortical supernatants did not decrease the reduced sulfhydryl groups. Finally, the activities of the main antioxidant enzymes were not altered by HMG exposure. Our data indicate that oxidative stress elicited in vitro by HMG may possibly contribute at least in part to the pathophysiology of the brain injury in HMGLD. © 2007 Wiley-Liss, Inc. [source] 1-Methylcyclopropene affects the antioxidant system of apricots (Prunus armeniaca L. cv. Búlida) during storage at low temperatureJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 4 2010Isabel Egea Abstract BACKGROUND: Apricots (Prunus armeniaca cv. Búlida) were treated with 1 mL L,1 1-methylcyclopropene (1-MCP) immediately after harvest and stored in air at 2 °C for 21 days. Antioxidant levels (ascorbic acid and carotenoids), enzymatic antioxidant activities (superoxide dismutase (SOD) and unspecific peroxidase (POX)) and total antioxidant capacity (trolox equivalent antioxidant capacity (TEAC)) were determined. The level of oxidative stress was also established by measuring ion leakage during storage. The changes in the antioxidant potential of apricots were related to the capacity of 1-MCP to increase their commercial life. RESULTS: 1-MCP-treated fruits exhibited higher SOD activity, whereas POX activity was significantly higher only after 21 days at 2 °C. Treated fruits also exhibited better retention of ascorbate and carotenoids and higher TEAC during storage. In accordance with these observations, lower ion leakage values were detected in 1-MCP-treated apricots. CONCLUSION: Taken together, these results suggest that 1-MCP conferred a greater resistance to oxidative stress. This, along with the reduction in ethylene production, could contribute to the increase in commercial life and nutritional value observed in 1-MCP-treated apricots. Copyright © 2010 Society of Chemical Industry [source] Evaluation of lignans and free and linked hydroxy-tyrosol and tyrosol in extra virgin olive oil after hydrolysis processesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2006Nadia Mulinacci Abstract We describe chemical hydrolytic procedures to evaluate the total amount of tyrosol and hydroxy-tyrosol free and/or linked to secoiridoidic molecules (acid hydrolysis). At the same time a rapid determination of the lignans in complex minor polar compound (MPC) extracts is proposed (alkaline hydrolysis). High-performance liquid chromatography/diode array detection (HPLC/DAD) and HPLC/MS were applied as reference methods to evaluate the quantitative results from the hydrolysis experiments. The optimized acid hydrolysis procedures were first applied to an oleuropein standard and then to MPC fractions extracted from several commercial extra virgin olive oils. The results confirm the applicability of the method, consisting in the acid hydrolysis of complex mixtures of secoiridoidic derivatives, to determine the antioxidant potential in terms of MPC. These data can contribute to forecasting the potential ageing resistance of an extra virgin olive oil in terms of antioxidant potency. Finally, alkaline hydrolysis allows confirmation and easy determination of the amount of lignans, especially in those MPC fractions which are particularly complex. Copyright © 2006 Society of Chemical Industry [source] Enhanced coloration reveals high antioxidant potential in new sweetpotato cultivarsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2003Martin Philpott Abstract Sweetpotato is one of the world's most important food crops, particularly in developing countries. The storage roots have high carbohydrate and vitamin A contents and possess strong antioxidant potential, previously attributed to their hydroxycinnamic acid content. We report on several new purple sweetpotatoes developed for their high anthocyanin content. Although the antioxidant activity of purple sweetpotato extracts was greater than that of sweetpotato lacking anthocyanins, anthocyanins alone could not account for all the activity. Extract components were separated by 2D paper chromatography, and their relative contributions to antioxidant activity were determined. The antioxidant activity of the extracts from sweetpotato was shown to be due to both anthocyanins and hydroxycinnamic acids, additively. Neither the anthocyanin content nor the antioxidant activity of sweetpotato flesh was affected by common cooking methods. These findings may be important in the light of the health-protective properties attributed to both antioxidants and anthocyanins. Copyright © 2003 Society of Chemical Industry [source] Carbon Monoxide has Antioxidative Properties in the Liver Involving p38 MAP Kinase Pathway in a Murine Model of Systemic InflammationMICROCIRCULATION, Issue 7 2010JÜRGEN BRUGGER Please cite this paper as: Brugger, Schick, Brock, Baumann, Muellenbach, Roewer and Wunder (2010). Carbon Monoxide has Antioxidative Properties in the Liver Involving p38 MAP Kinase Pathway in a Murine Model of Systemic Inflammation. Microcirculation17(7), 504,513. Abstract Objective:, Reactive oxygen species (ROS) are important in the hepatocellular injury process during a systemic inflammation. We examined the role of carbon monoxide (CO) on the hepatic generation of ROS with in-vivo and in-vitro models of systemic inflammation. Methods:, Using a murine model of bilateral hindlimb ischemia-reperfusion (I/R) we examined the effect of CO treatment on hepatic ROS formation, oxidative status, and cell injury. Cultured HUVEC were used to investigate intracellular pathways. Results:, CO treatment reduced hepatic lipid peroxidation, re-established total hepatic glutathione and glutathione disulfide (GSH/GSSG) levels and reduced hepatocellular injury. Inhibition of heme oxygenase (HO) during treatment with CO during hindlimb I/R failed to alter the antioxidant qualities provided by CO. The production of ROS after tumor necrosis factor-, (TNF-,) stimulation in HUVEC was diminished after exposure to CO. Treatment with CO during HO inhibition reduced both ROS formation and cell injury. Inhibiting the p38 MAPK (mitogen-activated protein kinase) pathway with pyridinyl imidazol (SB203580) revealed that the antioxidant potential of CO involved the activation of p38 MAPK. Conclusions:, CO has direct antioxidant potential independently of any HO activity during systemic inflammation. The antioxidant effects afforded by CO involve the activation of the p38 MAPK pathway. [source] GSTM1 and GSTT1 null genotypes as possible heritable factors of rosaceaPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 4 2006Ayca Cordan Yazici Purpose: Rosacea might be related to an increased activity of reactive oxygen species (ROS) and deficient function of the antioxidant system. Glutathione S-transferases (GSTs) play a primer role in cellular defense against electrophilic chemical species and radical oxygen species. We hypothesized that increased ROS activity or decreased antioxidant potential, possibly induced by GST gene polymorphism, might have a pathogenic role in rosacea. Methods: The study group consisted of 45 patients with rosacea and 100 control subjects. DNA samples were isolated from blood samples using high pure polymerase chain reaction (PCR) Template preparation Kit. The GSTM1, GSTT1, and P1 polymorphisms were detected using a real-time PCR and fluorescence resonance energy transfer with a Light-Cycler Instrument. Associations between specific genotypes and the development of rosacea were examined using logistic regression analyses to calculate odds ratios (OR) and 95% confidence intervals (CI). Results: GSTM1 and GSTT1 null genotypes were found to be statistically different from control (P=0.005, P=0.009, respectively), and associated with an increased risk of rosacea (OR [95% CI]: 2.84 [1.37,5.89]; OR [95% CI]: 2.68 [1.27,5.67], respectively). There was a statistically significant relationship between both null combination of the GSTM1 and GSTT1 genotype polymorphisms and rosacea (P=0.003, OR [95% CI]: 4.18 [1.57,11.13]). There were no statistically significant differences between patient and control groups for the GSTP1 Ile/Ile, Ile/Val, and Val/Val genotypes (P>0.05). Conclusion: We demonstrated a significant association between the GSTT1 and/or GSTM1 null genotypes and rosacea. However, the potential role of GSTs as markers of susceptibility to rosacea needs further studies in larger patient groups. [source] Capsaicin modulates pulmonary antioxidant defense system during benzo(a)pyrene-induced lung cancer in swiss albino micePHYTOTHERAPY RESEARCH, Issue 4 2008P. Anandakumar Abstract The effect of a pungent ingredient of red pepper, capsaicin, on oxidative stress induced changes in the antioxidant defense system by benzo(a)pyrene in the lungs of mice was studied. Oral gavage administration of benzo(a)pyrene (50 mg/kg body weight) to mice led to a marked increase in oxidative stress indicated by alterations in pulmonary lipid peroxidation, enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione- S -transferase and glucose-6-phosphate dehydrogenase) and non-enzymic antioxidants (reduced glutathione, vitamin C, vitamin E and vitamin A). Pre-co-treatment with capsaicin (10 mg/kg body weight i.p.) restored cellular normalcy, highlighting the antioxidant potential of capsaicin in mitigating the oxidative stress mediated damage produced during benzo(a)pyrene-induced lung cancer. Copyright © 2008 John Wiley & Sons, Ltd. [source] Phenolic compounds in peach (Prunus persica) cultivars at harvest and during fruit maturationANNALS OF APPLIED BIOLOGY, Issue 1 2008C. Andreotti Abstract Six peach and six nectarine cultivars were evaluated for the phenolic content in their pulp and peel tissues. Chlorogenic acid, catechin, epicatechin, rutin and cyanidin-3-glucoside were detected as the main phenolic compounds of ripened fruits. The concentration was always higher in peel tissue, with average values ranging from 1 to 8 mg g,1 dry weight (DW) depending on cultivar. Of the tested varieties, the white-flesh nectarine ,Silver Rome' emerged as the cultivar with the highest amount of total phenolics. Phenolic compounds were also profiled during fruit growth and ripening in the yellow nectarine cv. ,Stark Red Gold', which showed a decreasing concentration during fruit development in both peel and pulp tissues. Average amounts of total phenolics were approximately 25 mg g,1 DW 60 days after full bloom and decreased to 3 mg g,1 DW at ripening in pulp tissue. Differences among peel and pulp composition show the different dietetic and antioxidant potential of fruits consumed unpeeled and peeled. [source] Erythrocyte Susceptibility to Oxidative Stress in Chronic Renal Failure Patients Under Different Substitutive TreatmentsARTIFICIAL ORGANS, Issue 1 2005Leonardo Lucchi Abstract:, An increased oxidative stress is now considered one of the major risk factors in chronic renal failure (CRF) patients that may be exacerbated by dialysis. It has been postulated that this increased oxidative stress might cause an augmented red blood cell (RBC) membrane lipid peroxidation with the consequent alteration in membrane deformability. The aim of this study was to evaluate RBC susceptibility to an in vitro induced oxidative stress and RBC antioxidant potential in different groups of CRF patients undergoing different substitutive treatment modalities. Fifteen end-stage CRF patients were evaluated in conservative treatment, 23 hemodialysis (HD) patients, 15 continuous ambulatory peritoneal dialysis (CAPD) patients, 15 kidney transplanted patients, and 16 controls. Their RBCs were incubated with the oxidative stress-inducing agent tert-butylhydroperoxide both in the presence and in the absence of the catalase inhibitor sodium azide, and the level of malondialdehyde (MDA) (a product of lipid peroxidation), was measured at 0, 5, 10, 15, and 30 min of incubation. In addition, the RBC content of reduced glutathione (GSH) was measured by HPLC. As opposed to the controls, RBCs from end-stage CRF patients exhibited an increased sensitivity to oxidative stress induced in vitro, both in the absence and presence of a catalase inhibitor, as demonstrated by a significantly higher level of MDA production at all the incubation times (P < 0.05). Different substitutive treatments had different impacts on this phenomenon; CAPD and kidney transplantation were able to normalize this alteration while HD was not. GSH appeared to be related to the increase in RBC susceptibility to oxidative stress; its content being significantly elevated in end-stage CRF and HD patients as compared with CAPD and transplanted patients and controls (P < 0.05). No significant changes were observed in the RBC glutathione content during the HD session. The increase of GSH in RBCs of end-stage CRF and HD patients seems to indicate the existence of an adaptive mechanism under increased oxidative stress occurring in vivo. Unlike HD, the beneficial effect of CAPD on the anemia of dialysis patients might partly be due to a condition of lower oxidative stress that might in addition counterbalance the cardiovascular negative effects of dislipidemia ,of, CAPD, patients. [source] Effects of Embelin on Lipid Peroxidation and Free Radical Scavenging Activity against Liver Damage in RatsBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 4 2009Dharmendra Singh Carbon tetrachloride (CCl4) treatment to rats has been more susceptible to peroxidative damage through production of reactive metabolites, namely trichloromethyl-free radicals (CCl?3 and/or CCl3OO?) as measured by thiobarbituric acid reactive species. After the induction of liver damage by CCl4 intoxication to rats, the concentration of lipid peroxidation was significantly (P , 0.001) higher in liver and serum, along with concomitant decrease in the levels of antioxidants and cytochrome P450 enzyme in liver as compared to vehicle controls. The activities of marker enzymes , transaminases (AST, ALT), alkaline phosphatase (ALP), ,-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH) , along with the total bilirubin and total protein levels were altered significantly (P , 0.001) in the serum of CCl4 -treated rats. When these rats received embelin orally (25 mg/kg) from day 1 to day 15, peroxidative damage was minimal in both liver and serum along with effectively inducing the antioxidant potential in CCl4 -treated rats. The biochemical results were compared with the standard drug silymarin , a combination of flavonolignans of Silybum marianum and histology of liver sections. In conclusion, this study suggests that embelin acts as a natural antioxidant against hepatotoxicity induced in rats. [source] Antioxidant and Hepatoprotective Effects of Cyathea phalerata Mart. (Cyatheaceae)BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 1 2008Mariana Appel Hort The in vitro antioxidant potential of the crude extract (CE), precipitate (PPT), aqueous fraction (AQF), n-butanolic fraction (BUF) and ethyl acetate fraction (EAF) from C. phalerata was evaluated through the scavenging of diphenyl-1-picryl-hydrazyl-hydrate (DPPH), superoxide anion (O2,,) (nitroblue tetrazolium assay) and hydroxyl radicals (OH,) (deoxyribose assay), and lipid peroxidation in rat liver homogenate. In these assays, it was observed that EAF had marked antioxidant potential, especially as a scavenger of the OH, radical and in inhibiting lipid peroxidation. The in vivo evaluation of oxidative stress (DNA fragmentation, membrane lipoperoxidation and carbonyl protein formation) and the antioxidant defenses (concentration of reduced glutathione, as well as catalase and glutathione S-transferase activities) were measured in mice pre-treated with EAF (10, 30 or 100 mg/kg, orally) and later exposed to carbon tetrachloride (CCl4). The EAF decreased thiobarbituric acid reactive substances levels, DNA damage and carbonyl protein contents, and increased catalase and glutathione S-transferase activities. Based on these results, it is concluded that the EAF from C. phalerata protects liver from oxidative stress induced by CCl4 in mice and these effects are probably related to the antioxidant activity associated with the free radical scavenging property of this fraction. [source] Carotenoids in evolutionary ecology: re-evaluating the antioxidant roleBIOESSAYS, Issue 10 2009Lorenzo Pérez-Rodríguez Abstract The antioxidant role of carotenoids in the living organism was proposed as a possible basis for the honesty of carotenoid-based signals. However, recent studies have questioned the relevance of carotenoids as powerful antioxidants in vivo. Current evidence does not seem to support the "antioxidant role" hypothesis, but it does not allow us to reject it either. This paper proposes some steps to solve this controversy, such as taking a dynamic approach to antioxidant responses, designing protocols that expose individuals to oxidative challenges, analyzing tissues other than blood, and obtaining measures of antioxidant capacity and oxidative damage simultaneously. However, it should be considered that, irrespective of their antioxidant potential, carotenoids might still give information on oxidative stress levels if they are particularly sensitive to free radicals. Finally, lumping together the immunostimulatory and antioxidant roles of carotenoids should be avoided as these functions are not necessarily associated. [source] Protective effect of L -carnitine on testicular ischaemia,reperfusion injury in rats,CELL BIOCHEMISTRY AND FUNCTION, Issue 6 2007Dikmen Dokmeci Abstract Testicular torsion is a urological emergency referred to as ,acute scrotum', because inappropriate treatment can lead to male subfertility and infertility. A possible cause of testicular damage is the ischaemia,reperfusion (I/R) injury attributed to oxygen free radicals. L -carnitine, a vitamin-like antioxidant, plays a pivotal role in the maturation of spermatozoa within the reproductive tract. The aim of the present paper was to determine the protective effect of L -carnitine on testicular I/R-induced injury. Thirty-two male rats were divided into 4 groups (n,=,8). Testicular torsion was created by rotating the right testis 720° in a clockwise direction. Group 1: sham-operated control; group 2: ischaemia; group 3: I/R; group 4: ischaemia,L -carnitine treatment,reperfusion group. L -carnitine (500,mg,kg,1, intraperitoneally) was administered before 30 min of detorsion in Group 4. After torsion (5,h) and detorsion (5,h), bilateral orchidectomy was performed. The malondialdehyde (MDA) level was evaluated in testes. Histopathologically, Johnsen's spermatogenesis criteria and mean seminiferous tubule diameter (MSTD) measurements were used. Testicular MDA levels were higher in the torsion group compared to the sham-control group (p,<,0.05). Detorsion (reperfusion) caused a further increase in MDA levels (p,<,0.05). Pretreatment with L -carnitine prevented a further increase in MDA levels (p,<,0.05). Histologically, torsion caused some separation among germinal cells in the seminiferous tubules, which became much more prominent in the I/R group but was attenuated with L -carnitine pretreatment. In conclusion, L -carnitine pretreatment may have a protective effect in experimental testicular torsion,detorsion model in rats by its well-known antioxidant potential. Copyright © 2006 John Wiley & Sons, Ltd. [source] The relationship between potency of oxidative stress and severity of depressionACTA NEUROPSYCHIATRICA, Issue 4 2004Medaim Yanik Background:, Oxidative stress is one of the suggested mechanisms in major depression. Objective:, To determine the oxidative and antioxidative status of plasma of patients with major depression and to investigate whether there is a relationship between the potency of oxidative stress and the severity of depression. Methods:, To determine the antioxidative status of plasma, total and individual antioxidant levels which are total antioxidant potential (TAOP), total protein, albumin, uric acid, vitamin C and total bilirubin were measured. To determine the oxidative status, total peroxide level of plasma was measured in patients with drug-free depressive patients and compared with those of controls. Per cent ratio of total peroxide to TAOP was evaluated as oxidative stress index (OSI). Results:, Plasma TAOP and individual antioxidant levels were found to be lower in patients with depression than those of controls. On the contrary, the patients had high total plasma peroxide levels. OSI values of the patients were significantly higher than those of controls (P = 0.002), and a significant positive correlation between Hamilton Depression Rating Scale (HDRS) and OSI values was found (r = 0.54, P = 0.01). Conclusions:, The patients with major depression are exposed to oxidative stress, and OSI may be useful to reflect the severity of the disease. [source] Chronic effect of ferulic acid from Pseudosasa japonica leaves on enhancing exercise activity in micePHYTOTHERAPY RESEARCH, Issue 10 2010Yanghee You Abstract Ferulic acid derived from Pseudosasa japonica leaves, which possessed antioxidative potentials with DPPH- (54%) and ABTs- (65%) radical scavenging activities, and lipid-peroxidation inhibitory activity (71%), was orally administered to mice for 12 days in order to investigate its effects on exercise endurance capacity and alterations of antioxidant defense systems. Exhaustive swimming time was increased in the ferulic acid-supplemented group compared with the control group on days 6 and 12 (1.7- and 1.8-fold, respectively). When the mice were exhaustively exercised for 2 consecutive days, a high decrease (53%) was shown in the control group, but no change was found in the ferulic acid-treated group. The administration of ferulic acid significantly protected the depletion of enzymatic- and non enzymatic-antioxidants due to exhaustive exercise. Also, lipid-peroxidation levels decreased in the ferulic acid-treated group compared with the non exercised- and control-groups. These results suggest that ferulic acid from Pseudosasa japonica leaves has a chronic effect on endurance exercise capacity, which is attributed to its ability to ameliorate oxidative stress by improving antioxidant potentials. Copyright © 2010 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||