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Concept: Oxygen radical absorbance capacity


BACKGROUND: Methylsulfonylmethane (MSM) has been reported to provide anti-inflammatory and antioxidant effects in both animal and man. Strenuous resistance exercise has the potential to induce both inflammation and oxidative stress. Using a pilot (proof of concept) study design, we determined the influence of MSM on markers of exercise recovery and performance in healthy men. METHODS: Eight, healthy men (27.1 +/- 6.9 yrs old) who were considered to be moderately exercise-trained (exercising <150 minutes per week) were randomly assigned to ingest MSM at either 1.5 grams per day or 3.0 grams per day for 30 days (28 days before and 2 days following exercise). Before and after the 28 day intervention period, subjects performed 18 sets of knee extension exercise in an attempt to induce muscle damage (and to be used partly as a measure of exercise performance). Sets 1--15 were performed at a predetermined weight for 10 repetitions each, while sets 16--18 were performed to muscular failure. Muscle soreness (using a 5-point Likert scale), fatigue (using the fatigue-inertia subset of the Profile of Mood States), blood antioxidant status (glutathione and Trolox Equivalent Antioxidant Capacity [TEAC]), and blood homocysteine were measured before and after exercise, pre and post intervention. Exercise performance (total work performed during sets 16--18 of knee extension testing) was also measured pre and post intervention. RESULTS: Muscle soreness increased following exercise and a trend was noted for a reduction in muscle soreness with 3.0 grams versus 1.5 grams of MSM (p = 0.080), with a 1.0 point difference between dosages. Fatigue was slightly reduced with MSM (p = 0.073 with 3.0 grams; p = 0.087 for both dosages combined). TEAC increased significantly following exercise with 3.0 grams of MSM (p = 0.035), while homocysteine decreased following exercise for both dosages combined (p = 0.007). No significant effects were noted for glutathione or total work performed during knee extension testing (p > 0.05). CONCLUSION: MSM, especially when provided at 3.0 grams per day, may favorably influence selected markers of exercise recovery. More work is needed to extend these findings, in particular using a larger sample of subjects and the inclusion of additional markers of exercise recovery and performance.

Concepts: Antioxidant, Oxidative stress, Muscle, Physical exercise, Weight training, Exercise physiology, Likert scale, Oxygen radical absorbance capacity


Chickpeas are rich sources of highly nutritious protein and dietary fibre; the health benefits of consuming legumes such as antioxidant activity (AoxA) could be effective for the expansion of their food uses. The technological properties and antioxidant potential of five pigmented chickpea cultivars were evaluated. Protein content of the grains varied from 24.9 to 27.4 g/100 g sample (dw). The cooking time (CT) of the whole grains ranged from 90.5 to 218.5 min; the lowest CT corresponded to Black ICC3761 cultivar. The total phenolic content (TPC) and AoxA [oxygen radical absorbance capacity (ORAC) value] varied from 1.23 to 1.51 mg GAE/g sample (dw) and from 5011 to 5756 μmol TE/100 g sample (dw), respectively; Red ICC13124 showed the highest ORAC value. The differences in technological properties and AoxA among cultivars could be used in chickpea breeding programmes. Chickpea cultivars could contribute significantly to the management and/or prevention of degenerative diseases associated with free radical damage.

Concepts: Nutrition, Senescence, Antioxidant, Oxidative stress, Oxygen radical absorbance capacity, Chickpea, Cicer, Cicero


Thirty-five different yacon (Smallanthus sonchifolius Poepp. & Endl) accessions were evaluated as potential alternative sources of fructooligosaccharides (FOS) and phenolic type natural antioxidants. FOS, total phenolics (TPC) and antioxidant capacity (AC) contents in the ranges of 6.4-65g/100g of dry mater (DM), 7.9-30.8mg chlorogenic acid (CAE)/g of DM and 23-136μmol trolox equivalente (TE)/g DM were found. Accession AJC 5189 sparked attention for its high FOS content while DPA 07011 for its high TPC and AC. In addition, the prebiotic effect of yacon FOS was tested in vivo with a guinea pig model. A diet rich in yacon FOS promoted the growth of bifidobacteria and lactobacilli, resulting in high levels of short chain fatty acids (SCFAs) in the cecal material and enhancement of cell density and crypt formation in caecum tissue, being indicative of colon health benefits. This study allowed identification of yacon cultivars rich in FOS, AC and/or FOS and AC for nutraceutical applications.

Concepts: Nutrition, Antioxidant, Vitamin C, Resveratrol, Oxygen radical absorbance capacity, Fructooligosaccharide, Prebiotics, Cecum


In addition to nine known bromophenol derivatives, five new nitrogen-containing bromophenols were isolated from an ethyl acetate extract of the marine red alga Rhodomela confervoides. By using spectroscopic methods, the structures of the new compounds were identified as 3-(2,3-dibromo-4,5-dihydroxybenzyl)pyrrolidine-2,5-dione (1), methyl 4-(2,3-dibromo-4,5-dihydroxybenzylamino)-4-oxobutanoate (2), 4-(2,3-dibromo-4,5-dihydroxybenzylamino)-4-oxobutanoic acid (3), 3-bromo-5-hydroxy-4-methoxybenzamide (4), and 2-(3-bromo-5-hydroxy-4-methoxyphenyl)acetamide (5). All of these bromophenols showed potent scavenging activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals, with IC(50) values ranging from 5.22 to 23.60μM. These compounds also displayed moderate activity against ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonate) radicals, with Trolox Equivalent Antioxidant Capacity values (TEAC) ranging from 2.11 to 3.58mM. The results obtained in this study demonstrate that the bromophenols obtained from R. confervoides may have potential application in food and/or pharmaceutical fields as natural antioxidants.

Concepts: Nutrition, Antioxidant, Acetic acid, Vitamin C, Oxygen radical absorbance capacity, Red algae, Trolox equivalent antioxidant capacity, Trolox


A novel antioxidant regenerating system consisting of cellobiose dehydrogenase (CDH), cellobiose and phenolic antioxidants with potential application for continuous quenching of free radical species in chronic wounds was developed. This antioxidant regenerating system, continuously quenched in situ produced .NO, O(2)(•-) and OH(•) radicals and the produced oxidized phenolic antioxidants were regenerated back to their original parent compounds by CDH using cellobiose as electron donor. This system therefore prevented the accumulation of oxidized phenolic antioxidants. Interestingly, this study also challenges the relevance of using total antioxidant capacities values of plant crude extracts obtained using biologically none relevant radical species like (2,2-diphenyl-1-picrylhydrazyl (DPPH), Trolox Equivalent Antioxidant Capacity (TEAC) etc. when applied as medicinal remedies. This is because methoxylated phenolic antioxidants like sinapic acid, ferulic acid; 2,6-dimethoxyphenol readily donate their electrons to these radicals (DPPH, TEAC etc.) thereby greatly influencing the total antioxidant values although this study showed that they are not at all effective in quenching O(2)(•-) radicals and again are not the most effective quenchers of .NO and OH(•) radicals as demonstrated during this study.

Concepts: Atherosclerosis, Oxidative stress, Radical, Vitamin C, Nitric oxide, Free-radical theory, Matrix-assisted laser desorption/ionization, Oxygen radical absorbance capacity


Abstract Context: The search for new sources of natural antioxidants from plant material may have beneficial therapeutic potential for those diseases associated with oxidative stress. The medicinal plant Haplophyllum tuberculatum (Forsskal) A. Juss. (Rutaceae) contains phenolic compounds as main phytochemicals; however, there are no reports on its antioxidant properties. Objective: To evaluate antioxidant and cytoprotective potential of ethanol extract of Haplophyllum tuberculatum aerial parts. Materials and methods: Total phenol content was determined using Folin-Ciocalteu reagent; antiradical activity was measured using ORAC assay and the analysis of the major polyphenols was carried out using a HPLC-MS method. The antioxidant and cytoprotective effect were also investigated by the MTT assay and DCFH-DA method. The human astrocytoma U373-MG cell line was pretreated with ethanol extract (from 0.025 to 250 µg/mL) for 24 h, prior to 1 mM H2O2 exposure (30 min). Results and conclusion: Total phenol content was 46.2 mg gallic acid/g sample and ORAC value was 1.283 µmol TE/mg sample. Chemical constituents were methoxyflavones, flavonols (mainly quercetin derivatives), cinnamic acids and benzoic acids. In cell system model of oxidative stress, pretreatments with ethanol extract at the concentrations of 2.5, 0.25 and 0.025 µg/mL significantly attenuated H2O2-induced loss in viability by 13.5, 17 and 20.5%, respectively. Furthermore, these ethanol extract concentrations markedly inhibited intracellular ROS production with IC50 0.026 µg/mL. These findings demonstrate the beneficial properties of ethanol extract of Haplophyllum tuberculatum aerial parts, rich in phenolic compounds, as antioxidant and radical scavenger ameliorating ROS-related processes and diseases such as several neurodegenerative disorders.

Concepts: Antioxidant, Oxidative stress, Catechin, Quercetin, Resveratrol, Phenols, Polyphenol antioxidant, Oxygen radical absorbance capacity


Hypochlorite is a strong oxidant able to induce deleterious effects in biological systems. The goal of this work was to investigate the use of PGR and PYR as probes in assays aimed at evaluating antioxidant activities towards hypochorite and apply it to plant extracts employed in Chilean folk medicine. The consumption of PGR and PYR was evaluated from the decrease in the visible absorbance and fluorescence intensity, respectively. Total phenolic content was determined by the Folin Ciocalteau assay. PGR and PYR react with hypochlorite with different kinetics, being considerably faster the consumption of PGR. Different stoichiometric values were also determined: 0.7 molecules of PGR and 0.33 molecules of PYR were bleached per each molecule of added hypochlorite. Both probes were protected by antioxidants, but the rate of PGR bleaching was too fast to perform a kinetic analysis. For PYR, the protection took place without changes in its initial consumption rate, suggesting a competition between the dye and the antioxidant for hypochlorite. Plant extracts protected PYR giving a PYR-HOCl index that follows the order: Fuchsia magellanica » Marrubium vulgare » Tagetes minuta > Chenopodium ambrosoides » Satureja montana > Thymus praecox. Based on both the kinetic data and the protection afforded by pure antioxidants, we selected PYR as the best probe. The proposed methodology allows evaluating an antioxidant capacity index of plant extracts related to the reactivity of the samples towards hypochlorite.

Concepts: Nutrition, Antioxidant, Molecule, Lamiaceae, Medicinal plants, Oxygen radical absorbance capacity, Herbs, Tagetes minuta


The benzophenone, iriflophenone-3-C-glucoside, was isolated from Cyclopia genistoides using a combination of fluid-fluid extraction, high performance counter-current chromatography (HPCCC) and semi-preparative high performance liquid chromatography (HPLC). The microplate oxygen radical absorbance capacity (ORAC) assay, with fluorescein as probe, was adapted for use in an on-line HPLC configuration. The method was validated using a mixture of authentic standards including iriflophenone-3-C-glucoside, and the xanthones, mangiferin and isomangiferin. Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) was included in the mixture for calculation of Trolox equivalent antioxidant capacity (TEAC) values. Using the on-line HPLC-ORAC assay, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(+)) on-line assays, the antioxidant activity of iriflophenone-3-C-glucoside and isomangiferin was demonstrated for the first time. Iriflophenone-3-C-glucoside presented no radical scavenging ability against DPPH, but scavenged ABTS(+) and peroxyl radicals (TEACABTS of 1.04 and TEACORAC of 3.61). Isomangiferin showed slightly lower antioxidant capacity than mangiferin against DPPH (TEACDPPH of 0.57 vs. 0.62), but higher capacity against ABTS(+) (TEACABTS of 1.82 vs. 1.67) and peroxyl radical (TEACORAC of 4.14 vs. 3.69) than mangiferin. The on-line HPLC-ORAC assay was shown to be more sensitive for radical scavengers, but at the same time less selective for rapid radical scavengers than the DPPH assay.

Concepts: Protein, Antioxidant, ELISA, Chromatography, High performance liquid chromatography, Biochemistry, Oxygen radical absorbance capacity, Trolox


The aim of this study was to identify, quantify, and compare the phytochemical contents, antioxidant capacities, and antibacterial activities of Aloe vera lyophilized leaf gel (LGE) and 95% ethanol leaf gel extracts (ELGE) using GC-MS and spectrophotometric methods.

Concepts: Nutrition, Antioxidant, Oxygen radical absorbance capacity


Recent evidence suggests that oxidative stress may contribute to the pathogenesis of type 2 diabetes. The diet, and especially fruit and vegetables, contains a variety of compounds with antioxidant activity, which may have cumulative/synergistic antioxidant effects. The total antioxidant capacity, an index derived from dietary intake, is a single estimate of antioxidant capacity from all dietary antioxidants. The main aim of this study was to investigate the relationship between total antioxidant capacity and risk of type 2 diabetes.

Concepts: Nutrition, Diabetes mellitus type 2, Antioxidant, Oxidative stress, Oxidative phosphorylation, Glutathione, Vitamin C, Oxygen radical absorbance capacity