scholarly journals The relationship between antioxidant activity, first electrochemical oxidation potential, and spin population of flavonoid radicals

2019 ◽  
Vol 70 (2) ◽  
pp. 134-139 ◽  
Author(s):  
Ante Miličević
Keyword(s):  
Antioxidant Activity ◽  
Electrochemical Oxidation ◽  
Atomic Orbital ◽  
Oxidation Potential ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Reducing Ability ◽  
Trolox Equivalent ◽  
Spin Populations ◽  
The One ◽  
Semi Empirical

AbstractI have shown that by averaging antioxidant activity (AA) values measured by different methods it is possible to obtain an excellent correlation (R2=0.960) between the first electrochemical oxidation potential, Ep1, and AA. Separate correlations using the AA values obtained with each of the four methods [R2 were 0.561 for diphenyl-1-picrylhydrazyl (DPPH), 0.849 for Folin Ciocalteu reagent (FCR), 0.848 for the ferric-reducing ability of plasma (FRAP), and 0.668 for the Trolox equivalent antioxidant capacity (TEAC)] were all worse, and in some cases not useful at all, such as the one for DPPH. Also, the sum of atomic orbital spin populations on the carbon atoms in the skeleton of radicals ( s(C) Σ AOSPRad), calculated with the semi-empirical parameterisation method 6 (PM6) in water, was used to correlate both Ep1 and AA, yielding R2=0.926 and 0.950, respectively. This showed to be a much better variable for the estimation of Ep1 and AA than the bond dissociation energy (BDE), R2=0.854 and 0.901 for Ep1 and AA, respectively, and especially the ionisation potential (IP), R2=0.445 and 0.435 for Ep1 and AA, respectively.

scholarly journals Changes in Markers of Oxidative Stress and α-Amylase in Saliva of Children Associated with a Tennis Competition

2020 ◽  
Vol 17 (17) ◽  
pp. 6269 ◽  
Author(s):  
José María Giménez-Egido ◽  
Raquel Hernández-García ◽  
Damián Escribano ◽  
Silvia Martínez-Subiela ◽  
Gema Torres-Luque ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Capacity ◽  
Psychological Stress ◽  
Antioxidant Status ◽  
Perceived Exertion ◽  
Progressive Increase ◽  
Rating Of Perceived Exertion ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Reducing Ability ◽  
Trolox Equivalent

The purpose of this paper was to analyze the changes caused by a one-day tennis tournament in biomarkers of oxidative stress and α-amylase in saliva in children. The sample was 20 male active children with the following characteristics: (a) age of players = 9.46 ± 0.66 years; (b) weight = 34.8 ± 6.5 kg; (c) height = 136.0 ± 7.9 cm; (d) mean weekly training tennis = 2.9 ± 1.0 h. The tennis competition ran for one day, with four matches for each player. Data were taken from the average duration per match and the rating of perceived exertion (RPE). Four biomarkers of antioxidant status: uric acid (AU), Trolox equivalent antioxidant capacity (TEAC), ferric reducing ability of saliva (FRAS, cupric reducing antioxidant capacity (CUPRAC) and salivary alpha-amylase (sAA) as a biomarker of psychological stress were measured in saliva. The time points were baseline (at home before the tournament), pre-competition (immediately before the first match) and post-match (after each match) measurements. The four biomarkers of antioxidant status showed a similar dynamic with lower values at baseline and a progressive increase during the four matches. Overall one-day tennis competition in children showed a tendency to increase antioxidant biomarkers in saliva. In addition, there was an increase in pre-competition sAA possibly associated with psychological stress. Further studies about the possible physiological implications of these findings should be performed in the future.

scholarly journals Evaluation of theIn VitroandIn VivoAntioxidant Potentials ofSudarshanaPowder

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Weerakoon Achchige Selvi Saroja Weerakoon ◽  
Pathirage Kamal Perera ◽  
Dulani Gunasekera ◽  
Thusharie Sugandhika Suresh
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Capacity ◽  
Thiobarbituric Acid ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Control Group ◽  
Thiobarbituric Acid Reactive Substance ◽  
Trolox Equivalent ◽  
Antioxidant Effects

Sudarshanapowder (SP) is one of the most effective Ayurveda powder preparations for paediatric febrile conditions. The objective of the present study was to evaluate thein vitroandin vivoantioxidant potentials of SP. Thein vitroantioxidant effects were evaluated using ABTS radical cation decolourization assay where the TROLOX equivalent antioxidant capacity (TEAC) was determined. Thein vivoantioxidant activity of SP was determined in Wistar rats using the Lipid Peroxidation (LPO) assay in serum. Thein vitroassay was referred to as the TROLOX equivalent antioxidant capacity (TEAC) assay. For thein vivoassay, animals were dosed for 21 consecutive days and blood was drawn to evaluate the MDA level. Thein vitroantioxidant activity of 0.5 μg of SP was equivalent to 14.45 μg of standard TROLOX. The percentage inhibition against the radical formation was50.93±0.53%. The SP showed a statistically significant (p<0.01) decrease in the serum level of thiobarbituric acid-reactive substance in the test rats when compared with the control group. These findings suggest that the SP possesses potent antioxidant activity which may be responsible for some of its reported bioactivities.

Chronic quercetin ingestion and exercise-induced oxidative damage and inflammation

2008 ◽  
Vol 33 (2) ◽  
pp. 254-262 ◽  
Author(s):  
Steven R. McAnulty ◽  
Lisa S. McAnulty ◽  
David C. Nieman ◽  
John C. Quindry ◽  
Peter A. Hosick ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Antioxidant Capacity ◽  
Flavonoid Compound ◽  
Trolox Equivalent Antioxidant Capacity ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Reducing Ability ◽  
Trolox Equivalent ◽  
Exercise Induced

Quercetin is a flavonoid compound that has been demonstrated to be a potent antioxidant in vitro. The objective of this study was to evaluate if quercetin ingestion would increase plasma antioxidant measures and attenuate increases in exercise-induced oxidative damage. Forty athletes were recruited and randomized to quercetin or placebo. Subjects consumed 1000 mg quercetin or placebo each day for 6 weeks before and during 3 d of cycling at 57% work maximum for 3 h. Blood was collected before and immediately after exercise each day, and analyzed for F2-isoprostanes, nitrite, ferric-reducing ability of plasma, trolox equivalent antioxidant capacity, and C-reactive protein. Statistical analyses involved a 2 (treatment) × 6 (times) repeated measures analysis of variance to test main effects. F2-isoprostanes, nitrite, ferric-reducing ability of plasma, trolox equivalent antioxidant capacity, and C-reactive protein were significantly elevated as a result of exercise, but no group effects were found. Despite previous data demonstrating potent antioxidant actions of quercetin in vitro, this study indicates that this effect is absent in vivo and that chronic quercetin ingestion does not exert protection from exercise-induced oxidative stress and inflammation.

scholarly journals Changes of salivary biomarkers under different storage conditions: effects of temperature and length of storage

2018 ◽  
Vol 29 (1) ◽  
pp. 94-111 ◽  
Author(s):  
Tomás Barranco ◽  
Asta Tvarijonaviciute ◽  
Damián Escribano ◽  
Fernando Tecles ◽  
José J Cerón ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Room Temperature ◽  
Storage Conditions ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Long Term Storage ◽  
Reducing Ability ◽  
Trolox Equivalent ◽  
The Stability ◽  
Term Storage

Introduction: In this report, we aimed to examine the stability of various analytes in saliva under different storage conditions. Materials and methods: Alpha-amylase (AMY), cholinesterase (CHE), lipase (Lip), total esterase (TEA), creatine kinase (CK), aspartate aminotransferase (AST), lactate dehydrogenase (LD), lactate (Lact), adenosine deaminase (ADA), Trolox equivalent antioxidant capacity (TEAC), ferric reducing ability (FRAS), cupric reducing antioxidant capacity (CUPRAC), uric acid (UA), catalase (CAT), advanced oxidation protein products (AOPP) and hydrogen peroxide (H2O2) were colorimetrically measured in saliva obtained by passive drool from 12 healthy voluntary donors at baseline and after 3, 6, 24, 72 hours, 7 and 14 days at room temperature (RT) and 4 ºC, and after 14 days, 1, 3 and 6 months at – 20 ºC and – 80 ºC. Results: At RT, changes appeared at 6 hours for TEA and H2O2; 24 hours for Lip, CK, ADA and CUPRAC; and 72 hours for LD, Lact, FRAS, UA and AOPP. At 4 ºC changes were observed after 6 hours for TEA and H2O2; 24 hours for Lip and CUPRAC; 72 hours for CK; and 7 days for LD, FRAS and UA. At – 20 ºC changes appeared after 14 days for AST, Lip, CK and LD; and 3 months for TEA and H2O2. At – 80 ºC observed changes were after 3 months for TEA and H2O2. Conclusions: In short-term storage, the analytes were more stable at 4 ºC than at room temperature, whereas in long-term storage they were more stable at - 80 ºC than at – 20 ºC.

scholarly journals Quantification of the Antioxidant Activity of Plant Extracts: Analysis of Sensitivity and Hierarchization Based on the Method Used

Antioxidants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 76 ◽  
Author(s):  
Natividad Chaves ◽  
Antonio Santiago ◽  
Juan Carlos Alías
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Capacity ◽  
Plant Species ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Antioxidant Compounds ◽  
Frap Assay ◽  
Trolox Equivalent

Plants have a large number of bioactive compounds with high antioxidant activity. Studies for the determination of the antioxidant activity of different plant species could contribute to revealing the value of these species as a source of new antioxidant compounds. There is a large variety of in vitro methods to quantify antioxidant activity, and it is important to select the proper method to determine which species have the highest antioxidant activity. The aim of this work was to verify whether different methods show the same sensitivity and/or capacity to discriminate the antioxidant activity of the extract of different plant species. To that end, we selected 12 species with different content of phenolic compounds. Their extracts were analyzed using the following methods: 2,2-di-phenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, ferric reducing (FRAP) assay, Trolox equivalent antioxidant capacity (ABTS) assay, and reducing power (RP) assay. The four methods selected could quantify the antioxidant capacity of the 12 study species, although there were differences between them. The antioxidant activity values quantified through DPPH and RP were higher than the ones obtained by ABTS and FRAP, and these values varied among species. Thus, the hierarchization or categorization of these species was different depending on the method used. Another difference established between these methods was the sensitivity obtained with each of them. A cluster revealed that RP established the largest number of groups at the shortest distance from the root. Therefore, as it showed the best discrimination of differences and/or similarities between species, RP is considered in this study as the one with the highest sensitivity among the four studied methods. On the other hand, ABTS showed the lowest sensitivity. These results show the importance of selecting the proper antioxidant activity quantification method for establishing a ranking of species based on this parameter.

scholarly journals Tomato Oil Encapsulation by α-, β-, and γ-Cyclodextrins: A Comparative Study on the Formation of Supramolecular Structures, Antioxidant Activity, and Carotenoid Stability

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1553
Author(s):  
Miriana Durante ◽  
Francesco Milano ◽  
Monica De Caroli ◽  
Livia Giotta ◽  
Gabriella Piro ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Aqueous Media ◽  
Storage Period ◽  
Attenuated Total Reflection ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Scanning Calorimetry ◽  
Freeze Dried ◽  
Oil In Water ◽  
Trolox Equivalent ◽  
Morphological Differences

Cyclodextrins (CDs) are oligosaccharides, comprising 6 (α), 7 (β), or 8 (γ) glucose residues, used to prepare oil-in-water emulsions and improve oil stability towards degradation. In this research, the aptitude of α-, β-, and γ-CDs to form complexes with a supercritical CO2 extracted lycopene-rich tomato oil (TO) was comparatively assessed. TO/CD emulsions and the resulting freeze-dried powders were characterized by microscopy, Fourier transform infrared-attenuated total reflection (FTIR-ATR), and differential scanning calorimetry (DSC), as well as for their antioxidant activity. Furthermore, carotenoid stability was monitored for 90 days at 25 and 4 °C. Confocal and SEM microscopy revealed morphological differences among samples. α- and β-CDs spontaneously associated into microcrystals assembling in thin spherical shells (cyclodextrinosomes, Ø ≈ 27 µm) at the oil/water interface. Much smaller (Ø ≈ 9 µm) aggregates were occasionally observed with γ-CDs, but most TO droplets appeared “naked”. FTIR and DSC spectra indicated that most CDs did not participate in TO complex formation, nevertheless structurally different interfacial complexes were formed. The trolox equivalent antioxidant capacity (TEAC) activity of emulsions and powders highlighted better performances of α- and β-CDs as hydrophobic antioxidants-dispersing agents across aqueous media. Regardless of CDs type, low temperature slowed down carotenoid degradation in all samples, except all-[E]-lycopene, which does not appear efficiently protected by any CD type in the long storage period.

scholarly journals Phenolic Compounds from the Fruits of Medemia argun, a Food and Medicinal Plant of Ancient Egypt

2016 ◽  
Vol 11 (3) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Milena Masullo ◽  
Arafa I. Hamed ◽  
Usama A. Mahalel ◽  
Cosimo Pizza ◽  
Sonia Piacente
Keyword(s):  
Antioxidant Activity ◽  
Chemical Composition ◽  
Ancient Egypt ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Phenolic Fraction ◽  
Oxidative Reactions ◽  
Phytochemical Investigation ◽  
Trolox Equivalent ◽  
In Vitro Antioxidant Activity

Medemia argun is a mysterious and little known monotypic fan palm from the Nubian Desert Oases of southern Egypt and northern Sudan. Its fruits have been found in the tombs from the 5th Dynasty (ca. 2500 BC) to Roman times (6–7th century AD), including the celebrated tomb of Tutankhamun. In ancient Egypt, the fruits of this palm were widely distributed and were highly valued, as confirmed by their frequent occurrence in offerings in the tombs. İn order to elucidate the chemical composition of the phenolic fraction, phytochemical investigation of the BuOH extract of fruits was carried out to afford eight compounds (1–8), among which was the new 2,4-dihydroxy-6-methylacetophenone 2- O-β-D-glucopyranoside (1). With the aim to investigate if the high shelf life of M. argun fruits could be related to the occurrence of antioxidant principles that were able to prevent oxidative reactions, the evaluation was carried out of the in vitro antioxidant activity by Trolox equivalent antioxidant capacity (TEAC) assay of the extract and isolated compounds.

scholarly journals Impact of Bovine Lipocalin-2 Gene on the Antioxidant Activity of Milk from Polish Holstein-Friesian Cows

Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 992 ◽  
Author(s):  
Joanna Pokorska ◽  
Dominika Kułaj ◽  
Agata Piestrzyńska-Kajtoch ◽  
Anna Radko
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Capacity ◽  
Antioxidant Properties ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Lipocalin 2 ◽  
Holstein Friesian ◽  
Total Antioxidant ◽  
Trolox Equivalent ◽  
Daily Milk Yield ◽  
Friesian Cows

In the recent years, antioxidant properties of food products have become an important aspect for consumers. Milk is a very good source of easily absorbable proteins and minerals, as well as a valuable source of antioxidants. Lipocalin-2 (LCN2), given that, inter alia, it is produced in large quantities by various types of cells in response to oxidative stress caused by physical or chemical factors, it can be considered a protein that determines the total antioxidant capacity of milk. The main objective of this study was to analyze polymorphisms within the lipocalin-2 gene and to determine their impact on antioxidant activity of milk from Holstein-Friesian cows. The genotyping was carried out by sequencing of PCR products. To determine the antioxidant activity of milk, the Trolox equivalent antioxidant capacity (TEAC) method was used. A total of four polymorphic sites were identified in the examined segment of the bovine lipocalin-2 gene. It was shown that cows of the CC genotype at the locus g.98793763G>C produced milk of significantly higher antioxidant capacity. The antioxidant capacity of milk also varied according to the age of cows, their daily milk yield, and SCC in milk.

scholarly journals Uncovering Phenotypic Diversity and DArTseq Marker Loci Associated with Antioxidant Activity in Common Bean

Genes ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 36 ◽  
Author(s):  
Muhammad Azhar Nadeem ◽  
Müttalip Gündoğdu ◽  
Sezai Ercişli ◽  
Tolga Karaköy ◽  
Onur Saracoğlu ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Common Bean ◽  
Phenotypic Diversity ◽  
Radical Scavenging ◽  
Genotype By Environment Interaction ◽  
Mixed Linear Model ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Environment Interaction ◽  
Seed Color ◽  
Trolox Equivalent

Antioxidants play an important role in animal and plant life owing to their involvement in complex metabolic and signaling mechanisms, hence uncovering the genetic basis associated with antioxidant activity is very important for the development of improved varieties. Here, a total of 182 common bean (Phaseolus vulgaris) landraces and six commercial cultivars collected from 19 provinces of Turkey were evaluated for seed antioxidant activity under four environments and two locations. Antioxidant activity was measured using ABTS radical scavenging capacity and mean antioxidant activity in common bean landraces was 20.03 µmol TE/g. Analysis of variance reflected that genotype by environment interaction was statistically non-significant and heritability analysis showed higher heritability of antioxidant activity. Variations in seed color were observed, and a higher antioxidant activity was present in seeds having colored seed as compared to those having white seeds. A negative correlation was found between white-colored seeds and antioxidant activity. A total of 7900 DArTseq markers were used to explore the population structure that grouped the studied germplasm into two sub-populations on the basis of their geographical origins and trolox equivalent antioxidant capacity contents. Mean linkage disequilibrium (LD) was 54%, and mean LD decay was 1.15 Mb. Mixed linear model i.e., the Q + K model demonstrated that four DArTseq markers had significant association (p < 0.01) for antioxidant activity. Three of these markers were present on chromosome Pv07, while the fourth marker was located on chromosome Pv03. Among the identified markers, DArT-3369938 marker showed maximum (14.61%) variation. A total of four putative candidate genes were predicted from sequences reflecting homology to identified DArTseq markers. This is a pioneering study involving the identification of association for antioxidant activity in common bean seeds. We envisage that this study will be very helpful for global common bean breeding community in order to develop cultivars with higher antioxidant activity.

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