scholarly journals Antioxidants: Terminology, Methods, and Future Considerations

Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 297 ◽  
Author(s):  
Khiena Brainina ◽  
Natalia Stozhko ◽  
Marina Vidrevich

Unreliable terminology and incompatible units of antioxidant activity/concentration expression lead to the failure of antioxidant clinical trials, ambiguity of conclusions about the effect of a chosen therapy in medicine and evaluation of food quality, diet, difficulties using information in monitoring the training process in sports, etc. Many different terms (antiradical activity, antioxidant activity, antioxidant capacity, antioxidant power, antioxidant ability) and methods: Trolox equivalent capacity assay (TEAC), Ferric Reducing Antioxidant Power assay (FRAP), Cupric Reducing Antioxidant Capacity assay (CUPRAC), antioxidative activity assay (ABTS), the oxygen radical absorbance capacity (ORAC), and different options of electrochemical ones) proposed for the determination of antioxidants are described. Possible approaches to the development of this field of science and practice are considered.

2013 ◽  
Vol 59 (3) ◽  
pp. 63-75 ◽  
Author(s):  
Paulina Malinowska

Abstract The aim of this work was to evaluate the antioxidant capacity and flavonoids content in 10 commercial cosmetic plant extracts used in cosmetics industry. Antioxidant activity of plant extracts were measured using two methods: FRAP (Ferric Reducing Antioxidant Power) and TEAC (Trolox Equivalent Antioxidant Capacity). The relationship between flavonoids content and antioxidant capacity of plant extracts were checked. As a result of this research it was found that FRAP and TEAC values of plant extracts significantly depend on the flavonoids content. The highest antioxidant activity, both in FRAP and TEAC assays, was observed for arnica flowers, hawthorn flowers and lungwort herb extracts. These extracts can be used as source of natural antioxidants for the prolongation of the oxidative stability of cosmetic products. Additionally, they can replace synthetic antioxidants


2010 ◽  
Vol 5 (3) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Rasyidah Razab ◽  
Azlina Abdul Aziz

Plants that contain high amounts of polyphenolic compounds are potential candidates for natural antioxidant sources. Studies are on going in the search for new sources of antioxidants. Not much data are available on the antioxidant capacity of tropical herbs. With this in mind, 19 commonly consumed Malaysian herbs were analyzed for their polyphenolic content and antioxidant activities. A majority of these plants have never been studied before with regards to their polyphenolic content and antioxidant activities. The shoots of Anacardium occidentale, the shoots and fruits of Barringtonia racemosa, Pithecellobium jiringa and Parkia speciosa had high polyphenolic contents (> 150 μg gallic acid equivalents/mg dried plant) and antioxidant activities when measured using the ferric reducing antioxidant power (FRAP) (>1.2 mM) and Trolox equivalent antioxidant capacity (TEAC) assays (>2.4 mM). A strong correlation was observed between the two antioxidant assays (FRAP vs TEAC) implying that the plants could both scavenge free radicals and reduce oxidants. There was also a strong correlation between the antioxidant activities and polyphenolic content suggesting the observed antioxidant activities were contributed mainly by the polyphenolics in the plants.


2020 ◽  
Vol 8 (2) ◽  
pp. 244-255
Author(s):  
Inssaf Skanderi ◽  
Ourida Chouitah

Cedrus atlantica Manetti Tar was analyzed by gas chromatography coupled to mass spectrometry, it was subjected to analyzes to know their total polyphenolic and condensed tannins contents, also their Ferric-reducing antioxidant power and Total antioxidant capacity. Chemical characterization identified 88 constituents where Himachalene and α-atlantone isomers (14.51 % - 4.07 %), Calacorene (3.52 %) and ar-Turmerone 3.35 %, were the major components, the total polyphenolic content and condensed tannins contents were 57.15 ± 0.15 milligrams equivalent of gallic acid /g tar and 4.41 ± 0.05 milligrams equivalent of catechin /g tar respectively .This extract showed remarkable Ferric-reducing antioxidant power with effective concentration equal to 50 ± 0.075 mg /mL ± 0,00028 and total antioxidant capacity equal to 262.75 mg equivalents of ascorbic acid /g tar ± 14,43. The experimental results indicated that our tar has promotive antioxidant activity.


2019 ◽  
Vol 49 (10) ◽  
Author(s):  
Emilio Soto ◽  
Luis Bustos ◽  
Mario Juan Simirgiotis ◽  
Claudio Parra

ABSTRACT: Baccharis alnifolia Meyen & Walp. is a native and medicinal, Chilean Altiplano herb that is used as a poultice and also consumed as an infusion to relieve inflammation. This study evaluated the antioxidant and cytotoxic effect of the ethanolic extract of B. alnifolia and their infusion. It was reported that the ethanol extract contains 4.42 mg GAE/g of dry weight and the infusion contains 35.86 mg GAE/L of total polyphenols. Also, it determined the antioxidant capacity using Ferric reducing antioxidant power (FRAP), Oxygen Radical Absorbance Capacity (ORAC) and Trolox equivalent antioxidant capacity (TEAC) assay. Moreover, seven metabolites including between phenolic acids and flavonoids were identified for the first time in both extracts of the medicinal plant Baccharis alnifolia. The UHPLC-DAD chromatograms revealed the majority presence of ferulic acid and luteolin, both could be responsible for the antioxidant and cytotoxic activity. Furthermore, we realized a preliminary screening of cytotoxicity in different tumor cell lines, finding that these extracts have cytotoxic potential on kidney cells.


2020 ◽  
Vol 85 (4) ◽  
pp. 517-529
Author(s):  
Stanislava Gorjanovic ◽  
Ferenc Pastor ◽  
Sofia Loupassaki ◽  
Mile Veljovic ◽  
Predrag Vukosavljevic ◽  
...  

Serbian aromatized wine ?Bermet? from grapes grown on Fruska Gora Mountain has been in production since the 15th century. Ten commercial Bermets produced according to the traditional procedure by different manufacturers, and six prepared within the scope of this study were assessed for antioxidant (AO) activity using electrochemical, chemiluminescent and spectrophotometric AO assays. Direct current polarographic assay based on the decrease of anodic current of [hydrogen(peroxido)(1-)]hydroxidomercury(II) complex formation in alkaline H2O2 solution at potential of mercury oxidation, chemiluminescent H2O2 scavenging assay, as well as commonly used spectrophotometric assays (2,2?-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) based Trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1- picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP)) were used. Total phenolic content (TPC) was determined by Folin?Ciocalteu assay. The results obtained were correlated using regression analysis, ANOVA and F-test. An integrated approach to AO capacity determination allowed a more comprehensive comparison between samples. The approach is based on the introduction of the relative antioxidant capacity index, calculated by assigning each AO assay equal weight, and by PCA analysis. In addition, the introduction of phenolic antioxidant coefficients, calculated as the ratio between individual AO capacity and TPC, enabled a better understanding of their relation.


2009 ◽  
Vol 27 (No. 5) ◽  
pp. 338-351 ◽  
Author(s):  
J. Oszmiański ◽  
A. Wojdyło

The objective of this research was to evaluate the effect of blackcurrant mash blended with apple pulp during juice production and storage on its phenolic composition, antioxidant activity, L-ascorbic acid, and colour. Five variants of samples were prepared: apple juices from two cultivars: the Shampion and Idared cultivars without and with 20% of blackcurrant pulp and blackcurrant juice which were stored at 4°C and 30°C for 6 months. The apple juices prepared from the Idared and Shampion cultivars had a very low L-ascorbic acid contents (1.32 mg/l and 6.26 mg/l, respectively) whereas blackcurrant juice showed the highest amount of L-ascorbic acid, i.e. 704.3 mg/l. The addition of 20% of blackcurrant pulp before apple crashing resulted in a great difference between L-ascorbic acid contents in juices. The addition of blackcurrant fruits before apple crushing had a statistically significantly different (<i>P</i> < 0.05) influence on phenolic compounds, especially in Idared blended pulp. As compared with the control samples, flavan-3-ol concentration increased 4 times in juices made from 80% of Idared apples blended with 20% of blackcurrant fruits. Apple pulp blended with blackcurrant was richer in hydroxycinnamic acids (especially caffeic, <i>p</i>-coumaric, and neochlorogenic acids) than juices made only from apples. The results ranged from 83.05 to 3297.6µM T/100 ml for DPPH (1,1-diphenyl-2-picrylhydrazyl radical), from 20.64 to 490.93µM T/100 ml for ABTS (2,2’azinobis-(3-ethylbenzthiazoline-6-sulphonic acid)), and from 1.52 to 37.35µM T/ml for FRAP (Ferric reducing antioxidant power assay) for apple juice made from the Idared cultivar and for blackcurrant juice, respectively. The highest level of the antioxidant capacity (<i>P</i> < 0.05) observed in the blackcurrant sample was due to the effect of the high anthocyanin and ascorbic acid contents. The apple juice colour showed a moderate degradation with time as indicated by the slight reduction of <i>L</i>* values in the samples stored at 4°C for 6 months, and a much higher decrease of <i>L</i>* values in the samples stored at 30°C. The lightness of the apple blended with blackcurrant increased during storage as a result of the coloured anthocyanin degradation. The temperature during the sample storage (30°C) had a significant influence, resulting in a higher degradation of all phenolics compounds analysed, colour and antioxidant activity.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Xiu-Li Zhang ◽  
Yong-Dong Zhang ◽  
Tao Wang ◽  
Hong-Yun Guo ◽  
Qi-Ming Liu ◽  
...  

Several assays have been frequently used to estimate antioxidant capacities includingABTS•+, DPPH, and FRAP assays. Xanthohumol (XN), the major prenylated flavonoid contained in beer, witnessed various reports on its antioxidant capacity. We systematically evaluated the antioxidant activity of XN using three systems, 2,2,-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS•+) scavenging assays, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assays, and ferric reducing antioxidant power (FRAP) assays. The results are expressed as Trolox equivalent antioxidant capacity (TEAC). The TEAC of XN was0.32±0.09 μmol·l−1by the ABTS assay and0.27±0.04 μmol·l−1by the FRAP. Meanwhile, the XN did not show obviously scavenging effect on DPPH radical reaction system. These results showed that different methods in the evaluation of compound antioxidant capicity, there may be a different conclusion.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4001
Author(s):  
Xiaoxi Liao ◽  
Phillip Greenspan ◽  
Ronald B. Pegg

Two common extraction solvent systems, namely acidified aqueous methanol and acidified aqueous acetone, were used to extract blackberry phenolics, and the antioxidant properties of the recovered extracts were compared. The crude extracts were fractionated into low- and high-molecular-weight phenolics by Sephadex LH-20 column chromatography. The hydrophilic-oxygen radical absorbance capacity (H-ORACFL), ferric reducing antioxidant power (FRAP), and the cellular antioxidant activity (CAA) assays were employed as indices to assess antioxidant capacity of the extracts and their respective fractions. The methanolic solvent system displayed a greater efficiency at extracting anthocyanin and flavonol constituents from the blackberries, while the acetonic solvent system was better at extracting flavan-3-ols and tannins. Anthocyanins were the dominant phenolic class found in the blackberries with 138.7 ± 9.8 mg C3G eq./100 g f.w. when using methanol as the extractant and 114.6 ± 3.4 mg C3G eq./100 g f.w. when using acetone. In terms of overall antioxidant capacity of blackberry phenolics, the acetonic solvent system was superior. Though present only as a small percentage of the total phenolics in each crude extract, the flavan-3-ols (42.37 ± 2.44 and 51.44 ± 3.15 mg/100 g f.w. in MLF and ALF, respectively) and ellagitannins (5.15 ± 0.78 and 9.31 ± 0.63 mg/100 g f.w. in MHF and AHF, respectively) appear to account for the differences in the observed antioxidant activity between the two solvent systems.


Author(s):  
Reine Raïssa Rolande Aworet Samseny ◽  
Line-Edwige Mengome ◽  
Sophie Aboughe Angone

Aims: Free radicals are involved in many diseases. Antioxidants help control them. The overproduction of free radicals or reduction of natural antioxidants promotes the destruction of cells in our body, for example in neurodegenerative diseases. The aim of our study is to evaluate the correlation between the level of polyphenol and antioxidant activity of Dichrostachys cinerea barks he work was carried out at the phytochemistry department of the Institute of Pharmacopoeia and Traditional Medicine (Gabon). Methodology: Different extracts of Dichrostachys cinerea barks were obtained with polarity solvent (dichloromethane, ethyl acetate, butanol, methanol and water).  The antioxidant activity is evaluating using respectively FRAP method (Ferric Reducing Antioxidant Power), antiradical activity by the method of inhibition of DPPH radical (2.2-diphenyl-1-picrylhydrazyl), cations ABTS radical (2.2'-azinobis-[3-acid-6-sulfonic ethylenzothiazoline]). Results: Ethyl acetate and dichloromethane extract have the higher value for polyphenolic compounds, respectively 52,27±0,66 mg EAG / g and 49,72±0,55 mg EAG / g. Aqueous extract have the lower value 20,67±1,05 mg EAG / g. The different fractions of Dichrostachys cinerea have antioxidant effect, and this effect is in correlation with its constituents: polyphenols, tannins and flavonoids. Results were compared to standard antioxidants such as ascorbic acid and quercetin. Conclusion: This study confirms higher is the level of polyphenols greater is the antioxidant power.


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