Determination Of Total Antioxidant Activity Research Articles

Salt Tolerance Assessment in Triticum Aestivum and Triticum Durum.

Salt stress is a multicomponent phenomenon; it includes many processes that directly or indirectly affect the plant. Attempts have been made to comprehensively consider the processes of salt stress in plants Triticum aestivum (variety Orenburgskaya 22) and Triticum durum (variety Zolotaya). The study used methods of light and fluorescence microscopy, methods of immunofluorodetection, expression of DNA methyltransferase genes, genes of the ion transporter and superoxide dismutase families, as well as biochemical determination of total antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) reagent. According to morphometric indicators, the Orenburgskaya 22 variety showed greater tolerance to the action of 150 mM NaCl than the Zolotaya variety. The level of expression of genes of the HKT ion transporter family in the Orenburgskaya 22 variety is higher than in the Zolotaya variety. It was found that the expression of the DNA methyltransferase gene DRM2.1, which post-translationally methylates cytosine residues, is 22.3 times higher in Zolotaya compared to Orenburg 22 when exposed to salt. The accumulation of toxic ions is accompanied by an increase in reactive oxygen species (ROS) and increased damage to root tissue, especially in the Zolotaya variety. Using fluorescence microscopy using the Carboxy-H2DFF marker in the Orenburgskaya 22 variety at high NaCl concentrations, the highest fluorescence intensity was determined in the cap zone; in the Zolotaya variety-in the zones of the cap and root meristem. Excess ROS is more successfully removed in the Orenburgskaya 22 variety, which has a higher level of antioxidant activity (AOA), as well as the level of expression of the Cu/ZnSOD and MnSOD superoxide dismutase genes. Using programmed cell death (PCD) markers based on the release of cytochrome c from mitochondria into the cytoplasm, DNA breakage and the release of phosphatidylserine from mitochondria, the degree of damage to root cells was assessed in both wheat varieties. It has been proven that wheat cell death occurs through the mitochondrial pathway. It was noted that the salt-sensitive variety Zolotaya had a significant number of necrotic cells. Based on the data obtained, it was concluded that the Orenburgskaya 22 variety exhibits greater resistance to salinity than the Zolotaya variety. These data may be of practical importance for enhancing protective mechanisms under abiotic stress.

Association between adherence to a low carbohydrate dietary (LCD) pattern with breast milk characteristics and oxidative markers in infants’ urine: a cross-sectional study

BackgroundBreast milk (BM) is a dynamic fluid that varies over time and between women. The variations in BM components are most likely associated with maternal diet quality. This study aimed to assess adherence to a low carbohydrate dietary (LCD) pattern with oxidative stress markers of BM characteristics and infants’ urine.Materials and methodsIn this cross-sectional study 350 breastfeeding mothers and their infants were recruited. BM samples were collected from mothers, and urine specimens were obtained from each infant. To evaluate LCD scores, subjects were divided into 10 deciles according to the percent of energy obtained from carbohydrates, proteins, and fats. Determination of total antioxidant activity was conducted using the ferric reducing antioxidant power (FRAP), 2, 2′-diphenyl-1-picrylhydrazyl (DPPH), thiobarbituric acid reactive substances (TBARs), and Ellman’s assay. Biochemical assays of samples including calcium, total protein, and triglyceride level were also performed using commercial kits.ResultsParticipants with the greatest LCD pattern adherence were placed into the last quartile (Q4), and those with the minimum LCD were in the first quartile (Q1). Individuals in the highest LCD quartile had significantly higher levels of milk FRAP, thiol, and protein, as well as infant urinary FRAP and lower milk MDA levels than those in the lowest quartile. Multivariate linear regression analyses indicated that higher score of the LCD pattern was associated with a higher level of milk thiol, protein, and lower level of milk MDA (p < 0.05).ConclusionOur findings show that adherence to a LCD, as defined by a low level of carbohydrates in daily food intake, is linked with improved BM quality and markers of oxidative stress in infant urine.

Electrochemical approaches based on micro- and nanomaterials for diagnosing oxidative stress.

This review article comprehensively discusses the various electrochemical approaches for measuring and detecting oxidative stress biomarkers and enzymes, particularly reactive oxygen/nitrogen species, highly reactive chemical molecules, which are the byproducts of normal aerobic metabolism and can oxidize cellular components such asDNA, lipids, and proteins. First, we address the latest research on the electrochemical determination of reactive oxygen species generating enzymes, followed by detection of oxidative stress biomarkers, and final determination of total antioxidant activity (endogenous and exogenous). Most electrochemical sensing platforms exploited the unique properties of micro- and nanomaterials such as carbon nanomaterials, metal or metal oxide nanoparticles (NPs), conductive polymers and metal-nano compounds, which have been mainly used for enhancing the electrocatalytic response of sensors/biosensors. The performance of the electroanalytical devices commonly measured by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in terms of detection limit, sensitivity, and linear range of detection is also discussed. This article provides a comprehensive review of electrode fabrication, characterization and evaluation of their performances, which are assisting to design and manufacture an appropriate electrochemical (bio)sensor for medical and clinical applications. The key points such as accessibility, affordability, rapidity, low cost, and high sensitivity of the electrochemical sensing devices are also highlighted for the diagnosis of oxidative stress. Overall, this review brings a timely discussion on past and current approaches for developing electrochemical sensors and biosensors mainly based on micro and nanomaterials for the diagnosis of oxidative stress.

Evaluation of Factors Affecting Tree and Shrub Bark's Antioxidant Status.

The importance of using the barks of trees and shrubs as powerful natural antioxidants suggests the necessity to evaluate the effect of different environmental factors on bark extracts’ quality. The determination of total antioxidant activity (AOA) and polyphenol content (TP) in the bark of 58 tree and shrub species from 7 regions differing in mean annual temperature, insolation, humidity, salinity level, and altitude was performed. The above stress factors positively affected bark AOA but did not have a statistically significant effect on TP. The bark of trees grown in the seashore proximity was characterized by significantly higher AOA than samples gathered in other areas, similarly to the trees grown at high altitude. The bark antioxidant status of 18 species was described for the first time. New sources of powerful antioxidants were represented by the ornamental shrubs Cornus sanguinea and Cornus alba, which showed the highest AOA (169–171 mg GAE g−1 d.w.). Among the typical halophytes, Calligonum and Tamarix had high AOA (172 and 85 mg GAE g−1 d.w.), while in the bark of tamarisk, an Se accumulator, an Se concentration of about 900 µg kg−1 d.w. was recorded. A significant positive correlation was found between leaves and bark AOA in the Karadag Nature Reserve’s deciduous trees (r = 0.898, p < 0.01). The relationship between bark AOA and TP was highly significant (r = 0.809; p < 0.001) for all samples except the mountainous ones. The results of the present research revealed new opportunities in successive bark utilization.

Antioxidant and physicochemical properties of Chrysophyllum albidum fruit at different ripening stages

Chrysophyllum albidum (African Star Apple) fruit is an indigenous African fruit. The African Star Apple plant popularly referred to as the “alasa” tree grows widely in tropical Africa. Ripening influences biochemical processes and subsequently affects the nutritional and bioactive characteristics of the fruits. This study sampled Chrysophyllum albidum fruit of three maturity stages and determined the colour, proximate, total phenol and antioxidant characteristics of the fruits. Spectrophotometric methods were used in the determination of total antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2-azinobis,3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and Ferric reducing ability of plasma (FRAP) assay. Significant differences (p&lt;0.05) were observed in the colour of the fruit across all the ripening stages. The ripe stage of the fruit recorded the highest extent of lightness among all the other ripening stages. Both the ripe and over-ripe fruits appeared reddish in colour with the ripe fruit demonstrating a higher red intensity than the over-ripe fruit. The calculated metric chroma of the Chrysophyllum albidum fruits were in the range of 2.33-21.67 for the three ripening stages. Hue angle values recorded were in the range 46.46-92.00. Browning and colour indices for fruits of all the stages of development were of range 6.40-80.30 and -14.30-16.96, respectively. Proximate analysis of the three fruit categories showed that the unripe fruits had higher carbohydrate (69.27 %), crude protein (8.17 %), and crude fat (7.99 %) content relative to fruits which were ripe and over-ripe. The over-ripe fruit had higher crude fibre (7.36 %) and ash (3.86 %) content. Total phenolic content for the unripe fruit (20μg GAE/mg) was also higher than fruits of the other ripening stages. The antioxidant ability of the Chrysophyllum albidum fruit showed that the unripe stage recorded the highest DPPH (29.24 %) and ABTS (99.09 %) radical scavenging activity. The ferric reducing antioxidant potential of the fruit at different ripening stages was significantly different (p&lt;0.05) with the unripe stage recording the highest potential. The unripe fruits demonstrated higher proximate and antioxidant composition than the ripe and over-ripe fruits. Extracts from the unripe fruit can serve as useful nutraceuticals in functional food formulations.

Determination of Angelica archangelica’s Antioxidant Capacity and Mineral Content

AbstractThe aim of this study was to determine the mineral contents by ICP‐MS and the antioxidant capacity of Angelica archangelica plant, which is not well known in the literature. For this purpose, ethyl alcohol extracts of the branches and leaves of the plant; different bioanalytical methods such as reducing capacity by Fe3+−Fe2+ transformation method, Fe3+‐TPTZ reducing capacity by FRAP method, Cu2+‐Cu+ reducing capacity by CUPRAC method, the ferric ions (Fe2+) chelating activity by using bipyridyl reagent, DPPH (1,1‐diphenyl‐2‐picryl‐hydrazyl) free radical, DMPD (N,N‐dimethyl‐p‐phenylenediamine), ABTS (2,2’‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulfonic acid) radical scavenging activities, total antioxidant activity determination according to thiocyanate method, total phenolic and total flavonoid activity were used. As standard, BHT, BHA, α‐Tocopherol, Trolox were used. A. archangelica branches and leaves demonstrated 88.13 % and 93.90 % inhibition of linoleic acid emulsion peroxidation at 20 mg mL−1 concentration. Also, it was determined that both leaves and branches of A. archangelica plant were dense with P, Mg, Ca and K minerals with ICP‐MS device. It is considered that the results of the manuscript will guide the antioxidant studies, medicine, cosmetics, pharmacology and food sector.

Antioxidant activity and total phenolic content of fresh and cured rhizomes of Curcuma longa and Etlingera philippinensis

The search for effective natural antioxidants has been increasing nowadays due to human health concern. Further investigation of the Zingiberaceae plants such as Etlingera philippinensis, a Philippine endemic plant, and Curcuma longa (turmeric) is key towards alleviating this concern. The present work aimed to provide fundamental information on the total antioxidant activity (TAA), total phenolic content (TPC), and curcumin content of the ethanolic extracts of the fresh and cured rhizomes of C. longa and E. philippinensis. Healthy and fresh rhizomes of E. philippinensis were collected from Kibawe, Bukidnon, while C. longa were from Musuan, Bukidnon, Philippines. TAA determination was done using phosphomolybdenum method, while TPC and curcumin content using spectrophotometric method. Results showed that the TAA of fresh and cured rhizomes of C. longa were significantly higher than those of fresh and cured rhizomes of E. philippinensis. The TPC of fresh and cured rhizomes of C. longa were significantly higher than those of fresh and cured rhizomes of E. philippinensis. Significantly higher curcumin content was also observed in the rhizomes of C. longa as compared to that in the fresh and cured rhizomes of E. philippinensis. Generally, the ethanolic extracts of the cured rhizomes of E. philippinensis and C. longa exhibited higher TAA, TPC, and curcumin content than the fresh one. TAA, TPC, and curcumin were significantly correlated with each other. It can thus be concluded that E. philippinensis could also be a source of valuable curcumin.

ИЗУЧЕНИЕ ВОЗМОЖНОСТИ ИСПОЛЬЗОВАНИЯ ПОРОШКОВ УНАБИ ПРИ ПРОИЗВОДСТВЕ ХЛЕБОБУЛОЧНЫХ ИЗДЕЛИЙ

The problem of creating bakery products with functional properties is considered by many authors, but, despite this, all new additives from vegetable raw materials with various functional properties appear. In our work, fruit culture of unabi is considered, not very long ago regionalized in the south of Russia, the Crimea and the North Caucasus. In our work, studies were conducted on the fruits of unabi, which are widely grown in the Krasnodar Territory, the common variety Chinese-2, recommended for cultivation in the Crimea, and new varieties of unabi of the Nikitsky Botanical Garden (Koktebel, Sinit, Tsukerkovy, Radoslav). In the fresh fruits, the weight-measuring characteristics and organoleptic characteristics were determined, which made it possible to assign the varieties Sinit and Koktebel to the varieties for canning, and the rest to the dessert varieties. In the present work, the antioxidant properties of powders obtained from the fruit of boneless unabi were determined. The use of powders will solve the problem of seasonality of raw materials. Determination of total antioxidant activity in powders and buns was determined spectrophotometrically with aluminum chloride and Triton X100 using the FRAP method. As a result of research, it was found that powders of all varieties of fruit. In our work, the component composition of sugars in powders was studied by gas chromatography. The grade “Chinese-2” contained 48.8% sucrose from the total amount of sugars, which determined its pronounced sweet taste. In all powders, 2 fractions of glucose α-glucose and β-glucose were determined; the mannose content did not exceed 8.2% (Croctebel variety). Based on a study of the organoleptic and physico-chemical indicators of the buns, the optimal amount of the added additive was established – 5%, despite the fact that the antioxidant activity when introducing 10% of the additive was 1.5 times higher.

Impact of germination on antioxidant capacity of garden cress: New calculation for determination of total antioxidant activity

The aim of the present study is to evaluate the antioxidant capacity of garden cress seeds during germination. The total phenolic and flavonoid contents increased several times during germination. Sixteen phenolic acids and flavonoids were detected in sprouts with high concentrations compared with fourteen in dry seeds using HPLC. Similar antioxidant activities, using Trolox equivalent (TE), were detected in the same days of germination by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS) assays. The IC50 values, the concentrations of phenolic compounds required to scavenge 50% of free radicals, for the same days of germination using ABTS assay were lower than those recorded for DPPH assay by 4–6 folds. The low IC50 value reflects the high antioxidant activity. Therefore, a new calculation for determination of the total antioxidant activity based on the total phenolic content and IC50 was established: Total antioxidant activity = the total phenolic content/IC50. The new calculation appeared that the total antioxidant activities in the same days of germination using ABTS were also increased than those recorded for DPPH by 4–6 folds. The results proved that the use of IC50 for calculating the total antioxidant activity was more accurate than TE. Generally, the antioxidant activity increased during germination of garden cress and reached to highest activity on day six. A strong correlation between oxidoreductase enzymes and antioxidant capacity during germination of garden cress was observed. In conclusion, the garden cress sprouts are recommended to consume instead of dry seeds to utilize their quality as foodstuff and health enhancer.

Polyphenols analysed by UHPLC-ESI-MS/MS and antioxidant activities of molasses, acorn and leaves of oak (Quercus robur subsp. pedunculiflora)

Objectives: The leaves of oak trees have been boiled in water and the extracts have been evaporated to produce oak molasses. Colloidal precipitants have been widely used as dietary molasses since have very effective antiseptic functions as alternative medicine for ages in some parts of the world. Present study aimed to investigate the biological activities of oak products for elucidating the scientific basis of alternative medicine. Thus, antioxidant activities of ethanol and water extracts of acorn, leaves and molasses of oak trees (Quercus robur subsp. pedunculiflora) were evaluated. Results: We determined antioxidant activities of extracts by different in vitro methods including DPPH free radical scavenging, ABTS•+ radical scavenging, total antioxidant activity determination by ferric thiocyanate method, reducing power by FRAP methods, separately. The results were compared with BHA, BHT and ascorbic acid as standard antioxidant compounds. The acorn seed extract, which presented the highest antioxidant potential, was the most effective scavenger against DPPH free radical. Also, phenolic compounds of the molasses were identified by UHPLC-ESI-MS/MS. The highest phenolic compound was quinic acid (4556 ± 219 ppb). Conclusion: Acorns and leaves of oak trees (Quercus robur subsp. pedunculiflora), as well as traditional oak molasses” have high antioxidant potential for the food industry as a food ingredient to produce functional food products.

Approaches to the determination of antioxidant activity of extracts from bee bread and safflower leaves and flowers

The main objective of this study was to develop approaches for the determination of total antioxidant activity of natural products (bee bread and safflower extracts) using DPPH radical scavenging assay. Considering that analytical procedures and results related to this assay and reported by many authors are significally differed between each other and depend on many factors (the nature of tested extracts, the nature of solvents for extraction, a reaction time of DPPH with a sample, DPPH solvents and concentration, ratio between DPPH and an extract, etc.), the methodology of the evaluation of antioxidant capacity of different origin extracts by DPPH radical scavenging assay was developed. Ascorbic acid (AA) was used as standard antioxidant and the correlation between the percentage of DPPH scavenging and AA concentration was determined at two different initial absorbances of DPPH solution. Average concentration of AA which inhibited 50% of DPPH radicals (IC50) was equal to 156.0 - 171.26 µg.mL-1. The reaction kinetics of DPPH inhibition by bee bread and safflower extracts was described by the curves of the dependence of the total antioxidant activity on time with squared correlation coefficients (R2) in the range of 0.89 - 0.98. The reaction times for these extracts were from 40 to 70 min at the correct ratio of volumes between the tested extracts and a DPPH solution. These studies demonstrated that the extracts obtained from bee bread of 2016 year of pollen collection had significantly higher the total antioxidant activity compared with the extracts of bee bread of pollen collection of 2015 considering the ratio of bee bread and the solvent in the extracts and volume of the extract for the procedure. This fact is explained not only botanical origin bun also the time of the storage of bee bread before the preparation of extracts. There was not found significant differences in the total antioxidant activity of extracts from flowers of safflower sown in fall and in spring. Antioxidant activity of the extracts from leaves of spring sown safflower was higher compared with the total antioxidant activity of the extracts from fall sown plants. Ascorbic acid equivalents of the tested extracts could be ranged as follows: bee bread of 2016 pollen collection &gt;bee bread of 2015 pollen collection &gt;leaves of safflower spring sown &gt;flowers of safflower spring sown &gt;flowers of safflower fall sown &gt;leaves of safflower fall sown.

In English

Number of dietary supplements under the trade name of Phytosils based on fumed silica as enterosorbent and highly dispersed native medicinal plants in various combinations and ratio aimed on specific therapeutic action were developed by the authors. Essential bioactive components of Phytosils are p lant poly phenols known for their antiallergenic, antiatherogenic, antiinflammatory, antimicrobial, antioxidant, antithrombotic, cardioprotective and vasodilatory effects which are attributed mainly to their antioxidant activity. Therefore, the value of antioxidant activity in relation to total phenolic content could be used for the standardization of these new herbal dietary supplements. Asimple, rapidand sensitive spectrophotometric method for the determination of total antioxidant activity of herbal products has been developed and tested on seven Phytosil multiherbal dietary supplements. The method was based on the reducing of yellow (λ′ max =268 nm, λ max ′′=298 nm)copper(II) tetrabenzo-[b,f,j,n][1,5,9,13]- tetraazacyclohexadecine complex (CuTAAB 2+ ) by natural antioxidants with formation of blue (λ max = 660–712 nm) copper(I) complex CuTAAB + . It has been shown that total antioxidant activity of Phytosil dietary supplements strongly correlates to their total phenolic content (all r 2 values ≥ 0.960) confirming that phenoliccompounds are dominant antioxidant components in these preparations. It can be concluded that antioxidant activity values determined by the proposed CuTAAB 2+ reducingmethod and total phenolic content determined at optimized wavelength can be used for good quality assurance and standardization of Phy tosil dietary supplements and other multi herbal preparations .

Determination of total antioxidant activity of fruit juices widely consumed in Syria

Fruits are considered essential constituents of a healthy diet. They possess antioxidant properties which can be attributed mainly to their phenolic compounds. Two samples of the following fruit juices (orange, grapefruit, blackberry, black mulberry, black sweet cherry, strawberry, pomegranate, organic tomato, greenhouse tomato, black plum, black grape and red grape) were investigated for their phenolic content and total antioxidant activity. Total phenolic content was determined according to Folin-Ciocalteu method. Black mulberry juice showed the highest results with amounts from 8.6gGAE/Ljuice to 11.2gGAE/Ljuice, while the lowest was red grape juice with amounts from 0.3 gGAE/Ljuice to 0.7gGAE/Ljuice. Total Antioxidant activity was subsequently determined using Ferric Reducing Antioxidant Power (FRAP) assay and reducing power assay. The results were in accordance with Folin-Ciocalteu method since black mulberry juice had the highest antioxidant power, while red grape juice had the lowest. The study indicates that black mulberry juice is the richest source of phenolic compounds and provides the highest antioxidant potential compared with other fruit juices in this study. Reducing power assay gave a similar order compared to FRAP assay. Both assays depend on reducing the ferric complex to its ferrous form which could explain the similarity in juice order considering their antioxidant activity.

Determination of Phytochemical and Antioxidant Activities in Adible Flowers

In the present study, edible flower samples belonging to 14 different genera were evaluated by employing various in vitro antioxidant assay such as total antioxidant activity determination by CUPRAC and FRAP, total phenolic content and plant pigments viz. Lycopene and β-carotene to investigate their antioxidant potential with specific Phytochemicals composition. The results showed that extracts Vinca Red flower exhibited highest antioxidant capacity viz. CUPRAC 32.33 µmol trolox/g followed by Vinca Pink 30.46 while, least was observed in Gomphrina 4.983 µmol while its counterpart FRAP was highest (2.07 µmol /g) in poppy as well as in Vinca pink and least (0.22) in wild salvia. The total phenolic content (TPC) was found to be highest in Pusa Narangi (2282.54 µg GAE/gfw). A negative correlation was found between phenols and three carotenes. β- Carotene was found to have negative correlation with the three antioxidant factors (CUPRAC, FRAP and Phenols) while lycopene and total caroteniods showed a positive correlation with CUPRAC and FRAP. The results revealed the presence of antioxidants, phenols and caroteniods in most of the flowers confirming flowers as a potential source of these phytonutrient.

Investigation of antioxidant capacity of the extracts of bilberry (VACCINUM MYRTILLIS L.) by voltammetry

This paper deals with the urgent issue of the search of new drugs based on plant raw materials that have an influence on various stages of oxidation processes occurring in the human body. The aim of this paper is to determine the antioxidant activity of the bilberry extracts that are used in the medicine practice by a cathodic voltammetry method.We consider the influence of water and alcohol bilberry extracts on the process of oxygen electroreduction. From these extracts the most activity relation to the process of cathodic oxygen reduction showed alcohol (40%) bilberry extract. It was also stated that the alcohol extract of bilberry has a greater antioxidant activity than other known antioxidants such as ascorbic acid, glucose, dihydroquercetin.Thus, after consideration of a number of plant objects, we showed the possibility of applying the method of cathodic voltammetry for the determination of total antioxidant activity of plant material and identifying and highlighting the most perspective sources of biologically active substances (BAS), as well as the ability of identifying extractants that fully extract BAS from plant raw materials. The activity data of extracts of plant raw materials gives an opportunity of establishing an effective yield phytopreparation based on bilberry that has an antioxidant effect.

Pistachio (Pistacia vera L.) Gum: a potent inhibitor of reactive oxygen species

In the present study, in order to evaluate antioxidant and radical scavenging properties of Pistachio gum (P-Gum), different bioanalytical methods such as DPPH• scavenging activity, DMPD•+ radical scavenging activity, total antioxidant activity determination by ferric thiocyanate, reducing ability Fe3+–Fe2+ transformation, Cuprac and FRAP assays, scavenging by riboflavin-methionine-illuminate system and ferrous ions (Fe2+) chelating activities by 2,2′-bipyridyl reagent were performed separately. P-Gum inhibited 54.2% linoleic acid peroxidation at 10 µg/ml concentration. On the other hand, BHA, BHT, α-tocopherol and trolox, pure antioxidant compounds, indicated inhibition of 80.3%, 73.5%, 36.2% and 72.0% on peroxidation of linoleic acid emulsion at the same concentration, respectively. In addition, all of sample had an effective DPPH•, DMPD•+ and scavenging, Fe3+ reducing power by Fe3+–Fe2+ transformation and FRAP assay, Cu2+ reducing ability by Cuprac method and Fe2+ chelating activities.

Spectroscopic studies on the antioxidant activity of ellagic acid

Ellagic acid (EA, C14H6O8) is a natural dietary polyphenol whose benefits in a variety of diseases shown in epidemiological and experimental studies involve anti-inflammation, anti-proliferation, anti-angiogenesis, anticarcinogenesis and anti-oxidation properties. In vitro radical scavenging and antioxidant capacity of EA were clarified using different analytical methodologies such as total antioxidant activity determination by ferric thiocyanate, hydrogen peroxide scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and superoxide anion radical scavenging, ferrous ions (Fe2+) chelating activity and ferric ions (Fe3+) reducing ability. EA inhibited 71.2% lipid peroxidation of a linoleic acid emulsion at 45μg/mL concentration. On the other hand, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), α-tocopherol and ascorbic acid displayed 69.8%, 66.8%, 64.5% and 59.7% inhibition on the peroxidation of linoleic acid emulsion at the same concentration, respectively. In addition, EA had an effective DPPH• scavenging, ABTS+ scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe3+) reducing power and ferrous ions (Fe2+) chelating activities. Also, those various antioxidant activities were compared to BHA, BHT, α-tocopherol and ascorbic acid as references antioxidant compounds. These results suggested that EA can be used in the pharmacological, food industry and medicine because of these properties.

Spectroscopic studies on the antioxidant activity of p-coumaric acid

p-coumaric acid (4-hydroxycinnamic acid), a phenolic acid, is a hydroxyl derivative of cinnamic acid. It decreases low density lipoprotein (LDL) peroxidation and reduces the risk of stomach cancer. In vitro radical scavenging and antioxidant capacity of p-coumaric acid were clarified using different analytical methodologies such as total antioxidant activity determination by ferric thiocyanate, hydrogen peroxide scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activity and superoxide anion radical scavenging, ferrous ions (Fe2+) chelating activity and ferric ions (Fe3+) reducing ability. p-Coumaric acid inhibited 71.2% lipid peroxidation of a linoleic acid emulsion at 45μg/mL concentration. On the other hand, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and ascorbic acid displayed 66.8%, 69.8%, 64.5% and 59.7% inhibition on the peroxidation of linoleic acid emulsion at the same concentration, respectively. In addition, p-coumaric acid had an effective DPPH scavenging, ABTS+ scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe3+) reducing power and ferrous ions (Fe2+) chelating activities. Also, those various antioxidant activities were compared to BHA, BHT, α-tocopherol and ascorbic acid as references antioxidant compounds. These results suggested that p-coumaric acid can be used in the pharmacological and food industry because of these properties.

Radical Scavenging and Antioxidant Capacity of Serotonin

Serotonin is a monoamine neurotransmitter and biochemically derived from tryptophan. The present paper examines the in vitro antioxidant and radical scavenging capacity of serotonin using different in vitro methodologies. For the determination of antioxidant activity of serotonin, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH-) scavenging, 2,2´- azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, total antioxidant activity determination by ferric thiocyanate, total reducing ability determination by Fe3+-Fe2+ transformation method, superoxide anion radical scavenging by riboflavin-methionine-illuminate system, H2O2 scavenging and ferrous ions (Fe2+) chelating activities of serotonin were performed. Also, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and trolox, a water-soluble analog of α-tocopherol, were used as the reference antioxidant radical scavenger compounds. Serotonin completely inhibited lipid peroxidation of a linoleic acid emulsion at 15 µg/mL concentration. On the other hand, the above mentioned standard antioxidants displayed inhibition of 92.2, 99.6, 84.6 and 95.6% on peroxidation of linoleic acid emulsion, respectively at the 45 µg/mL concentration. In addition, serotonin was effective in DPPH· scavenging, ABTS•+ radical scavenging, superoxide anion radical scavenging, H2O2 scavenging, ferric ions (Fe3+) reducing power and metal chelating on ferrous ions (Fe2+) activities. Also, those various antioxidant activities were compared to BHA, BHT α-tocopherol and trolox as references antioxidant compounds. Keywords: Serotonin, antioxidant activity, metal chelating, reducing power, radical scavenging.

Comparative Electrochemical Determination of Total Antioxidant Activity in Infant Formula with Breast Milk

The aim of this study is to investigate the significance of breast milk and infant formula in the prevention of oxidative stress, by electrochemical determination of the total antioxidant potential, demonstrating the relationship between the antioxidant capacity of milk and postnatal age. Human breast milk, commercial UHT milk, and infant formulas supplemented with prebiotics were used. Samples were diluted in phosphate buffer solution, and the total antioxidant activity was potentiometrically measured by the iodine/iodide redox couple with the Pt Fisher electrode as a working electrode and saturated calomel as a reference electrode. Cyclic voltammograms and differential pulse voltammograms were recorded with the glassy carbon electrode as the working electrode, an accessory platinum electrode, and an Ag/AgCl reference electrode. The potentiometric measurement indicates that human breast milk has the highest redox potential, while the commercial UHT milk has very low potential. Infant formulas also have high potential. The main advantage of electrochemical methods used to assess the total antioxidant activity of milk was that they directly monitored the electron-donating ability of the compounds and could be used for the quantitative analysis of the total antioxidants of different types of milk.