Trolox Equivalent Antioxidant Capacity Values Research Articles

All aspects of the toxic effects of lipopolysaccharide on rat liver and the protective effect of vitamin E and sodium selenite

This work was planned to research the effects of lipopolysaccharide (LPS) and/or vitamin E (VE) and sodium selenite (SS), which have antioxidant properties, administered to the liver tissue of male rats. For this purpose, histopathology, immunohistochemistry, antioxidant capacity, terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling assay, liver function, and DNA structure tests were performed. The lipid profile was also evaluated in this study. Rats that were administered LPS were treated with VE and/or SS. The liver function tests and lipid profile parameters showed statistically significant changes and histological alterations in the LPS treated groups. The number of cells entering apoptosis was increased by LPS administration when compared to the control group. LPS treatment increased the DNA damage and decreased the ferric reducing antioxidant power and trolox equivalent antioxidant capacity values when compared to the control group. VE and/or SS provided protective effects against the examined parameters. These results indicated that we can assume that the treatment of VE and SS together may be more efficient than using them individually against LPS.

Bell Pepper (Capsicum annum L.) under Colored Shade Nets: Plant Growth and Physiological Responses

Use of colored shade nets has shown benefits in bell pepper and other horticultural crops. There is still, however, limited information on plant growth and physiology of bell pepper crop grown under colored shade nets. The objective was to determine the effects of colored shade nets on plant growth, leaf gas exchange, and leaf pigments of field-grown bell pepper. Experimental design was a randomized complete block with four replications and five shade treatments (black, red, silver, and white nets, and an uncovered control). Mean and maximal air temperature and midday root zone temperature (RZT) were highest in the unshaded treatment. Differences in air temperatures between shade net treatments were smaller compared with the differences in RZT between treatments. Plant fresh weight and stem diameter were reduced in the unshaded treatment, and there were no plant fresh weight and stem diameter differences among shade nets. The incidence of Phytophthora blight (caused by Phytophthora capsici) was greatest in the unshaded treatment. Leaf stomatal conductance (gS) and photosystem II efficiency were reduced and leaf temperature increased in unshaded conditions. Leaf net photosynthesis, gS, internal CO2, and PSII efficiency decreased with increasing leaf temperature. Differences in leaf temperature among shade net treatments were because of differences in solar radiation captured by leaves. Leaf total carotenoids were lowest in unshaded conditions and there were no differences in total carotenoids among the shade nets. Chlorophyll a concentration and chlorophyll a/b ratio was lowest in unshaded conditions. Leaf total phenols, flavonoids, and cupric reducing antioxidant capacity (CUPRAC) values were highest in red net and in unshaded conditions. Trolox equivalent antioxidant capacity (TEAC) values were highest in red net and lowest in silver net. In conclusion, compared with unshaded conditions, shade nets resulted in improved bell pepper plant growth and leaf gas exchange. These responses were due primarily to the reduced leaf and root zone temperatures under shaded conditions, regardless of the color of shade net. The differences in plant growth and function due to color of shade net were inconsistent or minor for most of the plant variables measured.

Heterocyclic β-keto sulfide derivatives of carvacrol: Synthesis and copper (II) ion reducing capacity.

Sixteen β-keto sulfide derivatives of carvacrol (4-19) incorporating phenyl or N, O and S heterocyclic moieties were synthesized in three steps. The relationships between heterocyclic structure and cupric, Cu(II), ion reducing antioxidant capacity (CUPRAC) were examined. Nine of the compounds (8-9 and 13-19) showed better CUPRAC activity than trolox at neutral pH, with trolox equivalent antioxidant capacity (TEAC) coefficients ranging between 1.20 and 1.75. Two derivatives (11-12) showed comparable reducing capacity to trolox, with TEAC values of 0.95 for 11 and 1.02 for 12. Compounds 8-9 and 11-19 were more effective at reducing the Cu(II) ion than ascorbic acid and the parent compound, carvacrol. The most effective antioxidants were those containing an oxadiazole, thiadiazole or triazole moiety. In particular, the methyl thiadiazole derivative (15) had the highest Cu(II) ion reducing capacity, with a TEAC coefficient of 1.73.

Physical and Chemical Attributes of Pomegranate (Punica granatum L.) Cultivars Grown in Humid Conditions in Georgia

Pomegranate (Punica granatum L.) is a nonclimacteric fruit sold fresh as whole fruit or arils (fleshy seeds). It is also used for the production of juice, wine, and syrup. Pomegranate is popular due to its numerous health benefits. In the United States, it is grown primarily in California and other semi-arid regions, with Wonderful being the most widely grown cultivar. However, preliminary research has shown that ‘Wonderful’ produces low yields in Georgia, thus indicating the need to identify cultivars better suited for warm and humid conditions, such as those of the southeastern United States. The objective of this study was to determine the physical and chemical quality attributes of pomegranate cultivars grown in Georgia. Pomegranate fruit from 40 cultivars were harvested during 2012 to 2017. Individual fruit weight varied from 124 g for ‘Utah Sweet’ to 631 g for ‘C1’. The total fruit weight percentage accounted for by fresh aril weight (aril fraction) ranged from 22% for ‘C8’ to 70% for ‘JC’. Individual aril weight ranged from 174 mg for ‘Utah Sweet’ to 638 mg for ‘Cloud’. Across cultivars, individual fruit weight increased linearly with the increasing number of arils. Aril color varied from white to deep red. The arils L* value ranged from 15.7 (dark arils) for ‘Crown Jewel’ to 46.1 (light arils) for ‘Utah Sweet’. The a* values ranged from 0.6 (white arils) for ‘Cloud’ to 20.5 (red arils) for ‘Crab’. The b* values ranged from 8.7 for ‘DJ Forry’ (from a store) to 62.5 for ‘R9’. The Chroma* values ranged from 13.4 for ‘Cloud’ to 24.3 for ‘Crab’. The hue° values ranged from 29.7 for ‘Wonderful’ (from a store) to 87.1 for ‘Cloud’. Rind color was related to the color of the arils; high a* values in the rind and arils were associated with the red color. The fruit juice content ranged from 174 mL·kg−1 fruit for ‘Utah Sweet’ to 638 mL·kg−1 fruit for ‘Cloud’. Cultivars varied from tart to sweet. The fruit soluble solids concentration (SSC) ranged from 10.8% for ‘Sin Pepe’ to 16.4% for ‘Crown Jewel’. Fruit titratable acid (TA) ranged from 0.27% for ‘Sin Pepe’ to 6.20% for ‘Utah Sweet’. The juice maturity index measured as the SSC/TA ratio ranged from 1.9 for ‘Utah Sweet’ to 39.5 for ‘Sin Pepe’. The juice total phenols (measured as gallic acid equivalents) ranged from 463 mg·L−1 for ‘JC’ to 2468 mg·L−1 for ‘Wonderful’ (Georgia). Trolox equivalent antioxidant capacity values of juice ranged from 10,001 µM for ‘King’ to 59,821 µM for ‘I11’. Cupric reducing antioxidant capacity values in juice ranged from 7471 µM for ‘Azadi’ to 20,576 µM for ‘Wonderful’ (Georgia). Juice total anthocyanins varied from 1.7 mg·L−1 for ‘R19’ to 50.0 mg·L−1 for ‘Wonderful’ (Georgia). Pomegranate cultivars showed large variability in physical and chemical attributes. Such pomegranate variability represents opportunities for breeding, for the retail market, and for the development of different products by the food industry.

Discovery of Antibacterial Dietary Spices That Target Antibiotic-Resistant Bacteria.

Although spice extracts are well known to exhibit antibacterial properties, there is lack of a comprehensive evaluation of the antibacterial effect of spices against antibiotic-resistant bacteria. In the present study, ethanolic extracts from a total of 67 spices were comprehensively investigated for their in vitro antibacterial activities by agar well diffusion against two common food-borne bacteria, Staphylococcus aureus and Salmonella enteritidis, with multi-drug resistance. Results showed that S. aureus was generally more sensitive to spice extracts than S. enteritidis. Of the 67 spice extracts, 38 exhibited antibacterial activity against drug-resistant S. aureus, while only four samples were effective on drug-resistant S. enteritidis. In addition, 11 spice extracts with inhibition zones greater than 15 mm were further verified for their broad-spectrum antibacterial properties using another 10 drug-resistant S. aureus strains. It was found that five spice extracts, including galangal, fructus galangae, cinnamon, yellow mustard seed, and rosemary, exhibited the highest antibacterial capacity. Further cytotoxicity of these 11 spices was determined and LC50 values were found to be more than 100 μg/mL except for galangal, rosemary, and sage, whose LC50 values were 9.32 ± 0.83, 19.77 ± 2.17, and 50.54 ± 2.57, respectively. Moreover, the antioxidant activities (ferric-reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity (TEAC) values) and total phenolic content (TPC) of spice extracts were determined to establish possible correlations with the antibacterial activity. Although the antibacterial effect was positively correlated with the antioxidant activities and TPC, the correlation was weak (r < 0.5), indicating that the antibacterial activity could also be attributed to other components besides antioxidant polyphenols in the tested spice extracts. In conclusion, dietary spices are good natural sources of antibacterial agents to fight against antibiotic-resistant bacteria, with potential applications as natural food preservatives and natural alternatives to antibiotics in animal feeding.

Physico‐chemical characteristics and antioxidant capacity of chickpea and wheat flour blends

Type‐2 diabetes is becoming a serious metabolic disease in the State of Kuwait. We wanted to make use of chickpea flour which is known to offer many benefits to the diabetic person especially in maintaining their blood sugar levels in acceptable range. The chemical composition and antioxidant capacity of white flour (WF), whole wheat flour (WWF) and chickpea flour (BF), in addition to the effect of replacement of WF and WWF with BF on the Texture Profile Analysis, and objective color of these blends, in terms of L* a* b* values were also investigated. Trolox Equivalent Antioxidant Capacity (TEAC), Malondialdehyde (MDA) and Total Phenolic Content (TPC) values varied significantly among all the three flour samples. WWF had the highest TEAC (117.42/100g) value, followed by WF (73.98/100g) and BF (60.67/100g). The TPC content also followed the similar trend, as the Gallic Acid Equivalent (GAE) values were the highest (8.67 GAE/g) for WWF, followed by WF (5.65GAE/g) and BF (3.45 GAE/g). Compared with WF and WWF, the b* values for BF were the highest (16.89) indicating higher yellowness in this sample. The TPA carried on the WF, WWF and their blends with BF showed significant variations in hardness and compressibility values, dough becoming less hard and less compressible when the replacement of WF and WWF with BF was increased from 0 to 40%. To overcome the deleterious effects of adding BF to WF and WWF on the rheological properties will be an interesting challenge, when a good quality pan bread or Arabic flat bread have to be produced during the follow up study.Support or Funding Information(Study funded by Research Administration, Kuwait University, Project No. WF01/13)(No human subjects used in this study)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Comparison of Phenolic Compounds and Antioxidant Activities of the Extracts of Grape Seed, Rosemary, Green Tea and Olive Leaf

Objective: Total antioxidant activities and phenolic compounds of ethanol extract of grape seed, rosemary, green tea and olive leaf were investigated in this study.Material and Methods: The total antioxidant activities of plant extracts were analyzed by two different methods, including 2.2-diphenyl-1-picrylhydrazyl hydrate (DPPH) radical scavenging activity and trolox equivalent antioxidant capacity (TEAC). Carnosic acid, rosmarinic acid in rosemary extract (RE), total catechins in green tea extract (GTE) and oleuropein in olive leaf extract (OLE) were identified by high performance liquid chromatography (HPLC) method. Condensed tannins of grape seed extract (GSE) was analyzed by butanol-HCl method.Results: The total phenolic contents of plant extracts determined by the Folin-Ciocalteu method ranged from 141.7 to 315.56 mg of gallic acid equivalents (GAE) g-1. According to results obtained this study, RE exhibited the highest DPPH radical scavenging activity, and GTE exhibited highest TEAC activity. Additionally, obtained data revealed high linear correlation (r=0.82) between total phenolic contents and TEAC values and low linear correlation (r=0.47) between total phenolic contents and DPPH values.Conclusion: The potent antioxidant activity of plant extracts provided from agro-industrial by-products, medicinal and aromatic plants makes it possible used them as natural sources of antioxidants in feed, food and pharmaceutical industries.

Phenolic Composition and Antioxidant Activities of Soybean (Glycine max (L.) Merr.) Plant during Growth Cycle

It is important to identify the growth stage at which the plant has the maximum antioxidant properties for the production of bioactive compounds from crops or agricultural by-products or for forage as a possible source of antioxidants in livestock. Therefore, we investigated the phenolic composition and antioxidant capacity of the aerial part of soybean at seven stages classified as vegetative stages (V5 and V6) and reproductive stages (R1, R2, R3, R4, and R5). Aqueous-methanol extracts were evaluated for their total phenolic content (TPC), ferric-reducing antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC), antioxidant activity as determined by photochemiluminescence assay (PCL-ACL), Fe2+ chelating ability, and antiradical activity against DPPH•. The extracts with the highest TPC content were obtained at stages V6 and R5. The phenolic compounds profile, as determined by DAD-HPLC, was characterized by 19 compounds, that differed significantly by growth stage (p &lt; 0.05). Antioxidant tests showed significant differences among stages (p &lt; 0.05). The lowest TEAC value was found for the R2 stage and the highest values for the R3 and R1 stages. FRAP values ranged from 623 to 780 μmol Fe2+/g extract. PCL-ACL values ranged from 516 to 560 μmol Trolox eq./g extract; Fe2+ chelation ability ranged from 36.5 to 51.7%. The highest antiradical activity against DPPH• was found in the extract from the V5 stage, which had the lowest EC50 value. The extracts of soybean plant can be used in pharmacy for the production of nutraceuticals by virtue of their good antioxidant activity and content of flavonols and other bioactive constituents.

Effects of Electrostatic Spray and Natural Antioxidants on Chemical Quality of Grass-Finished Beef Strips Steaks

ObjectivesThis study was aimed to determine how electrostatic spray of natural antioxidants impacts chemical quality of grass-finished beef strip steaks.Materials and MethodsTwenty certified grass-finished beef loins from ten animals were purchased from a certified grass-fed beef purveyor. Two loins of the same animals were cut into sixteen 2.5-cm thick steaks (eight steaks per loin) without the gluteus medius muscle. A factorial arrangement of 4 treatments, including a negative control (no spraying; NEG) and 1000-ppm of electrostatic spray of cherry extract rich in ascorbic acid (ES-ACE), electrostatic spray of rosemary and green tea extract rich in polyphenols (ES-RGT), and pressurized spray of ACE (PS-ACE), and 2 retail time points (0 and 5 d) was randomized within an animal, resulting in two steaks receiving a treatment × day combination within an animal. Five loins were randomly selected for chemical analyses (n = 10 per treatment × day combination). Meat antioxidants were extracted in methanol. The extracted antioxidants were reacted with ABTS+ radical cation (2,2′-azino-bis(3-ethylbenzthiazoline)-6-sulphonic acid diammonium salt) solution diluted to an absorbance of 0.85 to measure Trolox Equivalent Antioxidant Capacity (TEAC) at 734 nm. The extract was also reacted with Folin-Ciocalteu (FC) reagent to measure total phenolic compounds at 765 nm. Thiobarbituric acid reactive substances (TBARS) were extracted in 10% trichloroacetic acid and reacted with thiobarbituric acid and the resulted pigment was measured at 532 nm. Data were analyzed by the GLIMMIX procedure of SAS v9.4 and actual probability was reported.ResultsOn d 0, NEG steaks had less FC values than all treatment steaks (P < 0.001), of which the ES_ACE steaks had 14 and 100% more than PS_ACE and ES_RGT steaks, respectively (P ≤ 0.005). Only ES_ACE steaks had greater FC value than NEG steaks on d 5 (P < 0.001). As a result, TEAC value of ES_ACE steaks was 17 and 75% more than that of PS_ACE and ES_RGT steaks (P ≤ 0.005) and remained greater than that of NEG steaks on d 5 (P = 0.064). Greater antioxidant capacity in ES_ACE and PS_ACE steaks decreased lipid oxidation by 56% (0.9 µg MDA/kg less in ES_ACE and PS_ACE on d 5) as compared with NEG steaks in ES_ACE steaks in contrast to the other treatments (P < 0.001).ConclusionElectrostatic spray of cherry extract rich in ascorbic acid was the most effective antioxidant application to prevent lipid oxidation in grass-finished beef strips steaks.

Green tea supplementation improves oxidative stress biomarkers and modulates IL-6 circulating levels in obese women.

Introduction: obesity is associated with high levels of oxidative stress (OS) and inflammation. There is a lot of evidence that some polyphenols, such as green tea, have a positive impact on the OS state and consecutively, on inflammation. Objectives: the purposes of this study were: a) evaluate OS biomarkers in both obese and normal weight women; and b) evaluate if green tea supplementation has an impact on OS and inflammatory cytokine biomarkers of obese women. Methods: we evaluated obese (body mass index [BMI] ≥ 40 kg/m²) and normal weight (BMI between 18.5 and 24.9 kg/m²) women. Blood samples were used to access malondialdehyde (MDA), trolox equivalent antioxidant capacity (TEAC) and inflammatory cytokines. We randomly chose obese patients (18 individuals) and then gave them green tea supplementation for eight weeks. Statistical analysis included the Shapiro-Wilk, Wilcoxon, independent and paired t tests; p < 0.05 were considered as significant. Results: we enrolled 42 obese (BMI: 48.2 ± 9.3kg/m2) and 21 normal weight (BMI: 22.5 ± 2 kg/m2) women with an average age of 36.2 ± 9.1 years old. The serum levels of MDA were higher in obese (2.52 ± 0.31 µmol/l) than in eutrophic women (2.13 ± 0.26 µmol/l; p = 0.000). On the other hand, lower TEAC values were observed in the obese (0.75 ± 0.06 mM/l) than in the eutrophic group (0.78 ± 0.04 mM/l; p = 0.009). After the green tea intervention, MDA decreased 4.7% and TEAC increased 10%. Interleukin-6 (IL-6) serum levels decreased 12.7% after treatment (p = 0.03). Conclusions: a) the obese group had lower antioxidant capacity than eutrophic; and b) green tea supplementation ameliorated TEAC and MDA and reduced serum levels of IL-6 in obese women.

Novel antioxidant peptides obtained by alcalase hydrolysis of Erythrina edulis (pajuro) protein.

Oxidative reactions are responsible for the changes in quality during food processing and storage. Oxidative stress is also involved in multiple chronic diseases, such as cardiovascular and neurodegenerative disorders, diabetes, cancer, and aging. The consumption of dietary antioxidants has been demonstrated to help to reduce the oxidative damage in both the human body and food systems. In this study, the potential of Erythrina edulis (pajuro) protein as source of antioxidant peptides was evaluated. Pajuro protein concentrate hydrolyzed by alcalase for 120 min showed potent ABTS·+ and peroxyl radical scavenging activity with Trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) values of 1.37 ± 0.09 µmol TE mg-1 peptide and 2.83 ± 0.07 µmol TE mg-1 peptide, respectively. Fractionation of the hydrolyzate to small peptides resulted in increased antioxidant activity. De novo sequencing of most active fractions collected by chromatographic analysis enabled 30 novel peptides to be identified. Of these, ten were synthesized and their radical activity evaluated, demonstrating their relevant contribution to the antioxidant effects observed for pajuro protein hydrolyzate. The sequences identified represent an important advance in the molecular characterization of the pajuro protein, demonstrating its potential as a source of antioxidant peptides for food and nutraceutical applications. © 2018 Society of Chemical Industry.

Comparative Study of 1,1‐Diphenyl‐2‐picryl‐hydrazyl Radical (DPPH•) Scavenging Capacity of the Antioxidant Xanthones Family

AbstractThis study compares the antioxidant capacities of the xanthone family and analyzes structure‐activity relationship. Thirty xanthones with various structural features were selected as the references and their antioxidant capacities were determined using the 1,1‐diphenyl‐2‐picryl‐hydrazyl radical (DPPH•) scavenging assay. The results of the assay indicated that these xanthones could scavenge the DPPH• in a dose‐dependent manner. It was found that their Trolox equivalent antioxidant capacity (TEAC) values varied by the presence or absence of hydroquinone (or catechol) group within the molecule. The former 15 xanthones (1‐15, TEAC=2.030‐0.568) with hydroquinone (or catechol) pattern possessed much higher TEAC values than the latter 15 xanthones (16‐30, TEAC=0.019‐0.002) without hydroquinone (or catechol) pattern. It was concluded that the presence of the hydroquinone (or catechol) group governs the antioxidant capacity of xanthone family. Other structural factors, such as isoprenylation, methylation, and glycosidation, play a minor role, unless they remove the hydroquinone (or catechol) pattern. These findings can be used to directly predict the antioxidant capacity of xanthone.

Chemical constituents, cytotoxic and antioxidant activities of extract from the rhizomes of Osmunda japonica Thunb

Thirty-three compounds (1–33) were isolated from the rhizomes of Osmunda japonica. Their structures were elucidated on the basis of spectral analysis and identified as ent-kaurene terpenoids (1–3), anthraquinones (4–8), flavonoids (9–12), steroids (13–15), and other compounds (16–33). Compound 1–14, 19–27 were isolated from the genus osmunda for the first time. Compound 28–29 were isolated from the plant for the first time. Cytotoxicities of all compounds against Hela, HepG2 and A549 cell lines were measured by MTT assay, and their antioxidant activities were determined by DPPH and ABTS radical scavenging assays. Compound 2 exhibited potent cytotoxicity against Hela, HepG2 cell lines with IC50 values of 9.31 and 9.66 μM, respectively. Compound 9 showed good antioxidant activity. The Trolox-equivalent antioxidant capacity (TEAC) value was 0.95 mM in ABTS assay, and the IC50 value was 18.63 μM in DPPH assay.

Bioactive Compounds and Antioxidant Capacity of Rosa rugosa Depending on Degree of Ripeness.

Maturity stage affects the bioactive compounds as well as the antioxidant capacity in the fruit. This study was designed to identify and quantify carotenoids, as well as to evaluate vitamin E, vitamin C, antioxidant capacity and total phenolic compounds of Rosa rugosa hips at different degrees of ripeness. HPLC (high performance liquid chromatography) analysis showed different types of carotenoids at different stages of maturity of R. rugosa hips with significant differences (p ˂ 0.05), where the maximum concentration was observed at late harvesting. In the hips investigated, only α-tocopherol was detected, the maximum concentration of both vitamin E and vitamin C was obtained in the orange hips with significant difference (p ˂ 0.05). On the other hand, the highest hydrophilic and lipophilic TEAC (Trolox equivalent antioxidant capacity) values, as well as total phenolic contents, were determined in the mature hips (red colour) with significant difference (p < 0.0001) and (p < 0.001) respectively, whereas ORAC (oxygen radical absorbance capacity) showed lower activity in the mature hips with significant difference (p ˂ 0.05). Late harvesting is recommended if a high content of carotenoids is desired, while harvesting should be carried out earlier if a higher vitamin E and vitamin C content is desired, which in turn affects the antioxidants capacity.

Kinetic changes of antioxidant parameters, ascorbic acid loss, and hydroxymethyl furfural formation during apple chips production

In this study, the kinetic change of the antioxidant properties were determined during apple chips production using three different cultivars. Using a rotary forced-air dryer, apple slices were dried at three different temperatures (65, 70, and 75°C). The ascorbic acid content, total phenolic content (TPC), total flavonoid content (TFC), Oxygen Radical Absorbance Capacity (ORAC) and Trolox Equivalent Antioxidant Capacity (TEAC), and hydroxymethylfurfural content were analyzed. Phenolic compounds of apple chips were also identified by chromatographic separation. Thermal degradation of ascorbic acid was fitted to first-order reaction kinetics. TPC, TFC, ORAC, and TEAC values, and hydroxymethylfurfural content increased with drying time and temperature where the data were fitted to first-order and zero-order reaction kinetics. Reaction rate constants were influenced by temperature, based on the Arrhenius model. The primary phenolic compounds of apple chips were gallic acid, chlorogenic acid, catechin, caffeic acid, epicatechin, and rutin. Practical applications Dietary antioxidants with health benefits have increased attention on fruit and vegetable products. The processing of fruits and vegetables affects their antioxidant properties as well as their quality. Apple chips are dehydrated, ready to eat, fruit-based snacks with desirable sensory properties. The results of this article will contribute to an understanding of the thermal kinetics of antioxidant properties and phenolic content during apple chip production. The kinetic results may be useful for the design of dryers and optimization of the drying conditions.

Antioxidant Potential of Grass Pea Seeds from European Countries.

Phenolic compounds were extracted from seeds of 30 varieties of grass pea (Lathyrus sativus) into 80% (v/v) methanol. The total phenolics compounds content of the extracts and their antioxidant activity were determined using Folin-Ciocalteu’s phenol reagent and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric-reducing antioxidant power (FRAP) methods, respectively. Total phenolic contents ranged from 1.88 to 7.12 mg/g extract and 20.3 to 70.3 mg/100 g seeds. The extracts and seeds were characterized using Trolox equivalent antioxidant capacity values of 0.015–0.037 mmol Trolox/g extract and 0.158–0.372 mmol Trolox/100 g seeds, and FRAP values of 0.045–0.120 mmol Fe2+/g extract and 0.487–1.189 Fe2+/100 g seeds. The total phenolics content of grass pea extract was correlated with the results of the ABTS (r = 0.881) and FRAP (r = 0.781) assays. The same correlation was observed between the results of both assays (r = 0.842). Two derivatives of p-coumaric acid were the dominant phenolic compounds of the Derek cultivar of grass pea.

Antioxidant property of Taraxacum formosanum Kitam and its antitumor activity in non-small-cell lung cancer cells

BackgroundNon-small-cell lung cancer (NSCLC) is known to exhibit resistance to various therapeutic agents and become progressively incurable. Taraxacum formosanum is a medicinal Chinese herb that has been clinically used in Taiwan. However, the investigations of the effects of whole plant on lung cancer are limited. PurposeThis study evaluated the in vitro antioxidant, antiproliferative, and antimigration effects of the ethanol extract of T. formosanum (ETF). The possible molecular mechanism underlying its antitumor effects on cultured human NSCLC cell lines was also elucidated. MethodsThe antioxidant effects of the ETF were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Trolox equivalent antioxidant capacity (TEAC) assays, and its antiproliferative and antimigration effects were determined using trypan blue exclusion and wound healing assays, respectively. In addition, changes in the mitogen-activated protein kinase (MAPK) signaling pathway were investigated using Western blot analyses. Various inhibitors were used to determine the roles of the MAPK signaling pathway involved in the molecular mechanism of the ETF. ResultsOur results showed that the ETF exhibited strong reducing power, a high Trolox equivalent antioxidant capacity (TEAC) value, and potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and Fe+2-chelating abilities. The ETF also exerted antiproliferative and antimigration effects on NSCLC cells in a dose-dependent manner. These effects may be mediated by the inhibitory effects of the ETF on the activation of extracellular signal-regulated kinase. ConclusionsThis study performed the first pharmacological exploration of T. formosanum. Our results demonstrated the antioxidant and antitumor effects of the ETF on NSCLC cell lines, indicating their potential preventive and therapeutic values for lung cancer.

Green Extraction of Natural Antioxidants from the Sterculia nobilis Fruit Waste and Analysis of Phenolic Profile.

The waste of Sterculia nobilis fruit was massively produced during food processing, which contains lots of natural antioxidants. In this study, antioxidants in the Sterculia nobilis fruit waste were extracted using the green microwave-assisted extraction (MAE) technique. The effects of five independent variables (ethanol concentration, solvent/material ratio, extraction time, temperature, and microwave power) on extraction efficiency were explored, and three major factors (ethanol concentration, extraction time, and temperature) showing great influences were chosen to study their interactions by response surface methodology. The optimal conditions were as follows: 40.96% ethanol concentration, 30 mL/g solvent/material ratio, 37.37 min extraction time at 66.76 °C, and 700 W microwave power. The Trolox equivalent antioxidant capacity value obtained in optimal conditions was in agreement with the predicted value. Besides, MAE improved the extraction efficiency compared with maceration and Soxhlet extraction methods. Additionally, the phenolic profile in the extract was analyzed by UPLC-MS/MS, and eight kinds of phenolic compounds were identified and quantified, including epicatechin, protocatechuic acid, ferulic acid, gallic acid, p-coumaric acid, caffeic acid, quercetin, and p-hydroxycinnamic acid. This study could contribute to the value-added utilization of the waste from Sterculia nobilis fruit, and the extract could be developed as food additive or functional food.

Determination of antioxidant capacity of thiol-containing compounds by electron spin resonance spectroscopy based on Cu2+ ion reduction

Electron spin resonance spectroscopy was applied to determining the antioxidant capacity of eight thiol-containing compounds, including reduced glutathione, N-acetyl-L-cycsteine, methimazole, captopril, and tiopronin with one thiol group, 1,4-dithioerythritol and 2,3-dimercapto-1-propanol with two thiol groups, as well as L-cystine with no free thiol group. Cu2+ ion gives an electron spin resonance signal and is reduced to Cu+ ion with no electron spin resonance signal by the free thiol group in the compounds. Trolox equivalent antioxidant capacity (TEAC) was used to evaluate the reducing ability of the thiol-containing compounds and the TEAC values were found to be relevant to the number of thiol groups contained in the compounds. For the purpose of comparison, the UV-vis spectrophotometry, cupric reducing antioxidant capacity (CUPRAC) method, and Ellman assay were applied to the determination of the antioxidant capacity of the thiol-containing compounds. The TEAC values obtained by the present method were very close to those obtained by UV-vis method. However, compared with CUPRAC method, for methimazole the present method gave a more reasonable TEAC value. The present method was also applied to the quantification of N-acetyl-L-cycsteine, methimazole, captopril, and tiopronin in their pharmaceutical formulations.

Three ABTS•+ radical cation-based approaches for the evaluation of antioxidant activity: fast- and slow-reacting antioxidant behavior

This work focuses on the behavior and comparative assessment of the antioxidant activity of several well-known antioxidants using three different approaches with the same ABTS•+/potassium persulfate radical-generating system: a decolorization assay, kinetic assay, and visual-spectrophotometric titration assay. The decolorization assay is the most common approach but gives little information on antioxidant behavior. The kinetic assay can be used for an in-depth study of the specific features of a particular antioxidant and facilitates identification of the mechanism of action. The visual-spectrophotometric titration assay is complementary to the above assays and subdivided into two stages to demonstrate the contribution of the “fast” and “slow” scavenging properties to the total antioxidant activity. The trolox equivalent antioxidant capacity (TEAC) value ranges for several flavonoids and the endogenous antioxidants derived from these assays vary from 0.7 to 5.1, 0.5–2.8, and 0.4–3.7, respectively, while the sequence of the weakest antioxidant to the strongest is similar. The analysis of the kinetic curves for some flavonoids showed that their interaction with ABTS•+ has an atypical character. Based on the results of the kinetic and visual-spectrophotometric titration assays, fast-reacting (trolox, α-tocopherol), slow-reacting (naringenin, apigenin) and moderate-reacting antioxidant (dihydroquercetin, quercetin, rutin, morin, and glutathione) compounds were distinguished.