mM Of Trolox Research Articles

Bioaccessibility and Antioxidant Activity of Faba Bean Peptides in Comparison to those of Pea and Soy after In Vitro Gastrointestinal Digestion and Transepithelial Transport across Caco-2 and HT29-MTX-E12 Cells.

In this study, the transepithelial transport of bioactive peptides derived from faba bean flour gastrointestinal digestates was investigated, in vitro, using a Caco-2 and HT29-MTX-E12 coculture monolayer, in comparison to those of pea and soy. The profile of transported peptides was determined by mass spectrometry, and the residual antioxidant activity was assessed. The ORAC value significantly (p < 0.05) decreased after transepithelial transport (24-36% reduction) for all legumes, while the antioxidant activity in ABTS assay significantly (p < 0.05) increased, as shown by the EC50 decrease of 26-44%. Five of the nine faba bean peptides that crossed the intestinal cell monolayer exhibited antioxidant activity. Two of these peptides, TETWNPNHPEL and TETWNPNHPE, were further hydrolyzed by the cells' brush border peptidases to smaller fragments TETWNPNHP and TWNPNHPE. These metabolized peptides were synthesized, and both maintained high antioxidant activity in both ABTS (EC50 of 1.2 ± 0.2 and 0.4 ± 0.1 mM, respectively) and ORAC (2.5 ± 0.1 and 3.4 ± 0.2 mM of Trolox equivalent/mM, respectively) assays. These results demonstrated for the first time the bioaccessibility of faba bean peptides produced after in vitro gastrointestinal digestion and how their bioactive properties can be modulated during transepithelial transport.

Assessment of physicochemical parameters in argentinian Yerba Mate: Variability among different commercial brands

Yerba mate (YM) is a traditional plant-based product used in the preparation of hot beverages. YM is composed of dried leaves of Ilex paraguariensis A. St.-Hil., which are slightly toasted and milled. The present study analyses the variability of physicochemical sensorial-linked characteristics among six of the most renowned argentinian brands of YM. The samples consist of particles that were categorised as coarse (61%), intermediate (34%), and fine (5%). The average moisture and ash content were 7.8% and 5.4%, respectively, and their average loose bulk density was 285 g/L. The average colour parameters were L* = 49, a* = − 1.25, b* = 15.5, with the total colour difference being lower than 1 among samples of the same brand. On average, 1 g of YM absorb 2.6 g of hot water. This study introduced a description of the mechanical response to compression for YM. All samples underwent easy compression under small stresses owing to the material’s open structure; compressibility exhibited a positive correlation with moisture due to the plasticizing effect of water. The relaxation response of the YM was associated with its spatial arrangement and the presence of smaller particles that could facilitate elastic behaviour. Mate tea presented an average pH of 5.77 and a refractive index of 1.3340. The content of phenolics in mate teas significantly differs among the studied YM brands, with its average equivalent to 2.32 g of chlorogenic acid per litre and its antioxidant capacity equivalent to 15 mM of Trolox. The phenolic concentration showed a negative correlation with the quantity of fine fraction and moisture content, and positive correlation was observed with water absorption capacity. This suggests that greater microporosity of the material might facilitate increased water-solid interaction, consequently leading to higher phenolic extraction. These results may contribute to explaining certain sensory attributes observed in YM samples.

P-323 Should We Measure Oxidative Stress Biomarkers In Follicular Fluid Of Women With Endometriosis Undergoing IVF?

Abstract Study question Do levels of Oxidative stress (OS) biomarkers differ in the follicular fluid of women with endometriosis compared to tubal factor infertility? Summary answer 8-Isoprostane is a promising biomarker in diagnosing oxidative stress in women with endometriosis opening a window of opportunity for improving outcomes. What is known already A delicate balance between oxidants and antioxidants is required for oocyte development and maturation. Any perturbation in the oocyte microenvironment which is the follicular fluid results in hampered oocyte quality and further affects the embryo development. As endometriosis causes destruction of the oocyte milieu, various OS biomarkers have been explored with inconclusive results. The present study aimed to compare these biomarkers in follicular fluid of women with endometriosis and tubal factor infertility undergoing in-vitro fertilization and correlate with ART outcomes. Study design, size, duration In a cross sectional study conducted at the assisted conception unit at a tertiary care hospital from 2017-2018 women undergoing their first IVF cycles for endometriosis and tubal factor infertility were recruited in the study. The study included a total of 107 patients with 50 in the endometriosis group (Group1) and 57 in the tubal group (Group 2). Participants/materials, setting, methods Follicular fluid from women undergoing IVF in both the groups was collected and evaluated for Oxidative stress biomarkers including Reactive Oxygen species (ROS), Total Antioxidant Capacity (TAC), 8-Isoprostane (8-IP) levels. ROS levels were detected by chemiluminescence and TAC and 8-IP using enzyme immunoassays. Main results and the role of chance Levels of ROS {(39.6 cpm vs 54.8 cpm) (p = 0.2)}were comparable in both the groups. Levels of 8-IP were significantly higher in group 1 as compared to the group 2 {(85.2 pg/ul vs 39.2 pg/ul) (p = 0.01)}. TAC levels were higher in endometriosis group compared to the tubal group {(5.4 mM of Trolox vs 4.1 mM of Trolox) (p = 0.005)} which could explain comparable ongoing clinical pregnancy rate in both groups (24.0% vs 24.5%, p = 0.34). There was no correlation of OS biomarkers with ART outcomes in tubal factor. Follicular fluid in Group 1 revealed a negative correlation of ROS with cleavage rate (r = - 0.42, p = 0.002) and positive correlation of TAC with fertilization rate (r = 0.44, p = 0.001) and Good grade embryos (r = 0.4, p = 0.001). Limitations, reasons for caution The main limitation is the inability to assess the dietary intake and blood oxidative stress biomarkers in both the groups. Wider implications of the findings OS biomarkers especially 8-IP could be useful in prognosticating IVF outcomes in women with endometriosis with a potential role of addition of antioxidants in culture media during IVF in these women. Trial registration number Not Applicable

Sweetpotato Leaves Inhibit Lipopolysaccharide-Induced Inflammation in RAW 264.7 Macrophages via Suppression of NF-κB Signaling Pathway

Limited information is available regarding the health-promoting activities of sweetpotato leaves (SPL). The present study investigated antioxidant and anti-inflammatory effects, and phenolic contents in 29 SPL cultivars harvested in 2018 and 2019. Extracts showed total phenolic contents 9.4–23.1 mg gallic acid equivalent/g, and DPPH radical scavenging activity indicated 36.6–247.3 mM of Trolox equivalent/g. SPL extracts were identified to contain bioactive components such as, chlorogenic acid (11.7–22.1 μg/mg), 3,4-dicaffeoylquinic acid (16.3–59.9 μg/mg), 3,5-dicaffeoylquinic acid (50.9–72.7 μg/mg), chlorophyll B (6.1–12.3 μg/mg), lutein (1.9–4.9 μg/mg), chlorophyll A (2.7–4.3 μg/mg) and β-carotene (0.1 ≤ μg/mg). RAW 264.7 murine macrophage cells were pretreated with 100–200 μg/mL of SPL extracts and 20 μM of dexamethasone, and inflammation was stimulated by lipopolysaccharide (LPS, 100 ng/mL) treatment for 24 h. In LPS-treated cells, prostaglandin E2 production and COX-2 expression were not downregulated by pretreatment of SPL extracts. However, SPL pretreated cells showed significant suppression of nitric oxide (NO), TNF-α, and IL-1β levels under the LPS-induced inflammatory condition. In addition, SPL extracts induced an anti-inflammatory effect in LPS-stimulated RAW 264.7 cells through suppression of NF-κB nuclear translocation, IKK-α and IκB-α phosphorylation, and iNOS expression. These results indicate that SPL extract can be utilized as a functional food ingredient.

Bioactivity of Hydrolysates Obtained from Chicken Egg Ovalbumin Using Artichoke (Cynara scolymus L.) Proteases.

The aim of this work was to obtain chicken egg ovalbumin hydrolysates using aspartic proteinases present in extracts from the artichoke flower (Cynara scolymus L.) and evaluate their antioxidant, antimicrobial, and angiotensin I-converting enzyme (ACE) inhibitory activity in vitro. Hydrolysis time and molecular weight (<3 kDa) had a significant influence on the hypertensive and antioxidant activity of the hydrolysates. The <3 kDa fraction of the 16 h hydrolysate had an ACE inhibitory activity with an IC50 of 64.06 µg peptides/mL. The fraction <3 kDa of ovalbumin hydrolysate at 2 h of hydrolysis showed a DPPH radical scavenging activity of 30.27 µM of Trolox equivalents/mg peptides. The fraction <3 kDa of the hydrolysate of 16 h had an ABTS+ caption activity of 4.30 mM of Trolox equivalents/mg peptides. The fraction <3 kDa of the hydrolysate of 2 h had an iron (II) chelating activity of 32.18 µg peptides/mL. From the peptide sequences identified in the hydrolysates, we detected four peptides (from the BIOPEP database) that were already in their bioactive form (IAAEVYEHTEGSTTSY, HLFGPPGKKDPV, PIAAEVYEHTEGSTTSY, and YAEERYPIL), and are reported to display antioxidant and ACE inhibitory activity.

Single‐Atom Iron Boosts Electrochemiluminescence

AbstractThe traditional luminol–H2O2 electrochemiluminescence (ECL) sensing platform suffers from self‐decomposition of H2O2 at room temperature, hampering its application for quantitative analysis. In this work, for the first time we employ iron single‐atom catalysts (Fe‐N‐C SACs) as an advanced co‐reactant accelerator to directly reduce the dissolved oxygen (O2) to reactive oxygen species (ROS). Owing to the unique electronic structure and catalytic activity of Fe‐N‐C SACs, large amounts of ROS are efficiently produced, which then react with the luminol anion radical and significantly amplify the luminol ECL emission. Under the optimum conditions, a Fe‐N‐C SACs–luminol ECL sensor for antioxidant capacity measurement was developed with a good linear range from 0.8 μm to 1.0 mm of Trolox.

Single-Atom Iron Boosts Electrochemiluminescence.

The traditional luminol-H2 O2 electrochemiluminescence (ECL) sensing platform suffers from self-decomposition of H2 O2 at room temperature, hampering its application for quantitative analysis. In this work, for the first time we employ iron single-atom catalysts (Fe-N-C SACs) as an advanced co-reactant accelerator to directly reduce the dissolved oxygen (O2 ) to reactive oxygen species (ROS). Owing to the unique electronic structure and catalytic activity of Fe-N-C SACs, large amounts of ROS are efficiently produced, which then react with the luminol anion radical and significantly amplify the luminol ECL emission. Under the optimum conditions, a Fe-N-C SACs-luminol ECL sensor for antioxidant capacity measurement was developed with a good linear range from 0.8 μm to 1.0 mm of Trolox.

Effect of adding aqueous extract of Melissa officinalis leaves and some other antioxidants to milk–based extender on post-cooling and post- cryopreservative sperm’s individual motility and live sperm percentage of Holstein bulls

This study was conducted to explore the effect of adding aqueous extract of Melissa officinalis leaves (AEMOL), some antioxidants and their combinations to the milk-based extenderfor increase on sperm's cells individual motility percentage on and live sperms percentage semen for Holstein bulls following different preservation periods. The study was executed at the Department of Artificial Insemination, Abu-Ghraib belong to the Directorate of Animal Resource, Ministry of Agriculture, during the period from October 2015 to February 2016 using ten Holstein bulls of 2.5-3 years old. Semen was collected via artificial vagina in one ejaculate per bull per week for the 7-week experimental period. Pooled semen was equally divided into ten groups within one experiment. In this experiment, AEMOL (0.062mg/100 ml; A2), WEMOL (0.031 mM) + 5 mM of vitamin C (A3), AEMOL (0.062mg/100 ml + 0.08 mM of Trolox (A4),AEMOL (0.062mg/100 ml + 100 IU of catalase (A5),100 IU of catalase (A6), 5 mM of vitamin C (A7), 0.08 mM of Trolox (A8), 0.2 mM of vitamin E (A9) and AEMOL (0.062mg/100 ml +0.2 mM of vitamin E (A10). The effect of these additives on semen characteristics of Holstein bulls for different preservation periods (cooling at 5◦C, 48 hrs., 1, 2 and 3 months post cryopreservation, PC) were studied. The A2 group exhibited greater (P≤ 0.01) sperm's cell individual motility, live sperm percentage, as compared with A1 group at all preservation periods. Greater sperm's cells individual motility, live sperm percentage noticed in A4 group in comparison with the A1 group at all preservation time periods. On the other hand, A5 group exhibited greater (P≤ 0.01) sperm's cell individual motility, live sperm percentage, as well as, adding of vitamin E alone (A9) or combined with AEMOL (A10) to milk-based extender had a positive (P≤ 0.01) effect in improving sperm's cell individual motility and live sperm percentage at all preservation time periods. In conclusion, adding of AEMOL as alone or combined with the other synthetic antioxidants to milk-based extenders had a crucial role in improving PC sperm's cell individual motility and live sperm percentage of Holstein bulls. This was reflected positively on increasing pregnancy rates of the inseminated cows.

Effect of adding aqueous extract of Melissa officinalis leaves and some other antioxidants to Tris extender on post-cooling and post- cryopreservative plasma membrane and acrosome integrity percentages of Holstein bulls

This study was conducted to explore the effect of adding aqueous extract of Melissa officinalis leaves (AEMOL), some antioxidants to Tris extender on sperm’s plasma membrane and acrosome integrity for Holstein bulls following different preservation periods. The study was executed at the Department of Artificial Insemination, Abu-Ghraib belong to the Directorate of Animal Resource, Ministry of Agriculture, during the period from October 2015 to February 2016 using ten Holstein bulls of 2.5-3 years old. Semen was collected via artificial vagina in one ejaculate per bull per week for the 7-week experimental period. Pooled semen was equally divided into ten groups using Tris extender. In this experiment, AEMOL (0.062mg/100 ml; A2), WEMOL (0.062mg/100 ml) + 5 mM of vitamin C (A3), AEMOL (0.062mg/100 ml + 0.08 mM of Trolox (A4), AEMOL (0.062mg/100 ml + 100 IU of catalase (A5),100 IU of catalase (A6), 5 mM of vitamin C (A7), 0.08 mM of Trolox (A8), 0.2 mM of vitamin E (A9) and AEMOL (0.062mg/100 ml +0.2 mM of vitamin E (A10) and comparisons in response were made with the control group (Tris extender, A1). The effect of these additives on semen characteristics of Holstein bulls for different preservation periods (cooling at 5◦C, 48 h, 1, 2 and 3 months post cryopreservation, PC) were studied. The A2 group exhibited greater (P≤0.01) plasma membrane and acrosome integrity percentage as compared with A1 group at all preservation time periods. Greater (P≤ 0.01) plasma membrane and acrosome integrity percentage were noticed in comparison with the A1 group at all preservation time periods. On the other hand, A5 group exhibited greater (P≤ 0.01) plasma membrane and acrosome integrity percentage, as well as, Adding of vitamin E alone (A9) or combined with AEMOL (A10) to Tris extender had positive (P≤ 0.01) effect in improving all the semen characteristics at all preservation time periods. In conclusion, adding of AEMOL as alone or combined with the other synthetic antioxidants to Tris extenders had a crucial role in improving PC sperm's plasma membrane and acrosome integrity percentage of Holstein bulls. This was reflected positively in increasing pregnancy rates of the inseminated cows and owner's income consequently.

Investigation of Galatella villosa and G. tatarica for Antioxidant, α-Amylase, Tyrosinase, Lipoxygenase and Xanthine Oxidase Inhibitory Activities

In the present work two Galatella species, Galatella villosa Rchb.f. and Galatella tatarica (Less.) Novopokr collected from Kazakhstan were subjected to hydrodistillation to yield essential oils (EOs), and to maceration in methanol to yield extracts (MEs). The EOs and MEs were evaluated for antioxidant and in vitro inhibitory activities against α-amylase, tyrosinase, lipoxygenase and xanthine oxidase enzymes. The EOs of G. villosa and G. tatarica were investigated for chemical composition using GC-FID and GC/MS techniques. The composition of MEs was investigated with LC-MS/MS technique. Monoterpenes, β-pinene (23.6 %) and α-pinene (14.4 %) were the main constituents of G. tatarica essential oil, while the oil of G. villosa was characterized not only with monoterpene α-pinene (9.0 %), but also fatty acid, hexadecanoic acid (10.2%). 3-, 5-, 1,5- and 3,4-caffeoylquinic acids, 3-, 4- and 5-feruloylquinic acids, quercetin and its different glycosides were detected in MEs according to mass spectral data. G. tatarica (IC50=74.3 μg/mL) and G. villosa (IC50=78.5 μg/mL) extracts showed significant antioxidant activity. In the β-carotene bleaching test, the extracts demonstrated noteworthy activity (%Inh 44.46 and 41.14). The extracts scavenged ABTS radical as 1.85 mM and 1.27 mM of Trolox. In a concentration of 0.5 mg/mL, the oils showed 89% and 85% inhibition of α-amylase, while the extracts showed 86% and 78% inhibition at 2 mg/mL concentration, respectively. The EOs demonstrated noteworthy potent LOX enzyme inhibition ranging between 45% and 57%. In xanthine-xanthine oxidase model system, the extracts demonstrated the highest inhibitory potency ranging between 43% and 39%. The present work is the first contribution to the chemistry and biological activities of G. tatarica and G. villosa.

Rapid sensing of antioxidant capacity based on electrochemiluminescence induced by electrochemically generated reactive oxygen species

A simple and rapid electrochemiluminescence (ECL) method for the measurement of antioxidant capacity using a portable ECL device with a screen-printed electrode is described. The ECL method is based on the luminous reaction of reactive oxygen species (ROS), luminol radicals and antioxidants. ROS are generated by the electrochemical reduction of dissolved oxygen and competitively react with the luminol and antioxidants. The ECL intensity depends on the antioxidant capacity because the radicals are neutralized by the antioxidants, suppressing the luminous reaction. An antioxidant standard curve was generated using different concentrations of known amounts of Trolox by ECL measurement and the detection limit for antioxidant capacity was found to be 0.06mM of Trolox. An antioxidant capacity of beverages (22 types) was evaluated by comparing with the standard curve of Trolox. The time necessary for the ECL measurement of antioxidant capacity is only two minutes after combining the sample solution with luminol on a screen-printed electrode.

Total antioxidant capacity of honeybee haemolymph in relation to age and exposure to pesticide, and comparison to antioxidant capacity of seminal plasma

Oxidative stress is defined as a disturbance in the balance between the production of reactive oxygen species and antioxidant defences. We measured total antioxidant capacity (TAC) in honeybee haemolymph and seminal plasma and analysed TAC of haemolymph in relation to age and exposure to pesticide. TAC of haemolymph increased with age of bees (1.18 vs 1.97 mM of (±)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox) for 1- and 30-day-old bees, respectively, P ≤ 0.05). Exposure to imidacloprid (IMD) affected TAC of haemolymph of 1-day-old but not 30-day-old honeybees. TAC in haemolymph of 1-day-old bees was lower in treatments with the addition of 5 and 200 ppb IMD (1.57–1.46 mM of Trolox in treated bees compared with 2.37 mM of Trolox in controls; P ≤ 0.05). In conclusion, antioxidant protection of honeybees seems to be related to age and may be disturbed by exposure to IMD. Older bees with higher antioxidant protection seem to be less susceptible to IMD toxicity. The toxic effect of pesticide seems to be particularly dangerous in early life stages of honeybees.

Total antioxidant capacity of fish seminal plasma

Total antioxidant capacity (TAC) was measured in the seminal plasma of 13 fish species using a commercial assay kit. TAC values are quite variable among the 13 species studied, from 0.008mM of Trolox for rainbow trout to 1.909mM of Trolox for Eurasian perch. Two species of percid fish were distinguished by high values of TAC. Most of TAC was attributed to fraction≤2kDa which suggests that TAC in seminal plasma is related to low molecular weight antioxidants. The assay kit was not useful for measurements of TAC in fish blood plasma.

Chemical Composition and Biological Activities of Polar Extracts and Essential Oil of Rose‐scented Geranium, Pelargonium graveolens

Pelargonium graveolens (Geraniaceae) was characterized with respect to its chemical composition, antioxidant potential and antimicrobial activities. This is the first investigation focusing on the comparison of both essential oil and polar extracts from this species. The chemical composition of the essential oil of the aerial parts of P. graveolens was analyzed by gas chromatography/mass spectrometry. The main constituents of the oil were found to be β-citronellol (21.9%), citronellyl formate (13.2%), geraniol (11.1%), 10-epi-γ-eudesmol (7.9%), geranyl formate (6.2%) and (l)-linalool (5.6%). Nine flavonoids were identified by high-performance liquid chromatography-MS in leaf and flower extracts. Kaempferol 3-O-rhamnoside-glucoside, isorhamnetin aglycone, quercetin 3-O-glucoside, kaempferol 3,7-di-O-glucoside, quercetin 3-O-pentose and kaempferol 3-O-glucoside, quercetin 3-O-rhamnoside-glucoside, quercetin 3-O-pentoside-glucoside, myrisetin 3-O-glucoside-rhamnoside flavonoids were detected in methanolic and aqueous extracts, respectively. The total flavonoids ranged between 29.9 and 78.2 mg QE/g in flower water and methanol extracts, respectively, and 22.5 and 71.2 mg QE/g dry weight in leaf water and methanol extracts, respectively. The highest antioxidant activities using two methods of free radical scavenging capacities were obtained with the essential oil (9.16 mM of Trolox and 2.68 µg/ml). All P. graveolens essential oil and polar extracts were active against at least one bacterium.

Evaluation of the electrochemical properties of 3-hydroxyflavone using voltammetric methods

Abstract Electrochemical behavior of ring C of 3-hydroxyflavone (3-HF) has been investigated by cyclic and differential pulse voltammetry, using a glassy carbon electrode (GCE) in different buffer systems. It exhibited a sensitive diffusion controlled anodic peak at 0.70 V (vs Ag/AgCl) in a buffer system at pH 2.0. At higher pH, 8.0, while the peak at 0.70 V shifted to 0.41 V, a new peak at 0.8 V appeared. Moreover, electrochemical method was applied to investigate the antioxidant effect and metal chelating properties of 3-HF with Cd2+, Cu2+, Hg2+ and Pb2+ as they could have possible toxicological effects, for which fluorescence technique were also applied. Antioxidant effect was determined in terms of trolox equivalent antioxidant capacity (TEAC) using the peak areas of cyclic voltammetry (CV), which indicated that 1.0 mM 3-HF is equivalent to 0.2 mM of trolox. Such a result might be another indication of the importance of hydroxyl groups on the other rings of flavones. Electrochemical and fluorescence spectroscopic methods revealed that the best interactions of the cations could be obtained depending on the pH of the medium. Selective interactions of Cd2+ and Cu2+ at pH 2 and 7, respectively, were observed.

Antioxidant Activity of Constituents from the Methanolic Extract of Acacia confusa Leaves

In this study, the antioxidant activities of the leaf extract of Acacia confusa and constituents isolated from its ethyl acetate (EtOAc) fraction were investigated for the first time using various in vitro assays. Ten antioxidant compounds, namely, 3,4,5-trihydroxybenzoic acid methyl ester (1), 5,7,3',4'-tetrahydroxyl-flavone (2), myricetin 3-O-(3”-O-galloyl)-α-rhamnopyranoside (3), myricetin 3-O-(3”-O-galloyl)-α-rhamnopyranoside 7-methyl ether (4), myricetin 3-O-(2”-O-galloyl)-α-rhamnopyranoside 7-methyl ether (5), myricetin-3-O-β-glucopyranoside (6), myricetin-3-O-α-rhamnopyranoside (7), myricetin 3-O-(2”-O-galloyl)-α-rhamnopyranoside (8), quercetin-3-O-α-rhamnopyranoside (9), and europetin-3-O-α-rhamnopyranoside (10) were isolated and identified from the leaf extract. In addition, their 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, superoxide radical-scavenging activity, and trolox equivalent antioxidant capacity (TEAC) were compared with catechin (as the positive control). As to the DPPH-scavenging activity, all compounds except for 1 and 2 displayed greater antioxidant capacities than catechin (EC50=10.3 μM), and all of their TEAC values were higher than that of catechin (3.49 mM of trolox) except for 1, 6, 9, and 10. In addition, all compounds except for 1, 2, 5, and 6, also expressed as high a superoxide radical scavenging activity as catechin (EC50=7.4 μM).

Antioxidant activity of 50% aqueous--ethanol extract from Acantholippia deserticola.

The antioxidant properties oí Acantholippia deserticola, a herb used in traditional northern Chilean medicine was studied using free radical-generating systems. The 50% aqueous-ethanol extract oí Acantholippia deserticola protected against non-enzymatic lipid peroxidation in microsomal membranes of rat, induced by an Fe++-ascorbate system and measured spectrophotometrically by the TBARS test, and had strong free radical scavenging capacities on stable ABTS and DPPH radicals. The results shows that the IC50 value of the 50% aqueous-ethanolic extract of A.deserticola is 18 +/- 0.5 microg/mL in DPPH radical-scavenging, 15 +/- 0.8 microg/mL in lipid peroxidation , Total Antioxidant Activity (TAA) is 0.95 mM of Trolox per mg/mL of extract. The total phenolics content of extract is 725 +/- 12 mg of gallic acid equivalent per g of dried extract. The results indicate that the 50% aqueous-ethanol extract of Acantholippia deserticola clearly has antioxidant properties.

Antioxidant activity of 50% aqueous - ethanol extract from Acantholippia deserticola

The antioxidant properties oí Acantholippia deserticola, a herb used in traditional northern Chilean medicine was studied using free radical-generating systems. The 50% aqueous-ethanol extract oí Acantholippia deserticola protected against non-enzymatic lipid peroxidation in microsomal membranes of rat, induced by an Fe++-ascorbate system and measured spectrophotometrically by the TBARS test, and had strong free radical scavenging capacities on stable ABTS and DPPH radicals. The results shows that the IC50 value of the 50% aqueous-ethanolic extract of A.deserticola is 18 +/- 0.5 microg/mL in DPPH radical-scavenging, 15 +/- 0.8 microg/mL in lipid peroxidation , Total Antioxidant Activity (TAA) is 0.95 mM of Trolox per mg/mL of extract. The total phenolics content of extract is 725 +/- 12 mg of gallic acid equivalent per g of dried extract. The results indicate that the 50% aqueous-ethanol extract of Acantholippia deserticola clearly has antioxidant properties.

Automatic flow system for sequential determination of ABTS [rad]+ scavenging capacity and Folin-Ciocalteu index: A comparative study in food products

In the present work, an automatic flow procedure for the sequential spectrophotometric determination of Folin-Ciocalteu reducing capacity (FC assay) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS +) scavenging capacity expressed as the trolox equivalent (TEAC assay) is proposed for a comparative study of antioxidant properties in food products. Exploiting the flexibility of flow management associated to the computer control offered by multisyringe flow injection analysis, both methodologies were carried out in the same manifold using gallic acid and trolox as standard compounds. The proposed system configuration allowed the performance of each method separately or in tandem, providing 24 determinations per hour, which accounts for its application in routine analysis. The present methodology was applied to a large number of beverages ( n = 72), namely red and white wines, herbal and tea infusions, juices and beers. The results obtained showed that FC reducing capacity and TEAC values of red wines were significantly different from those obtained for the other beverages, while tea infusions provided significantly higher TEAC values when compared to white wines, herbal infusions, juices and beers. A good correlation was found between TEAC and FC reducing capacity ( R > 0.9) for red wines, herbal and tea infusions, and beers. For these beverages, similar slope values were found (106–140 mg L −1 of gallic acid per mM of Trolox), except for beers that showed a higher response for FC assay. These results provided evidence that the correlation between these assays vary according to the type of sample, reinforcing the idea that more than one method should be used for evaluation of antioxidant capacity.

Automatic sequential determination of the hydrogen peroxide scavenging activity and evaluation of the antioxidant potential by the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation assay in wines by sequential injection analysis

An automatic system that performs two analytical procedures, allowing the evaluation of the relative antioxidant capacity of wine samples, was developed. Automation was carried out using a sequential injection analysis (SIA) system that allowed, thanks to its versatility, the development of two methodologies. One is based on the decolorization assay of the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical, using a spectrophotometric detector. A second methodology allowed the evaluation of the hydrogen peroxide scavenging activity by measuring the oxidation of homovanylic acid (HVA) to its fluorescent dimer, using a fluorescent detector. The developed automatic methodologies were evaluated using trolox as standard and subsequently using other antioxidant substances as gallic acid, caffeic acid, ascorbic acid, catechin and taxifolin which are abundant in wine and whose antioxidant activities were compared to that shown by trolox. The spectrophotometric and fluorimetric assays showed linearity intervals between 0.001 and 0.01 mM, and 0.001 and 0.008 mM of trolox, respectively. The evaluation of the antioxidant power of 20 white and red wine samples, from different Portuguese wine producing regions, was carried out sequentially, in the automatic system. The results were expressed in trolox equivalent antioxidant capacity (TEAC) and presented, for the ABTS and hydrogen peroxide scavenging activity methodologies, detection limits of 8.4 × 10 −7 and 1.4 × 10 −4 mM and relative standard deviation (R.S.D. (%)) in the range 0.6–2.4 and 1–1.8, respectively.