Measurement Of Total Antioxidant Capacity Research Articles

English

Beta-thalassemia major (β-TM) in children is associated with an increase in the risk of premature cardiovascular complications caused by accelerated atherosclerosis which significantly contributes to morbidity and mortality. The molecular mechanisms underlying β-TM associated atherosclerosis and its relation to biochemical risk factors still remain obscure. We aimed to investigate the association between SIRT1 single nucleotide polymorphism (SNP), lipid profile, ferritin, malondialdehyde (MDA), 8-hydroxydeoxy guanosine (8-OHdG) and total antioxidant capacity (TAC) in relation to carotid intima media thickness (CIMT) trying to explain some mechanisms of cardiovascular complication in beta-Thalassemia major (β-TM) children. This study was carried out on 100 Egyptian children with β-TM (Group II) subdivided equally according to CIMT into Group IIa, with CIMT<0.5 mm and Group IIb with CIMT ≥ 0.5 mm, in addition to 50 healthy children as controls (Group I). All groups were subjected to measurement of plasma Ferritin, lipid profile, MDA and TAC colorimetrically. 8-OHdG levels were estimated by enzyme-linked immunosorbent assay (ELISA) in addition genotyping pattern for the SIRT1 (rs7069102) SNP was evaluated using PCR-CTPP technique. Values for AIP, ferritin, MDA and 8-OHdG levels, were significantly higher in β-TM groups compared to control with higher levels in patients with CIMT more than 0.5 mm but values of TAC and (HDL-C) showed significant decrease. CIMT was significantly correlated with age, atherogenic index of plasma (AIP), ferritin, MDA and 8-OHdG, HDL-C and TAC. There was significant difference in C allele distribution of SIRT1 rs7096102 was 57% in control subjects, 29% in Group IIa and 23% in Group IIb. However, the allele G distribution was 43% in control subjects, 71% in Group IIa and 77% Group IIb. Significant association of SIRT1 (rs7069102) polymorphism with dyslipidemia, ferritin and oxidative stress may conduct atherosclerotic potential in β-TM by affecting the severity of CIMT. Key words: Beta-thalassemia major, carotid intima media thickness.

Effects of CeO2 nanoparticles on the HO-1, NQO1, and GCLC expression in the testes of diabetic rats.

CeO2 nanoparticles (CNPs) as effective ROS scavengers exhibit potent antioxidant activity. In this study the effect of CNPs investigated was on HO-1, NQO1, and GCLC expression in the streptozotocin (STZ)-induced diabetic rats. Twenty-four male Wistar rats were divided into 4 groups: controls did not receive any treatment; diabetic rats received STZ (60 mg/kg daily); CNPs group received CNPs 30 mg/kg daily for 2 weeks; and rats in STZ + CNPs group received CNPs 30 mg/kg daily for 2 weeks following STZ injection. Oxidative stress was evaluated by measurement of total antioxidant capacity (TAC) and total oxidative status (TOS levels). HO-1, NQO1, and GCLC expression was measured using quantitative real-time PCR. Following STZ injection, significant lower levels of TAC and higher levels of TOS were observed. CNPs could alleviate deleterious effects of diabetes through the enhancement of TAC levels and a significant decline in TOS levels. HO-1, NQO1, and GCLC expression in the diabetic rats were lower than controls. HO-1, NQO1, and GCLC was upregulated in the diabetic rats treated with CNPs. There were significant correlations between NQO1 and GCLC, NQO1 and HO-1, and between HO-1 and GCLC expression. Moreover, Nrf2 was associated with NQO1, GCLC, and HO-1 expression. CNPs as Nrf2 upregulator confer protection against oxidative stress in the testes of STZ-induced diabetic rats by upregulating HO-1, GCLC, and NQO1 cytoprotective genes.

Heparin-stabilized gold nanoparticles-based CUPRAC colorimetric sensor for antioxidant capacity measurement

Sensing of total antioxidant capacity (TAC) as an integrated parameter showing the collective action of various antioxidants is an important challenge in food, biochemical and drug analysis. A novel heparin-stabilized gold nanoparticles (AuNPs)-based ‘cupric reducing antioxidant capacity’ (CUPRAC) colorimetric sensor was designed for TAC measurement. Heparin, a sulfated polysaccharide, was both the reducing and stabilizing agent for distinct negatively-charged AuNPs synthesis. The stabilized AuNPs were added to the copper(I)-neocuproine (Cu(I)-Nc) solution formed from the reaction of Cu(II)-Nc with antioxidants, and the absorbance of the resulting Cu(I)-Nc-AuNPs (Cu(I)-Nc cationic chelate electrostatically adsorbed on gold nanoparticles) was measured at 455 nm. As opposed to other similar AuNPs-based sensors, the proposed nano-sensor exhibited excellent (1000-fold) tolerance toward inert electrolytes without aggregation. The linear range was wider than that of conventional CUPRAC, with lower LOD (0.2 µM for trolox) and higher molar absorptivity (8.36 × 104 M−1 cm−1 for quercetin). The ‘trolox equivalent antioxidant capacity’ (TEAC) values and activity order for a number of antioxidants were in accordance with those of the reference CUPRAC assay. Antioxidant additions to black tea extract gave recoveries of 93–97% and RSD 2–6%. This green sensor significantly reduced reagent consumption, and operated in complex food samples with a simple, reliable and robust methodology.

New potential biomarkers of oxidative stress in Mytilus galloprovincialis: Analytical validation and overlap performance.

The aim of the present report was to develop and validate new automated spectrophotometric assays for measurement of total antioxidant capacity (TAC), thiols, and advanced oxidation protein products (AOPP) in mussel gills, digestive gland and hemolymph samples, and to evaluate their possible utility in biomonitoring programs. Total antioxidant capacity (TAC) was measured by different methods: trolox equivalent antioxidant capacity (TEAC1 and TEAC2), cupric reducing antioxidant capacity (CUPRAC), and ferric reducing ability of plasma (FRAP). The assays were precise, accurate and provided low limits of detection. When oxidative stress was promoted by inducing hypoxia and the behaviour of these biomarkers between hypoxic and controls mussels were compared, statistically significant differences were observed in all biomarkers and tissues evaluated. The results of the present study demonstrated that these biomarkers, not previously studied in mussels, show a potential use as biomarkers of oxidative stress in this species since they were validated and showed changes under a state of oxidative stress.

Relationship between serum levels of oxidative stress and metabolic syndrome components

AimsThis study aimed to investigate the relationship between the total antioxidant capacity (TAC) and Malondialdehyde (MDA) with number of metabolic syndrome (Mets) components on the personnel working in Shahroud University of Medical Sciences. MethodsThis cross-sectional study was conducted on 167 personnel aged 30–60 years old. ATP III criteria were used to diagnose patients with MetS. Oxidative stress indicators were measured. The data was analyzed via one-way ANOVA, and Pearson and Spearman correlation coefficients. ResultsThe result showed that TAC had a significant positive correlation with HDL and a significant negative correlation with abdominal obesity. In addition, there was a significant positive association between the level of MDA and age, BMI, abdominal obesity, diastolic blood pressure, triglycerides, and LDL; however, it had a negative significant correlation with HDL. ConclusionsThe measurement of TAC and MDA biomarkers can increase the early diagnosis of patients at risk of developing Mets.

Diagnostic and Prognostic Value of Talin-1 and Midkine as Tumor Markers in Hepatocellular Carcinoma in Egyptian Patients

Background:Hepatocellular carcinoma (HCC) is a main cause of cancer death all over the world. Treatment and outcome of HCC based on its early diagnosis. This study was conducted to estimate the role of talin-1 and midkine in combination with total antioxidant capacity (TAC) as tumor markers in HCC patients.Methods:Serum levels of talin-1 and midkine were measured in 90 Egyptian subjects including 44 patients with HCC, 31patients with cirrhosis and 15 healthy controls using enzyme-linked immunosorbent assay (ELISA) technique. While a colorimetric method was used for measurement of TAC.Results:Serum talin-1 in HCC patients was significantly lower than that in patients with cirrhosis (P<0.001) and normal control (P<0.001). In addition, increased invasion and metastasis correlated with reduced talin-1 level. Serum midkine in HCC patients was significantly higher compared to cirrhotic patients (P<0.001) and normal control (P<0.001). Midkine at a cut off value of 1683 pg/ml showed a sensitivity of (81.82%) and specificity of (83.87%). While alpha-fetoprotein (AFP) at a cut off value of 200 ng/ml had a sensitivity of (52.27%), while specificity was (96.77%). Midkine was positive in 80.9% of HCC patients with negative AFP. Serum TAC was significantly decreased in HCC patients when compared with control group (P<0.001).Conclusion:Talin-1 may be implicated in the carcinogenesis and metastasis of HCC and can be used as a useful tumor marker for HCC. Midkine may be a potential diagnostic marker for HCC and may be used in addition to AFP to increase the sensitivity of HCC detection.

Tools to assess effects of human pharmaceuticals in fish: A case study with gemfibrozil

There is an increasing need to assess animal welfare and subtle alterations that may indicate the presence of environmental stressors. Among the most widely used endpoints are the assessment of the activities of specific enzymes and the alterations of the expression levels of target genes. Enzymes associated with oxidative stress are frequently assessed but the results frequently render enzyme-dependent altered levels that make analyses difficult. In this study, Sparus aurata (gilthead sea bream) juveniles, were exposed, via water, to gemfibrozil (GEM) for a 96 h period to i) validate methods to measure total oxidative status (TOS), total antioxidant capacity (TAC), and esterase activity (EA) in gills; ii) study the relation between assessed gills’ oxidative stress responses and the mRNA levels of genes related to stress and immune function (in the gills and head kidney); iii) contribute to the knowledge of the effects of this human pharmaceutical on marine fish species. Overall, the obtained data confirmed the methodological precision and accuracy of TOS, TAC and EA measurements in the gills. GEM exposure did not alter TAC in gills but increased TOS. GEM modulated mRNA levels of genes, such as glutathione peroxidase 1 (gpx1) and interleukin 1β (il1 β) in the gills and head kidney of S. aurata.

A novel luminol-based enhanced chemiluminescence antioxidant capacity microplate assay for use in different biological matrices

IntroductionReactive oxygen species (ROS) are normal metabolic products of living cells. However, a decrease of the defense mechanisms against the effects of ROS or increased ROS production maybe one important causative factor of cellular damage. A non-enzymatic scavenger system is considered to be responsible for the maintenance of total antioxidant capacity (TAC) as a protection against oxidative injuries that exist in all higher plants and in mammals as well. MethodsIn our work, we optimized and validated a luminol-peroxidase-4-iodophenol-H2O2 enhanced chemiluminescence-based (ECL) TAC measurement technique. BSA was applied in the reagent to prevent peroxidase from auto-oxidation. The ECL method was suitable for plant extracts and for human blood serum as well. Our TAC technique was adapted to microplates and compared to ORAC assay using plant extracts. Results and discussionThe ECL method is fast (10min) with an interassay precision of <10% as CV. TAC values of ethanolic extracts of 10 plant species did correlate (ECL vs ORAC assay data: r=0.84, 95% confidence interval, CI=0.78–0.89, P<0.001) but with systematic bias. Analysis of serum samples obtained from septic and control patients showed significantly higher TAC values in the patient group compared to those of controls (p<0.01). Moreover, we could discriminate between surviving and non-surviving patients, based on their TAC values (p<0.01). Pearson's statistics showed the strongest positive correlation with serum uric acid (r=0.73). Besides the routine laboratory parameters, our novel TAC method might give complementary information on the severity of systemic inflammation.

Evaluation of Oxidative Stress in Sheep Infected with Psoroptes Ovis using Total Antioxidant Capacity, Total Oxidant Status, and Malondialdehyde Level.

IntroductionThe study aimed at evaluating oxidative stress using malondialdehyde (MDA), total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) markers in sheep naturally infected with Psoroptes ovis(Acari).Material and MethodsThe study was performed on 40 sheep divided into two equal groups: a healthy group (group I) and a group naturally infected with Psoroptes ovis (group II). The sera were obtained by centrifuging blood samples collected from the vena jugularis and serum MDA level changes in the samples were measured spectrophotometrically. Commercially available test kits were used for the measurement of TAC and TOS levels. The percentage ratio of TOS level to TAC level was accepted as OSI.ResultsThe serum malondialdehyde, total oxidant status levels, and oxidative stress index increased significantly (P < 0.01) in group II, while the serum total antioxidant capacity levels decreased significantly (P < 0.01) in this group. Negative correlations between total antioxidant capacity and total oxidant status and total antioxidant capacity and malondialdehyde, and a positive correlation between total oxidant status and malondialdehyde were found in infected sheep.ConclusionThe obtained results indicated the relationship between oxidant/antioxidant imbalance and Psoroptes ovis infection in sheep. Their MDA, TAC, TOS, and OSI markers may be used to determine the oxidative stress in natural infections with Psoroptes ovis.

Cover Picture: Measurement of Total Antioxidant Capacity by Electrogenerated Iodine at Disposable Screen Printed Electrodes (Electroanalysis 5/2017)

Cover Picture: Measurement of Total Antioxidant Capacity by Electrogenerated Iodine at Disposable Screen Printed Electrodes (Electroanalysis 5/2017)

Poly(vinyl alcohol) capped silver nanoparticles for antioxidant assay based on seed-mediated nanoparticle growth

A simple and rapid method for measurement of total antioxidant capacity (TAC) was developed. In this work, gallic acid was used as the antioxidant standard. Poly(vinyl alcohol) embedded silver nanoparticles (PVA-AgNPs) were employed as a colorimetric sensor. The detection principle was based on the seed-mediated nanoparticle growth technique. The PVA-AgNPs act as a catalyst in the reduction of Ag+ by gallic acid by providing nucleation seeds. Ag+ was reduced to Ag° and accumulated on the PVA-AgNP surface, leading to an increase in the size of particles. The absorbance of the colloidal solution was drastically enhanced with a small red shift. Under optimal conditions, a linear response was established between the change in absorbance and the TAC value expressed in terms of gallic acid equivalents. The linear range was from 25 to 200μM with a detection limit of 22.1μM. Satisfactory precision was obtained with % relative standard deviation (RSD) of 2.17. The developed sensor was successfully applied for TAC assessment of commercial ginger products. The PVA-AgNP sensor offers rapid analysis (within 5min) compared to other nanoparticle-based antioxidant assays. Synthesis of the particles and assay involved less-toxic chemicals, and is therefore a “greener” method.

Measurement of Total Antioxidant Capacity by Electrogenerated Iodine at Disposable Screen Printed Electrodes

AbstractTotal antioxidant capacity is an important parameter for the evaluation of the oxidative status in different kinds of biological samples such as plant extracts, or in food industry. We report a fast, easy, portable, cost‐effective electroanalytical method to measure total antioxidant capacity, based on the reaction of natural antioxidants with electrogenerated iodine using disposable platinum screen‐printed electrodes. This reaction can be measured by the increment of the electrochemical current signal of iodide oxidation to iodine during a voltammetric cycle. Iodine reacts with reducing compounds such as glutathione, ascorbate, gallic acid and NADH without interference of the corresponding oxidized counter‐parts. The addition of ascorbate oxidase also allows the concentration of ascorbate to be determined. The method was tested with real samples of plant extracts and the results correlated well with those obtained with a standard spectrophotometric method.

Beneficial Effect of Aqueous Garlic Extract on Inflammation and Oxidative Stress Status in the Kidneys of Type 1 Diabetic Rats.

One of the most important complications of diabetes is nephropathy. This study investigates the effects of aqueous garlic extract on inflammation and oxidative stress status in the kidneys of diabetic rats. Male rats were divided into four groups- control rats, diabetic rats, garlic extract-treated diabetic rats, garlic extract-treated normal rats. The glucose, urea, uric acid, and creatinine levels were measured in sera using colorimetric methods. To determine the oxidative stress condition in the kidney tissues, total antioxidant capacity (TAC), malondialdehyde (MDA), and total oxidant status (TOS) were measured using colorimetric methods. Inflammation status was evaluated by the determination of tumor necrosis factor-alpha (TNF-α) gene and protein expression using qRT-PCR and ELISA respectively, while nitric oxide (NO) level in these tissues was measured using the Griess method. Histological examination of Kidneys was carried out by H&E staining. The levels of glucose, urea, and uric acid were found to increase in the serum of diabetic rats and decrease in that of diabetic rats after treatment with garlic. Measurement of MDA, TOS, and TAC revealed oxidative stress in diabetic rats, which improved after receiving the extract. The NO and TNF-α protein levels in diabetic rats were higher than those in control rats. After treatment with garlic, the levels of TNF-α protein and NO became close to the normal levels. Histological results confirmed certain other data as well. Garlic has antioxidant properties; therefore, it can reduce oxidative stress, which plays an important role in the development of diabetic nephropathy. Reduction in oxidative stress has beneficial effects on inflammation because it leads to a decrease in the level of TNF-α.

Measurement of p-nitrophenyl acetate esterase activity (EA), total antioxidant capacity (TAC), total oxidant status (TOS) and acetylcholinesterase (AChE) in gills and digestive gland of Mytilus galloprovincialis exposed to binary mixtures of Pb, Cd and Cu.

The aims of the present work were (1) to evaluate oxidative stress biomarkers and AChE in two tissues of wild mussel (Mytilus galloprovincialis) of high biochemical activity and accumulation capacity (gills and digestive gland) and (2) to study the behaviour of these biomarkers in presence of heavy metals. For this, EA, TOS, TAC and AChE were measured in tissues of mussels exposed to binary combination of Pb, Cd and Cu. Mussels (n=36) were exposed to one of the binary mixtures of Pb (1000μgL-1), Cd (100μgL-1) and Cu (100μgL-1) for 7days, under controlled conditions. Gills and digestive gland were extracted and frozen at -80°C until analysis. The automatic methods employed for the measurement of EA, TAC, TOS and AChE in M. galloprovincialis revealed higher levels of these biomarkers in digestive gland than gills. Study results suggest that gills would be the tissue of election for study oxidative stress markers, whereas digestive tissue should be selected for AChE measurements in case of evaluation of combined metal toxicity in mussels.

Determination of total antioxidant capacity of humic acids using CUPRAC, Folin–Ciocalteu, noble metal nanoparticle- and solid–liquid extraction-based methods

Total antioxidant capacity (TAC) of humic acid (HA) samples was determined using CUPRAC (CUPric Reducing Antioxidant Capacity), FC (Folin–Ciocalteu), QUENCHER-CUPRAC, QUENCHER-FC, Ag-NP (Silver nanoparticle)‒ and Au-NP (Gold nanoparticle)‒based methods. Conventional FC and modified FC (MFC) methods were applied to solid samples. Because of decreased solubility of Folin–Ciocalteu's phenol reagent in organic solvents, solvent effect on TAC measurement was investigated using QUENCHER-CUPRAC assay by using ethanol:distilled water and dimethyl sulfoxide:distilled water with varying ratios. To see the combined effect of solubilization (leaching) and TAC measurement of humic acids simultaneously, QUENCHER experiments were performed at 25°C and 50°C; QUENCHER-CUPRAC and QUENCHER-FC methods agreed well and had similar precision in F-statistics. Although the Gibbs free energy change (ΔG°) of the oxidation of HA dihydroxy phenols with the test reagents were negative, the ΔG° was positive only for the reaction of CUPRAC reagent with isolated monohydric phenols, showing CUPRAC selectivity toward polyphenolic antioxidants. This is the first work on the antioxidant capacity measurement of HA having a sparingly soluble matrix where enhanced solubilization of bound phenolics is achieved with coupled oxidation by TAC reagents.

Increased oxidative stress in pemphigus vulgaris is related to disease activity and HLA-association

Pemphigus vulgaris (PV) is a rare blistering skin disorder characterized by the disadhesion of keratinocytes due to autoantibody attack against epidermal targets including desmoglein (Dsg) 3, Dsg 1 and possibly other adhesion and non-adhesion molecules. The mechanisms leading to immune-mediated pathology in PV are multifactorial and not fully understood. Recently, oxidative stress (antioxidant/oxidant disequilibrium) has been proposed as a contributory mechanism of autoimmune skin diseases, including PV. In this study, we directly assessed oxidative stress via measurement of total antioxidant capacity (TAC) using ELISA in 47 PV patients, 25 healthy controls and 18 bullous pemphigoid (BP) patients. We also performed microarray gene expression analysis on a separate set of 21 PV patients and 10 healthy controls to evaluate transcriptional dysregulation in oxidative stress-related pathways. Our data indicate that there is a significant reduction in TAC levels in PV patients compared with healthy controls, as well as BP patients. Furthermore, PV patients with active disease have significantly lower TAC levels than PV patients in remission. We also find that HLA allele status has a significant influence on oxidative stress. These findings are corroborated by microarray analysis showing differentially expressed genes involved in oxidative stress between the aforementioned groups. Collectively, our findings provide support for a role of oxidative stress in PV. Whether increased oxidative stress leads to disease manifestation and/or activity, or if disease activity leads to increased oxidative stress remains unknown. Future longitudinal studies may help to further elucidate the relationship between PV and oxidative stress.

Esterase activity (EA), total oxidant status (TOS) and total antioxidant capacity (TAC) in gills of Mytilus galloprovincialis exposed to pollutants: Analytical validation and effects evaluation by single and mixed heavy metal exposure

The aims of the present study were to optimize and validate methods for esterase activity (EA), total oxidant status (TOS) and total antioxidant capacity (TAC) determination in mussel' gills, and to establish the relationships between these biomarkers and Pb, Cd and Cu pollution, in single form and ternary mixture. Two different buffers for sample homogenization, the need of ultracentrifugation, and analytical validation were evaluated. Coefficients of variation, when buffer without additives and ultracentrifugation were used, were <15%, and recovery were 97%–109% in all cases. The EA response tends to decrease with treatments, TOS decreased significantly in Cd and ternary groups, while TAC tended to increase in treatments with Pb, Cd and ternary groups. In conclusion, the methods for EA, TOS and TAC measurements in gills of mussel were precise and accurate and could be interesting resources in biomonitoring programmes.

Comparison between ATR-IR, Raman, concatenated ATR-IR and Raman spectroscopy for the determination of total antioxidant capacity and total phenolic content of Chinese rice wine

The application of attenuated total reflectance infrared spectroscopy (ATR-IR), Raman spectroscopy (RS) and combination of ATR-IR and RS for measurements of total antioxidant capacity (TAC) and total phenolic content (TPC) of Chinese rice wine (CRW) were investigated in this study. Synergy interval partial least-squares (SiPLS), support vector machine (SVM) and principal component analysis (PCA) were applied to process the merged data from two individual instruments. It was observed that the performances of models based on the RS spectra were better than those based on the ATR-IR spectra. In addition, SVM models based on the efficient information extracted from ATR-IR and RS spectra were superior to PLS models based on the same information and PLS models based on ATR-IR or RS spectra. The overall results demonstrated that integrating ATR-IR and RS was possible and could improve the prediction accuracy of TAC and TPC in CRWs.

Antioxidants and Antioxidant Capacity of Human Milk / Antioksidansi i antioksidativni kapacitet humanog mleka

SUMMARY Milk contains plenty of enzymatic and non-enzymatic antioxidant components that probably account for the vital antioxidant protection of the infants at early stages of life against the development of complications induced by oxygen free radicals. Indigenous milk enzymes play a key role in regulating lactogenesis, including active involution of mammary gland. Moreover, they are essential constituents of antioxidation and the innate immune system of milk. Among antioxidant enzymes, superoxide dismutase, catalase and selenium-containing glutathione peroxidase have been demonstrated in human milk. Mainly, the enzyme content of colostrum is higher than that in corresponding mature milk. Beside lipophilic antioxidant in human milk, tocopherols, carotenoids and vitamin A are of great interest. Those components demonstrate the highest levels in colostrum and decline during early lactation, despite the fact that total lipids increase. The complete list of active antioxidant components in human milk is not yet known. This review reports the main findings of enzymatic and non-enzymatic antioxidants, as well as antioxidant capacity of human milk. Synergism of action of several antioxidants helps to eliminate free radicals in newborns. Bearing in mind that milk contains a number of antioxidants, many reactions are possible and it is difficult to define the exact contribution and function of each antioxidant. Besides qualitative and quantitative analysis of human milk antioxidants, the measurement of total antioxidant capacity could be a useful tool for examination of this dynamic, complex fluid

High-density Lipoprotein Antioxidant Responses To High-intensity Interval And Steady-state Moderate-intensity Exercise

High-intensity interval exercise (HIIE) may impart health benefits beyond what is acquired through moderate-intensity steady state exercise (SSE). Paraoxonase 1 (PON1), an antioxidant associated with high-density lipoprotein (HDL), may be altered with exercise; however, it is unclear whether HIIE provides a greater stimulus for increasing PON1 antioxidant activity than a comparable or greater amount of SSE. PURPOSE: Determine the influence of HIIE on PON1 concentration and activity relative to a comparable amount of moderate-intensity SSE and a dose that is half that of SSE. METHODS: Seventeen male participants (age 27.8 ± 6.4 yr; weight 80.6 ± 9.0 kg; BMI 25.1 ± 2.4 kg/m2; %fat = 19 ± 5; VO2max 52.1 ± 7.5 ml/kg/min) underwent HIIE by treadmill running (90% and 40% of VO2reserve in 3:2 min ratio) to expend 500 kcals (H500); HIIE to expend 250 kcals (H250), and; SSE at 70% VO2reserve to expend 500 kcals (M500) in a randomized crossover design. Intensities of all exercise conditions averaged 70% VO2reserve. Blood measures of total antioxidant capacity (TAC) in copper reducing equivalents, HDL (μg/mL), apolipoprotein A-1 (ApoA1: g/L), PON1 concentration (PON1c: μg/mL) and arylesterase activity (PON1a: kU/L) were obtained just before, immediately after, 2 hr and 24 hr after exercise. Significant differences were determined using 3 by 4 repeated measures ANOVAs. Effect sizes were calculated to determine the magnitude of dependent variable responses to exercise. RESULTS: Pre-exercise HDL concentration was lower in H250 and increased most in H250 versus other exercise conditions (p < 0.001, ES = 0.83). Other antioxidant responses were similar across exercise conditions. ApoA1 (+ 8.0%) and PON1a (+ 9.3%) increased immediately after exercise and remained elevated 24 hr after exercise (p < 0.0001 for each; ApoA1 ES = 0.85, PON1a ES = 0.57). PON1c was increased 2.4% above baseline at 2 hr post-exercise (p = 0.0296, ES = 0.18) and TAC was elevated 8.6% above baseline at 24 hr post-exercise (p = 0.0227, ES = 0.48). SUMMARY: HDL and HDL antioxidant properties are transiently potentiated by HIIE with as little as 250 kcals of energy expenditure. HDL antioxidant activity and total antioxidant capacity are elevated with HIIE and SSE of moderate intensity in a similar manner and are observed for up to 24 hr after exercise.