Age-related changes in the peroxyl radical scavenging capacity of human plasma

Evaluation of antioxidant status and lipid peroxidation in dogs with myxomatous mitral valve degeneration stage B1

Myxomatous mitral valve degeneration (MMVD) is the most common naturally occurring heart disease in dogs. There is a lack of data on antioxidant status and oxidative damage in dogs with MMVD stage B1 according to the American College of Veterinary Internal Medicine (ACVIM B1). The aim of this study was to investigate antioxidant status (plasma vitamin E, lipid-standardized vitamin E (LS-VitE), antioxidant capacity of lipid-(ACL) and water-soluble antioxidants, whole blood glutathione peroxidase and erythrocyte superoxide dismutase), and lipid peroxidation [malondialdehyde (MDA)] in dogs with MMVD ACVIM B1. Serum cholesterol and triglyceride concentrations were measured to calculate LS-VitE. Fourteen dogs with MMVD ACVIM B1 and 12 control dogs were included in the study. Dogs with MMVD had significantly higher vitamin E, ACL, MDA, and cholesterol concentrations and significantly higher LS-VitE values than control dogs. No significant correlations between MDA and antioxidant parameters were determined in either group. In conclusion, oxidative damage to lipids is already present and the antioxidant status is altered but not depleted in dogs with MMVD ACVIM B1. The antioxidant response to increased oxidative damage consists mainly of the activation of fat-soluble antioxidants. Further research is needed to evaluate the efficacy and targets of early antioxidant supplementation to prevent or ameliorate oxidative stress and mitigate disease progression in dogs with early-stage MMVD.

Impact of Lifestyles (Diet and Exercise) on Vascular Health: Oxidative Stress and Endothelial Function

Healthy lifestyle and diet are associated with significant reduction in risk of obesity, type 2 diabetes, and cardiovascular diseases. Oxidative stress and the imbalance between prooxidants and antioxidants are linked to cardiovascular and metabolic diseases. Changes in antioxidant capacity of the body may lead to oxidative stress and vascular dysfunction. Diet is an important source of antioxidants, while exercise offers many health benefits as well. Recent findings have evidenced that diet and physical factors are correlated to oxidative stress. Diet and physical factors have debatable roles in modulating oxidative stress and effects on the endothelium. Since endothelium and oxidative stress play critical roles in cardiovascular and metabolic diseases, dietary and physical factors could have significant implications on prevention of the diseases. This review is aimed at summarizing the current knowledge on the impact of diet manipulation and physical factors on endothelium and oxidative stress, focusing on cardiovascular and metabolic diseases. We discuss the friend-and-foe role of dietary modification (including different diet styles, calorie restriction, and nutrient supplementation) on endothelium and oxidative stress, as well as the potential benefits and concerns of physical activity and exercise on endothelium and oxidative stress. A fine balance between oxidative stress and antioxidants is important for normal functions in the cells and interfering with this balance may lead to unfavorable effects. Further studies are needed to identify the best diet composition and exercise intensity.

Intraocular Oxygen and Antioxidant Status: New Insights on the Effect of Vitrectomy and Glaucoma Pathogenesis

PURPOSE

The purpose of this study was to investigate correlations of partial pressure of oxygen (pO₂) in the ocular anterior segment of human eyes and aqueous humor antioxidant levels of ascorbate (AsA) and total reactive antioxidant potential (TRAP) with glaucoma and vitreous status.

METHODS

This prospective, cross-sectional study stratified patients (n = 288 eyes) by lens and vitreous status and the presence of primary open-angle glaucoma for statistical analyses. Intraocular pO₂ concentrations were measured using a fiberoptic probe in patients at the beginning of planned glaucoma and/or cataract surgery. Aqueous humor specimens were obtained for antioxidant analysis of AsA and TRAP.

RESULTS

Following prior pars plana vitrectomy, pO₂ levels were significantly higher than in the reference group of cataract surgery in the anterior chamber angle (16.2 ± 5.0 vs. 13.0 ± 3.9 mm Hg; P = .0171) and in the posterior chamber (7.6 ± 3.1 vs. 3.9 ± 2.7 mm Hg; P < .0001). AsA and TRAP levels were significantly lower (1.1 ± 0.4 vs. 1.4 ± 0.5 mM, respectively; 403.3 ±116.5 vs. 479.0 ± 146.7 Trolox units, respectively; P = .004 and P = .024, respectively) in patients after vitrectomy. In patients with an intact vitreous, neither pO₂ nor antioxidant status correlated with lens status or glaucoma.

CONCLUSIONS

Increased pO₂ and antioxidant depletion following vitrectomy suggests an alteration of the intraocular oxidant-antioxidant balance. Our study links physiologic factors such as increased pO₂ in the anterior chamber angle and the posterior chamber to decreased antioxidant levels in aqueous humor following vitrectomy. Oxidative stress/damage to the trabecular meshwork in such post-vitrectomy cases may contribute to intraocular pressure elevation and increased risk of glaucoma. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Plasma Total Antioxidant Capacity and Activities of Blood Glutathione Peroxidase and Superoxide Dismutase Determined in Healthy Dogs by Using Commercially Available Kits

Data on the values of selected blood antioxidant parameters, i.e. total antioxidant capacity, glutathione peroxidase, and superoxide dismutase in healthy dogs, are lacking. There are no published accepted standard reference methods for their determination. The aim of this study was to determine the values of plasma total antioxidant capacity and the activities of whole blood glutathione peroxidase and erythrocyte superoxide dismutase in 30 healthy client-owned dogs (19 females, 11 males). The effect of age and sex on the measured antioxidant parameters was also investigated. Antioxidant parameters were determined with an automated biochemical analyser, using the commercially available Randox kits. No significant difference in age, weight, and antioxidant parameters was determined between females and males. A significant positive effect of age (p = 0.002, r2 = 0.284) on superoxide dismutase activity was confirmed. There was no effect of sex on any of the antioxidant parameters measured. However, we observed a tendency of the effect of sex (p = 0.063, r2 = 0.118), as well as age (p = 0.073, r2 = 0.111), on the activity of glutathione peroxidase. Our results are in part comparable with the results of other studies in which the same types of methods and samples were used to determine antioxidant parameters. In conclusion, the sex and age of dogs should be taken into consideration when planning a study on antioxidant status parameters.

MnSOD and GPx1 polymorphism relationship with coronary heart disease risk and severity

BACKGROUND

Disturbance of the equilibrium between reactive oxygen species (ROS) and anti-oxidants (AOX) has been implicated in various diseases, including atherosclerosis, the most common pathologic process underlying coronary heart disease (CHD). Thus, the defense systems against ROS are critical protecting blood vessel walls against oxidative damage. In this study, we investigate whether Ala16Val MnSOD and Pro198Leu GPx polymorphisms are associated with CHD susceptibility and/or severity.

METHODS

Both polymorphisms were genotyped in a sample of 203 controls and 164 patients. CHD risk and severity, antioxidant status (enzymatic and/or non enzymatic) and biochemical parameters were assessed and analysed by genotype.

RESULTS

A significant association of MnSOD variant to CHD risk was revealed in males. Males harboring the Val/Val genotype were approximately at twofold increased risk of CHD compared to controls (Ala carriers vs Val/Val, adjusted OR 1.89; 95 % CI 1.18‒3.42, p = 0.03). Significant decreases in SOD activity and total antioxidant status (TAS) were observed in Val carriers and by CHD status. Whereas, no association of GPx variant genotype (Leu/Leu) and activity to cardiopathy events was discerned. CHD severity, as demonstrated by the number of vessel stenosis, was associated with significantly higher frequency of Val allele and LDL levels in CHD subjects.

CONCLUSIONS

Our results showed a lack of association of Pro198Leu GPx polymorphism to CHD risk and severity. However, they suggest that Ala16Val MnSOD polymorphism and decreased antioxidant defences are likely contributed to CHD risk in Tunisian men. Furthermore, the Val encoding MnSOD allele and decreased SOD activity were significantly correlated with CHD stenosis progression.

Plasma total antioxidant status and cognitive impairments in schizophrenia

Oxidative stress-induced damage to neurons may contribute to cognitive deficits during aging and in neurodegenerative disorders. Schizophrenia has a range of cognitive deficits that may evolve from oxidative stress, and this study examines this association of oxidative stress with cognitive deficits in schizophrenia. We recruited 296 chronic schizophrenia patients and 181 healthy control subjects and examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and plasma total antioxidant status (TAS) in both groups. Schizophrenia symptoms were assessed using the positive and negative syndrome scale (PANSS). Our results showed that TAS levels were significantly lower in patients than controls (179.6 ± 81.0 U/ml vs. 194.8 ± 46.0 U/ml, p<0.05). Cognitive scores on the RBANS and nearly all of its five subscales (all p<0.001) except for the Visuospatial/Constructional index (p>0.05) were significantly lower in schizophrenia patients than normal controls. For the patients, TAS was inversely associated with some domains of cognitive deficits in schizophrenia, such as Attention and Immediate Memory. Our findings suggest that oxidative stress may be involved in the pathophysiology of schizophrenia, and its associated cognitive impairment.

Walking the oxidative stress tightrope: a perspective from the naked mole-rat, the longest-living rodent

Reactive oxygen species (ROS), by-products of aerobic metabolism, cause oxidative damage to cells and tissue and not surprisingly many theories have arisen to link ROS-induced oxidative stress to aging and health. While studies clearly link ROS to a plethora of divergent diseases, their role in aging is still debatable. Genetic knock-down manipulations of antioxidants alter the levels of accrued oxidative damage, however, the resultant effect of increased oxidative stress on lifespan are equivocal. Similarly the impact of elevating antioxidant levels through transgenic manipulations yield inconsistent effects on longevity. Furthermore, comparative data from a wide range of endotherms with disparate longevity remain inconclusive. Many long-living species such as birds, bats and mole-rats exhibit high-levels of oxidative damage, evident already at young ages. Clearly, neither the amount of ROS per se nor the sensitivity in neutralizing ROS are as important as whether or not the accrued oxidative stress leads to oxidative-damage-linked age-associated diseases. In this review we examine the literature on ROS, its relation to disease and the lessons gleaned from a comparative approach based upon species with widely divergent responses. We specifically focus on the longest lived rodent, the naked mole-rat, which maintains good health and provides novel insights into the paradox of maintaining both an extended healthspan and lifespan despite high oxidative stress from a young age.

Age-related changes in brain mitochondrial DNA deletion and oxidative stress are differentially modulated by dietary fat type and coenzyme Q₁₀

Mitochondria-related oxidative damage is a primary event in aging and age-related neurodegenerative disorders. Some dietary treatments, such as antioxidant supplementation or the enrichment of mitochondrial membranes with less oxidizable fatty acids, reduce lipid peroxidation and lengthen life span in rodents. This study compares life-long feeding on monounsaturated fatty acids (MUFAs), such as virgin olive oil, and n-6 polyunsaturated fatty acids, such as sunflower oil, with or without coenzyme Q₁₀ supplementation, with respect to age-related molecular changes in rat brain mitochondria. The MUFA diet led to diminished age-related phenotypic changes, with lipoxidation-derived protein markers being higher among the older animals, whereas protein carbonyl compounds were lower. It is noteworthy that the MUFA diet prevented the age-related increase in levels of mitochondrial DNA deletions in the brain mitochondria from aged animals. The findings of this study suggest that age-related oxidative stress is related, at the mitochondrial level, to other age-related features such as mitochondrial electron transport and mtDNA alterations, and it can be modulated by selecting an appropriate dietary fat type and/or by suitable supplementation with low levels of the antioxidant/electron carrier molecule coenzyme Q.

WITHDRAWN: Oxidative stress in aging: Theoretical outcomes and clinical evidences in humans

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.biomag.2011.03.001. The duplicate article has therefore been withdrawn.

Protein antioxidant response to the stress and the relationship between molecular structure and antioxidant function

Background

Proteins have long been considered a principal target for oxidants as a result of their abundance in biological systems. However, there is increasing evidence about the significant antioxidant activity in proteins such as albumin. It is leading to new concepts that even consider albumin not only as an antioxidant but as the major antioxidant in plasma known to be exposed to continuous oxidative stress. Evidence presented here establishes a previously unrecognized relationship between proteins' antioxidant capacity and structural stress.

Methodology/Principal Findings

A chemiluminiscence based antioxidant assay was achieved to quantify the antioxidant capacity of albumin and other proteins. The capabilities of proteins as antioxidants were presented, but in addition a new and powerful component of the protein antioxidant capacity was discovered. The intrinsic component, designated as Response Surplus (RS), represents a silent reserve of antioxidant power that awakens when proteins face a structural perturbation (stressor) such as temperature, short wave UV light, the same reactive oxygen species, and more extreme changes like glucose or aldehyde-mediated structural modifications. The work also highlights the importance of structural changes in protein antioxidant properties and the participation of sulfhydryl groups (SHs) in the RS antioxidant component. Based on recent evidence about the SH group chemistry, a possible model for explaining RS is proposed.

Conclusions/Significance

The data presented show the significant antioxidant behavior of proteins and demonstrate the existence of a previously unrecognized antioxidant response to the stress. Several implications, including changes in elementary concepts about antioxidants and protein function, should emerge from here.

The Clinical Application of Ozonetherapy

The reader may be eager to examine in which diseases ozonetherapy can be proficiently used and she/he will be amazed by the versatility of this complementary approach (Table 9 1). The fact that the medical applications are numerous exposes the ozonetherapist to medical derision because superficial observers or sarcastic sceptics consider ozonetherapy as the modern panacea. This seems so because ozone, like oxygen, is a molecule able to act simultaneously on several blood components with different functions but, as we shall discuss, ozonetherapy is not a panacea. The ozone messengers ROS and LOPs can act either locally or systemically in practically all cells of an organism. In contrast to the dogma that “ozone is always toxic”, three decades of clinical experience, although mostly acquired in private clinics in millions of patients, have shown that ozone can act as a disinfectant, an oxygen donor, an immunomodulator, a paradoxical inducer of antioxidant enzymes, a metabolic enhancer, an inducer of endothelial nitric oxide synthase and possibly an activator of stem cells with consequent neovascularization and tissue reconstruction.

Plasma antioxidant capacity among middle‐aged men: The contribution of uric acid

OBJECTIVE

Although assays of plasma antioxidant capacity encompass interactions between various antioxidants, uric acid concentration can exert a predominant effect on results. Therefore, individual differences in uric acid concentration may explain a many of the differences in antioxidant capacity. The objective of this study was to measure the antioxidant capacity of plasma samples with and without uric acid in order to provide more information about how the concept of antioxidant capacity could be applied.

MATERIAL AND METHODS

Antioxidant capacity was measured using an enhanced chemiluminescence assay, and uric acid was removed from the samples using uricase.

RESULTS

Antioxidant capacity was positively correlated with uric acid concentration, body mass index, waist circumference, abdominal sagittal diameter and the concentrations of insulin and triglycerides. These correlations were not evident when uric acid was eliminated from the sample, but antioxidant capacity was correlated with lipid concentration; this may partly reflect tocopherols that are transported by lipid molecules.

CONCLUSIONS

The significance of the contribution of uric acid to the antioxidant capacity could differ according to the type of study. Antioxidant capacity measurements in cross-sectional studies may be presented both with and without the contribution of uric acid, because the absence of such data complicates interpretation of results when different populations are compared.

Antioxidant use in nutraceuticals

The focus of this contribution is oxidation generated by oxygen and by all other reactive species, with an emphasis on reactive oxygen species. This study considers the different pathways that generate oxidative stress, which is a physiologic process that can become dangerous if becomes excessive and overcomes the reserve of antioxidants. Some of the most important methods to determine oxidative stress in plasma, both in humans and in experimental animals, are discussed; particular attention is given to the d-ROMs test, which detects the hydroperoxides in plasma and is a very simple and reliable method. The antioxidant hierarchy also is discussed to indicate the most powerful physiological antioxidant and those derived from food intake or supplementation. As every antioxidant also can be a pro-oxidant, indications are given about their use and how to avoid the administration of high dosages of a single antioxidant.

Plasma antioxidants and human aging: a study on healthy elderly Tunisian population

The aging has been described by several theories. It was proposed that free radicals are the major factor involved in this process. This gave birth to the free radical theory of aging. This current theory provides the most popular explanation for how aging occurs at the biochemical/molecular level. Ever since 1956, this theory has received widespread attention and a large body of evidence has been accumulated in support of its hypotheses which were subsequently refined. The free radical theory of aging postulates that age-associated reductions in physiological functions are caused by an irreversible accumulation of oxidative alterations to macromolecules. This accumulation increases with age and is associated with the life expectancy of organisms. Moreover, this theory suggests the existence of an imbalance between reactive oxygen species (ROS)-producing pathways and (ROS)-scavenging pathways, which is responsible for the generation of oxidative stress syndrome. In this article, we evaluate the antioxidant status in a population of healthy elderly Tunisians in comparison with a group of healthy young Tunisian subjects. This study sets out to investigate the age-related changes in glutathione peroxidase (GPx), superoxide dismutase (SOD) activities, and in total antioxidant status (TAS) of human plasma. We have concluded that healthy aging is accompanied with a disturbed antioxidant status.

Age- and gender-related oxidative status determined in healthy subjects by means of OXY-SCORE, a potential new comprehensive index

Oxidative stress has been related to various diseases, gender and ageing, and has been measured by various markers. The authors developed a procedure to compute a global oxidative stress index (OXY-SCORE), reflecting both oxidative and antioxidant markers in healthy subjects. Its performance was tested in relation to age and gender and in coronary artery disease (CAD) patients. Eighty-two healthy subjects and 20 CAD patients were enrolled. Plasma free and total malondialdehyde (F- and T-MDA), glutathione disulphide/reduced form ratio (GSSG/GSH) and urine isoprostanes (iPF2alpha-III) levels were combined as oxidative damage markers (damage score). GSH, alpha- and gamma-tocopherol (TH) levels, and individual antioxidant capacity were combined as antioxidant defence indexes (protection score). The OXY-SCORE was computed by subtracting the protection score from the damage score. Among single parameters, T-MDA and iPF2alpha-III significantly correlated with age; only GSH and both tocopherols correlated with male gender in healthy subjects. The OXY-SCORE was positively associated with age (p=0.004) and male gender (p=0.03). As expected, the OXY-SCORE was higher in CAD with a very significant p-value (<0.0001), after adjusting for age, gender and smoking. Combining different markers can potentially provide a powerful index in the evaluation of oxidative stress related to age, gender and CAD status.

Clinical oxidation parameters of aging

Aging is a complex progressive physiological alteration of the organism which ultimately leads to death. During the whole life a human being is confronted with oxidative stress. To measure how this oxidative stress is developing during the aging process and how it changes the cellular metabolism several substances have been pronounced as biomarkers including lipid peroxidation (LPO) products, protein oxidation products, antioxidative acting enzymes, minerals, vitamins, glutathione, flavonoids, bilirubin and uric acid (UA). But none of them could develop to the leading one which is accepted by the whole scientific community to determine the life expectancy of the individual person or biological age or age-related health status. Further there are many conflicting data about the changes of each single biomarker during the aging process. There are so many different influences acting on the concentration or activity of single substances or single enzymes that it is not possible to measure only one clinical marker and determine how healthy an individual is or to predict the life expectancy of the corresponding person. Therefore, always a set or pattern of clinical biomarkers should be used to determine the oxidation status of the person. This set should include at least one marker for the LPO, the protein oxidation and the total antioxidative status and ideally also one for DNA damages.

Inhibitory effect of phenolic acids on the proliferation of 3T3-L1 preadipocytes in relation to their antioxidant activity

Obesity is an important topic in the world of public health and preventive medicine. Inhibition of preadipocyte proliferation plays an important role in the mechanisms of proposed antiobesity. In this in vitro study, the inhibitory effect of phenolic acids on 3T3-L1 preadipocytes was evaluated, and a relationship analysis was then conducted. The results showed that the addition of phenolic acids to the growth medium decreased the cell population growth of 3T3-L1 preadipocytes. The IC50 values of chlorogenic acid, gallic acid, o-coumaric acid and m-coumaric acid on 3T3-L1 preadipocytes were 72.3, 43.3, 48.2, and 49.2 microM, respectively. A relationship analysis indicated that there is a significant linear correlation between the influence of phenolic acids on cell population growth and their antioxidant activity (r = 0.77, p < 0.01). The cell cycle assay indicated that the treatment of 3T3-L1 preadipocytes with chlorogenic acid, o-coumaric acid, and m-coumaric acid caused cell cycle arrest in the G1 phase. Gallic acid did not affect the cell cycle profile; however, it increased the number of apoptotic cells (sub-G1 phase) in a time- and dose-dependent manner. Annexin V-fluorescein isothiocyanate (FITC)-propidium iodide (PI) apoptosis flow cytometric assay showed that gallic acid increased the number of early apoptotic (annexin V-FITC+/PI-) and late apoptotic cells (annexin V-FITC+/PI+) but not necrotic cells (annexin V-FITC-/PI+). The treatment of cells with gallic acid caused the loss of mitochondrial membrane potential (delta psi(m)). These results indicate that the inhibition of preadipocyte population growth by some phenolic acids might have further implication in in vivo antiobesity effects.

Age-associated analysis of oxidative stress parameters in human plasma and erythrocytes

Oxidative damage accumulation in macromolecules has been considered as a cause of cellular damage and pathology. Rarely, the oxidative stress parameters in healthy humans related to the individual age have been reported. The purpose of this study was to examine the redox status in plasma and erythrocytes of healthy individuals and determine correlations between these parameters and the aging process. The following parameters were used: malondialdehyde (MDA), protein carbonyls (PCO), 4-hydroxy-2,3-trans-nonenal (HNE), reduced glutathione (GSH), glutathione disulfide (GSSG) and uric acid (UA) in blood and plasma samples of 194 healthy women and men of ages ranging from 18 to 84 years. The results indicate that the balance of oxidant and antioxidant systems in plasma shifts in favor of accelerated oxidation during ageing. That is demonstrated by increases of MDA, HNE, GSSG and by the slight decrease of erythrocytic GSH with age. As the content of UA is more determined by metabolic and nutritional influences than by the balance between prooxidants and antioxidants there was no significant age-related change observed. For plasma concentrations of HNE the first time age-dependent reference values for healthy humans are presented.

Age-related mitochondrial DNA deletion in rat liver depends on dietary fat unsaturation

We fed male Wistar rats lifelong on virgin olive (rich in the monounsaturated oleic acid) or sunflower (rich in the polyunsaturated linoleic acid) oil-based diets. At 6 and 24 months, liver mitochondria were analyzed for a mitochondrial DNA (mtDNA) deletion, reactive oxygen species, antioxidants, and ultrastructural alterations. An aging-related increase in the relative amount of the deletion was observed for both dietary groups, being higher in animals fed sunflower oil. Oxidative stress was lower in virgin olive oil-fed animals. Aging led to higher superoxide dismutase, catalase, and glutathione peroxidase activities and increased alpha-tocopherol and coenzyme Q. Mitochondria from aged animals fed sunflower oil exhibited a lower number of cristae and a higher circularity. Results suggest that the age-related increase of the relative amount of deleted mtDNA depends on fat unsaturation. Moreover, the studied mtDNA deletion was correlated with mitochondrial oxidative stress and ultrastructural alterations.

Blood plasma antioxidant defense in patients with pancreatitis

OBJECTIVES

The aim of this study was to establish the main determinants of plasma antioxidant potential in different types of human pancreatitis: chronic pancreatitis (CP, n = 19), chronic pancreatitis exacerbated (CPE, n = 16), and acute pancreatitis (AP, n = 8).

METHODS

We measured the plasma thiobarbituric acid reactive substances (TBARS), total peroxyl radical trapping potential (TRAP), and the levels of antioxidants such as uric acid (UA), SH groups (SH), ascorbic acid (AA), and bilirubin (BIL).

RESULTS

In comparison to healthy volunteers (HV, n = 22) the average levels of TBARS in all types of pancreatitis were significantly higher (by 50%-90%), and plasma SH groups were lower (approximately 30%). In the multivariate regression models, the variability of plasma TRAP was explained in the HV group through UA only (36%), in the CP group through UA, AA, and BIL together (75%), and in CPE group through UA and AA together (81%). Plasma SH concentration did not enter the regression models in all groups. The AP group revealed "paradoxically" high concentrations of AA and TRAP and a negative, linear correlation between the level of TRAP versus UA concentration (R = -0.87).

CONCLUSIONS

The multivariate regression analysis points to different structures of antioxidant defense in healthy people and those with pancreatitis: they were much the same in the CP and CPE groups but fundamentally different in the AP group. AP may activate unidentified antioxidant defenses as an adaptive response against oxidative stress.

Positive association between plasma antioxidant capacity and n−3 PUFA in red blood cells from women

PUFA are susceptible to oxidation. However, the chain-reaction of lipid peroxidation can be interrupted by antioxidants. Whether an increased concentration of PUFA in the body leads to decreased antioxidant capacity and/or increased consumption of antioxidants is not known. To elucidate the relationship between plasma total antioxidant capacity (TAC), the concentration of antioxidant vitamins, and the proportion of PUFA in red blood cells (RBC), plasma TAC was measured by a Trolox equivalent antioxidant capacity assay in blood samples from 99 Icelandic women. Concentrations of tocopherols and carotenoids in the plasma were determined by HPLC, and the FA composition of RBC total lipids was analyzed by GC. Plasma TAC and the plasma concentration of alpha-tocopherol correlated positively with the proportion of total n-3 PUFA, 20:5n-3, and 22:6n-3 in RBC, whereas the plasma lycopene concentration correlated negatively with the proportion of total n-3 PUFA and 20:5n-3. On the other hand, plasma TAC correlated negatively with the proportion of n-6 PUFA in RBC. Plasma TAC also correlated positively with the plasma concentration of alpha-tocopherol, alcohol consumption, and age. Both the plasma concentration of alpha-tocopherol and age correlated positively with the proportion of n-3 PUFA in RBC; however, n-3 PUFA contributed independently to the correlation with plasma TAC. Because the proportion of n-3 PUFA in RBC reflects the consumption of n-3 PUFA, these results suggest that dietary n-3 PUFA do not have adverse effects on plasma TAC or the plasma concentration of most antioxidant vitamins.

Mangifera indica L. (Vimang) Protection against Serum Oxidative Stress in Elderly Humans

BACKGROUND

We searched for the protective effect of a natural extract from stem bark of Mangifera indica L. extract (Vimang) on age-related oxidative stress.

METHODS

Healthy subjects were classified in two groups, elderly (>65 years) and young group (<26 years). The elderly group received a daily dose of 900 mg of extract (three coated Vimang tablets, 300 mg each, before meals) for 60 days. Serum concentration of lipid peroxides, serum peroxidation potential, extracellular superoxide dismutase activity (EC-SOD), glutathione status (GSH, GSSG, GSSG/GSH ratio)) and total antioxidant status (TAS) were determined before (both experimental groups) and 15, 30, and 60 days after treatment (only elderly group). We confirmed the existence of an age-associated oxidative stress in human serum as documented by an age-related increase in serum lipoperoxides and GSSG and a decrease in serum antioxidant capacity and EC-SOD activity.

RESULTS

Vimang tablet supplementation increased EC-SOD activity (p <0.01) and serum TAS (p <0.01). It also decreased serum thiobarbituric reactive substances (p <0.01) and GSSG levels (p <0.05). We suggested that the antioxidant components of the extract could have been utilized by the cells (especially blood and endothelial cells), sparing the intra- and extracellular antioxidant system and increasing serum peroxil scavenging capacity, thus preventing age-associated increase in GSH oxidation and lipoperoxidation.

CONCLUSIONS

Vimang tablets prevent age-associated oxidative stress in elderly humans, which could retard the onset of age-associated disease, improving the quality of life for elderly persons.

Age-related oxidative stress and antioxidant parameters in middle-aged and older European subjects: the ZENITH study

OBJECTIVE

Oxidative stress has been reported to increase with ageing. However, the data in healthy humans remain controversial and studies in free-living elderly people are scarce. The objective of the present study was to compare age-related oxidative stress in late middle-aged and older free-living subjects.

DESIGN

The effect of ageing on oxidative stress and antioxidant parameters was investigated in 188 middle-aged subjects from Clermont-Ferrand (France) and Coleraine (UK), and in 199 older subjects from Grenoble (France) and Roma (Italy). Plasma thiol (SH) groups, define definition (TBAR's) and total glutathione (GSH), define definition (FRAP), and superoxide dismutase (SOD) activity were measured at baseline of the ZENITH study.

RESULTS

Plasma SH groups and FRAP and, surprisingly, TBAR's were significantly lower in free-living older subjects compared to younger subjects (P < 0.001, P < 0.001, P < 0.01, respectively), but there was no significant differences in GSH levels.

CONCLUSION

European free-living healthy older do not appear to be exposed to an acute oxidative stress. However, the highly significant positive correlation between plasma SH group oxidation or decreased FRAP and ageing is predictive of an increased risk of oxidative stress in older subjects. Moreover, the comparison between middle-aged and older subjects regarding oxidative stress parameters suggests also a progressive and slow decline of antioxidant status in healthy free-living older elderly and underline the impact on life-style factors on successful ageing.

Efficient antioxidant capacity against lipid peroxide levels in healthy elderly of Mexico City

We evaluated antioxidant activity against lipid peroxide levels (LPO) in healthy elderly and adults of Mexico City in comparison with a population of a rural area. The study included free-living subjects: 38 adults aged <60 years and 129 older subjects aged > or = 60 years of urban Mexico City in addition to 37 adults aged <60 years and 88 older subjects aged > or = 60 years of rural area (Actopan, Hidalgo State, Mexico). LPO were observed as higher in adults and elderly of the urban area than among rural subjects (P<0.01), although LPO levels were similar in rural adults and elderly (P>0.05); conversely, in urban area levels were higher in the elderly than in adults (P<0.01). On the other hand, the superoxide dismutase in urban elderly was higher than that in rural elderly (P<0.05) but similar between urban adults and urban elderly (P>0.05). Total oxidant status in urban elderly was higher than that in rural elderly (P<0.01). Our findings allow us to conclude that the urban elderly (residents of Mexico City) have higher oxidative stress than the rural-dwelling elderly, though the urban elderly have efficient antioxidant capacity as a response to elevated LPO.

Measurement of total antioxidant capacity in gingival crevicular fluid and serum in dogs with periodontal disease

OBJECTIVE

To determine whether gingival crevicular fluid (GCF) and serum total antioxidant capacities (TACs) correlate with the degree of severity of periodontal disease in dogs.

ANIMALS

41 Toy and Miniature Poodles.

PROCEDURES

After assessment of the degree of severity of naturally occurring periodontitis, GCF samples from both maxillary fourth premolars and a blood sample were collected from each dog. The condition of the periodontium of the entire dentition and at each site of GCF collection was recorded. Clinical parameters assessed included plaque index, gingival index, and probing depth. Radiographic analysis of alveolar bone level was also performed. Total antioxidant capacity was measured in GCF and serum samples by use of a commercial kit.

RESULTS

Dogs with gingivitis and minimal periodontitis had significantly higher TAC in GCF than dogs with advanced periodontitis. Bivariate regression analysis revealed significant negative correlations between TAC in GCF and clinical parameters and age. The TAC in serum was significantly negatively correlated with the degree of gingival inflammation but was not significantly correlated with age.

CONCLUSIONS AND CLINICAL RELEVANCE

TAC in GCF is related to the degree of severity of periodontal disease in dogs. This is likely the result of release of reactive oxygen species by activated phagocytes and fibroblasts in the inflamed periodontal tissues. The results of our study suggest that the local delivery of antioxidants may be a useful adjunctive treatment for periodontitis in dogs.

Life-long supplementation with a low dosage of coenzyme Q10 in the rat: effects on antioxidant status and DNA damage

Life-long low-dosage supplementation of coenzyme Q(10) (CoQ(10)) is studied in relation to the antioxidant status and DNA damage. Thirty-two male rats were assigned into two experimental groups differing in the supplementation or not with 0.7 mg/kg/day of CoQ(10). Eight rats per group were killed at 6 and 24 months. Plasma retinol, alpha-tocopherol, coenzyme Q, total antioxidant capacity and fatty acids were analysed. DNA strand breaks were studied in peripheral blood lymphocytes. Aging and supplementation led to significantly higher values for CoQ homologues, retinol and alpha-tocopherol. No difference in total antioxidant capacity was detected at 6 months but significantly lower values were found in aged control animals. Similar DNA strand breaks levels were found at 6 months. Aging led to significantly higher DNA strand breaks levels in both groups but animals supplemented with CoQ(10) led to a significantly lower increase in that marker. Aged rats showed significantly higher polyunsaturated fatty acids. This study demonstrates that lifelong intake of a low dosage of CoQ(10) enhances plasma levels of CoQ(9), CoQ(10), alpha-tocopherol and retinol. In addition, CoQ(10) supplementation attenuates the age-related fall in total antioxidant capacity of plasma and the increase in DNA damage in peripheral blood lymphocytes.

Dietary fat type (virgin olive vs. sunflower oils) affects age-related changes in DNA double-strand-breaks, antioxidant capacity and blood lipids in rats

This study was designed to investigate the possible effect on DNA double-strand breaks, antioxidant capacity and blood lipids of feeding rats lifelong with two different dietary fat sources: virgin olive oil (rich in the monounsaturated oleic acid) or sunflower oil (rich in the polyunsaturated linoleic acid). No changes in mean or maximal lifespan were observed. Overall, aging led to increased levels of plasma cholesterol, triglycerides, phospholipids, total lipids, polyunsaturated fatty acids and DNA double-strand breaks. All these parameters were higher in animals fed on sunflower oil diet. Aging diminished total antioxidant capacity with both diets, but in a lower extension for virgin olive oil diet. A very good inverse correlation (r= -0.715; P < 0.01, for sunflower oil group and r= -0.535; P < 0.01 for virgin olive oil group) between DNA damage and total antioxidant capacity was found. These results allow to conclude that dietary fat type should be considered in studies on aging, since the intake of oils with different polyunsaturation levels directly modulates total antioxidant capacity of plasma, DNA damage to peripheral blood lymphocytes and lead to important changes at the lipid metabolism level. In the present study best results were found after intake of virgin olive oil, which suggest the possible use of that edible oil to provide a healthier aging.

Age-related increases in plasma malondialdehyde and protein carbonyl levels and lymphocyte DNA damage in elderly subjects

OBJECTIVES

Increased oxidative stress has been hypothesized to play an important role in the aging process. A role for oxidative damage in normal aging is supported by studies in experimental animals, but there is limited evidence in humans. To investigate the relationship between the oxidative stress and aging in humans, we determined lipid and protein oxidation in plasma as well as DNA damage in lymphocytes in young and elderly subjects.

DESIGN AND METHODS

55 healthy subjects were divided into young (21-40 years) and elderly (61-85 years) groups. Plasma malondialdehyde (MDA), protein carbonyl (PC) levels, and grade of DNA damage in lymphocytes using comet assay as well as total ferric reducing antioxidant power (FRAP) in plasma were determined in young and elderly subjects.

RESULTS

Plasma MDA and PC levels were found to be increased in plasma of elderly subjects as compared to young subjects. Increases in endogenous and H2O2-induced DNA damage were also observed in lymphocytes of elderly subjects. In addition, we detected a significant decrease in FRAP values in elderly subjects. Plasma MDA, PC levels and endogenous and H2O2-induced DNA damage were positively correlated with aging, but negatively with FRAP values.

CONCLUSION

We evaluated MDA, PC levels and lymphocyte DNA damage altogether in both young and elderly subjects for the first time. The results of this study strongly support the presence of increased oxidative stress in elderly subjects.

Effects of phenolic acids on human phenolsulfotransferases in relation to their antioxidant activity

Sulfate conjugation by phenolsulfotransferase (PST) enzyme is an important process in the detoxification of xenobiotics and endogenous compounds. There are two forms of PST that are specific for the sulfation of small phenols (PST-P) and monoamines (PST-M). Phenoilc acids have been reported to have important biological and pharmacological properties and may have benefits to human health. In the present study, human platelets were used as a model to investigate the influence of 13 phenolic acids on human PST activity and to evaluate the relationship to their antioxidant activity. The results showed that chlorogenic acid, syringic acid, protocatechuic acid, vanillic acid, sinapic acid, and caffeic acid significantly (p < 0.05) inhibited the activities of both forms of PST by 21-30% at a concentration of 6.7 microM. The activity of PST-P was enhanced (p < 0.05) by p-hydroxybenzoic acid, gallic acid, gentisic acid, o-coumaric acid, p-coumaric acid, and m-coumaric acid at a concentration of 6.7 microM, whereas the activity of PST-M was enhanced by gentisic acid, gallic acid, p-hydroxybenzoic acid, and ferulic acid. The phenolic acids exhibited antioxidant activity as determined by the oxygen radical absorbance capacity (ORAC) assay and Trolox equivalent antioxidant capacity (TEAC) assay, especially gallic acid, p-hydroxybenzoic acid, gentisic acid, and coumaric acid, which had strong activity. The overall effect of phenolic acids tested on the activity of PST-P and PST-M was well correlated to their antioxidant activity of ORAC value (r = 0.71, p < 0.01; and r = 0.66, p < 0.01). These observations suggest that antioxidant phenolic acids might alter sulfate conjugation.

Influence of ageing, heat shock treatment and in vivo total antioxidant status on gene-expression profile and protein synthesis in human peripheral lymphocytes

Ageing results in a progressive, intrinsic and generalised imbalance of the control of regulatory systems. A key manifestation of this complex biological process includes the attenuation of the universal stress response. Here we provide the first global assessment of the ageing process as it affects the heat shock response, utilising human peripheral lymphocytes and cDNA microarray analysis. The genomic approach employed in our preliminary study was supplemented with a proteomic approach. In addition, the current study correlates the in vivo total antioxidant status with the age-related differential gene expression as well as the translational kinetics of heat shock proteins (hsps). Most of the genes encoding stress response proteins on the 4224 element microarray used in this study were significantly elevated after heat shock treatment of lymphocytes obtained from both young and old individuals albeit to a greater extent in the young. Cell signaling and signal transduction genes as well as some oxidoreductases showed varied response. Results from translational kinetics of induction of major hsps, from 0 to 24 h recovery period were broadly consistent with the differential expression of HSC 70 and HSP 40 genes. Total antioxidant levels in plasma from old individuals were found to be significantly lower by comparison with young, in agreement with the widely acknowledged role of oxidant homeostasis in the ageing process.

Influence of amalgam fillings on Hg levels and total antioxidant activity in plasma of healthy donors

In order to evaluate the influence of specific factors on mercury (P-Hg) levels and antioxidant power (P-FRAP) in human plasma, 26 healthy donors were examined by a dentist, their plasma analyzed for Hg by atomic absorption spectrometry and for total antioxidant activity by FRAP method. Hg plasma concentration was found to be correlated with the number of amalgam fillings, suggesting that Hg released from fillings is a source of Hg in non-occupational exposed subjects. P-FRAP correlated negatively with P-Hg suggesting a pro-oxidant role of the Hg released from amalgam fillings. Though age by itself was not significantly correlated with P-FRAP, when considered together with P-Hg in multivariate analysis, it was found to be a major related cofactor. Multivariate analysis showed no influence of fish consumption or cigarette smoking on P-FRAP.

Age-related changes in the mitochondrial depolarization induced by oxidative injury in human peripheral blood leukocytes

Aging is associated with impaired immunity and reduced host defenses. Mitochondrial bioenergetic dysfunctions and reduced antioxidative ability of immunocompetent cells may contribute to this phenomenon. In this study, 60 healthy volunteers of different age groups donated their blood after overnight fasting. Leukocytes were subjected to oxidative injuries by exposure to t-butylhydroperoxide, and were labeled with fluorochromes for measuring mitochondria transmembrane potential (delta psi m), membrane peroxidation and mitochondrial oxidant formation. delta psi m declined after t-butylhydroperoxide exposure, and the change was more prominent in leukocytes from older individuals. Cyclosporin A partly restored delta psi m, implying the contributing role of mitochondrial permeability transition pores. The mitochondrial depolarization was accompanied by increased oxidant formation and oxidation of pyridine nucleotides, which were more prominent in older subjects. The results support the view that the bioenergetic functions of mitochondria are more susceptible to oxidative injury in aged individuals. The decreased ability of leukocytes to resist oxidative stress may contribute to immunosenescence in humans.

The reduction of nitroblue tetrazolium by red blood cells: a measure of Red Cell membrane antioxidant capacity and hemoglobin-membrane binding sites

The reduction of nitroblue tetrazolium (NBT) with intact Red Blood Cells (RBCs) is biphasic with an initial rapid reduction followed by a slower second phase. This biphasic kinetics has been explained with the initial rapid phase attributed to antioxidants in the red cell which reduce membrane bound NBT and the slower phase associated with the reaction of NBT with membrane bound hemoglobin. This model has been confirmed by a utilization of a number of red cell modifications which either increase the red cell antioxidants (vitamin C and vitamin E) or damage the red cell membrane (cumene hydroperoxide and N-ethylmaleimide). The utilization of this assay for human blood samples was investigated by studying a series of 20 human subjects ranging between 34 and 87 years of age. It was possible to fit all of these samples with two adjustable parameters which reflect the red cell membrane antioxidant capacity (x) and the hemoglobin membrane interactions (m). The antioxidant capacity shows a significant (p < .002; R = -.67) decrease with age. This finding is consistent with a decrease in the level of antioxidants in aged subjects. In addition, the number of hemoglobin membrane sites are negatively correlated with the antioxidant capacity (p < .02; R = -.52) suggesting that the oxidative stress associated with reduced antioxidants results in increased hemoglobin-membrane interactions.

Total antioxidant levels, gender, and age as risk factors for DNA damage in lymphocytes of the elderly

During past years, the association of oxidative stress with DNA damage and its possible clinical translation into chronic degenerative illnesses, such as atherosclerosis, cancer, diabetes mellitus and Alzheimer's disease, has been demonstrated. In addition, it has been pointed out that age and gender are factors that influence the generation of DNA damage; however, this is still controversial. We have previously reported the results of a study of 88 subjects older than 60 years of age in whom DNA damage is related with serum levels of total antioxidants. The results of this study demonstrate a greater frequency of DNA damage in elderly persons with normal levels of antioxidants, in addition to males, and in the younger group of subjects, i.e., 60-69 years. In this work, we enlarged our study sample to 160 elderly subjects; in this way, we were able to evaluate the consistency of the influence of total antioxidants, age, and gender on the magnitude and grade of DNA damage in lymphocytes of the elderly. The results demonstrated that 45% of the subjects showed DNA damage, measured by an alkaline unicellular electrophoresis technique (comet assay). Similarly, 62% of the subjects presented low levels of total antioxidant levels measured by a colorimetric method (Randox Kit). A greater percentage of DNA damage was observed in subjects with normal levels of antioxidants (48%) compared with subjects with low levels (43%), although the difference was not statistically significant. The group of subjects 70 years of age or older showed a greater percentage of DNA damage (50%) than the group of subjects of 60-69 years of age (41%). However, the difference was again not statistically significant (P>0.05). With respect to gender, 64% of males and 38% of females had DNA damage with an odds ratio (OR) of 2.86 and a 95% confidence interval (CI) of 1.31-6.32 (P<0.05). In the logistic regression analysis, the interaction of the male sex variables with low antioxidants had an OR of 2.5 (CI 95%, 1.33-4.68; P<0.01). We conclude that the interaction of male sex factors-low levels of antioxidants would justify the indication of antioxidant dietetic supplements.

Evaluation of Total Reactive Antioxidant Potential (TRAP) of Tissue Homogenates and Their Cytosols

This study evaluates the possibility of obtaining total reactive antioxidant potential (TRAP) indexes in homogenates and their cytosolic fractions by a procedure based on the quenching of luminol luminescence induced by the thermolysis of 2,2'-azo-bis(2-amidinopropane). Measurements were performed in rat brain, liver, kidney, and heart homogenates. TRAP indexes can be easily determined both in homogenates and their cytosolic fractions. The results obtained indicate that heart homogenates are the least and liver homogenates the most protected of the systems considered. Glutathione is the measured antioxidant that contributes the most to TRAP values, while uric acid makes a significant contribution only in liver. A calculation of theoretical TRAP values from the measured concentrations of the main antioxidants (glutathione, uric acid, ascorbic acid, and alpha-tocopherol) for the different homogenates shows that, in most tissues (liver, brain, and kidney), nearly 50% of the experimentally determined TRAP values are not accounted for. This difference is mainly due to the contribution of proteins to the measured TRAP.

Total antioxidant capacity as a tool to assess redox status: critical view and experimental data

The measure of antioxidant capacity (AC) considers the cumulative action of all the antioxidants present in plasma and body fluids, thus providing an integrated parameter rather than the simple sum of measurable antioxidants. The capacity of known and unknown antioxidants and their synergistic interaction is therefore assessed, thus giving an insight into the delicate balance in vivo between oxidants and antioxidants. Measuring plasma AC may help in the evaluation of physiological, environmental, and nutritional factors of the redox status in humans. Determining plasma AC may help to identify conditions affecting oxidative status in vivo (e.g., exposure to reactive oxygen species and antioxidant supplementation). Moreover, changes in the plasma AC after supplementation with galenic antioxidants or with antioxidant-rich foods may provide information on the absorption and bioavailability of nutritional compounds. Consequently, this review discusses the rationale, interpretation, confounding factors, measurement limits, and human applications of the measure of plasma AC.

Low plasma antioxidant activity is associated with high lesion volume and neurological impairment in stroke

BACKGROUND AND PURPOSE

Oxidative stress is probably involved in neuronal damage induced by ischemia-reperfusion. The purpose of this study was to assess the role of antioxidant activity in cerebral ischemic stroke.

METHODS

Antioxidant activity of blood plasma and cerebrospinal fluid was assessed in 22 patients with cerebral hemisphere infarction that was verified and quantified by MRI.

RESULTS

Low total peroxyl radical trapping potential of plasma, but not of cerebrospinal fluid, was associated with high lesion volume and high neurological impairment assessed by scores on NIH Stroke Scale, Barthel Index, and Hand Motor Score tests. The plasma concentrations of ascorbic acid, alpha-tocopherol, and protein thiols were also associated with the degree of neurological impairment.

CONCLUSIONS

These data suggest that the antioxidant activity of plasma may be an important factor providing protection from neurological damage caused by stroke-associated oxidative stress.

In vivo total antioxidant capacity: comparison of different analytical methods

Several methods have been developed to measure the total antioxidant capacity of a biological sample. The use of peroxyl or hydroxyl radicals as pro-oxidants in the oxygen radical absorbance capacity (ORAC) assay makes it different and unique from the assays that involve oxidants that are not necessarily pro-oxidants. An improvement in quantitation is achieved in the ORAC assay by taking the reaction between substrate and free radicals to completion and using an area-under-curve technique for quantitation compared to the assays that measure a lag phase. The interpretation of the changes in plasma or serum antioxidant capacity becomes complicated by the different methods used in detecting these changes. The interpretation also depends upon the conditions under which the antioxidant capacity is determined because the measurement reflects outcomes in a dynamic system. An increased antioxidant capacity in plasma or serum may not necessarily be a desirable condition if it reflects a response to increased oxidative stress. Similarly, a decrease in plasma or serum antioxidant capacity may not necessarily be an undesirable condition if the measurement reflects decreased production of reactive species. Because of these complications, no single measurement of antioxidant status is going to be sufficient, but a "battery" of measurements, many of which will be described in Forum articles, will be necessary to adequately assess oxidative stress in biological systems.

DNA damage in lymphocytes of elderly patients in relation with total antioxidant levels

DNA damage may occur as a result of an imbalance between the production and removal of free radicals, a process in which age plays an outstanding role. The purpose of this study was to analyze the relationship between total antioxidants and DNA damage in a sample of old age people in Mexico City. The sample included a total of 88 subjects, 15 males and 69 females, with a mean age of 65.5 years old (range between 60 and 79 years old), all of whom had lived in Mexico City during the last 10 years and had been diagnosed as clinically healthy. Results showed that 52% of the subjects presented DNA damage in peripheral blood lymphocytes which was assessed through an alkaline unicellular electrophoresis procedure (Comet Test), regardless of total antioxidant serum levels quantified through a colorimetric method (Randox Kit). Higher non-damage occurrences were observed in subjects with low antioxidant levels, a difference that was statistically significant (P < 0.05). Furthermore, the highest incidence of damaged cells was observed in subjects belonging to the 70-years-old-and-above group (P < 0.05). As to the magnitude and intensity of the damage associated to total antioxidant concentrations, a trend toward greater DNA damage in subjects with low serum levels was observed. It is concluded that low antioxidant levels are not always indicative of oxidative strain and therefore should not be considered as predictors of DNA damage in this population.

Plasma chain-breaking antioxidants in preterm infants with good and poor short-term outcome

Many complications of prematurity have been suggested to result from free radical generation and an inadequacy of antioxidative capacity. We measured the plasma total peroxyl radical-trapping capability (TRAP) and concentrations of the main chain-breaking antioxidants contributing to it, i.e. uric acid, ascorbic acid, alpha-tocopherol, protein sulfhydryl groups and bilirubin, in 21 preterm infants with a mean birth weight of 1440 g and gestational age of 30 wk. The infants were divided into two groups according to their short-term outcome; the good outcome group (GOG) (N = 11) with no signs of morbidity and the poor outcome group (POG) (N = 10) with intraventricular haemorrhage and/or bronchopulmonary dysplasia and/or retinopathy. Arterial blood samples were obtained 3 and 10 days postpartum. TRAP was measured with a chemiluminescent method. As a comparison, venous blood samples from 13 adults (aged from 18 to 34) were used. At day 3 the poor outcome group had significantly higher TRAP than the good outcome or control group, mainly because of elevated uric acid concentration. Also the concentration of unidentified antioxidants was significantly lower in GOG. By day 10 the TRAP decreased substantially in both groups. However, from the components of TRAP, both ascorbate and the unidentified fraction decreased more in POG (p = 0.017 and 0.021, respectively). Furthermore in POG on day 10 urate concentration did not significantly differ from day 3 values. In conclusion, in preterm infants high TRAP was associated with high plasma uric acid concentration and a poor short-term prognosis.