Search results for "Antioxidants."
showing 10 items of 824 documents
Oxidative stress in marathon runners: interest of antioxidant supplementation
2006
We have recently reported that xanthine oxidase is involved in the generation of free radicals in exhaustive exercise. Allopurinol, an inhibitor of xanthine oxidase, prevents it. The aim of the present work was to elucidate the role of exercise-derived reactive oxygen species in the cell signalling pathways involved in the adaptation to exercise in man. We have found that exercise causes an increase in the activity of plasma xanthine oxidase and an activation of NF-κB in peripheral blood lymphocytes after marathon running. This activation is dependent on free radical formation in exercise: treatment with allopurinol completely prevents it. In animal models, we previously showed that NF-κB a…
Increased oxidative stress levels and normal antioxidant enzyme activity in circulating mononuclear cells from patients of familial hypercholesterole…
2010
Familial hypercholesterolemia (FH) is a clinical condition with high risk for developing atherosclerosis. Increased oxidative stress (OS) and FH have been related to atherosclerosis, but no data are available on levels of OS and antioxidant enzyme activity in circulating mononuclear cells (CMCs) from FH patients. Circulating mononuclear cells are important mediators in atherosclerosis development, and chronically increased blood OS present in FH can induce modification in CMC activity. The objective of the study was to analyze the OS levels in CMCs from FH patients and controls. We have selected 30 nonrelated FH index patients and 30 normoglycemic and normocholesterolemic controls matched b…
Effects of the association of aging and obesity on lipids, lipoproteins and oxidative stress biomarkers: a comparison of older with young men.
2011
In this study, plasma lipids, lipoproteins and markers of oxidant/antioxidant status were investigated in young (n = 45) and older (n = 40) obese men and compared to those in young (n = 65) and older (n = 55) normal weight controls. The purpose was to determine whether obesity exacerbates or not lipid, lipoprotein abnormalities and oxidative stress in older men. Our findings showed that all obese patients had increased plasma triglyceride, cholesterol, LDL-cholesterol, -triglyceride and HDL-triglyceride levels concentrations compared to controls (P < 0.01). However, the younger obese men had relatively larger and accentuated changes in plasma lipids and lipoproteins than the older patients.…
Antenatal Steroids and Antioxidant Enzyme Activity in Preterm Infants: Influence of Gender and Timing
2009
Antenatal steroids have improved the survival of preterm infants; however, the mechanism of action is not fully understood. We aimed to establish an association between antenatal steroids and antioxidant activity and postnatal oxidative stress. In a prospective cohort study, extremely preterm neonates receiving antenatal steroids (CORT) or not (NOCORT) were enrolled. An association between antenatal steroids and activities of antioxidant enzymes and glutathione cycle enzymes in cord blood was found. In addition, reduced oxidative stress (GSH/GSSG ratio, CORT vs. NOCORT, 35.68 + or - 12.20 vs. 28.38 + or - 9.92; p < 0.01) and, decreased oxidation of proteins (ortho-tyrosine/phenylalanine rat…
Enhanced oxidative susceptibility and reduced antioxidant content of metabolic precursors of small, dense low-density lipoproteins.
2001
Abstract PURPOSE: Elevated plasma concentrations of low-density lipoproteins (LDL) increase risk for coronary heart disease. However, lipoprotein profiles rich in small, dense LDL particles confer greater risk than those that mainly consist of large, buoyant LDL. This may be due, in part, to the greater oxidative susceptibility of small, dense LDL. In the current studies, we tested whether differences in the oxidative behavior of buoyant and dense LDL arise from differences in their immediate metabolic precursors, intermediate-density lipoproteins. SUBJECTS AND METHODS: We compared the properties of intermediate-density lipoproteins and buoyant and dense LDL subfractions in 9 subjects with …
Nitric oxide metabolites and oxidative stress in mild essential hypertension
2010
Many papers have showed non univocal data about oxidative stress status and nitric oxide metabolites in essential hypertension. Considering this preamble we examined the total antioxidant status (TAS), the lipid peroxidation (LP), expressed as thiobarbituric acid-reactive substances (TBARS), the stable end products of nitric oxide (NOx) and LP/NOx ratio in 25 subjects with untreated mild essential hypertension. The obtained data show a significant increase in TBARS (p < 0.001) and NOx (p < 0.001) in hypertensives and no variation in TAS and in TBARS/NOx ratio. None of these parameters was statistically related to the metabolic parameters or to the blood pressure values. The high level of li…
Factors related to the impact of antihypertensive treatment in antioxidant activities and oxidative stress by-products in human hypertension
2004
The objective was to study factors related to the changes induced by antihypertensive treatment on oxidative status, antioxidant activities, and reactive oxygen species by-products in whole blood and mononuclear peripheral cells. Eighty-nine hypertensive patients (mean age 46 years, 46 men, average 24-h blood pressure 139/88 mm Hg, body mass index 29) were included. After 3 months of nonrandomized allocation to antihypertensive treatment (20 nonpharmacologic, 36 beta-blockers, 33 angiotensin receptor blocker), oxidized/reduced glutathione ratio and malondialdehyde were significantly reduced, and the activity of superoxide dismutase, catalase, and glutathione peroxidase was significantly inc…
AZT treatment induces molecular and ultrastructural oxidative damage to muscle mitochondria. Prevention by antioxidant vitamins.
1998
AIDS patients who receive zidovudine (AZT) frequently suffer from myopathy. This has been attributed to mitochondrial (mt) damage, and specifically to the loss of mtDNA. This study examines whether AZT causes oxidative damage to DNA in patients and to skeletal muscle mitochondria in mice, and whether this damage may be prevented by supranutritional doses of antioxidant vitamins. Asymptomatic HIV-infected patients treated with AZT have a higher urinary excretion (355+/-100 pmol/kg/d) of 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxo-dG) (a marker of oxidative damage to DNA) than untreated controls (asymptomatic HIV-infected patients) (182+/-29 pmol/kg/d). This was prevented (110+/-79 pmol/kg/d)…
Different patterns of in vivo pro-oxidant states in a set of cancer- or aging-related genetic diseases
2008
A comparative evaluation is reported of pro-oxidant states in 82 patients with ataxia telangectasia (AT), Bloom syndrome (BS), Down syndrome (DS), Fanconi anemia (FA), Werner syndrome (WS), and xeroderma pigmentosum (XP) vs 98 control donors. These disorders display cancer proneness, and/or early aging, and/or other clinical features. The measured analytes were: (a) leukocyte and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), (b) blood glutathione (GSSG and GSH), (c) plasma glyoxal (Glx) and methylglyoxal (MGlx), and (d) some plasma antioxidants [uric acid (UA) and ascorbic acid (AA)]. Leukocyte 8-OHdG levels ranked as follows: WS>BS approximately FA approximately XP>DS approximately AT appr…
Altered glutathione system is associated with the presence of distal symmetric peripheral polyneuropathy in type 2 diabetic subjects.
2015
Abstract Distal symmetric peripheral polyneuropathy (DSPN) is a highly prevalent complication of diabetes. However, underlying pathophysiological mechanisms are multiple and not well understood. The aim of our study was to analyze the oxidative stress levels in circulating mononuclear cells by measuring the glutathione system, malondialdehyde and oxidized-LDL, in 60 type 2 diabetic patients from a well-characterized cohort of 196 type 2 diabetic patients. Using a nested case–control design, we studied 30 type 2 diabetic patients with distal symmetric polyneuropathy and 30 diabetic controls without this complication, according to the Neuropathy Disability Score. We have found that diabetic p…