On the potential increase of the oxidative stress status in patients with abdominal aortic aneurysm.
; Defraigne, Jean-Olivier ; et al
in Redox Report : Communications in Free Radical Research (2012), 17(4), 139-44
BACKGROUND: Abdominal aortic aneurysm (AAA) is a major cause of preventable deaths in older patients. Oxidative stress has been suggested to play a key role in the pathogenesis of AAA. However, only few ... [more ▼]
BACKGROUND: Abdominal aortic aneurysm (AAA) is a major cause of preventable deaths in older patients. Oxidative stress has been suggested to play a key role in the pathogenesis of AAA. However, only few studies have been conducted to evaluate the blood oxidative stress status of AAA patients. METHODS AND RESULTS: Twenty seven AAA patients (mean age of 70 years) divided into two groups according to AAA size (</= 50 or > 50 mm) were compared with an age-matched group of 18 healthy subjects. Antioxidants (vitamins C and E, beta-carotene, glutathione, thiols, and ubiquinone), trace elements (selenium, copper, zinc, and copper/zinc ratio) and markers of oxidative damage to lipids (lipid peroxides, antibodies against oxidized patients, and isoprostanes) were measured in each subject. The comparison of the three groups by ordinal logistic regression showed a significant decrease of the plasma levels of vitamin C (P = 0.011), alpha-tocopherol (P = 0.016) but not when corrected for cholesterol values, beta-carotene (P = 0.0096), ubiquinone (P = 0.014), zinc (P = 0.0035), and of selenium (P = 0.0038), as AAA size increased. By contrast, specific markers of lipid peroxidation such as the Cu/Zn ratio (P = 0.046) and to a lesser extent isoprostanes (P = 0.052) increased. CONCLUSION: The present study emphasizes the potential role of the oxidative stress in AAA disease and suggests that an antioxidant therapy could be of interest to delay AAA progression. [less ▲]Detailed reference viewed: 7 (4 ULg)
In vitro evaluation of glutathione peroxidase (GPx)-like activity and antioxidant properties of some Ebselen analogues
Mouithys-Mickalad, Ange ; ; et al
in Redox Report : Communications in Free Radical Research (2004), 9(2), 81-87
Four analogues of Ebselen were synthesized and their glutathione peroxidase activity and antioxidant property evaluated and compared to Ebselen. Among the studied compounds, only diselenide  exhibited ... [more ▼]
Four analogues of Ebselen were synthesized and their glutathione peroxidase activity and antioxidant property evaluated and compared to Ebselen. Among the studied compounds, only diselenide  exhibited both glutathione peroxidase activity and radical-scavenging capability. Compounds  and  showed a strong inhibitory effect (53% and 43%, respectively) on the lipid peroxidation of linoleic acid compared to Ebselen and selenide derivatives ( and ) which were less active (28%, 26% and 18% inhibition, respectively). A concentration-dependent inhibitory effect was also found in the model of the formation of ABTS*+ radical cation: 65% and 89% inhibition for compound  at 10(-4) M and 5 x 10(-5) M, respectively, and 68% and 90% for compound , compared to 14% and 52% inhibition for Ebselen and the diselenides  and  (29%, 46% and 45%, 68%, respectively). By EPR spin trapping technique, the following inhibitory profile of the Ebselen analogues was observed towards the formation of thiyl radicals: Ebselen = >>>. Studies with compound  are in progress on oxidative stress cell models. [less ▲]Detailed reference viewed: 11 (1 ULg)
Oxygen consumption and electron spin resonance studies of free radical production by alveolar cells exposed to anoxia: inhibiting effects of the antibiotic ceftazidime.
; ; et al
in Redox Report : Communications in Free Radical Research (2002), 7(2), 85-94
By EPR spectroscopy, we investigated free radical production by cultured human alveolar cells subjected to anoxia/re-oxygenation (A/R), and tested the effects of ceftazidime, an antibiotic previously ... [more ▼]
By EPR spectroscopy, we investigated free radical production by cultured human alveolar cells subjected to anoxia/re-oxygenation (A/R), and tested the effects of ceftazidime, an antibiotic previously demonstrated to possess antioxidant properties. Two A/R models were performed on type II pneumocytes (A549 cell line), either on cells attached to culture dishes (monolayer A/R model; 3.5 h of anoxia, 30 min of re-oxygenation) or after cell detachment (suspension A/R model; 1 h of anoxia, 10 min of re-oxygenation). Ceftazidime and selective inhibitors (SOD, Tiron, L-NMMA) were added before anoxia. Free radical production was assessed by the EPR spin trapping technique. Oxygen consumption was monitored, in parallel with EPR studies, in the suspension A/R model. The production of free radical species was demonstrated by the generation of PBN-radical adducts: (a(N) = 15.2 G) in the monolayer A/R model and a six-line EPR spectrum (a(N) = 15.7 G and a(H) = 2.7 G) in the suspension A/R model. A kinetic study performed by oximetry, in parallel with EPR spectroscopy, demonstrated marked alterations of the cell respiratory function and that the free radical production started during anoxia and increased during re-oxygenation. In the suspension A/R model, the amplitude of EPR spectra were decreased upon the addition of 200 U/ml SOD (37% inhibition), 0.1 mM Tiron (67% inhibition) and 1 mM L-NMMA (43% inhibition). Addition of 1 mM ceftazidime decreased the amplitude of EPR spectra (37% inhibition) in both A/R models. Complementary in vitro EPR studies demonstrated that CAZ scavenged the hydroxyl radical (produced by the Fenton reaction). The protective effect of ceftazidime in the cell model could thus be linked to its ability to scavenge superoxide anions, nitrogen-derived species and hydroxyl radicals. [less ▲]Detailed reference viewed: 12 (1 ULg)