Search results for "Superoxide"
showing 10 items of 462 documents
Unveiling the reaction mechanism of novel copper N-alkylated tetra-azacyclophanes with outstanding superoxide dismutase activity.
2020
Quantum chemical and multiscale calculations reveal the mechanistic pathway of two superoxide dismutase mimetic N-alkylated tetra-azacyclophane copper complexes with remarkable activity. The arrangement of the binding site afforded by the bulky alkyl substituents and the coordinated water molecule as a proton source play key roles in the reaction mechanism.
Chemiluminescence response of ß-glucan stimulated leukocytes isolated from different tissues and peritoneal cavity of Dicentrarchus labrax
2003
Abstract The respiratory burst of leukocytes isolated from sea bass ( Dicentrarchus labrax ) pronephros, peritoneal cavity (P.C.), spleen and blood, was measured by a chemiluminescence (CL) assay after stimulation with β-glucan. The CL response by P.C. and pronephros leukocytes was significantly higher than that expressed by a similar number of cells separated from spleen and blood. This probably reflects the observation that the proportion of macrophages and neutrophils was highest in the populations of leukocytes from peritoneal cavity and pronephros. Comparative observations showed a higher degree of yeast phagocytosis by leukocytes taken from peritoneal cavity than the pronephros. Moreo…
Resuscitation with room air instead of 100% oxygen prevents oxidative stress in moderately asphyxiated term neonates.
2001
Background. Traditionally, asphyxiated newborn infants have been ventilated using 100% oxygen. However, a recent multinational trial has shown that the use of room air was just as efficient as pure oxygen in securing the survival of severely asphyxiated newborn infants. Oxidative stress markers in moderately asphyxiated term newborn infants resuscitated with either 100% oxygen or room air have been studied for the first time in this work. Methods. Eligible term neonates with perinatal asphyxia were randomly resuscitated with either room air or 100% oxygen. The clinical parameters recorded were those of the Apgar score at 1, 5, and 10 minutes, the time of onset of the first cry, and the tim…
Oxidative stress in asphyxiated term infants resuscitated with 100% oxygen
2003
Although room air is adequate for resuscitating asphyxiated newborn infants, guidelines recommend using 100% oxygen. Hyperoxemia, as has been noted in animal studies, could cause delayed breathing, increased oxygen consumption, and disordered cerebral circulation. In addition, 100% oxygen has caused prolonged oxidation of blood glutathione in neonates. In this study, 51 asphyxiated neonates born at term were randomly assigned to resuscitation with room air (RAR) and 55 to resuscitation with 100% oxygen (OxR). The goal was to learn whether using oxygen for resuscitation triggers oxidative stress. Critical criteria were the Apgar score, the time of the first cry, and sustained respiration. Si…
A new vicious cycle involving glutamate excitotoxicity, oxidative stress and mitochondrial dynamics
2011
Glutamate excitotoxicity leads to fragmented mitochondria in neurodegenerative diseases, mediated by nitric oxide and S-nitrosylation of dynamin-related protein 1, a mitochondrial outer membrane fission protein. Optic atrophy gene 1 (OPA1) is an inner membrane protein important for mitochondrial fusion. Autosomal dominant optic atrophy (ADOA), caused by mutations in OPA1, is a neurodegenerative disease affecting mainly retinal ganglion cells (RGCs). Here, we showed that OPA1 deficiency in an ADOA model influences N-methyl-D-aspartate (NMDA) receptor expression, which is involved in glutamate excitotoxicity and oxidative stress. Opa1enu/+mice show a slow progressive loss of RGCs, activation …
Altered antioxidant-oxidant status in the aqueous humor and peripheral blood of patients with retinitis pigmentosa.
2013
Retinitis Pigmentosa is a common form of hereditary retinal degeneration constituting the largest Mendelian genetic cause of blindness in the developed world. It has been widely suggested that oxidative stress possibly contributes to its pathogenesis. We measured the levels of total antioxidant capacity, free nitrotyrosine, thiobarbituric acid reactive substances (TBARS) formation, extracellular superoxide dismutase (SOD3) activity, protein, metabolites of the nitric oxide/cyclic GMP pathway, heme oxygenase-I and inducible nitric oxide synthase expression in aqueous humor or/and peripheral blood from fifty-six patients with retinitis pigmentosa and sixty subjects without systemic or ocular …
Study of enzymatic activity in human neuroblastoma cells SH-SY5Y exposed to zearalenone's derivates and beauvericin.
2021
Abstract Beauvericin (BEA), α-zearalenol (α-ZEL) and β-zearalenol (β-ZEL), are produced by several Fusarium species that contaminate cereal grains. These mycotoxins can cause cytotoxicity and neurotoxicity in various cell lines and they are also capable of produce oxidative stress at molecular level. However, mammalian cells are equipped with a protective endogenous antioxidant system formed by no-enzymatic antioxidant and enzymatic protective systems such as glutathione peroxidase (GPx), glutathione S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD). The aim of this study was evaluating the effects of α-ZEL, β-ZEL and BEA, on enzymatic GPx, GST, CAT and SOD activity in huma…
Expression of the ALS-causing variant hSOD1G93A leads to an impaired integrity and altered regulation of claudin-5 expression in an in vitro blood–sp…
2015
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive paralysis due to the loss of primary and secondary motor neurons. Mutations in the Cu/Zn-superoxide dismutase (SOD1) gene are associated with familial ALS and to date numerous hypotheses for ALS pathology exist including impairment of the blood–spinal cord barrier. In transgenic mice carrying mutated SOD1 genes, a disrupted blood–spinal cord barrier as well as decreased levels of tight junction (TJ) proteins ZO-1, occludin, and claudin-5 were detected. Here, we examined TJ protein levels and barrier function of primary blood–spinal cord barrier endothelial cells of presymptomatic hSOD1G93…
Red wine extract prevents neuronal apoptosis in vitro and reduces mortality of transgenic mice.
2007
In this work, we have investigated the effects of nutritional antioxidants as antidegenerative agents on glutamate-induced apoptosis in primary cultures of cerebellar granule neurons (CGNs). Glutamate-induced apoptosis is also associated with intracellular [Ca(2+)]i overload, generation of reactive oxygen species (ROS), depression of cell energy metabolism, cytochrome c release, and increase in caspase-3 activity. Pretreatment (3 h) with red wine extract (5 microg/mL) and ascorbic acid (30 microM) blocks glutamate-induced apoptosis in CGNs. In vivo experiments carried out on transgenic mice expressing the human mutated Cu, Zn superoxide dismutase (SOD1) G93A (mSOD1(G93A)) show that mice fed…
Cucurbitacin R Reduces the Inflammation and Bone Damage Associated with Adjuvant Arthritis in Lewis Rats by Suppression of Tumor Necrosis Factor-α in…
2006
The aim of this study was to investigate the effects of cucurbitacin R on an experimental model of adjuvant-induced arthritis in rats. The treatment of arthritic rats with cucurbitacin R (1 mg/kg p.o. daily) modified the evolution of the clinical symptoms, whereas the histopathology of paws demonstrated a reduction in the signs of arthritis. Compared with the control group, radiography of the tibiotarsal joints of cucurbitacin R-treated rats showed a decrease in joint damage and soft tissue swelling of the footpad. The in vivo study of the expression of proinflammatory enzymes (nitric-oxide synthase-2 and cyclooxygenase-2) with the aid of the Western blot technique, and that of tumor necros…