Search results for "OXIDASE"
showing 10 items of 927 documents
Oxidative Stress and Mitochondrial Damage in Neurodegenerative Diseases: From Molecular Mechanisms to Targeted Therapies
2020
The progression of Alzheimer's dementia is associated with neurovasculature impairment, which includes inflammation, microthromboses, and reduced cerebral blood flow. Here, we investigate the effects of β amyloid peptides on the function of platelets, the cells driving haemostasis. Amyloid peptide β1-42 (Aβ1-42), Aβ1-40, and Aβ25-35 were tested in static adhesion experiments, and it was found that platelets preferentially adhere to Aβ1-42 compared to other Aβ peptides. In addition, significant platelet spreading was observed over Aβ1-42, while Aβ1-40, Aβ25-35, and the scAβ1-42 control did not seem to induce any platelet spreading, which suggested that only Aβ1-42 activates platelet signalli…
Correlation between superoxide dismutase, glutathione peroxidase and catalase in isolated rat hepatocytes during fetal development
1981
Abstract Superoxide dismutase, glutathione peroxidase and catalase activities were determined in isolated fetal rat hepatocytes of various ages and compared with the values of neonatal and adult cells. The developmental pattern of superoxide dismutase and glutathione peroxidase were very similar with a low constant activity in the fetal cells and a postnatal burst. On the contrary catalase begins to increase already since the 18th day of the fetal life. The results suggest a functional correlation of superoxide dismutase and glutathione peroxidase in the antioxidative enzyme defense of liver cells.
Effects of ageing on peroxidase activity and localization in radish (Raphanus sativus L.) seeds.
2010
Peroxidase activity was assayed in crude extracts of integument, cotyledons and embryo axis of radish seeds, deteriorated under accelerated ageing conditions. Over five days of ageing, in which germination decreased from 100 to 52%, the enzyme activity in integument was higher than that in other seed parts, increasing in the first days of ageing and then decreasing sharply in extremely aged seeds. Polyacrylamide gel electrophoresis analysis showed four peroxidase isoenzymes with MM of 98, 52.5, 32.8 and 29.5 kDa in the embryo axis of unaged seeds, and only the 32.8 and 29.5 kDa MM isoforms in the integument and cotyledons. In these parts of the seed, only the 29.5 kDa MM isoenzyme increased…
Age-Related Changes of Liver Antioxidant Enzymes and 8-Hydroxy-2-Deoxyguanosine During FetalNeonate Transition and Early Rat Development
2000
We have studied the pro-antioxidant status of the rat liver on the last day of gestation and at 1, 15, and 30 days of extrauterine life. Representative variables, such as activities of superoxide dismutase (SOD), catalase, and glutathione peroxidase and concentrations of reduced glutathione and 8-hydroxy-2'-deoxyguanosine, were determined in liver to assess the degree of birth-associated oxidative stress during the fetal-neonatal transition and early development of the rat. Percentages by which liver Cu/ZnSOD activity increased over the basal value of the fetal liver were 54%, 95%, and 127% at neonatal days 1, 15, and 30, respectively. There was a lack of induction in the development profil…
Physiological changes in glutathione metabolism in foetal and newborn rat liver
1991
Glutathione metabolism was studied in isolated hepatocytes from foetal, newborn and adult rats. The GSH/GSSG ratio decreased 15-20-fold through the foetal-neonatal-adult transition. This was mainly due to an increase in GSSG. All enzyme activities involved in the glutathione redox cycle tend to increase during that transition, but the relative increases in glutathione peroxidase and glutathione S-transferase were 3-5 times those of glutathione reductase or glucose-6-phosphate dehydrogenase. GSH synthesis from methionine as a sulphur source was 6 times lower in foetal than in adult hepatocytes. However, when N-acetylcysteine was used as a sulphur donor to by-pass the cystathionine pathway, t…
The atypical cannabinoid O-1602 protects against experimental colitis and inhibits neutrophil recruitment.
2011
Background: Cannabinoids are known to reduce intestinal inflammation. Atypical cannabinoids produce pharmacological effects via unidentified targets. We were interested in whether the atypical cannabinoid O-1602, reportedly an agonist of the putative cannabinoid receptor GPR55, reduces disease severity of dextran sulfate sodium (DSS) and trinitrobenzene sulfonic acid (TNBS)-induced colitis in C57BL/6N and CD1 mice. Methods: DSS (2.5% and 4%) was supplied in drinking water for 1 week while TNBS (4 mg) was applied as a single intrarectal bolus. Results: Both treatments caused severe colitis. Injection of O-1602 (5 mg/kg intraperitoneally) significantly reduced macroscopic and histological col…
CB1 cannabinoid receptor-mediated aggressive behavior
2013
This study examined the role of cannabinoid CB1 receptors (CB1r) in aggressive behavior. Social encounters took place in grouped and isolated mice lacking CB1r (CB1KO) and in wild-type (WT) littermates. Cognitive impulsivity was evaluated in the delayed reinforcement task (DRT). Gene expression analyses of monoaminooxidase-A (MAO-A), catechol-o-methyl-transferase (COMT), 5-hydroxytriptamine transporter (5-HTT) and 5-HT1B serotonergic receptor (5HT1Br) in the median and dorsal raphe nuclei (MnR and DR, respectively) and in the amygdala (AMY) were performed by real time-PCR. Double immunohistochemistry studies evaluated COMT and CB1r co-localization in the raphe nuclei and in the cortical (AC…
Zanhasaponins A and B, Antiphospholipase A2 Saponins from an Antiinflammatory Extract of Zanha africana Root Bark
1997
A MeOH extract from Z. africana was examined for topical antiinflammatory activity and proved to be active against arachidonic acid (AA) acute edema, 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced chronic inflammation, and oxazolone delayed-type hypersensitivity in mice. The extract also showed significant inhibitory activity of Naja naja phospholipase A2 when a polarographic method was used. Two oleanane-type triterpene saponins, zanhasaponins A (1) and B (2), and the cyclitol pinitol (4), isolated from the extract, were active as inhibitors of PLA2. A further saponin, zanhasaponin C (3) was inactive in this assay.
Oxidative burst and neutrophil elastase contribute to clearance of Aspergillus fumigatus pneumonia in mice.
2014
Polymorphonuclear neutrophils (PMN) are important for the control of invasive aspergillosis (IA), a major threat to immunocompromised individuals. For clearance of Aspergillus fumigatus infections, PMN employ their potent oxidative and non-oxidative mechanisms. To clarify the relative contribution of these mechanisms, we analyzed p47(phox-/-), gp91(phox-/-) and elastase (ELA) deficient mice (ELANE) after intratracheal infection with A. fumigatus. Infected p47(phox-/-) and gp91(phox-/-) mice died within 4 days and had a significant higher fungal burden in the lungs compared to wild-type controls. Interestingly, the survival of ELANE mice after infection was unimpaired suggesting that ELA is …
Increase in stability and change in supramolecular structure of β-carotene through encapsulation into polylactic acid nanoparticles
2011
International audience; β-Carotene (BC) exhibits controversial antioxidant properties as it may act also as a prooxidant. Its stability toward oxidation depends on its dispersion form and can be increased through encapsulation. In this study, oxidation of BC from synthetic and natural origins was investigated after dispersion in Tween micelles or poly lactic acid (PLA) particles. Two oxidation systems were used: autooxidation and oxidation by xanthine oxidase-generated-reactive oxygen species. Results showed that synthetic BC formed nanometric negatively-charged particles in both Tween micelle and PLA systems, whereas the natural BC sample used was shown to be already pre-oxidised, forming …