Search results for "OXIDASE"
showing 10 items of 927 documents
Effect of high-pressure processing on carotenoids profile, colour, microbial and enzymatic stability of cloudy carrot juice
2019
Abstract The objective of this work was to assess the impact of high-pressure processing (HPP) on the carotenoid profile, colour as well as the microbial and enzymatic stability of cloudy carrot juice. The predominant carotenoids in the fresh juices were by far the provitamin A carotenoids β-carotene and α-carotene. Others were ζ-carotene, phytofluene, phytoene and lutein. HPP at 300 MPa in three cycles caused the highest carotenoids degradation (41%) whereas the lowest degradation (26%) was achieved at 600 MPa. The highest inactivation of POD (31%) and PPO (57%) was achieved with 600 MPa and 300 MPa applied in three cycles, respectively what indicates that POD is more responsible for carot…
A Thermophilic Tetramolecular G-Quadruplex/Hemin DNAzyme.
2017
International audience; The quadruplex-based DNAzyme system is one of the most useful artificial enzymes or catalysts; their unique properties make them reliable alternatives to proteins for performing catalytic transformation. The first prototype of a thermally stable DNAzyme system is presented. This thermophilic DNAzyme is capable of oxidizing substrates at high temperatures (up to 95 degrees C) and long reaction times (up to 18 h at 75 degrees C). The catalytic activity of the DNAzymes were investigated with the standard peroxidase-mimicking oxidation of 2,2'-azino-bis(3-ethylbenzothiozoline-6-sulfonic acid) (ABTS) by H2O2. The step-by-step design of this unique heat-activated G-quadrup…
Indicaxanthin inhibits NADPH oxidase (NOX)-1 activation and NF-κB-dependent release of inflammatory mediators and prevents the increase of epithelial…
2014
Dietary redox-active/antioxidant phytochemicals may help control or mitigate the inflammatory response in chronic inflammatory bowel disease (IBD). In the present study, the anti-inflammatory activity of indicaxanthin (Ind), a pigment from the edible fruit of cactus pear (Opuntia ficus-indica, L.), was shown in an IBD model consisting of a human intestinal epithelial cell line (Caco-2 cells) stimulated by IL-1β, a cytokine known to play a major role in the initiation and amplification of inflammatory activity in IBD. The exposure of Caco-2 cells to IL-1β brought about the activation of NADPH oxidase (NOX-1) and the generation of reactive oxygen species (ROS) to activate intracellular signal…
Hypersusceptibility of neutrophil granulocytes towards lethal action of free fatty acids contained in enzyme-modified atherogenic low density lipopro…
2008
Abstract Objective The bulk of LDL entrapped in the arterial intima is modified by hydrolytic enzymes, leading to extensive cleavage of cholesterylesters and liberation of fatty acids. The latter induce apoptosis in endothelial cells but are far less cytotoxic towards macrophages. We have compared the cytotoxic effects of enzymatically modified LDL (E-LDL) on macrophages and polymorphonuclear granulocytes (PMN). Methods and results E-LDL displayed toxicity towards PMN at far lower concentrations than towards monocyte-derived macrophages. Native or oxidized LDL had no effect. Free fatty acids contained in E-LDL were the cause of the observed toxicity, which could be mimicked by linoleic acid…
ON THE OCCURRENCE OF RESPIRATORY COMPONENTS IN RAT-LIVER NUCLEI.
1965
Summary 1. Low-temperature spectrophotometric studies have been carried out on rat-liver nuclei isolated by two different procedures. Comparison of nuclei prepared in non-aqueous media with those prepared in high-density sucrose reveals only small quantitative differences. 2. The presence of hemoglobin, cytochrome b 5 , and cytochrome c was detected in both types of nuclei. No cytochrome b , or cytochrome oxidase could be found. Studies on the possible origin of the hemoproteins suggest that hemoglobin and cytochrome b 5 are of extra-nuclear origin. The presence of cytochrome c as a nuclear component could not be ruled out completely although leakage from mitochondria was also considered a …
Estradiol decreases xanthine dehydrogenase enzyme activity and protein expression innon-tumorigenicand malignant human mammary epithelial cells
2009
The retinoic acid deficiency in breast tumour epithelial cells has been ascribed to an insufficient expression of either the enzyme(s) involved in its biosynthesis or the cellular retinol binding protein (CRBP) or both. In an attempt to define the mechanisms underpinning retinoic acid deficiency in these cell model systems, we have investigated the potential regulatory effect of oestrogen (17β-estradiol) on one key player in retinoic acid biosynthesis, the xanthine dehydrogenase (XDH). This enzyme is consistently expressed and very active in non-malignant human mammary epithelial cells (HMEC), as opposed to tumour MDA-MB231 and MCF7 cells. In these latter two cell lines, as opposed to HMEC …
Molecular mechanisms involved in the hormonal prevention of aging in the rat.
2008
Previous data from our group have provided support for the role of GH, melatonin and estrogens in the prevention of aging of several physiological parameters from bone, liver metabolism, vascular activity, the central nervous system (CNS), the immune system and the skin. In the present work data on the molecular mechanisms involved are presented. A total of 140 male and female rats have been submitted to different treatments over 10 weeks, between 22 and 24 months of age. Males have been treated with GH and melatonin. Females were divided in two groups: intact and castrated at 12 months of age. The first group was treated with GH and melatonin and the second with the two latter compounds an…
A common precursor for glia and neurons in the embryonic CNS of Drosophila gives rise to segment-specific lineage variants
1993
ABSTRACT The nervous system consists of two classes of cells, neurons and glia, which differ in morphology and function. They derive from precursors located in the neurogenic region of the ectoderm. In this study, we present the complete embryonic lineage of a neuroectodermal precursor in Drosophila that gives rise to neurons as well as glia in the abdominal CNS. This lineage is conserved among different Drosophila species. We show that neuronal and glial cell types in this clone derive from one segregating precursor, previously described as NB1-1. Thus, in addition to neuroblasts and glioblasts, there exists a third class of CNS precursors in Drosophila, which we call neuroglioblasts. We f…
The GABAergic system of the dorsal cortex of lizards: a combined HRP-GABA immunohistochemistry study.
1990
Abstract γ-Aminobutyric acid (GABA)-like immunoreactive (GABA-LI) neurons were found throughout the mediolateral and rostrocaudal axis of the dorsal cortex. They were horizontal, vertical and multipolar cells, mainly distributed in layers 1 and 3. GABA-LI boutons were diffusely distributed in layers 1 and 3, as well as forming basket-like images around layer 2 pyramidal perikarya. Double labelling experiments indicate that GABA-LI cells are an origin of and a target for rostrocaudal intrinsic projections within the dorsal cortex.
Phenylsulphonyl urenyl chalcone derivatives as dual inhibitors of cyclo-oxygenase-2 and 5-lipoxygenase
2005
Two series of phenylsulphonyl urenyl chalcone derivatives (UCH) with various patterns of substitution were tested for their effects on nitric oxide (NO) and prostaglandin E2 (PGE2) overproduction in RAW 264.7 macrophages. None of the tested compounds reduced NO production more than 50% at 10 microM but most of them inhibited the generation of PGE2 with IC50 values under the micromolar range. Me-UCH 1, Me-UCH 5, Me-UCH 9, Cl-UCH 1, and Cl-UCH 9 were selected to evaluate their influence on human leukocyte functions and eicosanoids generation. These derivatives selectively inhibited cyclo-oxygenase-2 (COX-2) activity in human monocytes being Me-UCH 5 the most potent (IC50 0.06 microM). Selecte…