Search

Showing total 4 results
Start Over Topic oxidative stress Language english
4 results

1. Protective effects of degraded Bletilla striata polysaccharides against UVB-induced oxidative stress in skin.

Author

Chen H, Lin C, Wu Y, Wang B, Kui M, Xu J, Ma H, Li J, Zeng J, Gao W, and Chen K

Subjects
Animals, Mice, Orchidaceae chemistry, Melanins metabolism, Reactive Oxygen Species metabolism, Humans, Molecular Weight, Cell Proliferation drug effects, Oxidative Stress drug effects, Ultraviolet Rays adverse effects, Polysaccharides pharmacology, Polysaccharides chemistry, Skin drug effects, Skin metabolism, Skin radiation effects, Antioxidants pharmacology, Antioxidants chemistry
Abstract

The Bletilla striata polysaccharides (BSP) extracted through alkali-assisted method exhibit significant antioxidant activity, but its bioaccessibility was inadequate due to its tightly filamentous reticulation structure and high molecular weight. The anti-photoaging and anti-melanogenesis effects of degraded BSP (DBSPs) against UVB-induced oxidative stress on the skin were investigated. The molecular weights of the DBSPs were reduced to 153.94 kDa, 66.96 kDa, and 15.54 kDa from an initial value of 298.82 kDa. The degradation treatment altered the branched chain structure of the DBSPs, while the backbone structure, triple-helix structure, and crystallinity remained. DBSPs with a lower molecular weight exhibit better in vitro antioxidant activity. DBSPs did not show cytotoxicity to HSF cells but inhibited B16F10 cell proliferation. The addition of DBSPs protected HSF and B16F10 cells from oxidative stress and reduced ROS levels, B16F10 melanin content, and B16F10 tyrosinase activity after UVB damage, but DBSP-10 particles were slightly less effective due to aggregation. In contrast, DBSP-5 demonstrated effectiveness in reducing MDA levels in cells stressed by oxidative stress, increased total antioxidant capacity, and inhibited melanogenesis in B16F10, suggesting that DBSP-5 has potential as a topical therapeutic agent for the treatment of skin diseases associated with oxidative stress., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Published
2024
Full Text
View/download PDF

2. Antioxidant properties and neuroprotective effects of isocampneoside II on hydrogen peroxide-induced oxidative injury in PC12 cells.

Author

Si CL, Shen T, Jiang YY, Wu L, Yu GJ, Ren XD, Xu GH, and Hu WC

Subjects
Animals, Apoptosis Regulatory Proteins biosynthesis, Apoptosis Regulatory Proteins genetics, Apoptosis Regulatory Proteins metabolism, Cell Survival drug effects, Chelating Agents pharmacology, Gene Expression Regulation drug effects, Hydrogen Peroxide antagonists & inhibitors, Hydrogen Peroxide toxicity, Nerve Tissue Proteins biosynthesis, Nerve Tissue Proteins genetics, Nerve Tissue Proteins metabolism, Neurons enzymology, Neurons metabolism, Oxidants antagonists & inhibitors, Oxidants toxicity, Oxidation-Reduction, Oxidoreductases metabolism, PC12 Cells, Rats, Reactive Oxygen Species antagonists & inhibitors, Reactive Oxygen Species metabolism, Antioxidants pharmacology, Apoptosis drug effects, Caffeic Acids pharmacology, Disaccharides pharmacology, Glycosides pharmacology, Lipid Peroxidation drug effects, Neurons drug effects, Neuroprotective Agents pharmacology, Oxidative Stress drug effects
Abstract

Oxidative stress has been considered as a major cause of cell damage in various neurodegenerative disorders. One of the reasonable strategies for delaying the disease's progression is to prevent reactive oxygen species (ROS) mediated cellular injury by dietary or pharmaceutical augmentation of free radical scavengers. Isocampneoside II (ICD) is an active phenylethanoid glycoside isolated from the medicinal hardwood genus Paulownia. This study was designed to explore free radical scavenging potential of ICD in different in vitro systems and its protective role in hydrogen peroxide (H₂O₂)-induced oxidative stress and apoptotic death in cultured rat pheochromocytoma (PC12) cells. The results showed ICD eliminated approximately 80.75% superoxide radical at the concentration of 0.1mg/ml and inhibited metal chelating by 22.07% at 8 mg/ml. Additionally, ICD showed a strong ability on reducing power and provided protection against oxidative protein damage induced by hydroxyl radicals. Pretreatment of PC12 cells with ICD prior to H₂O₂ exposure elevated cell viability, enhanced activity of superoxide dismutase and catalase, and decreased levels of malondialdehyde and intracellular ROS. Furthermore, ICD inhibited cell apoptosis and Bax/Bcl-2 ratio induced by H₂O₂. These findings suggested ICD may be considered as a potential antioxidant agent and should encourage for further research in neurodegenerative diseases., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Published
2013
Full Text
View/download PDF

3. Structure and function of theLeptospira interrogansperoxide stress regulator (PerR), an atypical PerR devoid of a structural metal-binding site

Author

Patrick Weber, Nadia Benaroudj, Frederick Saul, Sarah Dubrac, Annie Landier, Bénédicte Beaudeau, Raléb Taher, Mounira Kebouchi, Ahmed Haouz, Mathieu Picardeau, Biologie des Spirochètes / Biology of Spirochetes, Institut Pasteur [Paris], Cristallographie (Plateforme) - Crystallography (Platform), Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Biologie des Bactéries pathogènes à Gram-positif, This work was supported by the Institut Pasteur and Agence National de la Recherche Grant ANR-08-MIE-018., M. K., R. T., A. L., B. B., and P. W. performed experiments. F. S., A. H., S. D., M. P., and N. B. conceived, performed, and analyzed experiments. N. B. conceived and coordinated the study and wrote the paper. All authors approved the final version of the manuscript.We acknowledge SOLEIL for provision of synchrotron radiation facilities, and we thank the staff of beamline PROXIMA 1 for assistance. We are grateful to Gerald Murray and Ben Adler for providing the perR mutant. We thank Gouzel Karimova, Isabelle Michaud-Soret, and Victor Duarte for critically reading the manuscript and for helpful discussions., ANR-08-MIEN-0018,LEPTOVIR,Les leptospires : de la génétique à la pathogénèse(2008), Institut Pasteur [Paris] (IP), and Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS)

Subjects
MESH: Signal Transduction, 0301 basic medicine, MESH: Leptospira interrogans, [SDV]Life Sciences [q-bio], Mutant, Regulatory site, Metal Binding Site, Cell Cycle Proteins, spirochaetes, Biochemistry, Peroxide, chemistry.chemical_compound, Metalloprotein, oxidative stress, structural biology, spirochetes, MESH: Bacterial Proteins, Leptospira, chemistry.chemical_classification, biology, Chemistry, régulation transcriptionnelle, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, transcription regulation, Leptospira interrogans, Protein Binding, Signal Transduction, Repressor, Mitosis, PerR, reactive oxygen species (ROS), Microbiology, 03 medical and health sciences, MESH: Cell Cycle Proteins, Bacterial Proteins, métalloprotéine, MESH: Protein Binding, microbiologie, Molecular Biology, Binding Sites, metalloprotein, stress oxydatif, Cell Biology, MESH: Mitosis, biology.organism_classification, 030104 developmental biology, MESH: Binding Sites, Structural biology
Abstract

International audience; Peroxide sensing is essential for bacterial survival during aerobic metabolism and host infection. Peroxide stress regulators (PerRs) are homodimeric transcriptional repressors with each monomer typically containing both structural and regulatory metal-binding sites. PerR binding to gene promoters is controlled by the presence of iron in the regulatory site, and iron-catalyzed oxidation of PerR by H2O2 leads to the dissociation of PerR from DNA. In addition to a regulatory metal, most PerRs require a structural metal for proper dimeric assembly. We present here a structural and functional characterization of the PerR from the pathogenic spirochete Leptospira interrogans, a rare example of PerR lacking a structural metal-binding site. In vivo studies showed that the leptospiral PerR belongs to the peroxide stimulon in pathogenic species and is involved in controlling resistance to peroxide. Moreover, a perR mutant had decreased fitness in other host-related stress conditions, including at 37 °C or in the presence of superoxide anion. In vitro, leptospiral PerR could bind to the perR promoter region in a metal-dependent manner. The crystal structure of the leptospiral PerR revealed an asymmetric homodimer, with one monomer displaying complete regulatory metal coordination in the characteristic caliper-like DNA-binding conformation and the second monomer exhibiting disrupted regulatory metal coordination in an open non-DNA-binding conformation. This structure showed that leptospiral PerR assembles into a dimer in which a metal-induced conformational switch can occur independently in the two monomers. Our study demonstrates that structural metal binding is not compulsory for PerR dimeric assembly and for regulating peroxide stress.

Published
2018

4. Peroxisome proliferator-activated receptor-α activation as a mechanism of preventive neuroprotection induced by chronic fenofibrate treatment

Author

Olivier Pétrault, Bernard Dupuis, Isabelle Six, Régis Bordet, Patrick Gelé, Christophe Furman, Bart Staels, Dominique Deplanque, Roméo Cecchelli, Patrick Duriez, Muriel Bouly, Didier Leys, Jean-Charles Fruchart, Stéphane Nion, Université Lille 2 - Faculté de Médecine, Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), Récepteurs nucléaires, lipoprotéines et athérosclérose, Institut Pasteur de Lille, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille, Droit et Santé, Réseau International des Instituts Pasteur (RIIP), Université d'Artois (UA), Laboratoire de Physiopathologie de la Barrière Hémato-Encéphalique (LBHE), P.G. was supported by a grant from 'Conseil Régional Nord Pas de Calais et Centre Hospitalier Régional et Universitaire de Lille. ' This work was supported by grants from ' Génopole Lille Nord-Pas de Calais '(#01360124) and Institut National de la Santé et de la Recherche Médicale (CReS4CR02F)., and We thank Alexandra Tavernier-Sommerville for her assistance with the English version of this paper.

Subjects
Middle Cerebral Artery, Mouse, Nitric Oxide Synthase Type II, Receptors, Cytoplasmic and Nuclear, Peroxisome proliferator-activated receptor, medicine.disease_cause, Rats, Inbred WKY, Mice, 0302 clinical medicine, Fenofibrate, Mice, Knockout, chemistry.chemical_classification, 0303 health sciences, biology, General Neuroscience, Infarction, Middle Cerebral Artery, Cerebral Infarction, Intercellular Adhesion Molecule-1, Neuroprotection, Vasodilation, Nitric oxide synthase, Stroke, Neuroprotective Agents, Cerebrovascular Circulation, Middle cerebral artery, medicine.symptom, medicine.drug, PPAR-α, medicine.medical_specialty, Adhesion proteins, Nitric Oxide Synthase Type III, Development/Plasticity/Repair, Ischemia, Vascular Cell Adhesion Molecule-1, Mice, Transgenic, Inflammation, Time, 03 medical and health sciences, Apolipoproteins E, medicine.artery, Internal medicine, medicine, Animals, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, 030304 developmental biology, business.industry, Prevention, medicine.disease, Rats, Mice, Inbred C57BL, Disease Models, Animal, Endocrinology, chemistry, Oxidative stress, biology.protein, Nitric Oxide Synthase, business, 030217 neurology & neurosurgery, Transcription Factors
Abstract

International audience; The treatment of ischemic strokes is limited to the prevention of cerebrovascular risk factors and to the modulation of the coagulation cascade during the acute phase. Anew therapeutic strategy could be to preventively protect the brain against noxious biological reactions induced by cerebral ischemia such as oxidative stress and inflammation to minimize their neurological consequences. Here, we show that a peroxisome proliferator-activated receptor (PPAR-α) activator, fenofibrate, protects against cerebral injury by anti-oxidant and antiinflammatory mechanisms. A 14 d preventive treatment with fenofibrate reduces susceptibility to stroke in apolipoprotein E-deficient mice as well as decreases cerebral infarct volume in C57BL/6 wild-type mice. The neuroprotective effect of fenofibrate is completely absent in PPAR-α-deficient mice, suggesting that PPAR-α activation is involved as a mechanism of the protection against cerebral injury. Furthermore, this neuroprotective effect appears independently of any improvement in plasma lipids or glycemia and is associated with (1) an improvement in middle cerebral artery sensitivity to endothelium-dependent relaxation unrelated to an increase in nitric oxide synthase (NOS) type III expression, (2) a decrease in cerebral oxidative stress depending on the increase in numerous antioxidant enzyme activities, and (3) the prevention of ischemia-induced expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 in cerebral vessels without any change in NOS II expression. These data demonstrate that PPAR-α could be a new pharmacological target to preventively reduce the deleterious neurological consequences of stroke in mice and suggest that PPAR-α activators could preventively decrease the severity of stroke in humans.

Published
2003