Search results for "Oxidants"
showing 10 items of 878 documents
The Recent Crystal Structure of Human Tyrosinase Related Protein 1 (HsTYRP1) Solves an Old Problem and Poses a New One
2017
Show your metal: l-Tyrosine is converted into the protective antioxidative polymer melanin in a sequence of reactions. In humans, the catalytic pathway starts with the tyrosinase HsTYR and two tyrosinase-related proteins HsTYRP1 and HsTYRP2. All three enzymes have the same active site but the latter two contain two zinc ions instead of copper ions.
7keto-stigmasterol and 7keto-cholesterol induce differential proteome changes to intestinal epitelial (Caco-2) cells
2015
Abstract Recent studies have expanded the appreciation of the roles of oxysterols triggering inflammatory, immune cytotoxic and apoptotic processes, but have not been considered for proteome analysis. A comparative proteomic study in intestinal epithelial cell cultures incubated (60 μM/24 h) with 7keto-cholesterol or 7keto-stigmasterol was performed. The influence of both compounds was studied following the nLC-TripleTOF analysis. Findings were compared to results for control cultures. In the principal component analysis (PCA) of proteome patterns, two components were extracted accounting for 99.8% of the variance in the protein expression. PCA analysis clearly discriminated between the per…
Increased oxidative stress and impaired antioxidant response in Lafora disease.
2014
15 páginas, 10 figuras
Piclamilast inhibits the pro-apoptotic and anti-proliferative responses of A549 cells exposed to H(2)O(2) via mechanisms involving AP-1 activation.
2012
Reactive oxygen species (ROS) are involved in the pathogenesis of many inflammatory diseases such as chronic obstructive pulmonary disease (COPD). They can alter the expression of genes involved in cellular damage by activating transcription factors, including the NF-κB and the activator protein 1 (AP-1). Phosphodiesterase type 4 (PDE4) inhibitors have anti-inflammatory and antioxidant effects, as described in in vivo and in vitro COPD models. This study analysed the effects of piclamilast, a selective PDE4 inhibitor, on modulating the global gene expression profile in A549 cells exposed to H(2)O(2).Changes in gene expression were analysed using high-density Affymetrix microarrays and valid…
Antioxidant Bibenzyl Derivatives from Notholaena nivea Desv.
2011
Four new bibenzyl derivatives were isolated, together with other known bibenzyls, by bioassay-guided fractionation of a CHCl3-MeOH extract of Notholaena nivea Desv. (Pteridaceae) aerial parts. The structures were elucidated by NMR, ESIMS and other spectral analyses. Their antioxidative effects towards superoxide, lipidic peroxidation and the 2,2'- azino-bis-3- ethilbenzothiazoline-6-sulfonic acid (ABTS) radical were assayed. Results showed that the compound 3,12-dihydroxy-5-methoxybibenzyl (6) is the most active compound in the ABTS free-radical scavenging test, while in the coupled oxidation of ȕ-carotene and linoleic acid assay the compound 5,12-dihydroxy-3-methoxydibenzyl-6- carboxylic a…
Aza- and Azo-Stilbenes: Bio-Isosteric Analogs of Resveratrol
2020
Several series of natural polyphenols are described for their biological and therapeutic potential. Natural stilbenoid polyphenols, such as trans-resveratrol, pterostilbene and piceatannol are well-known for their numerous biological activities. However, their moderate bio-availabilities, especially for trans-resveratrol, prompted numerous research groups to investigate innovative and relevant synthetic resveratrol derivatives. This review is focused on isosteric resveratrol analogs aza-stilbenes and azo-stilbenes in which the C=C bond between both aromatic rings was replaced with C=N or N=N bonds, respectively. In each series, synthetic ways will be displayed, and structural sights will be…
Oxidative Stress and Respiratory System: Pharmacological and Clinical Reappraisal of N-Acetylcysteine
2014
Abstract The large surface area for gas exchange makes the respiratory system particularly susceptible to oxidative stress-mediated injury. Both endogenous and exogenous pro-oxidants (e.g. cigarette smoke) trigger activation of leukocytes and host defenses. These mechanisms interact in a ìmultilevel cycleî responsible for the control of the oxidant/antioxidant homeostasis. Several studies have demonstrated the presence of increased oxidative stress and decreased antioxidants (e.g. reduced glutathione [GSH]) in subjects with chronic obstructive pulmonary disease (COPD), but the contribution of oxidative stress to the pathophysiology of COPD is generally only minimally discussed. The aim of t…
Future Directions in the Pharmacologic Therapy of Chronic Obstructive Pulmonary Disease
2005
Current therapy for chronic obstructive pulmonary disease (COPD) fails to alter its relentless progression. This remains a significant challenge and unmet need. A recent advance is the demonstration that treatment with a fixed dose of an inhaled corticosteroid and a long-acting beta2-agonist in COPD improves lung function and quality of life, and reduces exacerbation more effectively than either drug alone. Other improvements include the introduction of tiotropium, a once-daily anticholinergic. In advanced clinical development are other once-daily bronchodilators and combinations of anticholinergic drugs and beta2-agonists. Increased understanding of the pathogenesis of COPD has led to nove…
Antioxidants: Role in the prevention and treatment of bronchopulmonary dysplasia
2022
Bronchopulmonary dysplasia (BPD) is one of the major causes of chronic respiratory diseases among infants. Both pharmacological and nonpharmacological approaches have been proposed for its management. Since oxidative stress is known to play a pivotal role in the pathogenesis of BPD, it is reasonable to consider the potential of antioxidant strategies in the prevention and treatment of this condition. Indeed, antioxidants can prevent or inhibit substrate oxidation. Some studies have evaluated the efficacy of the exogenous administration of vitamins and micronutrients in reducing the propagation of free radicals through their scavenging capacity. Nonetheless, encouraging preclinical results d…
CD40 ligation protects bronchial epithelium against oxidant-induced caspase-independent cell death.
2006
KEYWORDS CLASSIFICATION: 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide;Antigens,CD40;Apoptosis;Bronchi;cytology;Caspases;Cell Cycle;Cell Death;Cell Line,Transformed;Cell Survival;Cell Transformation,Viral;Cytoprotection;drug effects;Epithelial Cells;Humans;Italy;mechanisms of carcinogenesis;metabolism;Oxidants;pharmacology;physiology;Research;Simian virus 40;toxicity;Transcription Factor AP-1. CD40 and its ligand regulate pleiotropic biological responses, including cell proliferation, differentiation, and apoptosis. In many inflammatory lung diseases, tissue damage by environmental or endogenous oxidants plays a major role in disease pathogenesis. As the epithelial barrier is a major t…