Search results for "Reactive"
showing 10 items of 1469 documents
The Relationship between Alcohol–induced Apoptosis and Oxidative Stress in the Liver
2005
This chapter discusses the relationship of apoptosis and oxidative stress induced by alcohol in the liver. Oxidative stress is involved in the pathogenesis and progression of alcohol-induced liver disease. Chronic alcoholism always causes oxidative stress independently of the presence of liver disease. Two key mechanisms are responsible for it: (1) the mitochondrial respiratory chain and (2) cytochrome P450 2El activity. Increased production of reactive oxygen species at complexes I and III together with NADH overproduction would be the major cause for mitochondrial oxidative stress in chronic alcoholism. Reactive Oxygen Species (ROS) cause oxidative damage, which may lead to cell death by …
17β-Estradiol-dependent regulation of chaperone expression and telomerase activity in the marine sponge Geodia cydonium
1999
It is known that species belonging to the lowest metazoan phylum, the Porifera (sponges), do not develop tumors. Sponge cells share with tumor cells of higher animals at least one characteristic; they contain high levels of telomerase activity, suggesting that they possess a high proliferation capacity. This assumption, however, has not been substantiated experimentally. In addition, sponges show a specific bauplan, leading us to postulate that they undergo apoptosis to replace a given set of cells at a given time. In the present study, 17β-estradiol (βE2) was used as a defined agent to assess its effect on both the telomerase activity and the process of apoptosis in the marine sponge Geodi…
Oxidative stress in diabetic retinopathy
2020
Diabetic retinopathy (DR) is the leading cause of acquired blindness in working adults worldwide. Biochemical changes in DR contribute to both the microscopic structural and functional changes in the retina. All these alterations result in retinal damage that can be assessed by funduscopy, optical coherence tomography (OCT), and angioOCT. Reactive oxygen species (ROS) overproduction in the mitochondria is considered a causal link between elevated glucose and biochemical abnormalities in the pathophysiology of DR. Moreover, oxidative-induced pathways also seem to provide positive feedback to ROS production, resulting in a vicious cycle. ROS can directly damage lipids, proteins, and DNA, lead…
ChemInform Abstract: Investigations Concerning the COX/5-LOX Inhibiting and Hydroxyl Radical Scavenging Potencies of Novel 4,5-Diaryl Isoselenazoles.
2008
The aim of this study was to investigate 4,5-diaryl isoselenazoles as multiple target non-steroidal anti-inflammatory drugs (MTNSAIDs) which can intervene into the inflammatory processes via different mechanisms of action creating a new class of compounds. Here we describe the synthesis of COX/LOX inhibitors which additionally reduce the level of reactive oxygen species, such as hydroxyl radicals which are well known for supporting inflammation processes in Parkinson's disease, Alzheimer's disease and rheumatoid arthritis.
Biological Activity of Flavonoids Copper Complexes
2005
Three flavonoid copper(II) complexes Cu2(quercetin)(CH3COO)3(CH3OH) (1), Cu(anthrarufin)(CH3COO)·1/2H2O (2) and Cu(naringin)(OCH3)(CH3OH)2 (3) have been synthesized and characterized by elemental analysis, IR, electronic absorption and EPR (X-band) spectroscopy. The complexes have a strong protective action over the Δsod1 mutant of S. cerevisiae against reactive oxygen radicals generated by an external source of free radicals (H2O2 or the superoxide-generating, menadione). On the other hand, the complexes cleave DNA efficiently even in the absence of reducing agents. The main reactive oxygen species responsible for the DNA strand cleavage have been determined using radical scavengers. A pro…
Comparative Biological Properties and Mineralization Potential of 3 Endodontic Materials for Vital Pulp Therapy: Theracal PT, Theracal LC, and Bioden…
2021
INTRODUCTION The aim of this study was to assess the biological properties and mineralization potential of the new Theracal PT (Bisco Inc, Schaumburg, IL) compared with its predecessor Theracal LC (Bisco Inc) and the hydraulic silicate-based cement Biodentine (Septodont, Saint-Maur-des-Fosses, France) on human dental pulp stem cells (hDPSCs) in vitro. METHODS Standardized sample discs were obtained for each material (n = 30) together with 1:1, 1:2, and 1:4 material eluates. Previously characterized hDPSCs were cultured with the different materials in standardized conditions, and the following assays were performed: a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, a woun…
2015
The rationale of the study was two-fold: (i) develop a functional synthetic model of the Cytochrome c oxidase (CcO) active site, (ii) use it as a convenient tool to understand or predict the outcome of the reaction of CcO with ligands (physiologically relevant gases and other ligands). At physiological pH and potential, the model catalyzes the 4-electron reduction of oxygen. This model was immobilized on self-assembled-monolayer (SAM) modified electrode. During catalytic oxygen reduction, electron delivery through SAMs is rate limiting, similar to the situation in CcO. This model contains all three redox-active components in CcO's active site, which are required to minimize the production o…
One Enzyme, Two Functions
2010
The human enzyme paraoxonase-2 (PON2) has two functions, an enzymatic lactonase activity and the reduction of intracellular oxidative stress. As a lactonase, it dominantly hydrolyzes bacterial signaling molecule 3OC12 and may contribute to the defense against pathogenic Pseudomonas aeruginosa. By its anti-oxidative effect, PON2 reduces cellular oxidative damage and influences redox signaling, which promotes cell survival. This may be appreciated but also deleterious given that high PON2 levels reduce atherosclerosis but may stabilize tumor cells. Here we addressed the unknown mechanisms and linkage of PON2 enzymatic and anti-oxidative function. We demonstrate that PON2 indirectly but specif…
2021
Cardiovascular diseases (CVDs) rank the leading cause of morbidity and mortality globally. Obesity and its related metabolic syndrome are well-established risk factors for CVDs. Therefore, understanding the pathophysiological role of adipose tissues is of great importance in maintaining cardiovascular health. Oxidative stress, characterized by excessive formation of reactive oxygen species, is a common cellular stress shared by obesity and CVDs. While plenty of literatures have illustrated the vascular oxidative stress, very few have discussed the impact of oxidative stress in adipose tissues. Adipose tissues can communicate with vascular systems, in an endocrine and paracrine manner, throu…