Search results for "Active oxygen"

The efficacy of two immunostimulants against Flavobacterium columnare infection in juvenile rainbow trout (Oncorhynchus mykiss).

2009

Abstract Bacterium Flavobacterium columnare is the causative agent of columnaris disease in many wild and farmed fish species. Immunostimulants are used with success in aquaculture against many pathogens, but the ability to improve innate resistance to columnaris disease has not been studied. Fingerling rainbow trout were treated with two immunostimulants, yeast β-glucan and β-hydroxy-β-methylbutyrate (HMB). Selected innate immune function parameters, the production of reactive oxygen species (ROS) by whole blood and by isolated head kidney leukocytes, plasma lysozyme activity and complement bacteriolytic activity, were determined to assess the immune status of fish. The fish were then bath…

Synthetic/ECM-inspired hybrid platform for hollow microcarriers with ROS-triggered nanoporation hallmarks

2017

Reactive oxygen species (ROS) are key pathological signals expressed in inflammatory diseases such as cancer, ischemic conditions and atherosclerosis. An ideal drug delivery system should not only be responsive to these signals but also should not elicit an unfavourable host response. This study presents an innovative platform for drug delivery where a natural/synthetic composite system composed of collagen type I and a synthesized polythioether, ensures a dual stimuli-responsive behaviour. Collagen type I is an extracellular matrix constituent protein, responsive to matrix metalloproteinases (MMP) cleavage per se. Polythioethers are stable synthetic polymers characterized by the presence o…

Is Oxidative Stress the Link Between Cerebral Small Vessel Disease, Sleep Disruption, and Oligodendrocyte Dysfunction in the Onset of Alzheimer’s Dis…

2021

Oxidative stress is an early occurrence in the development of Alzheimer’s disease (AD) and one of its proposed etiologic hypotheses. There is sufficient experimental evidence supporting the theory that impaired antioxidant enzymatic activity and increased formation of reactive oxygen species (ROS) take place in this disease. However, the antioxidant treatments fail to stop its advancement. Its multifactorial condition and the diverse toxicological cascades that can be initiated by ROS could possibly explain this failure. Recently, it has been suggested that cerebral small vessel disease (CSVD) contributes to the onset of AD. Oxidative stress is a central hallmark of CSVD and is depicted as …

Cytotoxicity of the Urokinase-Plasminogen Activator Inhibitor Carbamimidothioic Acid (4-Boronophenyl) Methyl Ester Hydrobromide (BC-11) on Triple-Neg…

2015

BC-11 is an easily synthesized simple thiouronium-substituted phenylboronic acid, which has been shown to be cytotoxic on triple negative MDA-MB231 breast cancer cells by inducing a perturbation of cell cycle when administered at a concentration equal to its ED50 at 72 h (117 μM). Exposure of cells to BC-11, either pre-absorbed with a soluble preparation of the N-terminal fragment of urokinase-plasminogen activator (uPa), or in co-treatment with two different EGFR inhibitors, indicated that: (i) BC-11 acts via binding to the N-terminus of the enzyme where uPa- and EGF receptor-recognizing sites are present, thereby abrogating the growth-sustaining effect resulting from receptor binding

2007

We have recently demonstrated that the rheumatoid arthritis (RA) shared epitope (SE) acts as a ligand that triggers nitric oxide (NO) signaling in opposite cells. Given the known pro-oxidative effect of NO and the proposed role of oxidative stress in the pathogenesis of RA, this study explores whether SE-triggered signaling can increase cellular oxidative stress. cAMP levels, adenylyl cyclase activity, and protein kinase A activity were measured using commercial kits. Generation of reactive oxygen species (ROS) was quantified using the fluorochrome dichlorofluorescein diacetate. Oxidative DNA damage was quantified using the single-cell electrophoresis technique. Here, we report that cells e…

Interaction between 24-hydroxycholesterol, oxidative stress, and amyloid-β in amplifying neuronal damage in Alzheimer’s disease: three partners in cr…

2011

All three cholesterol oxidation products implicated thus far in the pathogenesis of Alzheimer's disease, 7β-hydroxycholesterol, 24-hydroxycholesterol, and 27-hydroxycholesterol, markedly enhance the binding of amyloid-beta (Aβ) to human differentiated neuronal cell lines (SK-N-BE and NT-2) by up-regulating net expression and synthesis of CD36 and β1-integrin receptors. However, only 24-hydroxycholesterol markedly potentiates the pro-apoptotic and pro-necrogenic effects of Aβ(1-42) peptide on these cells: 7β-hydroxycholesterol and 27-hydroxycholesterol, like unoxidized cholesterol, show no potentiating effect. This peculiar behavior of 24-hydroxycholesterol at physiologic concentrations (1 μ…

Abstract 1390: A combination of natural polyphenols, a NAD+ booster, and a Toll-like receptor 2/6 agonist exerts high radioprotection in normal tissu…

2021

Abstract Ionizing radiation damages cells via direct ionization of DNA and other cellular targets as well as by indirect effects through reactive oxygen species. The response to radiation exposure depends on the cell type and dose of radiation, inherent tissue sensitivity and repair, and modulating intracellular factors that include cell cycle status, O2 pressure, and levels of thiols and other antioxidants. Potentially protective agents against exposure to harmful radiation have been investigated for decades. However, no ideal radioprotector is currently available. A wide range of phytochemicals are antioxidants and, thus, potentially radioprotective. Topical administration of Pterostilben…

CTAB‐PLGA Curcumin Nanoparticles: Preparation, Biophysical Characterization and Their Enhanced Antifungal Activity against Phytopathogenic Fungus Pyt…

2020

Deglycosylated bleomycin triggers apoptosis in laryngeal carcinoma cells in a caspase and reactive oxygen species independent manner

2008

Background:  Bleomycin-A2, a member of a family of glycopeptide antibiotics, has potent antitumor activity against a range of lymphomas, head and neck cancer and germ cell tumors. However, little is known about the biologic activity of the carbohydrate moiety in Bleomycin-A2-induced cytotoxicity. Methods:  We compared the capacity of Bleomycin-A2 and its deglycosylated form (deglycoBleomycin-A2) to induce cell death. Apoptosis was analyzed by cell nuclear staining with Hoechst 33342 dye and DNA fragmentation. The signal transduction pathway was measured through Western blotting and production of reactive oxygen species (ROS). Results:  When tested on HEp-2 laryngeal carcinoma cells, Bleomyc…

Antioxidant activity of cerium dioxide nanoparticles and nanorods in scavenging hydroxyl radicals

2019

Cerium oxide nanoparticles (CeNPs) have been shown to exhibit antioxidant capabilities, but their efficiency in scavenging reactive oxygen species (ROS) and the underlying mechanisms are not yet well understood. In this study, cerium dioxide nanoparticles (CeNPs) and nanorods (CeNRs) were found to exhibit much stronger scavenging activity than ·OH generation in phosphate buffered saline (PBS) and surrogate lung fluid (SLF). The larger surface area and higher defect density of CeNRs may lead to higher ·OH scavenging activity than for CeNPs. These insights are important to understand the redox activity of cerium nanomaterials and provide clues to the role of CeNPs in biological and environmen…