Search results for "REACTIVE OXYGEN SPECIES"
showing 10 items of 879 documents
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…
Coping with Oxygen
2010
Sometime before 2.7 BYA, a new and biologically toxic substance began to appear in the environment. Biologically produced dioxygen, O2, probably first began to accumulate in small pools or layers above cyanobacterial mats. These photosynthesizers must have already developed ways to at least partially deal with dioxygen and, with greater difficulty, the reactive oxygen species (ROS) derived from it (see Chap. 1 and below). But for primitive anaerobes in the vicinity, these new substances must have been especially toxic. Nevertheless, it is clear that they evolved ways to cope with the new threats. One way was to simply avoid dioxygen altogether.
Peptide-metal complexes: obtention and role in increasing bioavailability and decreasing the pro-oxidant effect of minerals.
2020
Bioactive peptides derived from food protein sources have been widely studied in the last years, and scientific researchers have been proving their role in human health, beyond their nutritional value. Several bioactivities have been attributed to these peptides, such as immunomodulatory, antimicrobial, antioxidant, antihypertensive, and opioid. Among them, metal-binding capacity has gained prominence. Mineral chelating peptides have shown potential to be applied in food products so as to decrease mineral deficiencies since peptide-metal complexes could enhance their bioavailability. Furthermore, many studies have been investigating their potential to decrease the Fe pro-oxidant effect by f…
Special issue on “Oxidative stress and redox signaling in the gastrointestinal tract and related organs”
2013
A Radical Signal Activates the Epigenetic Regulation of Longevity
2013
Hormesis is an adaptive stress response implicated in longevity regulation. Schroeder et al. (2013) have now connected stress, epigenetic changes, and aging in yeast by showing that mitochondria-derived reactive oxygen species modulate the chromatin binding capacity of the histone demethylase Rph1p at subtelomeres, resulting in lifespan extension.