Objective. Artemisia ciniformis (Asteraceae) and A. biennis are two of 34 Artemisia species growing naturally in Iran. In this study we investigated whether different extracts of A. ciniformis and A. biennis have protective effect against hydrogen peroxide-induced cytotoxicity in rat cardiomyoblast cells (H9c2). Method. The dried and ground aerial parts of these two species were extracted succe...

Poly (N-isopropylacrylamide)-co-(acrylic acid) (pNIPAm-co-AAc) microgels composed of Ag nanoparticles (Ag NPs) have been synthesized and employed for the colorimetric sensing of H2O2. Each pNIPAm-co-AAc microgel, which exhibited a diameter of ∼800 nm, contained multiple Ag NPs (diameter of ∼5 nm), and solutions of these hybrid materials showed a UV-vis absorption band at ∼400 nm. This is due to...

Oxidative stress through the production of oxygen metabolites such as hydrogen peroxide (H2O2) increases vascular endothelial permeability. H2O2 stimulates ADP-ribose formation, which in turn opens transient receptor potential melastatin (TRPM)2 channels. Here, in endothelial cells, we demonstrate transcript and protein expression of TRPM2, a Ca2+-permeable, nonselective cation channel. We furt...

The ability of intact human red cells to scavenge extracellularly generated H2O2 and O2-, and to prevent formation of hydroxyl radicals and hypochlorous acid has been examined. Red cells inhibited oxidation of ferrocytochrome c by H2O2. Cells treated with aminotriazole no longer inhibited, indicating that protection was almost entirely due to intracellular catalase. Contribution by the GSH syst...

Vitiligo is a skin depigmentation disorder with an increasing prevalence. Among recognized mechanisms is the oxidative stress that affects melanocytes which are responsible for skin pigmentation. Studies have shown that high concentration of hydrogen peroxide, or H2O2, induces apoptotic activities. Few studies have been done with lower doses of H2O2. Using human skin melanocytes, we investigate...

Formation of oxyperoxidase from the reaction of ferryl horseradish peroxidase with H2O2 is inhibited by a small amount of tetranitromethane (TNM), a powerful scavenger of superoxide anion radical. The inhibition by TNM, however, does not exceed 35% as the TNM concentration is increased above 5 microM. The stoichiometry of the reaction in the presence of TNM suggests the following equation for T...

Transient receptor potential melastatin-related 2 (TRPM2) channel, a molecular sensor for reactive oxygen species (ROS), plays an important role in cognitive dysfunction associated with post-ischemia brain damage thought to result from ROS-induced TRPM2-dependent neuronal death during reperfusion. Emerging evidence further suggests that an alteration in the Zn2+ homeostasis is critical in ROS-i...

The oxidation of guanosine to 8-oxo-2'-deoxyguanosine (8-oxo-dG) in DNA is closely associated with induction of various diseases, but the endogenous oxidant species involved remains unclear. Hydrogen peroxides (H2O2) have been considered to be the oxidant, while lipid peroxides are another possible oxidant because generated easily in bio-membranes surrounding DNA. The oxidant potency was compar...

Treatment experiments of a landfill leachate were performed by wet air oxidation (WAO) with the addition of H2O2 (as free radical promoter), and a Fenton-type (at pH 7) process, in order to compare COD (chemical oxygen demand) and AOX (adsorbable organic halogen) reduction as well as biodegradability enhancement measured by OUR respirometric parameter. The WAO reactions were performed in a batc...

PURPOSE To detect intravitreal peroxides in vivo by a new fluorophotometric method with a hydrogen peroxide (H2O2)-sensitive fluorescent dye. METHODS The authors used a 2',7'-dichlorofluorescin (DCFH) assay to measure oxidative status in the rabbit vitreous. In the presence of H2O2 and lipid hydroperoxides, nonfluorescent DCFH in the vitreous is oxidized to highly fluorescent 2',7'-dichlorofl...