Under physiological and pathological conditions, the reactive oxygen species (ROS) are formed from both exogenous and endogenous sources. ROS are implicated in a wide number of disease processes, including atherosclerosis, autoimmune disorders, rheumatoid arthritis, neuronal degeneration, cardiovascular diseases and cancer. Among the reactive oxygen species produced in living cells, hydroxyl ra...

An ethanol extract of the stem of Opuntia ficus-indica var. saboten (OFS) was assessed to determine the mechanism(s) of its antioxidant activity. The ethanol extract exhibited a concentration-dependent inhibition of linoleic acid oxidation in a thiocyanate assay system. In addition, the OFS extract showed dose-dependent free-radical scavenging activity, including DPPH radicals, superoxide anion...

Hydroxyl radicals arising from the Fenton reagent remove metastable surface gold atoms (low coordinated high-energy surface atoms) on the Au surface, thus precluding the formation of stable oxides. The resultant smooth surface, upon hydroxyl-radical activation, electrocatalyzes oxygen evolution reaction in 0.1 M NaOH at overpotentials lowered by 190 mV @ 10 mA cm(-2).

Radicals known to play significant roles in hydrogen peroxide chemistry include the hydroxyl radical (OH ), superoxide radical (O2 ), and perhydroxyl radical (HO2 ). Different radicals dominate the reaction under different chemistry conditions, and are controlled by parameters such as concentration of the oxidant, catalyst, organic or inorganic solutes, and pH. This can affect performance as so...

The chlorine radical is a potent atmospheric oxidant, capable of perturbing tropospheric oxidative cycles normally controlled by the hydroxyl radical. Significantly faster reaction rates allow chlorine radicals to expedite oxidation of hydrocarbons, including methane, and in polluted environments, to enhance ozone production. Here we present evidence, from the CARIBIC airborne dataset, for exte...

Enterobacteriaceae that contain the High Pathogenicity Island (HPI), which encodes the siderophore yersiniabactin, display increased virulence. This increased virulence may be explained by the increased iron scavenging of the bacteria, which would both enhance bacterial growth and limit the availability of iron to cells of the innate immune system, which require iron to catalyze the Haber-Weiss...

OBJECTIVE Antioxidant, anti-inflammatory and venoconstrictor properties have been attributed to extracts from Aesculus hippocastanum. These unusual and diverse properties may be possibly basically linked with ability to scavenge free radicals. MATERIALS AND METHODS The scavenging capacity of dry horse chestnut extract of and escin have been investigated in vitro against superoxide anion radic...

The fate of hydrogen peroxide in a model wine system was studied under a competitive scenario in the presence of ferrous ions and sulfur dioxide. The metal-catalyzed reduction of hydrogen peroxide (H(2)O(2)), referred to as the Fenton reaction, yields hydroxyl radicals capable of oxidizing ethanol to acetaldehyde and is now thought to be a key step in nonenzymatic wine oxidation. It appears tha...