BACKGROUND The redox imbalance between nitric oxide and superoxide generated in the endothelium is thought to play a pivotal role in the development of endothelial dysfunction. A third reactive oxygen species (ROS), H2O2, is known to have both beneficial and detrimental effects on the vasculature. Nonetheless, the influence of the hydroxyl radical, a byproduct of H2O2 decay, is unclear, and the...

23 The antimicrobial mechanism of a lactococcal bacteriocin, lacticin Q, can be 24 described by the toroidal pore model without any receptor. However, lacticin Q 25 showed different degrees of activity (selective antimicrobial activity) against 26 gram-positive bacteria even among related species. The ability of lacticin Q to induce 27 pore formation in liposomes composed of lipids from differe...

The cytochrome P-450 mediated activation of paracetamol (PAR) to the reactive electrophilic intermediate N-acetyl-p-benzoquinone imine (NAPQI) has been studied by use of SV 6-31G ab initio energy calculations and spin distributions. A simplified model for cytochrome P-450 has been used by substituting the proposed biologically active ferric-oxene state of cytochrome P-450 by a singlet oxygen at...

BACKGROUND Pterostilbene, a methoxylated analog of Resveratrol, is gradually gaining more importance as a therapeutic drug owing to its higher lipophilicity, bioavailability and biological activity than Resveratrol. This study was undertaken to characterize its ability to scavenge free radicals such as superoxide, hydroxyl and hydrogen peroxide and to protect bio-molecules within a cell against...

A new, simple assay has been optimized to generate and detect hydroxyl radical by Fenton reaction. The assay is based on oxidation of catechol, monitored at 360 nm following incubation at room temperature for ca. 30 minutes, with linearity over 0.25 through 2.5 μmole H2O2 using Fe (II) (0.5 μmole) and acidified catechol (0.5 mg). The Fenton reaction has been characterized by registering: (i) ab...

Contractions of skeletal muscles produce increases in concentrations of superoxide anions and activity of hydroxyl radicals in the extracellular space. The sources of these reactive oxygen species are not clear. We tested the hypothesis that, after a demanding isometric contraction protocol, the major source of superoxide and hydroxyl radical activity in the extracellular space of muscles is mi...