MPO (myeloperoxidase) catalyses the oxidation of chloride, bromide and thiocyanate to their respective hypohalous acids. We have investigated the generation of HOBr by human neutrophils in the presence of physiological concentrations of chloride and bromide. HOBr was trapped with taurine and detected by monitoring the bromination of 4-HPAA (4-hydroxyphenylacetic acid). With 100 microM bromide a...

PURPOSE Carotenoids are present in many biological systems, often decreasing the formation of products of oxidative damage to biological molecules. In the macula their concentration is so high that it has been believed that the yellow color filters out damaging blue light. Recent reports that dietary lutein reduces the risk of cataract in the eye lens suggested that the antioxidant action of ca...

Recent studies indicate that oxygen radicals such as superoxide or singlet oxygen may be important in the functional activity of human granulocytes. We have examined the possible importance of these radicals in the functional capacity of human blood monocytes. Monocytes, like granulocytes, generate chemiluminescence during phagocytosis. Chemiluminescence is impaired 50-90% by superoxide dismuta...

Total pigment has been extracted from blackberries and its antioxidant activity against lipid peroxidation and scavenging capacities towards superoxide anion radicals, hydroxyl radicals and nitrite in different in vitro systems have been investigated. The total pigment extract from blackberries (TPEB) exhibited strong antioxidant activity against lipid peroxidation in a linoleic acid model syst...

Escherichia coli succinate dehydrogenase (SdhCDAB) catalyzes the oxidation of succinate to fumarate in the Krebs cycle, and during turnover, it produces superoxide radicals. SdhCDAB is a good model system for the succinate dehydrogenase (Sdh) found in the mitochondrial respiratory chain (complex II), as the subunits are structural homologues. Although mutations in sdh genes are reportedly assoc...

Generation of reactive oxygen species (ROS) is the hallmark of important biological processes and photodynamic therapy (PDT), where ROS production results from in situ illumination of certain dyes. Here we test the hypothesis that the yield, fate, and efficacy of the species evolved highly depend on the dye's environment. We show that Pd-bacteriopheophorbide (Pd-Bpheid), a useful reagent for va...

BACKGROUND AND PURPOSE It has been postulated that oxygen-derived free radicals are produced in significant quantities upon reperfusion of ischemic brain and that the free radicals play a pivotal role in triggering the ischemic neuronal damage causing delayed neuronal death. This study was undertaken to examine the effects of human recombinant superoxide dismutase on the delayed neuronal death ...