Showing papers in "Free Radical Biology and Medicine in 1999"

TL;DR: A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants.

TL;DR: This article serves as introduction to the FRBM Forum on glutathione and emphasizes cellular functions: What is GSH?

TL;DR: Because GSH plays a critical role in cellular defenses against electrophiles, oxidative stress and nitrosating species, pharmacologic manipulation of GSH synthesis has received much attention.

TL;DR: All individual isoenzymes are efficient peroxidases in principle, but beyond their mere antioxidant potential may exert cell- and tissue-specific roles in metabolic regulation, as is evident for PHGPx and may be expected for others.

TL;DR: No single measurement of antioxidant status is going to be sufficient, but a "battery" of measurements will be necessary to adequately assess oxidative stress in biological systems.

TL;DR: This review gives an overview of the applications in experimental and human situations of four main groups of products resulting from free radical damage, these include: lipid peroxidation products, isoprostanes, DNA-hydroxylation products and protein hydroxylated products.

TL;DR: Up to 2% of the oxygen consumed by the mitochondrial respiratory chain undergoes one electron reduction, typically by the semiquinone form of coenzyme Q, to generate the superoxide radical, and subsequently other reactive oxygen species such as hydrogen peroxide and the hydroxyl radical.

TL;DR: With superoxide, the results are consistent with each thiol reacting via a short chain that consumes oxygen and regenerates superoxide and the consumed oxygen recovered as hydrogen peroxide.

TL;DR: It is no longer appropriate to think of these probes as detecting a specific oxidizing species in cells, such as H2O2, but rather as detectors of a broad range of oxidizing reactions that may be increased during intracellular oxidant stress.

TL;DR: PON's ability to protect LDL against oxidation is accompanied by inactivation of the enzyme, suggesting the interaction of oxidized lipids in Ox-LDL with the PON's free sulfhydryl group.

TL;DR: The spectrum of different effects of NO in the circulation and the nervous system suggest the potential applications of PYC in immune and circulatory disorders as well as in neurodegenerative disease.

TL;DR: The current evidence is insufficient to conclude that antioxidant vitamin supplementation materially reduces oxidative damage in humans, with the only exception of supplemental vitamin E, and possibly vitamin C, being able to significantly lower lipid oxidativedamage in both smokers and nonsmokers.

TL;DR: This review is focused on the recent knowledge concerning some eukaryotic transcription factors, whose activation and DNA binding is controlled by the thiol redox status of the cell.

TL;DR: The Trolox equivalent antioxidant capacities (TEACs) of 42 different flavonoids are found to be mainly governed by the number and location of hydroxyl groups on the flavonoid ring system.

TL;DR: It is demonstrated, with an ESR spin-stabilization technique coupled to conventional spectrophotometry, that o-semiquinone and o-quinone are indeed the products of enzymatically catalyzed oxidative degradation of quercetin and the former radical might serve to facilitate the formation of superoxide and depletion of GSH.

TL;DR: Evidence is presented to show that protein oxidation products are sensitive markers of oxidative damage, that the pattern of products detected may yield information as to the nature of the original oxidative insult, and that the levels of oxidized side-chains can, in certain circumstances, be much higher than those of other markers of oxidation such as lipid hydroperoxides.

TL;DR: Age-dependent increases in 8-hydroxy-2-deoxyguanosine (OH8dG) and malondialdehyde (MDA) provided evidence for a role of oxidative damage in human aging which may contribute to age-dependent losses of muscle strength and stamina.

TL;DR: Overall, the epidemiological evidence suggests that vitamin A and carotenoids are important dietary factors for reducing the incidence of heart disease and carefully controlled experimental studies continue to indicate that these compounds are effective for mitigating and defending against many forms of cardiovascular disease.

TL;DR: DCF fluorescence cannot be used reliably to measure O2- in cells because O2*- itself is formed during the conversion of DCFH to DCF by peroxidases, and the use of this probe to measure H2O2 production in cells is problematic.

TL;DR: The results of this study demonstrate that resveratrol possesses cardioprotective effects which may be attributed to its peroxyl radical scavenging activity and suggest a probable mechanism involved in the protective ability of RVT.

TL;DR: Results indicate that H2O2 is the toxic ROS produced by activated leukocytes causing the inhibition of both sperm movement and ATP production and ATP levels inhibit sperm energy metabolism at a site independent of mitochondrial oxidative phosphorylation.

TL;DR: Redox changes in response to physiologic stimuli such as differentiation and enzyme inducers are of a sufficient magnitude to control the activity of redox-sensitive proteins, suggesting that physiologic modulation of the 2GSH/GSSG redox poise could provide a fundamental parameter for the control of cell phenotype.

TL;DR: Induction of GSH synthesis bymelatonin protects cells against oxidative stress and regulates cell proliferation, suggesting induction of cell arrest by melatonin requires GSH.

TL;DR: The results support the concept that the gene network regulating the cellular response to stress is functionally important in aging and longevity, and positively correlated with mammalian longevity.

TL;DR: The experimental results suggest that, in addition to supporting an increased activity of glutathione peroxidase, an antioxidant function that the three selenium compounds did with equal efficacy, catalytic selenite, and selenocystamine generated 8-hydroxydeoxyguanosine DNA adducts, induced apoptosis and were found to be cytotoxic in mouse keratinocytes.

TL;DR: The study of the interaction of two synthetic melanins with a wide range of oxidising and reducing free radicals using the pulse radiolysis technique suggests that the free radical scavenging properties of melanin may be important in the protection of melanotic cells against free radical damage.

TL;DR: The various effects of Flavonoids on metal-induced lipid peroxidation in LNA-loaded hepatocytes is discussed with regard to the change in redox potential of flavonoid-metal complexes.

TL;DR: Oral administration of alpha-lipoic acid can improve insulin sensitivity in patients with type-2 diabetes and this placebo-controlled explorative study confirms previous observations of an increase of insulin sensitivity after acute and chronic intravenous administration of ALA.

TL;DR: The adaptive response against oxidative stress induced by moderate endurance exercise constitutes a beneficial effect of exercise.