Oxygen-derived free radicals have been implicated in the pathogenesis of cardiac dysfunction during ischemia, postischemic myocardial "stunning," and reperfusion injury. We investigated the effects of oxygen-derived free radicals on cardiac function in intact isolated rabbit hearts and single guinea pig ventricular myocytes. In the intact rabbit ventricle, exposure to free radical-generating sy...

        The crude methanolic extract of the seeds of Celastrus paniculatus along with its organic soluble fractions were tested for their possible antioxidant and anti-alzheirmer (AD) activity. The extracts showed prominent DPPH free radical scavenging activity, inhibiting activity of authentic peroxynitrite (ONOO-) and inhibition of total reactive oxygen species (ROS) generation. In D...

With NADPH as the electron donor, rat liver NADPH cytochrome P-450 reductase (NADPH:ferricytochrome oxidoreductase, EC 1.6.2.4) catalyzes the single-electron reduction of several quinone antibiotics to a semiquinone or free radical state. The benzanthraquinones adriamycin, daunorubicin, carminomycin, 7-O-methylnogalarol, and aclacinomycin A and the N-heterocyclic quinones streptonigrin and mito...

Lipid peroxidation is a primary cause of quality deterioration in meat and meat products. Free radical chain reaction is the mechanism of lipid peroxidation and reactive oxygen species (ROS) such as hydroxyl radical and hydroperoxyl radical are the major initiators of the chain reaction. Lipid peroxyl radical and alkoxyl radical formed from the initial reactions are also capable of abstracting ...

In this study, the methanol extract of bark of Cordia dichotoma Forst., belonging to the family Boraginaceae was prepared by successive extraction procedure ( petroleum ether, ethyl acetate, methanol) in soxhlet apparatus and subsequently, the extract was evaluated for its phytoconstituents and pharmacological activity. Comparatively, higher yield (7.11%) of methanol extract was obtained. Phyto...

The reactive oxygen species (ROS) can damage the nucleic acids. The oxidative modification of the DNA constitutes the fundamental molecular event in carcinogenesis and that is why the interest in the study of the involvement of ROS in that process. On the other hand, oxidative DNA damage-induced mutagenesis is widely hypothesized to be a frequent event in the normal human cell. The enormous evi...

Deferoxamine accelerates the autooxidation of iron as measured by the rapid disappearance of Fe2+, the associated appearance of Fe3+, and the uptake of oxygen. Protons are released in the reaction. The formation of H2O2 was detected by the horseradish peroxidase-catalyzed oxidation of scopoletin, and the formation of hydroxyl radicals (OH.) was suggested by the formation of the OH. spin trap ad...

Direct electron spin resonance was used to detect tert-alkylperoxyl radicals generated by hematin and the corresponding hydroperoxides at near-physiological pH values. The spin-trapping method was necessary to detect the less persistent primary ethylperoxyl radical. Under a nitrogen atmosphere, the electron spin resonance signal of the tert-alkylperoxyl radicals decreased, and the ethylperoxyl ...

Human neutrophils generate oxygen reduction products as a consequence of membrane interactions with a number of stimuli. One oxygen-centered free radical (superoxide) has been unequivocally shown to result from this "respiratory burst," and some experimental evidence for another (hydroxyl radical) has been published, although debate remains as to its significance. The role of phagocyte-derived ...

Free radicals induce oxidative stress in vivo, leading to various disorders and diseases. In the present study, the effect of oxygen pressure on the cytotoxicity induced by free radicals was studied. It was found that alkyl radicals markedly aggravated Jurkat cell apoptosis under low oxygen pressure and this was ascribed to a hypoxic condition caused by the consumption of oxygen by alkyl radica...