Free RadicalsSuperoxidesSuperoxide DismutaseFree Radical ScavengersHydroxyl RadicalElectron Spin Resonance SpectroscopyAntioxidantsOxidative StressCatalaseOxidation-ReductionHydrogen PeroxideReactive Oxygen SpeciesXanthine OxidaseLipid PeroxidationPicratesHydroxidesCyclic N-OxidesNitrogen OxidesSpin LabelsOxygenSpin TrappingMalondialdehydeNADPH OxidaseAscorbic AcidLipid PeroxidesGlutathione PeroxidaseNitric OxideGlutathioneParaquatOxidantsPlant ExtractsXanthineBiphenyl CompoundsCopperIronThiobarbituric Acid Reactive SubstancesNeutrophilsKineticsDeferoxamineDitiocarbVitamin ERats, WistarPeroxynitrous AcidAntipyrineLuminescent MeasurementsMitochondria