The use of antioxidants to prevent intracellular free radical damage is an area currently attracting considerable research interest. The compound 2',7'-dichlorofluorescin diacetate (DCFH-DA) is a probe for intracellular peroxide formation commonly used in such studies. During our studies we unexpectedly found that incubation of Trolox, a water soluble vitamin E analog, with DCFH-DA in cell-free...

10260_0113_TTN080 Curcumin is also a potent antioxidant, able to neutralize unstable, reactive free radicals. Free radicals are molecules with a missing electron that stabilize themselves by “stealing” electrons from neighboring molecules, creating another free radical in the process. This chain reaction of free radical formation is known as a free radical cascade, and it can result in cellular...

Phenolphthalein, a widely used laxative, is the active ingredient in more than a dozen commercial nonprescription formulations. Fast-flow EPR studies of the reaction of phenolphthalein with horseradish peroxidase (HRP) and hydrogen peroxide permit the direct detection of two free radicals. One has EPR parameters characteristic of phenoxyl radicals. The other has a broad unresolved spectrum, pos...

The OH initiated oxidation of 1,3,5-trimethylbenzene (1,3,5-TMB) under NOx-free conditions has been investigated by using a home-made vacuum ultraviolet (VUV) photoionization aerosol mass spectrometer complemented high-level theoretical computations. chemical composition the nascent particles from reaction is measured on-line and high O2-bridged bicyclic compounds in particle phase are directly...

Alterations in liver mitochondria as consequence of rat poisoning with carbon tetrachloride (CCl4) have been reported over many years, but the mechanisms responsible for causing such damage are still largely unknown. Isolated rat liver mitochondria incubated under hypoxic conditions with succinate and ADP were found able to activate CCl4 to a free-radical species identified as trichloromethyl f...

The highly active, quinone-containing anticancer drugs, Adriamycin, daunorubicin, carminomycin, rubidazone, nogalamycin, aclacinomycin A, and steffimycin (benzanthraquinones); mitomycin C and streptonigrin (/V-heterocyclic quiñones);and lapacho! (naphthoquinone) interact with mammalian microsomes and function as free radical carriers. These quinone drugs augment the flow of elec trons from red...

The expression of regucalcin, a regulatory protein in the intracellular signaling system, in the hearts of rats was investigated. Regucalcin expression was examined using reverse transcription-polymerase chain reaction and Western blot analysis. Regucalcin mRNA and its protein levels in the hearts of male and female rats were significantly decreased with increasing age (50 weeks old) as compare...

The crossed molecular beam reactions of the meta-tolyl radical with 1,3-butadiene and D6-1,3-butadiene were conducted at collision energies of 48.5 kJ mol(-1) and 51.7 kJ mol(-1). The reaction dynamics propose a complex-forming reaction mechanism via addition of the meta-tolyl radical with its radical center either to the C1 or C2 carbon atom of the 1,3-butadiene reactant forming two distinct i...

Lipid peroxidation (LPO) in cellular membranes is associated with changes in physicochemical properties and impairment of protein functions located in membrane environment. Recent studies shows involvement of LPO in biological signaling and various diseases. Lipids are oxidized by three distinct mechanisms: enzymatic oxidation; non-enzymatic, free radical-mediated oxidation and non-enzymatic, n...