Biomaterial Database

Scavenging effect of melatonin on hydroxyl radicals generated by alloxan. 2000

H J Brömme, and W Mörke, and D Peschke, and H Ebelt, and D Peschke

Institutes of Pathophysiology Analytic, Martin Luther University, Halle-Wittenberg, Germany.

Alloxan can act as a generator of reactive oxygen species (ROS) as long as sufficient suitable reducing agents (e.g. reduced glutathione) and oxygen are available. Using electron spin resonance-spectroscopy and the oxygen-centered spin trap DEPMPO, we demonstrate that hydroxyl radicals (OH.) are formed in vitro by alloxan in the presence of glutathione (GSH) and chelated divalent iron. Furthermore, peroxidation of polyunsaturated fatty acids from phosphatidylcholine-containing liposomes with concomitant formation of malondialdehyde (MDA) was used as a further indicator for a preceding OH. formation. Melatonin, the main secretory product of the pineal gland, is an effective scavenger of OH.. The 50%-inhibitor concentration (IC50-value) for melatonin to scavenge OH. generated from the alloxan/GSH-reaction in the presence of ferrous ions was 23 micromol/L. In contrast to the ability to effectively scavenge OH., the potential of melatonin to prevent lipid peroxidation is considerably less pronounced.

UI	MeSH Term	Description	Entries
D008081	Liposomes	Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.	Niosomes,Transferosomes,Ultradeformable Liposomes,Liposomes, Ultra-deformable,Liposome,Liposome, Ultra-deformable,Liposome, Ultradeformable,Liposomes, Ultra deformable,Liposomes, Ultradeformable,Niosome,Transferosome,Ultra-deformable Liposome,Ultra-deformable Liposomes,Ultradeformable Liposome
D008315	Malondialdehyde	The dialdehyde of malonic acid.	Malonaldehyde,Propanedial,Malonylaldehyde,Malonyldialdehyde,Sodium Malondialdehyde,Malondialdehyde, Sodium
D008550	Melatonin	A biogenic amine that is found in animals and plants. In mammals, melatonin is produced by the PINEAL GLAND. Its secretion increases in darkness and decreases during exposure to light. Melatonin is implicated in the regulation of SLEEP, mood, and REPRODUCTION. Melatonin is also an effective antioxidant.
D004578	Electron Spin Resonance Spectroscopy	A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.	ENDOR,Electron Nuclear Double Resonance,Electron Paramagnetic Resonance,Paramagnetic Resonance,Electron Spin Resonance,Paramagnetic Resonance, Electron,Resonance, Electron Paramagnetic,Resonance, Electron Spin,Resonance, Paramagnetic
D005231	Fatty Acids, Unsaturated	FATTY ACIDS in which the carbon chain contains one or more double or triple carbon-carbon bonds.	Fatty Acids, Polyunsaturated,Polyunsaturated Fatty Acid,Unsaturated Fatty Acid,Polyunsaturated Fatty Acids,Acid, Polyunsaturated Fatty,Acid, Unsaturated Fatty,Acids, Polyunsaturated Fatty,Acids, Unsaturated Fatty,Fatty Acid, Polyunsaturated,Fatty Acid, Unsaturated,Unsaturated Fatty Acids
D005978	Glutathione	A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.	Reduced Glutathione,gamma-L-Glu-L-Cys-Gly,gamma-L-Glutamyl-L-Cysteinylglycine,Glutathione, Reduced,gamma L Glu L Cys Gly,gamma L Glutamyl L Cysteinylglycine
D000496	Alloxan	Acidic compound formed by oxidation of URIC ACID. It is isolated as an efflorescent crystalline hydrate.
D015227	Lipid Peroxidation	Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor.	Lipid Peroxidations,Peroxidation, Lipid,Peroxidations, Lipid
D016166	Free Radical Scavengers	Substances that eliminate free radicals. Among other effects, they protect PANCREATIC ISLETS against damage by CYTOKINES and prevent myocardial and pulmonary REPERFUSION INJURY.	Free Radical Scavenger,Radical Scavenger, Free,Scavenger, Free Radical,Scavengers, Free Radical
D017382	Reactive Oxygen Species	Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of SIGNAL TRANSDUCTION and GENE EXPRESSION, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.	Active Oxygen Species,Oxygen Radical,Oxygen Radicals,Pro-Oxidant,Reactive Oxygen Intermediates,Active Oxygen,Oxygen Species, Reactive,Pro-Oxidants,Oxygen, Active,Pro Oxidant,Pro Oxidants,Radical, Oxygen