Melatonin and structurally-related compounds protect synaptosomal membranes from free radical damage.
Since biological membranes are composed of lipids and proteins we tested the in vitro antioxidant properties of several indoleamines from the tryptophan metabolic pathway in the pineal gland against oxidative damage to lipids and proteins of synaptosomes isolated from the rat brain. Free radicals were generated by incubation with 0.1 mM FeCl(3), and 0.1 mM ascorbic acid. Levels of malondialdehyde (MDA) plus 4-hydroxyalkenal (4-HDA), and carbonyl content in the proteins were measured as indices of oxidative damage to lipids and proteins, respectively. Pinoline was the most powerful antioxidant evaluated, with melatonin, N-acetylserotonin, 5-hydroxytryptophan, 5-methoxytryptamine, 5-methoxytryptophol, and tryptoline also acting as antioxidants.
Millán-Plano
Sergio
S
Department of Pharmacology and Physiology, University of Zaragoza, Spain. tarodmaul@hotmail.com
Piedrafita
Eduardo
E
Miana-Mena
Francisco J
FJ
Fuentes-Broto
Lorena
L
Martínez-Ballarín
Enrique
E
López-Pingarrón
Laura
L
Sáenz
María A
MA
García
Joaquín J
JJ
D006916:5-Hydroxytryptophan / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D002243:Carbolines / Q000378:metabolism; D005609:Free Radicals / Q000633:toxicity*; D007425:Intracellular Membranes / Q000187:drug effects* / Q000378:metabolism; D007700:Kinetics; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology*; D018696:Neuroprotective Agents / Q000737:chemistry / Q000494:pharmacology*; D010084:Oxidation-Reduction / Q000187:drug effects; D051381:Rats; D013574:Synaptosomes / Q000187:drug effects* / Q000378:metabolism; D014364:Tryptophan / Q000378:metabolism
D000975:Antioxidants; D002243:Carbolines; D005609:Free Radicals; D018696:Neuroprotective Agents; D014364:Tryptophan; D006916:5-Hydroxytryptophan; D008550:Melatonin