title: The effect of melatonin and structural analogues on the lipid peroxidation of triglycerides enriched in omega-3 polyunsaturated fatty acids.
abstract: The lipid peroxidation of triglycerides enriched in polyunsaturated fatty acids was investigated by photoemission techniques and the TBARS assay. Butylated hydroxytoluene, 5-OH-tryptophan and N-acetylserotonin inhibited light emission and TBARS formation in a concentration dependent manner. However, it was enhanced in the presence of melatonin and 5-methoxytryptamine and was dependent on its concentration. The total relative luminic units were found to be lower in those systems incubated in the presence of butylated hydroxytoluene, N-acetylserotonin or 5-OH-tryptophan; this decreased proportionally to the concentration of the compound tested. The order of inhibition was 5-OH-tryptophan>N-acetylserotonin>butylated hydroxytoluene with the following IC50 values: 0.65, 6.5 and 9.0 mM respectively. The free-radical scavenging activity of the indole derivatives was also analyzed by the DPPH method, and the results indicate that 5-OH-tryptophan, and N-acetylserotonin exhibited a dose-dependent free-radical scavenging ability at all of the tested concentrations. Thus, at 10 microM concentration a decrease of 84.71% and 73.50% of initial DPPH was observed, compared to 51.00% of BHT. Melatonin and 5-methoxytriptamine decreased the initial concentration of DPPH only 1.85% and 5.0%, respectively. The possible formation of N(1)-acetyl-N(2) formyl-5-methoxykynuramine (AFMK) during lipid peroxidation of triglycerides enriched in PUFAs with cumene hydroperoxide in the presence of melatonin was also analyzed.
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CONICET, Casilla de Correo 16, Sucursal 4, (1900) La Plata, Argentina.
authors.forename: Natalia
authors.initials: N
authors.lastname: Fagali
authors.forename: Angel
authors.initials: A
authors.lastname: Catalá
mesh_terms: D008735:5-Methoxytryptamine / Q000737:chemistry / Q000494:pharmacology; D001555:Benzene Derivatives / Q000737:chemistry; D001713:Biphenyl Compounds; D002084:Butylated Hydroxytoluene / Q000737:chemistry* / Q000494:pharmacology; D002474:Cell-Free System; D004281:Docosahexaenoic Acids / Q000737:chemistry; D015525:Fatty Acids, Omega-3 / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry; D007735:Kynuramine / Q000031:analogs & derivatives / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects*; D008055:Lipids / Q000737:chemistry; D008163:Luminescent Measurements; D008550:Melatonin / Q000737:chemistry / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010851:Picrates / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry; D012701:Serotonin / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D017392:Thiobarbituric Acid Reactive Substances / Q000737:chemistry; D014280:Triglycerides / Q000737:chemistry*; D014364:Tryptophan / Q000737:chemistry / Q000494:pharmacology
chemical_list: D001555:Benzene Derivatives; D001713:Biphenyl Compounds; D015525:Fatty Acids, Omega-3; D016166:Free Radical Scavengers; D008055:Lipids; D010851:Picrates; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D014280:Triglycerides; D002084:Butylated Hydroxytoluene; D004281:Docosahexaenoic Acids; D012701:Serotonin; D007735:Kynuramine; D008735:5-Methoxytryptamine; C041550:N-acetyl-N-formyl-5-methoxykynurenamine; D014364:Tryptophan; C004931:1,1-diphenyl-2-picrylhydrazyl; D008550:Melatonin; C006389:N-acetylserotonin; C007164:cumene hydroperoxide