title: Inhibition of lipid peroxidation and protein oxidation by endogenous and exogenous antioxidants in rat brain microsomes in vitro.
abstract: Reactive oxygen and reactive nitrogen species oxidize and nitrate DNA, lipid and proteins thus leading to neuronal death. Both endogenous and dietary antioxidants were shown to afford neuroprotection either by scavenging free radicals or inducing antioxidant enzymes. That said, the differential contribution of endogenous versus nutritional antioxidants to prevent neurodegeneration is still debated. In this study the free radical scavenging activity of two endogenous antioxidants, such as bilirubin and its precursor biliverdin, was compared with that of the dietary antioxidant alpha-tocopherol in rat brain microsomes exposed to peroxyl radical or peroxynitrite in vitro. Bilirubin and biliverdin (1-200 μM) inhibited both peroxyl radical- and peroxynitrite-dependent lipid peroxidation with a greater potency and efficacy than alpha-tocopherol. However, both BV and BR displayed greater potency and efficacy in preventing peroxynitrite- than peroxyl radical-induced lipid peroxidation. The greater antioxidant effect of both bilirubin and biliverdin than alpha-tocopherol was also confirmed against peroxyl radical- and peroxynitrite-induced protein oxidation. In conclusion, both bilirubin and biliverdin exhibited a greater antioxidant activity than alpha-tocopherol in preventing oxidative stress damage in rat brain.
authors.affiliation: Institute of Pharmacology, Catholic University School of Medicine, Largo F. Vito, 1, 00168 Rome, Italy. cmancuso@rm.unicatt.it
authors.forename: Cesare
authors.initials: C
authors.lastname: Mancuso
authors.forename: Eugenio
authors.initials: E
authors.lastname: Barone
authors.forename: Pina
authors.initials: P
authors.lastname: Guido
authors.forename: Fiorella
authors.initials: F
authors.lastname: Miceli
authors.forename: Fabio
authors.initials: F
authors.lastname: Di Domenico
authors.forename: Marzia
authors.initials: M
authors.lastname: Perluigi
authors.forename: Rosaria
authors.initials: R
authors.lastname: Santangelo
authors.forename: Paolo
authors.initials: P
authors.lastname: Preziosi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001663:Bilirubin / Q000494:pharmacology*; D001664:Biliverdine / Q000494:pharmacology; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D008861:Microsomes / Q000187:drug effects*; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D024502:alpha-Tocopherol / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D011506:Proteins; D024502:alpha-Tocopherol; D001664:Biliverdine; D001663:Bilirubin