title: Enhanced anti-oxidant protection of liver membranes in long-lived rats fed on a coenzyme Q10-supplemented diet.
abstract: Coenzyme Q10 supplementation increases life-span of rats fed on a diet enriched with polyunsaturated fatty acids (Quiles, J.L., Ochoa, J.J., Huertas, J.R., Mataix, J., 2004b. Coenzyme Q supplementation protects from age-related DNA double-strand breaks and increased lifespan in rats fed on a PUFA-rich diet. Exp. Gerontol. 39, 189-194). Our study was set as a first attempt to establish a mechanistic link between life span extension and CoQ10 supplementation. When rats were fed on a PUFAn-6 plus CoQ10 diet, levels of CoQ10 were increased in plasma membrane at every time point compared to control rats fed on a PUFAn-6-alone diet. Ratios of CoQ9 to CoQ10 were significantly lower at every time point in both liver plasma membranes and homogenates of CoQ10-supplemented animals. CoQ10 supplementation did not affect cytosolic NAD(P)H:quinone oxidoreductase 1 (NQO1), which increased significantly with aging, but plasma membrane-bound NQO1 decreased significantly in the CoQ10-supplemented group at 12 months, when maximal incorporation of exogenous CoQ10 was observed. Neither aging nor the diet affected NADH-cytochrome b5 reductase levels. Glutathione-dependent anti-oxidant activities such as cytosolic glutathione-S-transferase (GST) and microsomal Se-independent glutathione peroxidase decreased with aging and supplementation with CoQ10 attenuated this decay. 2,2' Azobis amidinopropane (AAPH)-induced oxidation of membranes was significantly higher in aged rats, and supplementation with CoQ10 also inhibited this increase. Consistent with higher CoQ10 levels and enhanced anti-oxidant protection, plasma membrane Mg2+-dependent neutral sphingomyelinase was inhibited by dietary CoQ10 in aged rats. Our results support the involvement of thiol-dependent mechanisms in the potentiation of the anti-oxidant capacity of membranes in CoQ10-supplemented rats, further supporting the potentially beneficial anti-oxidative role of dietary CoQ10 during aging. The possibility that a decreased CoQ9/CoQ10 ratio in animals fed on the PUFAn-6-rich plus CoQ10 diet could also influence longevity is also discussed.
authors.affiliation: Departamento de Biología Celular, Fisiología e Inmunología, Facultad de Ciencias, Universidad de Córdoba, Campus Rabanales, Edificio Severo Ochoa, 3a planta; 14014 Córdoba, Spain.
authors.forename: Rosario I
authors.initials: RI
authors.lastname: Bello
authors.forename: Consuelo
authors.initials: C
authors.lastname: Gómez-Díaz
authors.forename: María I
authors.initials: MI
authors.lastname: Burón
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Alcaín
authors.forename: Plácido
authors.initials: P
authors.lastname: Navas
authors.forename: José M
authors.initials: JM
authors.lastname: Villalba
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003067:Coenzymes; D019587:Dietary Supplements; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage*; D005982:Glutathione Transferase / Q000378:metabolism; D015227:Lipid Peroxidation; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008136:Longevity; D008297:Male; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism; D018384:Oxidative Stress; D051381:Rats; D017208:Rats, Wistar; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism; D014451:Ubiquinone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D003067:Coenzymes; D043371:Fatty Acids, Omega-6; D014451:Ubiquinone; D016660:NAD(P)H Dehydrogenase (Quinone); D005982:Glutathione Transferase; C107180:Smpd3 protein, rat; D013108:Sphingomyelin Phosphodiesterase; C024989:coenzyme Q10; C030571:ubiquinone 9