title: Decline in glutathione peroxidase activity is a reason for brain senescence: consumption of green tea catechin prevents the decline in its activity and protein oxidative damage in ageing mouse brain.
abstract: The accumulation of oxidative damage is believed to contribute to senescence. We have previously found that the consumption of green tea catechins (GT-catechin), which are potent antioxidants, decreases oxidative damage to DNA and improves brain function in aged mice with accelerated senescence (SAMP10 mice). To investigate the mechanisms underlying the beneficial effects of GT-catechin, we measured the activities of antioxidative enzymes in the brains of aged SAMP10 mice. The activity of glutathione peroxidase (GPx), an essential enzyme for reduction of hydrogen and lipid peroxides, was significantly lower in aged mice than in younger ones. However, the decline in activity was prevented in aged mice that had consumed GT-catechin. The increased level of carbonyl proteins, a marker of oxidative damage in proteins, was also significantly reduced in aged mice that had consumed GT-catechin. The activities of superoxide dismutase and catalase were not decreased in aged mice. These results suggest that decreased activity of GPx importantly contributes to brain dysfunction in ageing SAMP10 mice. Furthermore, the intake of GT-catechin protected the decline in GPx activity and age-related oxidative damage in the brain.
authors.affiliation: Department of Medical Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kishido
authors.forename: Keiko
authors.initials: K
authors.lastname: Unno
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Yoshida
authors.forename: Daisuke
authors.initials: D
authors.lastname: Choba
authors.forename: Rie
authors.initials: R
authors.lastname: Fukutomi
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Asahina
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Iguchi
authors.forename: Naoto
authors.initials: N
authors.lastname: Oku
authors.forename: Minoru
authors.initials: M
authors.lastname: Hoshino
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D028241:Camellia sinensis / Q000737:chemistry; D002392:Catechin / Q000302:isolation & purification / Q000494:pharmacology*; D016922:Cellular Senescence / Q000187:drug effects*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D015536:Down-Regulation; D005979:Glutathione Peroxidase / Q000378:metabolism*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D018384:Oxidative Stress / Q000187:drug effects*; D050050:Protein Carbonylation / Q000187:drug effects; D011506:Proteins / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D011506:Proteins; D002392:Catechin; D005979:Glutathione Peroxidase