title: Age-associated changes in protein oxidation and proteasome activities in rat brain: modulation by antioxidants.
abstract: The free radical theory of ageing postulates that age-associated neurodegeneration is caused by an imbalance between pro-oxidants and antioxidants resulting in oxidative stress. The current study showed regional variation in brain susceptibility to age-associated oxidative stress as shown by increased lipofuscin deposition and protein carbonyl levels in male rats of age 15-16 months compared to control ones (3-5 months). The hippocampus is the area most vulnerable to change compared to the cortex and cerebellum. However, proteasomal enzyme activity was not affected by age in any of the brain regions studied. Treatment with melatonin or coenzyme Q10 for 4 weeks reduced the lipofuscin content of the hippocampus and carbonyl level. However, both melatonin and coenzyme Q10 treatments inhibited beta-glutamyl peptide hydrolase activity. This suggests that these molecules can alter proteasome function independently of their antioxidant actions.
authors.affiliation: Molecular Nutrition Group, School of Food Biosciences, University of Reading, P.O. Box 226, Whiteknights, Reading RG6 6AP, UK. m.m.a.e.mostafa@reading.ac.uk
authors.forename: Manal M
authors.initials: MM
authors.lastname: Abd El Mohsen
authors.forename: Mahmoud M
authors.initials: MM
authors.lastname: Iravani
authors.forename: Jeremy P E
authors.initials: JP
authors.lastname: Spencer
authors.forename: Sarah
authors.initials: S
authors.lastname: Rose
authors.forename: Atef T
authors.initials: AT
authors.lastname: Fahim
authors.forename: Tarek M K
authors.initials: TM
authors.lastname: Motawi
authors.forename: Nabila A F
authors.initials: NA
authors.lastname: Ismail
authors.forename: Peter
authors.initials: P
authors.lastname: Jenner
mesh_terms: D000375:Aging / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D003067:Coenzymes; D004789:Enzyme Activation / Q000187:drug effects; D008062:Lipofuscin / Q000378:metabolism*; D008297:Male; D008550:Melatonin / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D046988:Proteasome Endopeptidase Complex / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution; D014451:Ubiquinone / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D003067:Coenzymes; D008062:Lipofuscin; D009419:Nerve Tissue Proteins; D014451:Ubiquinone; D046988:Proteasome Endopeptidase Complex; C024989:coenzyme Q10; D008550:Melatonin