Age-associated changes in protein oxidation and proteasome activities in rat brain: modulation by antioxidants.
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.
Abd El Mohsen
Manal M
MM
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
Iravani
Mahmoud M
MM
Spencer
Jeremy P E
JP
Rose
Sarah
S
Fahim
Atef T
AT
Motawi
Tarek M K
TM
Ismail
Nabila A F
NA
Jenner
Peter
P
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
D000975:Antioxidants; D003067:Coenzymes; D008062:Lipofuscin; D009419:Nerve Tissue Proteins; D014451:Ubiquinone; D046988:Proteasome Endopeptidase Complex; C024989:coenzyme Q10; D008550:Melatonin