Relationship between antioxidants, lipid peroxidation and aging.
Experiments performed on species as different as flies, rats and frogs are not conclusive about the possibility that antioxidant defenses decrease in old animals. Even when these decreases are found, their physiological meaning is far from clear. Furthermore, a constancy of antioxidant capacity in old age is consistent with the fact that aging is a progressive phenomenon which occurs at a rather constant rate from the mature young to the very old animal, without showing a great acceleration rate in the aged. Nevertheless, experimental results strongly suggest that the maintenance of an appropriate antioxidant/prooxidant balance does have an important role in maintaining health in the aging animal. It is possible that the continuous presence of small amounts of free radicals in the adult tissues of both mature adults and old animals is an important factor in aging (a progressive phenomenon) and susceptibility to disease. Since, similarly to what occurs in procariota, the whole antioxidant system seems to be under homeostatic control in vertebrates, it is imperative to perform comprehensive and detailed studies on the effects of carefully controlled doses of antioxidants on biomarkers of health as well as on the different endogenous cellular antioxidant and prooxidant systems. These studies should have as a final goal the knowledge of which doses of antioxidants are high enough to increase antioxidant protection but low enough to avoid feedback depression of other endogenous antioxidants; this could further improve the health state of humans situated in the middle and last phases of their life span.
Barja de Quiroga
G
G
Departamento de Biología Animal-II (Fisiología Animal), Facultad de Biología, Universidad Complutense, Madrid, Spain.
López-Torres
M
M
Pérez-Campo
R
R
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001921:Brain / Q000254:growth & development / Q000378:metabolism; D006793:Houseflies / Q000254:growth & development; D006801:Humans; D015227:Lipid Peroxidation; D008099:Liver / Q000254:growth & development / Q000378:metabolism; D051381:Rats; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances