Aging, Exercise and Photochemicals: Promises and Pitfalls
Li Li Ji
Biodynamics Laboratory, 2000 Observatory Drive, Madison, WI 53706, USA
Reactive oxygen species (ROS) generation has an important implication
in the etiology of many diseases and in aging. Furthermore, strenuous
physical exercise has been shown to increase oxidative stress to
skeletal muscle and myocardium due to increased ROS generation. In
order to optimize exercise benefits in the elderly whereas to prevent
oxidative damage, we seek novel antioxidant protection, via dietary
supplementation of phytochemicals in vegetables, fruits, grains, herbs
and other natural sources. In one of our recent study, chronic dietary
supplementation of North American ginseng (Panax Quinquefolium) was
found to decrease ROS generation measured by dichlorofluorescin in
several tissues of young and aged rats and attenuated age-related
protein oxidative measured by reactive carbonyl derivatives. These
changes were partially explained by the increases in endogenous
antioxidant enzyme superoxide dismutase (SOD) and glutathione
peroxidase (GPX) activities due to ginseng supplementation. In another
study, we showed that dietary supplementation of a novel synthetic oat
antioxidant, avenathramides, for 50 days in rats attenuated
exercise-induced increase in ROS production in muscle and lipid
peroxidation in the heart, while increasing SOD and GPX activities in
these tissues. These studies are among a wide branch of literature
showing the potential of dietary phytochemical antioxidant supplement
to counteract oxidative stress due to aging and heavy exercise.
However, many controversies still exist. Future studies should explore
cellular and molecular mechanisms underlying the demonstrated
antioxidant effects, their protection against specific
pathophysiological conditions including aging, as well as novel ways to
incorporate them into food and beverage.
Key words:
antioxidant, aging, exercise, oxidative damage, phytochemical
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