Aging is defined as an extremely complex biological process
associated with a progressive functional decline in the performance
of most organs. Nearly all organisms manifest functional
declines as a result of aging. One current explanation
for aging is oxidative stress, which increases the production
of reactive oxygen species (ROS). Lipid peroxidation and oxidant-
related reactions occur that result in oxidative damage
(Golden & Melov, 2001). The brain is highly susceptible to
age-related oxidative damage because it consumes a large
amount of oxygen and generates a profusion of free radicals
during the aging process. The intracellular antioxidant
enzymes are effortlessly inactivated by lipid peroxides or
ROS, which results in decreased activities of these enzymes
and oxidative damage with age and in various age-related diseases
in the brain, such as Alzheimer’s disease and Parkinson’s
disease (Halliwell, 1997). Therefore, the general
strategy for prevention of brain age-related oxidative damage
includes reducing the production of reactive metabolites
using antioxidants. Antioxidants appear to act against brain
diseases by raising the levels of endogenous defences