The intracellular levels of antioxidant and free radical scavenging
enzymes are gradually altered during the aging process. An agedependent increase of oxidative stress occurring throughout the
lifetime is hypothesized to be the major cause of aging. The
current study examined the effects of L-malate on oxidative
stress and antioxidative defenses in the liver and heart of aged
rats. Sprague-Dawley male rats were randomly divided into four
groups, each group consisting of 6 animals. Group Ia and Group
IIa were young and aged control rats. Group Ib and Group IIb
were young and aged rats treated with L-malate (210 mg/kg
body weight per day). L-malate was orally administrated via
intragastric canula for 30 days, then the rats were sacrificed and
the liver and heart were removed to determine the oxidant
production, lipid peroxidation and antioxidative defenses of
young and aged rats. Dietary L-malate reduced the accumulation
of reactive oxygen species (ROS) and significantly decreased the
level of lipid peroxidation in the liver and heart of the aged rats.
Accordingly, L-malate was found to enhance the antioxidative
defense system with an increased activity of antioxidant
enzymes, such as superoxide dismutase (SOD) and glutathione
peroxidase (GPx) and increased glutathione (GSH) levels in the
liver of aged rats, a phenomenon not observed in the heart of
aged rats. Our data indicate that oxidative stress was reversed
and the antioxidative defense system was strengthened by
dietary supplementation with L-malate.
Effect of buchu (Allium tuberosum) on lipid peroxidation and antioxidative defense system in streptozotocin-induced diabetic rats
