A diet enriched in α-lipoic acid reverses the age-related compromise in antioxidant defences in rat cortical tissue

In this study we set out to establish whether age-related changes in reactive oxygen species production in cortical tissue might be modulated by a diet enriched in the proposed antioxidant, alpha -lipoic acid. Twenty-two month-old and 4 month-old rats were fed on control diet or alpha -lipoic acid-enriched diet for 2 months. We report that cortical tissue prepared from rats fed on control diet revealed an age-related increase in reactive oxygen species production, which was accompanied by an increase in activity of superoxide dismutase activity and decreases in activities of glutathione peroxidase and catalase. These changes were attenuated in rats fed on the experimental diet. There was an age-related increase in the concentration of interleukin-1 beta (IL-1 beta), which was reversed by dietary manipulation. IL-1 beta increased reactive oxygen species production in vitro, suggesting that it may also exert this effect in vivo. We observed an age-related increase in lipid peroxidation accompanied by a decrease in arachidonic acid concentration and suggest that these changes are a consequence of increased reactive oxygen species production. Dietary manipulation with alpha -lipoic acid reverses the age-related changes in activities of superoxide dismutase, catalase and glutathione peroxidase and accumulation of reactive oxygen species production adding support to the hypothesis that alpha -lipoic acid exerts antioxidant effects.