Improved psychomotor performance in aged mice fed diet high in antioxidants is associated with reduced ex vivo brain interleukin-6 production

Psychomotor performance is decreased in the aged. This study investigated the relationship between brain oxidative stress, interleukin-6 (IL-6) production by brain tissue ex vivo and psychomotor deficits during aging, and the effects of feeding an antioxidant-rich diet on ex vivo brain IL-6 production and motor function in aged mice. Male BALBc mice reared in SPF conditions and ranging in age from 3 to 24 months were studied. There was a precipitous decline in motor function after 12 months of age and an increase in brain lipid peroxidation and IL-6 production by coronal brain slices ex vivo. In another study, 12-month-old mice were fed diets formulated to provide a disparate range of antioxidants. At 18 months of age psychomotor coordination, motor learning, and ex vivo brain IL-6 production were evaluated. Mice fed an antioxidant-rich diet had improved psychomotor coordination compared to mice fed diet adequate or low in antioxidants. When mice were tested on successive days, only those fed adequate and high antioxidants exhibited motor learning. Analysis of IL-6 production by coronal brain slices indicated that as dietary antioxidants increased, IL-6 production decreased. Collectively, these data indicate that antioxidants improve psychomotor performance in aged mice, and suggest antioxidants may be useful for reducing brain IL-6 production, which has been shown to increase in aged mice.