Dietary strawberry supplementation protects against the age- accelerated CNS effects of oxidative stress

Increase in oxidative stress (OS) vulnerability have boon postulated as a causative factor in CNS functional declines in aging and age-related neurode-generative diseases. Exposure of rats to 100% O₂ (48 hrs) produces declines in several parameters that parallel changes in aging: 1) oxotremorine enhanced dopamine release (ox-K⁺-ERDA, 2) cerebellar β receptor augmentation of γ-amino butyric acid responding (CβAR) and 3) nerve growth factor (NGF) levels. Present studies examined the protective effects of diets high in antioxidants on these parameters. Control diets or those supplemented with strawberry extracts (SE) (9.4 g/kg dried aqueous extract) or Vitamin E (500 JU/kg) were fed to 6-8 mo old F344 rats for 8 weeks prior to oxygen exposure. SE (but not Vit E) rats demonstrated significant protection against O₂-induced deficits in all three parameters. For example, only 20% of the cerebellar cells in control, oxygen-exposed animals showed βAR while 78% of the cells in the strawberry fed O₂-exposed animais exhibited CβAR. SE also prevented O₂-induced declines in NGF levels and ox-K⁺-ERDA (e.g., ox-K⁺-ERDA, 75% decrease w/control diet; 15% W/SE). Thus, phytochemicals present in antioxidant rich foods, like strawberries, may be beneficial in reducing or retarding the functional CNS deficits seen in aging.