Annurca apple-rich diet restores long-term potentiation and induces behavioral modifications in aged rats

Abstract

The impairment of brain functions during aging could be prevented by an increase in antioxidative defenses. In fact, dietary manipulation with antioxidants or with antioxidant-rich extracts from vegetables and fruit can ameliorate age-associated behavioral alterations. Moreover, dietary supplements of antioxidants can reverse the age-dependent impairment to sustain long-term potentiation (LTP). There is evidence that fresh fruit could be more effective than antioxidant supplements or fruit and vegetable extracts but the effect of a diet enriched in fresh fruit on brain aging process has not been investigated until now. The aim of the present study was to verify whether dietary manipulation with fresh apples could influence age-induced changes in motor and emotional behavior and in LTP in rats. Groups of aged and young rats were fed with a standard diet or a diet supplemented with fresh apples of annurca variety for 10 weeks and assessed for behavioral performance in the open field and elevated plus maze tests and for the ability to sustain LTP. The brains were then removed, histochemically stained for superoxide dismutase (SOD) and SOD activity was measured by computer-assisted image analysis. The aged rats fed with the enriched diet showed a significant decrease in the anxiety level. Moreover, they improved in the ability to sustain LTP, reaching the level of the young rats. SOD activity was increased in the aged rats fed with the standard diet whereas SOD activity in the hippocampus of the aged rats treated with annurca apple was at the level of the young animals. These results suggest that a diet rich in annurca apple could have an important role in health-care during aging.