Hazelnut Modulates Neurobehaviour and Ameliorates Ageing-induced Oxidative Stress, and Caspase-3-Mediated Apoptosis in Mice

Background: Organismal aging has been associated with deleterious effects in different body tissues and organs, including the brain. There have been reports from ancient medicinal scripts of the beneficial effects of nuts like hazelnut in preventing aging induced-brain atrophy and memory loss. Objectives: This study examined the potential beneficial effects of a diet supplemented with two different (Italian and Turkish) cultivars of hazelnut on the brain of aged mice. Methods: Aged (24 months old) mice were randomly assigned into 7 groups of ten mice each. Mice were grouped as standard diet (SD) control, three groups of Turkish and three groups of Italian hazelnut incorporated into SD at 2, 4 and 8% respectively. Animals were fed standard or hazelnut diet for 8 weeks. On day 56, behaviours in the elevated plus maze, radial-arm maze, open field, and Y-maze paradigms were monitored and scored, following which animals were euthanized. The brains were removed, weighed and homogenized for the assessment of specific biochemical tests. Result: Results showed that hazelnut-supplemented diet was associated with significantly increased weight gain, with the Italian hazelnut being associated with greater weight gain. The hazelnut- supplemented diet also increased behavioural parameters such as horizontal locomotion and grooming, while it decreased rearing activity. Working-memory also improved significantly with both cultivars of hazelnut, while anxiety indices were reduced at lower concentrations of Italian, and higher concentrations of Turkish hazelnut. Both hazelnut varieties were associated with a reduction in acetylcholinesterase activity, superoxide dismutase activity, nitric oxide levels, caspase- 3 level, but increased dopamine level. Conclusion: Overall, hazelnut cultivars have beneficial effects on the brain in aged mice; suggesting a possible role in the prevention or management of age-related neurodegenerative changes.