ABSTRACT
Studies have shown that supplementation with berries rich in anthocyanins are effective in reducing oxidative stress associated with aging, and are beneficial in reversing age-related neuronal and behavioral changes. However, there are few reports on other biological activities of these polyphenols, such as genoprotective effects. The present experiments were performed to study the possible effects of 30-day administration of a lyophilized extract of Vaccinium ashei berries on cognitive performance using step-down inhibitory avoidance, open-field habituation and elevated plus-maze tasks, as well as on DNA damage in the hippocampus and cerebral cortex. The present study showed that the extract significantly enhanced long-term memory in the inhibitory avoidance task, induced an increase in the number of crossings during open-field habituation and had an anxiolytic effect in the elevated plus-maze task. Moreover, the extract reduced oxidative DNA damage in brain tissue in vitro. These results suggest that supplementation with V. ashei berries to mice improves performance on memory tasks and has a protective effect on DNA damage, possibly due to the antioxidant activity of polyphenols, including anthocyanins.
Subject(s)
Anthocyanins/pharmacology , Behavior, Animal/drug effects , Blueberry Plants , DNA Damage/drug effects , Fruit , Plant Extracts/pharmacology , Animals , Anti-Anxiety Agents/pharmacology , Avoidance Learning/drug effects , Cerebral Cortex/drug effects , Comet Assay , Habituation, Psychophysiologic/drug effects , Hippocampus/drug effects , Male , Maze Learning/drug effects , MiceABSTRACT
Epidemiological studies suggest that diets with a high intake of vegetables and fruits may reduce the incidence of degenerative disorders including Alzheimer's disease. Berries are some of the popular fruits consumed worldwide. They are considered to be rich in anthocyanin pigments, a group belonging to the flavonoids, a widespread class of phenolic compounds. Anthocyanins have notorious pharmacological properties, and have been used in humans for therapeutic purposes. The present experiments were performed to study the possible effects of prolonged administration of lyophilised Vaccinium berries (blueberry, bilberry) on cognitive performance using step-down inhibitory avoidance, open field, elevated plus-maze, and radial maze tasks. During this experiment the rats consumed approximately 3.2 mg kg(-1)day (oral), of the anthocyanins. The lyophilised berries were administered for 30 days before first training. The present study showed that lyophilised berries significantly enhanced short-term memory, but not long-term memory in the inhibitory avoidance task, and induced an increase in the number of crossings in the first exposure to the open field. However, treated rats did not present any improvement of memory retention in open field habituation. Additionally, prolonged treatment with lyophilised berries did not have any significant effects in the elevated plus-maze task. Another interesting finding was that lyophilised berries improved working memory in the radial maze, with significant differences observed during sessions 1-2 and 4, but did not alter reference memory in this task. These results suggest that lyophilised berries may be beneficial in the prevention of memory deficits, one of the symptoms related to AD, and corroborate previous findings showing that flavonoids present effects in several learning paradigms.
