Effects of chlorogenic acid, ferulic acid, gallic аcid and quercetin on learning and memory in the two-way active avoidance task in young/healthy rats

Abstract

The phenolic acids chlorogenic (CA), ferulic (FA) and gallic (GA) and the flavonoid quercetin (Q) are polyphenols abundant in natural food sources. Polyphenols exhibit strong antioxidant properties. There are data that they cross the blood-brain barrier and accumulate in the brain. These substances are tested in different models of impaired memory. The aim of the present study was to investigate their effects on learning and memory processes in young/healthy rats. Male Wistar rats were treated in the course of 7, 14, 21 and 30 days. Control groups were treated with saline. The other 4 groups received CA, FA, GA or Q at an equal dose of 20 mg/kg. At the end of each period, learning and memory processes were evaluated using the two-way active avoidance task (shuttle box). The number of avoidances was recorded in two learning sessions on two consecutive days and in a retention test 24 h after the 2nd training session. Administered for 7 days, the experimental substances had no significant effects on rat behavior. Applied for 14 days, GA and Q significantly increased the number of avoidances in both training sessions and on the retention test. After 21 and 30 days of treatment all tested polyphenols significantly improved the recorded indices of memory. The onset of the effect after 14/21 days of treatment may be explained by the accumulation of polyphenols in the brain following a long-term consumption. Our results suggest that CA, FA, GA and Q, applied subchronically, improve memory and cognition of young/healthy rats.