Effects of Acetone Extract of <i>Cola nitida</i> on memory and brain glutamate receptors in female Wistar rats

Abstract

Cola nitida is the seed of the Kola tree which is commonly grown in the tropical rainforest of Africa. It has been in vogue use for its caffeine and many other beneficial contents such as the obromine. This study aims to investigate the effects of acetone extract of Cola nitida on memory, plasma aspartate aminotransferase activity and metabotropic glutamate receptor 1a in female Wistar rats. 
Fifteen female Wistar rats were used and grouped into three. Control was given 1.2ml normal saline, low dose group was administered 50mg/kg body weight (bw) of Cola nitida extract and high dose group was administered 100mg/kg bw. Memory and cognition tests were evaluated using Morris water maze, Y-maze and using novel object recognition test. Plasma lactate dehydrogenase and aspartate amino transferase levels were estimated and immunohistochemical analysis of the hippocampus and amygdala was observed. 
There was significant (p<0.05) decrease in duration to get the escape platform in high dose group compared to control in the Morris water maze test. Also, there was a significant (p<0.05) increase in aspartate aminotrannsferase level in the group administered low dose of the extract of Cola nitida. Avivid stimulation of the glutamate receptors was observed following immunohistochemical analysis. 
In conclusion, Cola nitida enhance memory in female Wistar rats through the stimulation of glutamate receptors and increase in plasma aspartate glutamate receptors and increase in plasma aspartate aminotrannsferase level.