Nootropic activity of Albizzia lebbeck in mice.

The effect of saponin containing n-butanolic fraction (BF) extracted from dried leaves of Albizzia lebbeck on learning and memory was studied in albino mice using passive shock avoidance paradigm and the elevated plus maze. Significant improvement was observed in the retention ability of the normal and amnesic mice as compared to their respective controls. We have also studied the effects of BF on the behavior influenced by serotonin (5-HT), noradrenaline and dopamine. The brain levels of serotonin, gamma-aminobutyric acid (GABA) and dopamine were also estimated to correlate the behavior with neurotransmitter levels. The brain concentrations of GABA and dopamine were decreased, whereas the 5-HT level was increased. The data indicate the involvement of monoamine neurotransmitters in the nootropic action of BF of A. lebbeck.