Effect of leaf extract of Capparis zeylanica Linn. on spatial learning and memory in rats.

This study was designed to investigate the nootropic activity of Capparis zeylanica Linn. leaves in rats. The raw material of Capparis zeylanica leaves was successively extracted with petroleum ether and methanol using a Soxhlet apparatus and macerated to form an aqueous extract. The methanolic and aqueous extracts were evaluated for their effect on spatial learning and memory in rats using the Morris water maze task. Three doses (50, 100 and 150 mg/kg; p.o.) of methanolic and aqueous extracts of Capparis zeylanica were administered for 7 successive days to separate groups of animals. Results showed that both the extracts significantly enhanced memory, as shown by decrease in escape latency time. Furthermore, methanolic and aqueous extracts in all doses tested significantly increased the time spent in the target quadrant during the probe trial, indicating retention of spatial memory of the location of a previously placed platform in the target quadrant. These findings indicate that methanolic and aqueous extracts of Capparis zeylanica Linn. leaves have potent nootropic activity. The anti-oxidant property of Capparis zeylanica may contribute favorably to the memory enhancement effect. However, further studies are needed to identify the exact mechanism of action.