Treatment with Centalla asiatica (Linn) fresh leaf extract enhances learning ability and memory retention power in rats.

OBJECTIVE To investigate the role of Centella asiatica (CeA) fresh leaf extract treatment on the behavior, especially learning and memory, of adult rats. METHODS Adult rats (2.5 months old) were fed with 2, 4, and 6 ml/kg body of fresh leaf extract of CeA for 2, 4, and 6 weeks. After the treatment period the rats were subjected to spatial learning (T-Maze) and passive avoidance tests along with age matched normal and saline control rats. The data were compared with those of age matched control rats. The study was conducted at the Melaka Manipal Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India between December 2001 and February 2005. RESULTS The rats treated with a higher dose (6 ml) of CeA showed improvement in spatial learning performance, namely, increased (p<0.001) number of alternations and decreased (p<0.001) percentage bias during spontaneous alternation test and increased (p<0.001) percentage bias during rewarded alternation test. They also showed enhanced memory retention power, namely, less (p<0.001) time spent in the small compartment during the retention period of passive avoidance test. CONCLUSION This indicates that treatment with higher doses of CeA fresh leaf extract enhances learning ability and memory retention power in adult rats.