Effects of extract from Rhapontcum carthamoides (Willd) Iljin (Leuzea) on learning and memory in rats.

The effects of extract from Rhaponticum carthamoides (Willd) Ijin (Leuzea) on the processes of learning and memory in rats were investigated. R. carthamoides was administered orally in doses of 0.25, 0.5 and 2.5 g/kg body weight for 10 days prior to the training session. Using the maze-training method of active avoidance with punitive reinforcement, R. carthamoides improved the learning and memory indices to one degree or another depending on the dose applied. Using the "staircase-maze" method of training with food reinforcement, the low dose of R. carthamoides had no effect, while the high dose deteriorated learning. Using the method of step-through passive avoidance with punitive reinforcement, all three doses of R. carthamoides did not affect substantially the memory indices. R. carthamoides in a dose of 0.5 g/kg, administered orally for 10 days prior to the training, completely eliminated the scopolamine-induced memory impairment.