Evidence for nootropic effect of BR-16A (Mentat), a herbal psychotropic preparation, in mice.

BR-16A (Mentat 50-500 mg/kg) improved acquisition and retention of a passive avoidance task in a step-down paradigm in mice. BR-16A (50-500 mg/kg) reversed scopolamine (0.3 mg/kg)-induced disruption of acquisition and retention. BR 16-A (50 and 100 mg/kg) attenuated amnesia produced by the acute treatment with electroconvulsive shock (ECS), immediately after training. Chronic treatment with ECS, for 6 successive days at 24 h interval, disrupted memory consolidation on the 7th day. Daily administration of BR-16A (50 and 100 mg/kg) for 6 days significantly improved memory consolidation in mice receiving chronic ECS treatment. BR-16A (20-500 mg/kg), administered on the 7th day, also attenuated the disruption of memory consolidation produced by chronic treatment with ECS. On elevated plus-maze, BR-16A (50 and 100 mg/kg) reversed scopolamine (0.3 mg/kg)-induced delay in transfer latency on the 1st day. The above data suggests a nootropic effect of BR-16A in naive and amnesic mice.