Effects of red ginseng saponins and nootropic drugs on impaired acquisition of ethanol-treated rats in passive avoidance performance

Effects of single and repeated administration of red ginseng total saponins (ROTS) and nootropic drugs were examined on impairment of acquisition indu ced by single oral administration of 3 g/kg ethanol (EtOH) in a step throug h test. The inhibitory effect of EtOH on acquisition was significantly redu ced following single or repeated RGTS administration. The nootropic drugs, piracetam and N-methyl-D-glucamine, given orally significantly reduced impa irment of acquisition induced by EtOH. On the other hand, the inhibitory ef fect of repeated RGTS on the EtOH-induced amnesia was blocked by the pretre atment of alpha-methyl-rho-tyrosine (alpha-MT), an inhibitor of catecholami ne synthesis, in a dose-dependent manner but not rho-chlorophenylalanine (P CPA), an inhibitor of serotonin synthesis, whereas the inhibitory effect of repeated N-methyl-D-glucamine on the EtOH-induced amnesia was blocked neit her by alpha-MT nor PCPA. These results suggest that repeated RGTS and N-me thyl-D-glucamine ameliorate the impairing effect of EtOH on acquisition, an d the effect of RGTS on EtOH-induced amnesia is dependent on the catecholam inergic but not serotonergic neuronal activity, while RGTS and N-methyl-D-g lucamine seem to have a different mechanism on EtOH-induced amnesia. (C) 20 00 Published by Elsevier Science Ireland Ltd. All rights reserved.