Effects of ginsenosides on impaired performance caused by scopolamine in rats

The effects of five structurally different ginsenosides on the performance impaired by scopolamine in rats were studied in a radial-arm maze. Ginsenoside Re had an ameliorating effect, but the ginsenosides, 20-O-glucosyl-protopanaxadiol, F2, Rf, and Rh1, did not. We reported previously that ginsenoside Rg1 had an ameliorating effect but that ginsenosides Rb1 and Rd did not (Yamaguchi et al., 1995, Psychoneuroendocrinology 20, 645). The sugar moieties at C(6) and C(20), which are possessed by Re and Rg1, seem to be indispensable for an ameliorating effect on the performance impaired by scopolamine.