Anxiolytic-like effects of ginsenosides on the elevated plus-maze model in mice

In a previous study, we reported that ginseng extract has anxiolytic-like effects in the elevated plus-maze model and that the ginseng saponin fraction plays an important role. This experiment was performed to investigate the anxiolytic-like effects of ginsenosides Rb-1, Rg(1), Rg(3)-R, and Rg(3)-S, and the Rg(5) and Rk mixture isolated from the ginseng saponin fraction in the elevated plus-maze. Furthermore, the anxiolytic-effects of Rb-1, Rg(1), Rg(3)-R, Rg(3)-S, and the Rg(5) and Rk mixture were compared with those of a well-known active anxiolytic drug (diazepam). The oral administration of ginsenoside Rb-1 significantly increased the number of open arm entries and the time spent on the open arm compared with those in the vehicle-treated group. Ginsenoside Rg(1) and the Rg(5) and Rk mixture also significantly increased the number of open arm entries and the time spent on the open arm. However, ginsenosides Rg(3)-R and Rg(3)-S did not increase the number of open arm entries or the time spent on the open arm. On the other hand, ginsenoside Rb-1 and the Rg(5) and Rk mixture decreased locomotor activity in a manner similar to diazepam. These data indicate that ginsenosides Rb-1, Rg(1), and the Rg(5) and Rk mixture have anxiolytic-like effects, but ginsenosides Rg(3)-R and Rg(3)-S do not in this model. We provide evidence that some ginsenosides may be useful for the treatment of anxiety.