摘要：Attention was paid to Panax ginseng C. A. MEYER which plays an important role in Oriental medicine. Some pharmacological experiments were carried out with pure saponins [ginsenoside (GS)-Rb1, Rb2, Rc, Re and Rg1] isolated from the Panax ginseng root, a mixture of ginseng saponins [ginsenoside mixture B (GMB) obtained from the lateral root (Hakumo) and crude ginsenoside K (GSK) obtained from the main root (Hakusan)], and prosapogenins (PSG), partial hydrolyzates of Rb1, Rb2, Rc and Rd [20R-PSG, 20S-PSG and Δ20-PSG], by using specific repeatedly cold stressed (SART stressed) mice and in restraint and water immersion-stressed (RWIS) mice. A single i.p. administration of 10 mg/kg of GS or PSG gave no influence on pentobarbital-induced sleeping in non-stressed mice. The inhibition of a natural increase in body weight in SART stressed mice was markedly counteracted by administration with a daily dose of 2.5 mg/kg of Rb1, Rc, Re, 20S-PSG or GSK for 5 consecutive days during SART stressing. A single i.p. administration of 10 mg/kg of Rb2, Rc, Re, 20R-PSG or 20S-PSG increased the analgesic index by the modified Randall-Selitto method, and that of 20R-PSG or 20S-PSG decreased the writhing syndrome by the method of acetic acid in non-stressed mice. When SART stressed mice were used as test animals in place of non-stressed mice, the analgesic effect was further augmented. Prolonged actions were observed in SART stressed mice administered daily with 5-10 mg/kg of Rb2, Rc, Re, 20R-PSG or 20S-PSG. When analgesic effect was tested 60 min after the last administration by the modified method of Randall-Selitto, almost the same effect as the single administration was obtained. The inhibitory effect on acetic acid writhing of Rb1, Rb2, Re, Δ20-PSG, and GMB, which was ineffective by a single administration, in addition to Rg1, 20R-PSG and 20S-PSG, was observed. The decrease in ACh response of the isolated SART stressed mouse duodenum was inhibited by daily administration of Rb1, Rb2, Rc, Re, 20S-PSG, GMB, and GSK. The increase in ACh response of the isolated RWIS mouse duodenum was inhibited by three pretreatments with Rb1, Re, Rg1, 20S-PSG and GMB, but not with Rb2, Rc, or GSK. These findings suggest that the effects of ginseng saponins may be different from those of Saikosaponins reported previously. The former compounds have a weak analgesic action, and may improve some symptoms of vegetative stigmatism caused by SART stress and RWIS. The classification of GS and PSG based on their actions was attempted.
