摘要：The pharmacological actions of 7 pure Saikosaponins (a, b1, b2, b3, b4, c and d), the components of Saiko, which plays an important role in Oriental medicine, were studied with special attention to the analgesic effect in repeated cold stressed (SART stressed) mice. Single administration of 10 mg/kg of Saikosaponin (SS) in normal mice gave no analgesic effect, but the analgesic effect of b2 and c was great in SART stressed mice, and some analgesic effect was noted with a, b1, and b3 in SART stressed mice. Administration of 5 mg/kg/day of SS for 5 days in SART stressed mice gave an intense analgesic effect with b2 and c, and similar administration of a, b1, b3 and b4 also gave some analgesic effect. The inhibition of the body weight increase in SART stressed mice was counteracted in a dose-dependent manner by administration of 2.5-10 mg/kg/day of SSb2 and c for 5 consecutive days, but similar administration of d augmented the inhibition of body weight. The effect of administration of 5 mg/kg/day of SS for 5 days on the decrease of ACh-response in isolated duodenum from SART stressed mice, which were considered to be in partial vagotonia in small intestine, was studied. While c, b1, b2, b3, a and b4 were inhibitory, d was entirely ineffective. The effect of administration of SS on the increase of the ACh-response in isolated duodenum from mice stressed by restraint and water immersion, which were considered to be in partial sympathicotonia in small intestine, was also studied. An inhibitory effect was seen with d, which had been without effect in the specimen from SART stressed mice, while no effect of b2, c and a was noted, despite the positive effect in SART stressed mice. Three kinds of SS effects were distinguished, a central stimulating effect, a central inhibitory effect and a negative effect, based on the hypnotic effect on combined use with pentobarbital, result of measurement of motor activities in open field test in normal mice and experiment on electric resistance of the skin by GSR in SART stressed rats. According to the above results, particularly effects on the change of ACh-response in isolated duodenum, a classification of the action of SS was attempted.
