《中国药典》3种百部的止咳作用比较

目的:比较<中国药典>收载的对叶百部、直立百部、蔓生百部3种百部药材的止咳作用强弱.方法:采用小鼠氨水引咳法,以可待因作为阳性对照药,比较研究了3种百部(包括对叶百部3种化学类型)的水煎液、总生物碱和非生物碱提取物,以及各3个产地和2种百部炮制品的止咳作用,观察2 min内小鼠咳嗽次数.结果:3种百部的水煎液、总生物碱和非生物碱提取物均有止咳作用,且前两者有显著的剂量依赖性;ED_(50)值显示水煎液和总生物碱提取物止咳强度均为:对叶百部(Ⅰ型)＞直立百部＞蔓生百部;总生物碱提取物止咳作用强于水煎液和非生物碱提取物;对叶百部的3种不同化学类型止咳作用强弱为:对叶百部Ⅰ型＞对叶百部Ⅲ型＞对叶百部Ⅱ型;不同产地的同种药材间的止咳作用没有显著性差异,表明3种百部止咳作用强弱不受产地影响;蜜百部止咳作用强于百部片.结论:百部药材种内和种间的化学成分多样性、不同极性部位及炮制方法对其止咳作用均有影响.

Antitussive activity comparison of three kinds of Stemonae Radix in Chinese Pharmacopoeia

Objective: To compare the antitussive activity of three kinds of Stemonae Radix specified in the Chinese Pharmacopoeia, including roots of Stemona sessilifolia, S. japonica and S. tuberosa. Method: The antitussive activity was determined in mouse after cough induction by ammonia aerosol stimulation and the number of cough in 2 min were detected with codeine as positive control. Result: All the decoctions, the total alkaloid fractions and non-alkaloid fractions of S. sessilifolia, S. japonica and three chemical types of S. tuberosa showed significant antitussive effect and exhibited a dose-dependent inhibition of coughing. The ED₅₀values showed that the antitussive activity strength for both total alkaloid fractions and the decoctions are: S. tuberosa (Type I) > S. sessilifolia > S. japonica. The total alkaloid fractions had more potent atitussive activity than the decoctions and non-alkaloid fractions. The antitussive activity strength for the three chemical types of S. tuberosa is: Type I > Type III > Type II. The samples from different producing areas for the same species of Stemonae Radix had no significant differences in antitussive activity. The result also showed that the honey-processed slice had much stronger antitussive activity than raw slice. Conclusion: The antitussive efficacies of Stemonae Radix were influenced by chemical diversity both in same species and among different species, different fractions and processed method.