Xu Wu1, Shun-Wan Chan2, Jiang Ma3, Ping Li4, Pang-Chui Shaw5, Ge Lin6. 1. School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region; Li Dak Sum Yip Yio Chin R & D Centre for Chinese Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region; Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, PR China. Electronic address: wuxuandhl@gmail.com. 2. Department of Food and Health Sciences, Faculty of Science and Technology, Technological and Higher Education Institute of Hong Kong, Hong Kong Special Administrative Region. Electronic address: swchan@vtc.edu.hk. 3. School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region; Li Dak Sum Yip Yio Chin R & D Centre for Chinese Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region. Electronic address: majoriea@163.com. 4. State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, PR China. Electronic address: liping2004@126.com. 5. Li Dak Sum Yip Yio Chin R & D Centre for Chinese Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region; School of Life Sciences, Faculty of Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region. Electronic address: pcshaw@cuhk.edu.hk. 6. School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region; Li Dak Sum Yip Yio Chin R & D Centre for Chinese Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region. Electronic address: linge@cuhk.edu.hk.
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE: Fritillariae Bulbus (Beimu in Chinese) is derived from the bulbus of many Fritillaria species (family Liliaceae), which has been used as an antitussive herb in traditional Chinese medicine for more than 2000 years. Due to the complexity of plant origins and significant variations in chemical profiles, the characterization of the profile of the major bioactive constituents and its association with pharmacological activity are important for the quality control of Beimu herbs from different origins. AIM OF THE STUDY: This study aims to investigate the distribution of major bioactive isosteroidal alkaloids in Beimu herbs of different origins and its correlation with the tracheobronchial relaxant activity. METHODS: Quantification of 7 main bioactive 5α-cevanine isosteroidal alkaloids, including ebeiedine, ebeiedinone, hupehenine, isoverticine, verticine, verticinone and imperialine, in 23 Fritillaria species was performed using gas chromatography. The relaxant effect of different extracts of 4 commonly used Beimu herbs, namely Zhe-Beimu (F. thunbergii Miq.), Chuan-Beimu (F. cirrhosa D. Don), Hubei-Beimu (F. hupehensis Hsiao et K. C. Hsia) and Yi-Beimu (F. pallidiflora Schrenk), was evaluated using rat isolated tracheal and bronchial preparations pre-contracted with carbachol, the well established in vitro antitussive model. RESULTS: Amongst 23 Fritillaria species detected, significant variations of the types and quantities of 7 major isosteroidal alkaloids were determined, which served as an important indicator for the classification of different Beimu herbs with distinct geographic distributions. Based on the type and quantity of these alkaloids, different origins of Beimu could be clearly clustered into several subgroups by principal component analysis. Furthermore, both crude alkaloid and water extracts of all 4 Beimu herbs showed a dose-dependent tracheobronchial relaxation with different potencies. The total content of alkaloids (weight adjusted based on the activity of individual alkaloids) in Beimu extracts significantly correlated with their tracheobronchial relaxation effects (r2 > 0.9, p < 0.001). CONCLUSIONS: The results demonstrated that the differences in chemical profile of major bioactive isosteroidal alkaloids and pharmacological activity of Beimu could be incorporated into a simple and unified method for quality control and potential prediction of activity of Beimu herbs from different origins.
ETHNOPHARMACOLOGICAL RELEVANCE: Fritillariae Bulbus (Beimu in Chinese) is derived from the bulbus of many Fritillaria species (family Liliaceae), which has been used as an antitussive herb in traditional Chinese medicine for more than 2000 years. Due to the complexity of plant origins and significant variations in chemical profiles, the characterization of the profile of the major bioactive constituents and its association with pharmacological activity are important for the quality control of Beimu herbs from different origins. AIM OF THE STUDY: This study aims to investigate the distribution of major bioactive isosteroidal alkaloids in Beimu herbs of different origins and its correlation with the tracheobronchial relaxant activity. METHODS: Quantification of 7 main bioactive 5α-cevanine isosteroidal alkaloids, including ebeiedine, ebeiedinone, hupehenine, isoverticine, verticine, verticinone and imperialine, in 23 Fritillaria species was performed using gas chromatography. The relaxant effect of different extracts of 4 commonly used Beimu herbs, namely Zhe-Beimu (F. thunbergii Miq.), Chuan-Beimu (F. cirrhosa D. Don), Hubei-Beimu (F. hupehensis Hsiao et K. C. Hsia) and Yi-Beimu (F. pallidiflora Schrenk), was evaluated using rat isolated tracheal and bronchial preparations pre-contracted with carbachol, the well established in vitro antitussive model. RESULTS: Amongst 23 Fritillaria species detected, significant variations of the types and quantities of 7 major isosteroidal alkaloids were determined, which served as an important indicator for the classification of different Beimu herbs with distinct geographic distributions. Based on the type and quantity of these alkaloids, different origins of Beimu could be clearly clustered into several subgroups by principal component analysis. Furthermore, both crude alkaloid and water extracts of all 4 Beimu herbs showed a dose-dependent tracheobronchial relaxation with different potencies. The total content of alkaloids (weight adjusted based on the activity of individual alkaloids) in Beimu extracts significantly correlated with their tracheobronchial relaxation effects (r2 > 0.9, p < 0.001). CONCLUSIONS: The results demonstrated that the differences in chemical profile of major bioactive isosteroidal alkaloids and pharmacological activity of Beimu could be incorporated into a simple and unified method for quality control and potential prediction of activity of Beimu herbs from different origins.