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DOI: 10.1055/s-0029-1234861
Ethnopharmacological study of two plants of Northern Madagascar: bronchodilator activity of Tetracera madagascariensis and antispasmodic activity of Mascarenhasia arborescens
Ethnobotanical investigations were conducted with population and traditional healers in several villages in the North of Madagascar. From this field research, two plants have been selected to justify their traditional use.
Tetracera madagascariensis Willd. ex Schltdl. (Dilleniaceae), a species endemic to Madagascar, is traditionally used to treat respiratory disorders. The bronchial asthma is a widespread disease in Madagascar. Bioassay-guided fractionation using isolated guinea pig trachea pre-contracted with histamine at 2.10-5M led to the identification of methylene chloride extract as the main active fraction. This extract induced a concentration-dependant relaxation with a median effective concentration (EC50) of 53±0.5µg/ml (n=6). Subfractions are in analysis process.
Mascarenhasia arborescens A. DC. (Apocynaceae), a tree growing in the East of Africa and Madagascar, is widely used in Northern of Madagascar to treat intestinal disorders and diarrhoea. It is on account of these data that we investigated this species for antispasmodic activity. Bioassay-guided fractionation using isolated guinea pig ileum pre-contracted with histamine at 3.10-6M to monitor the activity led to the isolation of davidigenin (dihydrochalcone) as the main active constituent from methylene chloride fraction. Effectively, it induced a concentration-dependant relaxation of the histamine pre-contracted guinea pig ileum with an EC50 of 11.1±0.7µg/ml (n=4). This data is in accordance with the literature underlined an antispasmodic effect of davidigenin on mouse jejunum [1].
Acknowledgements: A. Rakotozafy (botanist, IMRA), J.P. Nicolas (association „Jardins du Monde“), population and healers surveyed.
Reference: [1] Sato, Y. et al. (2007) Biol. Pharm. Bull. 30:145–149.