Abstract

The plants Ceiba pentandra (L.) Gaertn. [Malvaceae previously Bombacaceae] and Cordia sebestena Linn. [Boraginaceae] used in this study were selected to investigate and justify their local use in the treatment of cough, catarrh, sore throat, pneumonia and tuberculosis, all of which are associated with respiratory tract infections. The antimycobacterial activities of these plants were investigated in Mycobacterium fortuitum ATCC 684, Mycobacterium smegmatis ATCC 19420, Mycobacterium abscessus and Mycobacterium phlei ATCC 19240. The agar cup diffusion method was used for the antimycobacterial screening at concentrations of 10, 20, 100 and 200 mg/ml while the agar dilution method was used for the determination of the minimum inhibitory concentration (MIC). Phytochemical screening revealed the presence of tannins, cardenolides, alkaloids, anthraquinones and saponins in all the plant samples except in C. sebestena leaf in which saponins and anthraquinones were absent. The inhibitory activity of methanolic extracts of the stem barks of C. pentandra and C. sebestena on the test organisms was dose-dependent. The MIC and the minimum bactericidal concentration (MBC) of the extracts ranged from 20 - 200 and 40 - 600 mg/ml, respectively. The results obtained in this study justify the ethnomedicinal use of the plants in conditions associated with respiratory tract infections. 

Key words: Inhibitory activities, Ceiba pentandra (L.) Gaertn., Cordia sebestena Linn., rapidly growing mycobacteria, in vitro.