Abstract

The development of effective and less toxic antimicrobial agents is required for the treatment of respiratory tract infections. This study was carried out to evaluate the phytochemical and antibacterial activities of Anogeissus leiocarpus (DC.) (Guill. & Perr.) and Terminalia glaucescens (Planch. ex Benth.) against non-tuberculous mycobacteria species. The methanol, dichloromethane and aqueous extracts were screened against five (5) non-tuberculosis mycobacteria (NTM) species by agar diffusion method. Minimum inhibitory concentration (MIC) was determined by agar dilution method while bactericidal studies were done by viable count technique. The methanol and aqueous extracts were active against all the test organisms with zones of inhibition ranging from 10±0.0 to 25±0.5 mm. The MIC and MBC range from 0.3125 to 2.5 and 1.25 to 10 mg/mL, respectively. Bactericidal activities of aqueous extracts against Mycobacterium smegmatis ATCC 19420 revealed a drastic dose-dependent decline in the surviving population after 6 h of exposure accompanied by a total (100%) kill after 24 h of exposure. The antimicrobial activities demonstrated by these plants suggest the presence of therapeutically important antimycobacterial compounds and thus justify as well as support the use of these medicinal plants for the treatment of respiratory tract infections.

Key words: Anogeissus leiocarpus (DC.) (Guill. & Perr.), Terminalia glaucescens (Planch. ex Benth.), antibacterial, nontuberculous mycobacteria species, bactericidal, in vitro.