Antimycobacterial Activity of Some Medicinal Plants in Niger State, Nigeria

Ten Nigerian medicinal plants Abrus precatorius, Annona senegalensis, Anogeissus leiocarpus, Crateva adansonii, Detarium microcarpum, Faba spp, Neocarya macrophylla, Ocimum gratissimum, Securidaca longpenduculata and Terminalia avicennioides used by traditional medicine practitioners for the management of infectious and chronic diseases such as tuberculosis and whooping cough were investigated for in vitro antimycobacterial activity against attenuated strains of Mycobacterium bovis (BCG). Hexane and methanol extracts of the plant materials were obtained by maceration. The antimycobacterial activity was determined by the broth microdilution method. The hexane extracts of Anogeissus leiocarpus and Terminalia avicennioides showed strong inhibitory activity at 312μg/ml. Eight of the ten plant extracts showed moderate inhibitory activity in either hexane or methanol extract at 1250μg/ml. While the hexane and methanol extracts of Detarium microcarpum and Neocarya macrophylla did not exhibit any significant activity. These observed activities could be associated with secondary metabolites in these plants. This study demonstrates the efficacy of Nigerian medicinal plants as potential agents in the management of the tuberculosis disease.