Methanol extract of three Nigerian medicinal plants were screened for antimicrobial activity using modified Kirby-Bauer disc diffusion and agar dilution techniques to determine the diameters of zone on inhibition and minimum inhibitory concentrations (MIC)of the extracts respectively. The extract of each of the plants were tested against five clinical bacterial isolates comprising of two Gram-positive bacteria (
Bacillus subtilis
and
Staphylococcus aureus
) and three Gram-negative bacteria (
Pseudomonas aeruginosa
,
Escherichia coli
and
Klebisella pneumonia
) organisms. All the extracts exhibited moderate to high level of antimicrobial activities against these microorganisms. Phytochemical screening of the powdered plant material revealed the presence of some secondary metabolites such as alkaloids, saponins, tannins, anthraquinones and flavonoids. These Nigerian medicinal plants could be developed into cheap, safe and culturally acceptable standardized herbal products and may served as source of new molecules for broad-spectrum antimicrobial agents.
