The methanolic leaf extract of
Newbouldia laevis was subjected to preliminary phytochemical screening and
in-vitro antimicrobial tests. The extract revealed the presence of flavonoids, tannins, terpenes, steroidal and cardiac glycosides. The antimicrobial activity of the plant extract was assayed by the agar plate disc diffusion and nutrient broth dilution techniques. Test microorganisms were
Pseudomonas aeruginosa
,
Escherichia coli
,
Staphylococcus aureus
,
Salmonella typhi
,
Klebsiella spp. and
Candida albicans
; all the organisms were laboratory isolates. The extract inhibited the growth of all the test organisms especially against
Klebsiella spp. and
S. aureus which had mean inhibition zone of 42.3±1.5 and 32.3±1.5 mm respectively. The results showed minimum inhibitory concentration (MIC) of 1.563 mg/ml against
Escherichia coli and
Klebsiella spp. and 3.125 mg/ml against
Pseudomonas aeruginosa,
Staphylococcus aureus and
Salmonella typhi. The minimal bactericidal concentration (MBC) against
Escherichia coli and
Staphylococcus aureus was 0.39 mg/ml. This study has justified the traditional use of this plant for the treatment of stomach discomfort, diarrhea, dysentery and as a remedy for wound healing whose causative agents are some of the organisms used in this study.
