Phytochemical and Antibacterial Activities of Newbouldia laevis leaves (Ogirishi) on two Drug Resistant Bacteria

This present study was aimed to investigate the phytochemical and antimicrobial activities of aqueous and methanolic extracts of Newbouldia laevis (Ogirishi) on Staphylococcus aureus and Escherichia coli. The phytochemical constituents of this medicinal plant were carried out using standard methods. Agar dilution method was used to determine the antibacterial activity of the plant extracts. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the plant extracts on the test isolates were determined by the agar dilution method. Phytochemical analysis shows the presence of Phenols, flavonoids, glycosides, tanins, oxalate, terpenoids, anthraquinolones, alkaloids and tanins in both methanolic and aqueous extracts of N. laevis. The antibacterial activities of aqueous and methanolic leave extract of Newbouldia laevis shows that the mean zone diameter of inhibition for S. aureus on the different extracts was between the range of 9mm to 22mm while that of E. coli was between 8mm to 24mm. Result from this work shows a greater zone of inhibition produced by the methanolic extracts of N. laevis at all concentrations used compared to that produced by the positive control drug gentamicin. The MIC of different extracts of S. aureus was between 6.25mg/ml to 25mg/ml while that of E. coli was between 6.25mg/ml to 25mg/ml. The MBC of different extracts of S. aureus isolates was between the ranges of 50 to 100mg/ml while that of E. coli was also between the ranges of 50 to 100mg/ml. In conclusion, the results obtained in this work indicate that the leave extracts of N. Laevis possesses natural potential to inhibit the growth of S. aureus and E. coli. The observed antibacterial effects may due to the presence of secondary metabolites in the plant. Our findings justify the claim that the leave extracts of N. Laevis could have antibacterial properties against the stated organisms