Abstract

Aqueous and ethanolic extracts of Ocimum gratissimum and xylopia aethiopicawere analyzed for their antimicrobial activities against five pathogenic organisms;Staphylococcus aureus, Escherichia coli, Streptococcus fecalis, Pseudomonasaeruginosa and Lactobacilli.  Ethanolic extracts of O. gratissimum had a minimum inhibitory concentration (MIC) of 30 mg/ml against S. aureus, E. coli, P. aeruginosa and lactobacilli while for S. fecalis the MIC was 15 mg/ml.  Aqueous extracts of O. gratissimum had an MIC of 12.5 mg/ml against S. aureus, E. coliand S. fecalis, while for P.  aeruginosa and lactobacilli the MIC was 6.25 and 25mg/ml, respectively.  Ethanolic extracts of X. aethiopica showed an MIC of 10mg/ml in the five organisms tested.  While its aqueous extract gave an MIC of 30mg/ml for S. aureus and Lactobacilli, and 15 mg/ml for E. coli, P. aeruginosa andS. fecalis. Our findings suggest that the anti-microbial activity of these spices reside in their aqueous fractions and also indicate that very low concentrations are required to achieve antimicrobial effects.

Key words: Antimicrobial effect, Xylopia aethiopica, Ocimum gratissimum,spice.