Antibacterial activity and phytochemical study of six medicinal plants used in Benin.

The ethanol extracts obtained from Psidium guajava, Flacourtia flavescens Boswellia dalzielii, Ficus exasperata, Pavetta corymbosa and Hybanthus enneaspermus, six species traditionally used in Benin to treat several infectious diseases, were evaluated for their in vitro antimicrobial activity against Staphylococcus aureus, Enteroccocus feacalis, Escherichia coli and Pseudomonas aeruginosa. The minimum inhibitory concentration of extracts was determinate using the microplate dilution method. The presence of major phytoconstituents was detected qualitatively. The diphenylpicrylhydrazine radical scavenging activity was also performed. The extracts exhibited antibacterial activities against the tested bacteria. Boswellia dalzielii, Psidium guayava, Pavetta corymbosa and Flacourtia flavescens exibited the lowest minimum inhibitory concentration values (0.313-2.5 mg mL(-1)). Pseudomonas aeruginosa was the lest sensitive microorganism with MIC values higher than 10 mg mL(-1). In antioxidant assay the crude extracts of B. dalzielii and P. corymbosa appeared to be as potent as quercetol with an inhibition percentage of 83 and 75.3% at 10 microg mL(-1) which is comparable to 75.9% for quercetol at the same concentration.