Abstract

Adebayo-Tayo, B. C. and Adegoke, A. A.*

Ethanolic extracts of six commonly used medicinal plants (by traditional medicine practitioners in Uyo and IkotEkpene), Vernonia amygdalina del. (“Etidod”), Ocimum gratissimum L. (“Nton”), Smilax anceps wild. (“Odufad”), Holarrhena floribunda (“Idid ikot”), Parkia biglobosa (“Epo igba”), and Khaya senegalensis (“Ogawo”), were analysed phytochemically and evaluated for their significant antimicrobial activity (P < 0.05) against different multiple drug resistant, MDR (pathogenic) organisms: Neisseria gonorrhea, Shigella flexineri, Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae. Mean inhibitory zones were calculated for each of the extracts. Five of the plant extracts contain saponins and tannins only; two contain salkowski, and keller-kilini only, while three extracts contain just one of alkaloids, plobatannins, liberman. The results revealed that each of the six plants extracts, at different concentrations of 80 and 40 mg/ml, exhibited various degrees of inhibition and activity index on the test organisms. The extract of the O. graissimum (“Nton”), had the highest mean inhibitory zone of 23 mm against S. flexineri. This was followed by H. floribunda (“Idid ikot”) with a mean inhibitory zone of 22 mm against N. gonorrhoea, V. amygdalina (“Etidod”) with a mean inhibitory zone of 19 mm against S. aureus and S. anceps wild (“Odufad”) had a mean inhibitory zone of 17 mm against both N. gonorrhoea and S. aureus. The MIC results of S. flexineri in 26.24 mg/ml of O. gratissimum excite us to analyse for its MBC which was 47.24 mg/ml. These results provide a rationalization for the traditional use of these plants for the treatment of infectious diseases.