Abstract

ANTIMICROBIAL EVALUATION OF ETHANOLIC AND AQUEOUS LEAF EXTRACTS OF SOUTHEAST NIGERIAN GROWN MORINGA OLEIFERA ON SOME ENTERIC ISOLATES

Ezeigbo I.C., Ike-Amadi C.A., Nwachukwu I. and *Ezeigbo O.R.

Abstract

Various plants have been reported to possess therapeutic properties; and this explains the reason for their wide use in the treatment of human diseases. The extracts of the plants are known to have bioactive agents and these are found to vary with the extraction solvent used. The antimicrobial activities of the leaf extract of Southeast Nigerian grown Moringa oleifera on bacterial and fungal isolates were investigated using two solvents, water and ethanol, to extract the bioactive agents. The zones of inhibition were determined using different concentrations of the leaf extracts ranging from 6.25%, 12.50%, 25.0%, 50.0% and 100% by employing Kirby Bauer disc diffusion method in triplicates. It was observed that the ethanolic extracts of M. oleifera leaf have more appreciable antimicrobial activity than water and the bacterial pathogens were more susceptible than the fungal pathogens. In the present study, M. oleifera produced the highest zone of inhibition on Staphylococcus species from 8mm to 17mm, followed by Escherichia coli (7mm to 15mm) while the least was Pseudomonas species with zone of inhibition ranging from 7mm to 13mm. The treatment with M. oleifera leaf extract on Candida species produced a zone of inhibition ranging from 6mm to 15mm compared to Nystacin with 17mm; Penicillium species with 6mm to 14mm compared with Nystacin with 16mm and Mucor species ranging from 6mm- 12mm, compared to the control with 14mm. The Minimum inhibitory concentration (MIC) of the leaf extract on the bacterial pathogens and Penicillium species was 12.5% while Candida, Aspergillus and Mucor species had MIC of 25%. The zones of inhibition of both ethanolic and aqueous leaf extracts were concentration dependent. The results obtained from the leaf extracts were comparable to the standard drugs used as control. This work therefore supports the use of M. oleifera leaf extract in drug formulation particularly antimicrobial drugs.

Keywords: Antimicrobial activity, Moringa oleifera, ethanolic extract, aqueous extract, enteric isolates.