Antibacterial activities of crude extracts of Nigerian spices and herbs on enteropathogens

Olaitan, Janet Olubukola; Shittu, Olufunke B.

doi:10.21608/eajbsg.2014.16501

Antibacterial activities of crude extracts of Nigerian spices and herbs on enteropathogens

Document Type : Original Article

Authors

¹ Department of Biological Sciences, Faculty of Basic and Applied Sciences, Osun State University, Osogbo, Osun State, Nigeria.

² Department of Microbiology, College of Natural Sciences, Federal University of Agriculture,

10.21608/eajbsg.2014.16501

Abstract

Aim: This study was designed to evaluate the antibacterial activities of water and ethanolic extracts of Nigerian herbs and spices against enteric pathogens.
Methodology: Crude extracts of fresh leaves of Ocimum gratissimum, Psidium guajava, Vernonia amygdalina, Kigelia africana, Azadrichata indica, Pistia stratiotes, Euphobia hirta;bulb of Allum sativum and rhizomes of Zingiber officinale and Curcuma longa were evaluatedusing the agar diffusion assay method and minimal inhibitory concentration (MIC) to determine the antibacterial activities against Vibrio cholerae, Escherichia coli and Salmonella sp. Gentamicin (28 mg/ml) was used as antibiotic control.
Results: Antimicrobial sensitivity test indicated that while Salmonella sp. was not inhibited by ethanolic extracts of Euphobia hirta and Curcuma longa, both water and ethanolic extracts of others inhibited the growth of Vibrio cholerae, Escherichia coli and Salmonella sp. to varying degree. The minimal inhibitory concentrations (MIC) determined for the crude extracts of the various herbs and spices, using water and aqueous ethanol inhibited the test isolates at high dilutions.
Conclusion: This study has shown the antibacterial potential of the herbs and spices against the tested enteric pathogens. The antibacterial activities of all the herbs and spices observed in this study justify their use in alternative medicine.

Keywords