Antimicrobial Activity of Crude Extract Obtained from the Root of <i>Plumbago zeylanica</i>
Ethanolic extract of Plumbago zeylanica root was investigated for its antimicrobial activities against 11 human pathogenic bacteria and 6 phytopathogenic fungi using disc diffusion method and poisoned food technique respectively. The extract exhibited good antibacterial and antifungal activities against the test organisms. Among the test bacteria, Vibrio cholerae was found to be the most sensitive to the extract showing the highest diameter of zone of inhibition and lowest minimum inhibitory concentration (MIC) value (200 Î¼g/ml). The extract was also very effective against Escherichia coli and Pseudomonas aeruginosa showing MIC value of 250 Î¼g/ml. Among the phytopathogenic fungi tested, Curvularia lunata exhibited the highest sensitivity to the extract with an MIC value of 150 Î¼g/ml, which was followed next by Colletotrichum corchori and Fusarium equiseti (MIC value 250 Î¼g/ml). The root extract from P. zeylanica seems promising since it showed both antibacterial and antifungal activities.
Keywords: Antimicrobial activity, Plumbago zeylanica, Ethanolic extract, Minimum inhibitory concentration (MIC)
Bangladesh J Microbiol, Volume 24, Number 1, June 2007, pp73-75