Studies on Antibacterial Effect of The Leaves Of Phyllanthus Niruri on Some Enteric Pathogens

Abstract

Studies were carried out on the antibacterial effect of Phyllanthus niruri (Linn) leaves using ethanol and aqueous extracts of the leaves at concentrations 400mg/ml, 200mg/ml, 100mglml, 50mg/ml and 25mg/ml. Gentamycin was employed as control at concentration of 50mg/ml. Pure isolates of Escherchia coli, Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa and Klebsiella aerogenes were employed as test organisms. Results showed that both the ethanolic and aqueous extracts had antibacterial activities against test bacteria but to varying degrees. P. aeruginosa was the most susceptible bacterium to the ethanolic extract, followed by S. typhi. E. coli was the least susceptible. For the aqueous extract, K. aerogenes was most susceptible followed by P. aeruginosa. S. typhi was the least susceptible. The minimum inhibition concentration (MIC) of the ethanolic extract for E. coli was found to be 50mg/ml while S. aureus, P. aeruginosa and K. aerogenes had a common MIC of 12.5mg/ml. However, S. typhi was inhibited in all concentrations used. For the aqueous extract; E. coli was inhibited in all concentrations used while S. typhi, and P. aeruginosa had the same MIC of 25mg/ml. S. aureus with MIC 12.5mg/ml was the most susceptible. Results of the Minimum Bactericidal concentration (MBC) of the ethanolic extracts showed that it had bacteriostatic effect on test bacteria in all the concentrations tested. The aqueous extracts had bacteriostatic effect on only K. aerogenes and had bactericidal effect on all other test bacteria. Statistical analysis revealed that the mean diameter zones of inhibition for gentamycin was significantly higher than those of the plant extracts at 0.05 level of probability though, 400mg/ml concentration exhibited high antibacterial activities in both extracts. This study has established the antibacterial effect of P. niruri leaves.

Keywords: Phyllanthus niruri; antibacterial; Jos; Enteric pathogens

Nig J. Biotech. Vol. 23 (2011) 22- 27