SOLVENT EXTRACTS OF DIFFERENT PARTS OF GHANAIAN PHYLLANTHUS NIRURI SHOW POTENT GROWTH INHIBITION AGAINST SIX HUMAN PATHOGENIC BACTERIA IN VITRO

Abstract

Objective: The development of resistanceagainst conventional antibiotics by pathogens isof great concern. The objective of the current research was to evaluate the effects of various parts of Phyllanthus niruri on the growth of some selected bacteria.

Methods: Whole plant, leaf, stem and root of Phyllanthus niruriwere separately extracted with 70 % ethanol and 70 % methanol and the crude extracts screened for phytochemicals.Six pathogenic microorganisms viz. Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Proteus mirabilis were assayed for susceptibility to the various extracts of P. niruri in vitro.

Results: Phytochemical screening of the extracts revealedthe presence of alkaloids, flavonoids, tannins, saponins, steroids, triterpenoids, terpenoids and phenols. Both ethanolic and methanolic extracts showed comparable antimicrobial effects against the selected pathogenic organisms. All the extracts of the plant showed significant (p<0.05) inhibition against all the tested pathogenic microbes at 100 mg mL^-1 and 200 mg mL^-1. The zones of inhibition of both the plant extracts ranged between 7.5-30.0 mm against the test organisms.Generally, the whole plant extract was the most active against the growth of the bacteria. S. aureuswas the most susceptible organism to the ethanolic extracts (whole plant, leaf, stem and root ethanolic extracts showed respective MIC values of 1.56, 3.125, 6.25 and 6.25 mg mL^-1against S. aureus). However, the most resistant bacterium against the ethanolic extracts was P. aeruginosa.

Conclusion: Results from present study reveal that P. niruri contains bioactive compounds with significant antibacterial properties and therefore represents a potential source for the discovery of novel antibacterial agents.