IN-VITRO ANTIBACTERIAL ACTIVITY OF AZADIRACHTA INDICA AGAINST HUMAN PATHOGENS

Abstract

The antibacterial activity of the plant parts extracts (stem, root, leaf, flower and whole plant) of Azadirachta indica was studied against Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris (Gram-negative), Bacillus subtilis and Staphylococcus aureus (Gram-positive) by the agar well diffusion method. The ethanol and methanolic extracts displayed broad spectrum activity against all the test organisms but root extracts of chloroform and Petroleum ether showed no activity against Gram-negative bacteria. The antibacterial activity of the extracts was compared to the drug Tetracycline. The minimum inhibitory concentration (MIC) of the ethanol and methanol extracts of leaf and whole plant determined by the agar dilution method ranged between 1.96-19.5 and 1.96 with that of Staphylococcus aureus being the least. Phytochemical screening of the plant revealed the presence of tannins, alkaloids, flavonoids and saponins. The results of this study support the traditional use of Azadirachta indica whole plant as an antibacterial agent.