Abstract

PRELIMINARY PHYTOCHEMICAL SCREENING AND ANTIBACTERIAL PROPERTIES OF CRUDE LEAVES EXTRACT AND FRACTIONS OF ACACIA NILOTICA (LINN.)

A. Abdulhamid*, Y. U. Dabai and Amar Mohamed Ismail

ABSTRACT

Infectious diseases caused by bacteria, fungi, parasites and viruses are still a major threat to public health. Their impact is particularly large in developing countries due to the relative unavailability of medicines and the emergence of widespread drug resistance. This has lead to the search of new antimicrobial agents mainly among plant extracts. As part of our ongoing research to purify, isolate and characterized antibacterial compounds from the extracts of some Nigerian medicinal plants, Acacia nilotica (Linn.) was screened for its preliminary phytochemical and antibacterial activity. The preliminary phytochemical screening of the extracts was carried out using standard methods while the antibacterial activity was done using disc diffusion method. The results for the phytochemical screening showed the presence of most of the phytochemicals tested. The results for the antibacterial activity of the crude methanolic extract and fractions of the leaf of Acacia nilotica showed varying degree of antibacterial activity against the bacterial isolates. However, crude methanolic extract, ethyl acetate and butanol fractions showed relatively high zone of inhibition (mm), minimum inhibitory concentrarion (MIC) and minimum bactericidal concentration (MBC). They were found to inhibit the growth of most of the test bacterial isolates comprising of both Grampositive and Gram-negative organisms. On the other hand, hexane and aqueous fractions shows little or no activity against tested isolate. These findings support previous reports on the antimicrobial activity of this plants. The result of the present study signifies the potential of Acacia nilotica leaf as a source of therapeutic agents, which may provide leads in the ongoing search for antimicrobial agents from plants.

Keywords: Acacia nilotica, antibacterial activity, phytochemicals and zone of inhibition.