Abstract

Albizzia lebbeck Benth. and Acacia leucophloea (Roxb.) Willd. are two very important medicinal plants growing wild in various parts of Pakistan. Various parts of both species are used by indigenous people as antimicrobial therapy however no detailed study exists regarding this activity. Crude methanolic extracts of pods, seeds, flowers and roots of Albizzia lebbeck Benth. and Acacia leucophloea (Roxb.) Willd. were tested in vitro for their antibacterial and antifungal activities. Antibacterial study performed against six bacterial species of both gram positive and gram negative types viz., Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhi, Proteus mirabilis and Bacillus subtilis,when compared with gentamicin and gatifloxacin, indicated that investigated plants have potent activity against all tested microorganisms. The antifungal activity of these extracts was performed against six fungal strains viz., Aspergilus parasiticus, Aspergilus Niger, Candida albicans, Aspergillus effusus, Fusarium solani and Saccharomyces cerevisiae and compared with Itraconazole and AmphoteracinB. The extracts showed significant activity against all fungal strains. The order of antibacterial and antifunagl activity, expressed as minimum inhibitory concentration (MIC) observed for both plants was seed> pod> flower > roots for all bacterial and fungal strains tested. The results authenticate their traditional use and indicate promising potential of both species to be developed as antimicrobial agents. Further work is needed for isolation, structure elucidation and characterization of bioactive constituents responsible for this activity. These natural products isolated should be screened in vivo and in vitro for antimicrobial activity and may be developed as cheap alternatives to costly synthetic antimicrobial agents available in market.

Key words: Antibacterial, antifungal, Albizzia lebbeck, Acacia leucophloea.