Evaluation of Antimicrobial Activity of Anacardium occidentale (Linn.)

The extracts of the leaves and stem bark of anacardium occidentale were screened for phytochemically for the presence of secondary metabolites and for in vitro antibacterial activity. The phytochemical screening revealed the presence of alkaloids and tannins. The methanol and aqueous leaf extracts and the methanol extract of the stem bark were tested against Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis, Salmonella typhi, Candida albicans and Escherichia coli using the agar dilution method. The leaf methanol extracts presented a higher activity than the aqueous extracts. The antibacterial activity was greatest against K. pneumoniae, Bacillus anthracis and Candida albicans. Also the leaf extracts showed greater activity than the stem bark extracts. Of the six organisms tested, the stem bark extracts had activity against three. The mean diameter of the zones of inhibition exhibited by the extracts was between 13mm and 22mm. Bacillus subtilis showed the highest zone of inhibition (22mm) to the leaf methanol extract. The extracts compared favourably with ampicillin used as a standard control.