Antimicrobial activity of Anacardium occidentale L. leaves and barks extracts on pathogenic bacteria

The aim of this study was to investigate the antibacterial activity of aqueous, ethanol, ethyl acetate and dichloromethane extracts of two different cashew tree parts (leaf and bark). The susceptibility of strains to the different extracts was evaluated in vitro by disc diffusion method on ten reference strains and nine foods strains. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined respectively by macro-dilution method and seeding on solid medium. Among the four types of extracts, only the ethanol and ethyl acetate extracts of the two organs inhibited the growth of both bacteria and yeast. The MIC varies respectively between 0.039 and 0.625 mg/ml for reference strains and from 0.078 to 2.5 mg/ml for food isolated strains. Concerning MBC, it varies from 0.313 to 20 mg/ml for food isolated strains and from 0.078 to 20 mg/ml for reference strains. The ethanol and acetyl acetate extracts of the two cashew organs displays both a bacteriostatic and bactericidal effects on tested microorganisms. Our results suggest that extracts from cashew leaves may provide novel precursors for antimicrobial drug development research.  Key words: Antibacterial activity, Anacardium occidentale L., Staphylococcus, Benin.