Antimicrobial activity of Terminalia macroptera root

Terminalia macroptera Guill et Perr. (Combretaceae) is a medicinal plant used in Guinea-Bissau and other West African countries to treat infectious diseases. The ethanol extract from T. macroptera decorticated root and their liquid-liquid partition fractions, were screened for antimicrobial activity, by the twofold serial microdilution assay against seven reference bacterial strains and against Candida albicans. The extract and fractions showed some activity against at least one of the test microorganisms. The best results were obtained against Shigella dysenteriae and Vibrio cholerae. The minimum inhibitory concentrations (MIC) of T. macroptera ethanol extract were also determined for about 100 clinical strains of Campylobacter sp., Escherichia coli, Salmonella sp., Shigella sp. and Vibrio cholerae. The ethanol extract activity against Campylobacter strains is similar to co-trimoxazole, higher than sulfamethoxazole but lower than tetracycline, erythromycin, ampicillin and streptomycin. Ellagitannins are the major compounds in the extract and active fractions. The obtained results suggest a potential importance of this medicinal plant in the treatment of enteric diseases, particularly in Campylobacter infections.