In vitro antimicrobial activity screenning of Terminalia macroptera leaf

Terminalia macroptera Guill. and Perr. (Combretaceae) is a West African species used on traditional medicine to treat infectious diseases.[1] Hereby we present the results of an antimicrobial activity screening performed by the twofold serial microdilution assay against seven reference bacterial strains and against Candida albicans, with a leaf hydroethanol extract (Tml) and liquid-liquid partition fractions Tml-1 (hexane), Tml-2 (diethyl ether), Tml-3 (ethyl acetate), Tml-4 (Tml water filtered fraction) and Tml-5 (Tml water precipitate fraction). Results are displayed on Table 1. In the range of tested concentrations (3200 to 50µg/ml), the extract was active against all tested microorganisms. The best results were obtained against Shigella dysenteriae and Vibrio cholerae and the most active fraction was identified as the ethyl acetate one (Tml-3). Chemical profile of this fraction includes polyphenols as main compounds.

Table 1: In vitro antimicrobial activity of T. macroptera leaf extract (Tml) and fractions (Tml-1 to Tml-5)

Microorganisms	Minimum inhibitory concentration (µg/ml)
	Tml	Tml-1	Tml-2	Tml-3	Tml-4	Tml-5
C. albicans	3200	>3200	>3200	800	3200	3200
E. coli	1600	>3200	>3200	800	800	3200
E. faecalis	3200	>3200	>3200	1600	1600	3200
P. aeruginosa	800	>3200	>3200	800	800	3200
S. aureus	3200	>3200	>3200	3200	1600	3200
S. dysenteriae	200	>3200	>3200	400	800	3200
S. typhimurium	800	>3200	>3200	800	800	3200
V. cholerae	200	>3200	>3200	200	400	3200

References: 1. Diniz MA. et al. (1996) The Biodiversity of African Plants (In: van der Maesen LJG., Ed. The Biodiversity of African Plants). Kluwer Academic Publishers. Dordrecht.