Antibacterial potential of the Albizia mahalao Capuron extracts, a Fabaceae from Madagascar

Document Type : Original Article

Authors

Laboratory of Applied Biochemistry to Medical Sciences, Fundamental and Applied Biochemistry Department, Faculty of Sciences, University of Antananarivo, P. O. Box 906, Antananarivo 101, Madagascar

Abstract

The aim of this study was to assess the antibacterial potential of Albizia mahalao, a Madagascar Fabaceae. Leaf methanolic extracts (LME), root bark methanolic extract (RME), stem bark methanolic extract (SME), and alkaloids extracted from leaves under basic and acidic conditions were used. All the methanol extracts contained alkaloids and saponins. The antimicrobial activity was tested against many bacteria spp. including; Listeria monocytogenes, Staphylococcus aureus, Clostridium perfringens, Enterobacter aerogenes, Salmonella enterica, Shigella flexneri, and Vibrio fischeri, using the Disc diffusion and the Microdilution assays. With the exception of the SME which is inactive, the other extracts exhibited broad spectrum potential against all the tested bacteria. The alkaloids are efficient against nearly all the bacteria under both of the basic and acidic conditions, with an inhibition zone diameter (IZ) of >17 mm, and minimum inhibitory concentration (MIC) of <100 µg/ ml. RME is the least efficient (IZ ≤ 10 mm, and 100< MIC < 1000 µg/ ml). S. enterica is the most sensitive bacterium (IZ= 23 mm, and MIC= 47 µg/ ml), whereas, Staph. aureus (IZ= 10 mm, and MIC >12000 µg/ ml) is the more resistant species. The majority of the extracts expressed bactericidal potency against the tested bacterial spp. Current results revealed the antibacterial potential of the Albizia mahalao leaves and root bark extracts thus could be used to treat infectious diseases. 

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