Tropical Journal of Pharmaceutical Research April 2010; 9 (2): 165-171

Erick Francisco Rakotoniriana1,2*, Jean François Rajaonarison1, Emmanuel Guy Raoelison1, Jacob Philémon, Rajaonarivelo1,
Nia Manga2, Marcellin Solofoniaina1, Benja Rakotonirina1, Denis Randriamampionona1, Christian Rabemanantsoa1,
Kiban Cheuk1, Suzanne Urveg-Ratsimamanga1 and Joëlle Quetin Leclercq2

1Laboratoire de microbiologie et de standardisation des médicaments, Institut Malgache de Recherches Appliquées,
BP3833, Avarabohitra, Antananarivo, Madagascar, 2Laboratoire de Pharmacognosie, Unité CHAM, Louvain Drug
Research Institute, Université catholique de Louvain, 72, UCL7230, Av. E. Mounier- 1200 Bruxelles, Belgium

Available online at http://www.tjpr.org
Research Article
Antimicrobial Activity of 23 Endemic Plants in Madagascar


Abstract
Purpose: To screen the crude methanol extracts obtained from 23 endemic plants in Madagascar for antimicrobial
activity.
Methods: In order to assess the antimicrobial properties of the extracts, their minimum inhibitory concentrations
(MICs) were obtained using the broth microdilution method. The six test pathogenic species used were Bacillus
subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa and Candida albicans.
Bioautography agar overlay test and phytochemical screening were also performed on the most active extracts.
Results: From the 23 plants tested, 16 of which are used in traditional medicine, Poivrea phaneropetala
(Combretaceae), Koehneria madagascariensis (Lythraceae) and Rhopalopilia perrieri (Opiliaceae) exhibited the
broad spectrum of activity, being active against all the test organisms, while Monoporus clusiifolius (Myrsinaceae)
showed the strongest antifungal activity against Candida albicans with a minimal inhibitory concentration of 0.250
mg/ml. Bioautography and phytochemical analysis of the five active extracts against bacterial strains and of one
active extract against C. albicans indicate that the active compounds responsible for antimicrobial activity may be
mainly flavonoids and/or terpenes.
Conclusion: These preliminary results are the first antimicrobial studies on these plants and lend support for the use
of some of them in traditional medicine.

Keywords: Antimicrobial properties, Traditional medicine, Microdilution assay, Bioautography, Madagascar.