Antimicrobial activities of Dilobeia thouarsii Roemer and Schulte, a traditional medicinal plant from Madagascar

• Published in: South African Journal of Botany
• Main Authors: Razafintsalama, Vahinalahaja, Sarter, Samira, Mambu, Lengo, Randrianarivo, Ranjana, Petit, Thomas, Rajaonarison, Jean F., Mertz, Christian, Rakoto, Danielle, Jeannoda, Victor
• Other Authors: Molécules de Communication et Adaptation des Micro-Organismes (MCAM), Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université d'Antananarivo, Démarche intégrée pour l'obtention d'aliments de qualité (UMR Qualisud), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de La Réunion (UR)-Université de Montpellier (UM)-Avignon Université (AU)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université Montpellier 1 (UM1), Laboratoire de Chimie des Substances Naturelles et des Sciences des Aliments (LCSNSA), Université de La Réunion (UR), Département de Biochimie Fondamentale et Appliquée
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: [CHIM]Chemical Sciences; Antarc*; Antarctica
• Online Access: https://hal.univ-reunion.fr/hal-01188116; https://doi.org/10.1016/j.sajb.2013.02.171

International audience The leaves of Dilobeia thouarsii (Roemer and Schulte), a tree that is endemic to Madagascar (Proteaceae), are used in traditional Malagasy medicine to treat bacterial skin infections and wounds. This study investigated the in vitro antibacterial activities of D. thouarsii leaf extracts and identified the bioactive compounds with the aim of providing a scientific basis for its use against skin diseases. Using broth microdilution method for leaf crude extract and its compounds, we investigated inhibition of the growth of Bacillus cereus, Bacillus megaterium, Staphylococcus aureus, Enterococcus faecalis, Vibrio harveyi, Vibrio fisheri, Salmonella Typhimurium, Salmonella antarctica, Escherichia coli, and Klebsiella pneumoniae. The two purified phenolic compounds from leaf ethyl acetate extracts (1, 2) were found to be more active than the crude extract itself. The structure of the two compounds was elucidated by NMR and mass spectrometry: compound 1 was identified as 4-aminophenol and compound 2 as 4-hydroxybenzaldehyde. A marked inhibitory effect (MIC&#xa0;<&#xa0;0.1&#xa0;mg/ml) was found against S. aureus, which is a major agent in skin infections. We observed moderate activities (MIC values of between 0.1 and 0.5&#xa0;mg/ml) for E. faecalis, Vibrio spp., and Bacillus spp. Neither compound was active against Salmonella spp., E. coli and K. pneumoniae (MICs&#xa0;>&#xa0;1&#xa0;mg/ml). To conclude, the high antimicrobial activity of D. thouarsii leaf extracts against S. aureus supports its traditional use to treat skin infections.