Planta Med 2009; 75 - PI38
DOI: 10.1055/s-0029-1234802

Chemical composition, antimicrobial and antioxidant activities of the essential oil of Guizotia scabra and Microglossa pyrifolia from Rwanda

MJ Mukazayire 1, 2, JC Tomani 2, JC Chalchat 3, C Stévigny 1, P Duez 1
  • 1Université Libre de Bruxelles (ULB), Laboratory of Pharmacognosy, Bromatology and Human Nutrition, CP 205–9, B-1050 Brussels, Belgium
  • 2Institute of Research Science and Technology (I.R.S.T.), Center of Research in Phytomedecine and life Science, B.P. 227 Butare, Rwanda
  • 3Laboratory of Photochemistry Molecular and Macromolecular, Chemistry of Essential Oils, Blaise Pascal Clermont University, 63177 Aubière Cédex, France

Guizotia scabra (Vis.) Chiov. and Microglossa pyrifolia (Lam.) Kuntze, Asteraceae, are collected and used for infection diseases in Rwanda [1]. Their essential oils obtained by hydrodistillation of leaves collected from Butare (Huye), Southern province of Rwanda, were simultaneously analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) [2,3,4,5]. As a result, a total of fifty components were characterized in Microglossa pyrifolia, representing 98% of the total oil with germacrene-D as the major component. 39 components were characterized in Guizotia scabra, representing 85.2% of the total oil with germacrene-D (26%) and limonene (10%) as the principal constituents.

The essential oils were evaluated for their antimicrobial activity using a microdilution assay resulting in the inhibition of a number of common human pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Shigella flexneri, Pseudomonas aeruginosa and Salmonella typhi. The minimum inhibitory concentrations (MIC) of both M. pyrifolia and G. scabra varied between 0.25 and 0.5mg/ml which is within a moderate antimicrobial activity range. Furthermore, the antioxidant capacity of the essential oils was examined using an in vitro radical scavenging activity test. The essential oils scavenged 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), resulting in IC50>30% Equivalent quercetine.

References: [1] Rwangabo, P.C. (1993) La médicine traditionnelle au Rwanda. Paris, Karthala et ACCT.

[2] Van Den Dool, H., Kratz, P.D. (1963)J. Chromatogr.11:463–471.

[3] McLafferty, F.W., Stauffer, D.B. (1989) The Wiley NBS registry of Mass Spectral Data. 2nd Edition. J.Wiley & Son. New York. 4. Adams, R.P. (2001) Identification of Essential Oil Components by Gas chromatrography/Quadrupole Mass Spectroscopy. Allured Publishing Corp., Carol stream, IL.

[5] Joulain, D., König, W.A. (1998) The Atlas of Spectral Data of Sesquiterpene Hydrocarbons.E.B.Verlag, Hamburg.