In vitro antimicrobial activity of the leaf extract of Harungana madagascariensis Lam. Ex Poir. (Hypericaceae) against strains causing otitis externa in dogs and cats.
Otitis externa in dogs and cats is always caused by a combination of yeasts and bacteria, among which the most important are Malassezia pachydermatis, Staphylococcus intermedius and Pseudomonas species. These organisms often develop resistance to classical antimicrobial agents. Therefore, the aim of this study was to investigate the antimicrobial activities of an ethyl acetate leaf extract of Harungana madagascariensis against the organisms cited, to carry out the phytochemical investigation of this extract and to determine its bioactive chemical class using dilution techniques, the bioautography method and the standard phytochemical method described by Harborne (1973). Phytochemical analysis revealed the presence of saponins, tannins, flavonoids, alkaloids and anthracenic derivatives. The bioassay showed that the antimicrobial properties may be attributed to astilbin, a flavanone derivative identified on the basis of its spectroscopic data. The results suggest that the extract could be used in an antimicrobial preparation effective against the whole range of organisms incriminated in otitis externa in dogs and cats, with a minimal inhibitory concentration (MIC) of 250 microg/ml.
Moulari
B
B
Equipe Sciences Séparatives et Biopharmaceutiques EA-3924, UFR de Médecine et de Pharmacie, Université de Franche-comté, Place Saint-Jacques, 25030 Besançon, France. bricemoulari@msn.com
Pellequer
Y
Y
Chaumont
J P
JP
Guillaume
Y C
YC
Millet
J
J
D000085:Acetates / Q000737:chemistry; D000818:Animals; D016956:Burkholderia cepacia / Q000187:drug effects* / Q000302:isolation & purification; D002371:Cat Diseases / Q000188:drug therapy / Q000382:microbiology*; D002415:Cats; D028084:Clusiaceae / Q000737:chemistry*; D004283:Dog Diseases / Q000188:drug therapy / Q000382:microbiology*; D004285:Dogs; D044948:Flavonols / Q000737:chemistry / Q000494:pharmacology; D008290:Malassezia / Q000187:drug effects* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D019906:Nuclear Magnetic Resonance, Biomolecular; D010032:Otitis Externa / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification
D000085:Acetates; D044948:Flavonols; D010936:Plant Extracts; C099069:astilbin; C007650:ethyl acetate