Planta Med 2011; 77 - PN4
DOI: 10.1055/s-0031-1282987

In vitro activity of different plants essential oils against the yeast-like alga Prototheca

BM Cosmina 1, F Nicodim 2, G Adrian 1, R Sorin 2, N George 2, B Pompei 1, T Marian 1, B Gabriel 1, N Andras 1, C Cornel 1
  • 1Department of Pathology, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Manastur street no 3–5, 400372, Romania
  • 2Department of Microbiology, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Manastur street no 3–5, 400372, Romania

Species of the genus Prototheca (family Chlorellaceae) are unicellular achlorophyllous microalgae, spherical, oval or kidney shaped with diameters ranging from 3 to 30µm. They are ubiquitous in nature and have a worldwide didtribution [1]. Of the five known species of the genus, P. wickerhamii causes human infection and P. zopfii is considered pathogenic for animals, particularly cows and dogs [2,3]. These algae do not respond to classic therapy so introduction of new therapeutic agents for treatment or prophylaxis is an important goal. Therefore this study aimed to investigate the antimicrobial activity of Mentha piperita L. (peppermint), Melaleuca alternifolia Cheel (tea tree), Origanum compactum Benth. (oregano) and grape seed essential oils, compared with Amphotericin B (A2942, Sigma-Aldrich). Ten P. zopfii isolates from cow mastitic milk samples and two P. zopfii isolates from bovine feces were submitted to antifungal susceptibility testing by broth microdilution assay following the CLSI guidelines for yeasts. The inhibitory effects, depends on the plant species from which the product was obtained, on their chemical composition as well as on the tested concentration. Peppermint (MIC of 0,125–0,5µg/mL) and tea tree (MIC of 1–2µg/mL) essential oils demonstrated the strongest antifungal efficacy against all tested strains. In contrast Amphotericin B showed eficacity at MIC of 25µg/mL. All tested isolates were resistant to oregano and grape seed essential oils. Difficulties in treating protothecosis and the potent in vitro activity of peppermint and tea tree essential oils demonstrated here raise the interest for further investigations on the therapeutic use of these natural products.

Keywords: Prototheca, essential oil, Mentha piperita, Maleleuca alternifolia, Origanum compactum, grape seed

Acknowledgement: This work was supported by CNCSIS-UEFISCSU grant number PN II RU 175/2010.

References: [1]. Pore RS (1985) Mycopathologia 90: 129–139.

[2]. Roesler U et al. (2006) Int J Syst Evol Microbiol 56: 1419–1425.

[3]. Lass-Florl C et al. (2007) Clin Microbio. Rev 20: 230–242.