Antimicrobial activity of Croton cajucara Benth linalool-rich essential oil on artificial biofilms and planktonic microorganisms

• Published in: Oral microbiology and immunology 2005-04, Vol.20 (2), p.101-105
• Main Authors: Alviano, W. S., Mendonça-Filho, R. R., Alviano, D. S., Bizzo, H. R., Souto-Padrón, T., Rodrigues, M. L., Bolognese, A. M., Alviano, C. S., Souza, M. M. G.
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Antifungal Agents - pharmacology; antimicrobial activity; Bacteria, Anaerobic - drug effects; Biofilms - drug effects; Biological and medical sciences; Candida albicans; Candida albicans - drug effects; Croton - chemistry; Croton cajucara; Croton cajucara Benth; Croton Oil - pharmacology; essential oil; Fundamental and applied biological sciences. Psychology; Humans; Lactobacillus casei; Lactobacillus casei - drug effects; linalool; Microbial Sensitivity Tests; Microbiology; Miscellaneous; Monoterpenes - pharmacology; Mouth - microbiology; Mycology; Oils, Volatile - pharmacology; oral microorganisms; Orthodontic Brackets; Plant Leaves - chemistry; Porphyromonas gingivalis; Porphyromonas gingivalis - drug effects; Staphylococcus aureus; Staphylococcus aureus - drug effects; Streptococcus mutans; Streptococcus mutans - drug effects; Streptococcus sobrinus; Streptococcus sobrinus - drug effects
• ISSN: 0902-0055; 1399-302X
• DOI: 10.1111/j.1399-302X.2004.00201.x

We have previously demonstrated that a linalool‐rich essential oil from Croton cajucara Benth presents leishmanicidal activity. In the present study, we demonstrate that this essential oil inhibits the growth of reference samples of Candida albicans, Lactobacillus casei, Staphylococcus aureus, Streptococcus sobrinus, Porphyromonas gingivalis and Streptococcus mutans cell suspensions, all of them associated with oral cavity disease. The purified linalool fraction was only inhibitory for C. albicans. Microbes of saliva specimens from human individuals with fixed orthodontic appliances, as well as the reference strains, were used to construct an artificial biofilm which was exposed to linalool or to the essential oil. As in microbial suspensions, the essential oil was toxic for all the microorganisms, while the purified linalool fraction mainly inhibited the growth of C. albicans. The compounds of the essential oil were separated by thin layer chromatography and exposed to the above‐cited microorganisms. In this analysis, the proliferation of the bacterial cells was inhibited by still uncharacterized molecules, and linalool was confirmed as the antifungal component of the essential oil. The effects of linalool on the cell biology of C. albicans were evaluated by electron microscopy, which showed that linalool induced a reduction in cell size and abnormal germination. Neither the crude essential oil nor the purified linalool fraction is toxic to mammalian cells, which suggests that the essential oil or its purified components may be useful to control the microbial population in patients with fixed orthodontic appliances.