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

Abstract

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.

Citral and carvone chemotypes from the essential oils of Colombian Lippia alba (Mill.) N.E. Brown: composition, cytotoxicity and antifungal activity

“…Recently, Sharma and Tripathi (2008) determined, through an agar diffusion method, a MIC value of 0.3 µg/mL against A. niger for a Citrus sinensis essential oil, which has a limonene concentration of 87%. Linalool and linalool-rich essential oils from Croton cajucara are active against C. albicans, with MIC values of 0.7 µg/mL and 13.4 µg/mL, respectively (Alviano et al 2005). Duarte et al (2005) showed that a L. alba linalool-chemotype essential oil, with 76.3% of linalool, is active against C. albicans, with an MIC of 0.6 mg/mL.…”

Microbiological Studies on the Production of Antimicrobial Agent by Saponin Aloe vera Linn Against Streptococcus sanguinis

“…for purposes other than to dissolve the compounds present in Aloe vera powder chinensis, extract also to get a bit so that the water content is more easily evaporated at low temperature to obtain the extract concentrated. Concentrated extract can be obtained by evaporating the solvent in a vacuum (in vacuo) at low temperatures so as not to damage the material that can not stand the heat (thermolabile) (Alviano et al, 2005).…”

Microbiological Studies on the Production of Antimicrobial Agent by Saponin Aloe vera Linn against Streptococcus sanguinis

“…This because, such techniques can be used to obtain plant extracts was thought to contain antimicrobial agents and antimicrobial activity to be tested, (Alviano et al, 2005). Methanol was chosen as, the solvent extraction study, since almost all the plant compounds that have antimicrobial activity of an aromatic compound, or dissolved in an organic compound, can be dissolved through the initial extraction using ethanol/methanol (Dey and Harborne, 1991).…”

“…Concentrated extract can be obtained by evaporating the solvent in a vacuum (in vacuo) at low temperatures so as not to damage the material that can not stand the heat (thermolabile) (Alviano et al, 2005).…”