RESUMO
The antimicrobial properties of volatile aromatic oils have been recognized since antiquity. Oregano and clove oils have been shown to possess a broad spectrum of antimicrobial activity. In this paper, the fungicidal action of these two essential oils was studied on the yeast model Saccharomyces cerevisiae. Yeast cell lysis was shown by the release of substances absorbing at 260 nm. In addition, scanning electron microscopy analyses revealed that the surface of treated cells by oregano and clove oils was significantly damaged.
Assuntos
Antifúngicos/farmacologia , Origanum , Fitoterapia , Óleos de Plantas/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Syzygium , Antifúngicos/administração & dosagem , Antifúngicos/uso terapêutico , Parede Celular/diagnóstico por imagem , Citosol/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Óleos de Plantas/administração & dosagem , Óleos de Plantas/uso terapêutico , Saccharomyces cerevisiae/metabolismo , UltrassonografiaRESUMO
AIMS: This study aims to bring some information about the mechanism of the fungicidal action of thymol and eugenol; phenolic major components of thyme and clove essential oils respectively. Saccharomyces cerevisiae was used as yeast model. METHODS AND RESULTS: Treatment of yeast cells with these components led to their lysis as shown by the release of substances absorbing at 260 nm. In addition, scanning electron microscope observations revealed that the surface of the treated cells was significantly damaged. CONCLUSIONS: Antifungal activity of thymol and eugenol involve alteration of both membrane and cell wall of the yeast. SIGNIFICANCE AND IMPACT OF THE STUDY: This work is a preliminary contribution aiming to develop a new generation of efficient and natural antifungal agents.
Assuntos
Eugenol/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Timol/farmacologia , Antifúngicos/farmacologia , Parede Celular/ultraestrutura , Contagem de Colônia Microbiana , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Óleos Voláteis/química , Saccharomyces cerevisiae/ultraestrutura , Espectrofotometria UltravioletaRESUMO
The emulsifying agents used to disperse essential oils in culture media can interfere in the estimation of essential oils antimicrobial activity; we showed in this study that 0.2% Agar suspension was sufficient to obtain a stable dispersion of oregano and clove essential oils in liquid media comparable to the dispersions obtained with tween 80 (0.25%) or ethanol (0.2%). The dispersion with agar was as homogenous as a true solution in absolute ethanol. Furthermore, minimal inhibitory concentration and minimal lethal concentration for different bacterial species in presence of agar were significantly lower than those observed in presence of tween 80 or ethanol. This demonstrates the fact that solvents and detergents often used in antimicrobial studies significantly decreases the antibacterial activity of essential oils.