Atividade antifúngica e possível mecanismo de ação do óleo essencial de folhas de ocimum gratissimum (linn.) sobre espécies de candida

Abstract

Ocimum gratissimum (Linn.) is a medicinal plant popularly known as "wild basil" widely used in traditional medicine. The plant has numerous compounds, and eugenol is the major constituent of its essential oil and likely responsible for its antimicrobial activity. The aim of this study was to determine the antifungal activity and the potential mechanism of action of the essential oil extracted from the leaves of O. gratissimum L. (OEOg) against standard strains of Candida. The following experiments were performed: determination of Minimum Inhibitory Concentration (MIC), determination of the effect of exposure time to OEOg; evaluation of the modulating effect of OEOg in antifungal (ATF) activity for clinical use; determination of the effects of the OEOg on different growth phases of Candida spp; determination of crystal violet (CV) uptake and the microculture of yeast technique. OEOg showed good antifungal activity against Candida, being able to reduce microbial growth during 24 hours of contact and also the number of viable cells at all stages of growth. OE positively modulates the activity of ketoconazole for C. tropicalis ATCC 13803.Increased uptake of CV and also the inhibition of Candidavirulence factors were also observed, which indicates the occurrence of damage in the cell envelope. These findings, coupled with the low toxicity of OEOg on human erythrocytes, indicate that "wild basil" is a promising plant for the development of a new drug with a potential activity to treat fungal diseases.