INHIBITORY ACTIVITY OF ESSENTIAL OILS EXTRACTED FROM PLANTS AGAINST FLUCONAZOLE-RESISTANT CANDIDA GLABRATA

Abstract

Introduction: Oral candidiasis is a fungal infection diagnosed mainly in patients with immunosuppression or in denture wearers with deficient hygiene habits. Synthetic antifungal agents, such as fluconazole, have been used to treat this infection, but some strains are resistant to these drugs. Objective: This study aimed to evaluate the antifungal effect of the essential oils from Persia americana (avocado), Cinnamomum zeylanicum (cinnamon - leaf), Cinnamomum cassia (cinnamon - bark) and Cymbopogon winterianus (citronella) against Candida glabrata. Materials and Methods: The essential oils were screened for their antifungal activity using the solid medium diffusion method, with fungal inoculum adjusted to 1 x 106 CFU/mL. The Minimum Inhibitory Concentration (MIC) was determined by the microdilution technique. The essential oils were evaluated at concentrations ranging between 1,000 µg/mL and 7.81 µg/mL, while fluconazole and nystatin were evaluated at concentrations between 64 µg/mL and 0.5 µg/ mL. Results: The zones of inhibition measured varied between 8.2 and 9.2 mm diameter for C. winterianus and C. cassia, respectively. The essential oils from C. winterianusand and C. zeylanicum had MIC of 125 µg/ml, while C. cassia essential oil had MIC of 62.5 µg/ml. The drugs used as controls showed MIC values of 16 µg/mL (fluconazole) and 2.0 µg/mL (nystatin). P. americana essential oil showed no antifungal activity at the concentrations evaluated. Conclusion: We conclude that the essential oils from cinnamon (bark and leaf) and citronella showed antifungal activity against fluconazole-resistant C. glabrata. DESCRIPTORS Phytotherapy. Candida. Products with Antimicrobial Action. http