Lavandula dentata L. essential oil: a promising antifungal and antibiofilm agent against oral Candida albicans.

Candida albicans is the main fungal species involved in oral candidiasis, and its increasing resistance to pharmacological treatment encourages the search for improved antifungal agents. Lavandula dentata L. essential oil (LD-EO) has been recognized for its antimicrobial activity, but little is known about its role against oral C. albicans. This study evaluated the antifungal and antibiofilm activities, mechanisms of action, and toxicity of LD-EO from Brazil against oral strains of C. albicans. Antifungal activity was assessed based on Minimum Inhibitory Concentration (MIC), Minimum Fungicidal Concentration (MFC), association study with miconazole (Checkerboard method), and sorbitol and ergosterol assays. Inhibition of biofilm formation and disruption of preformed biofilm were considered when studying the effects of the product. Additionally, the toxicity of LD-EO was evaluated by a hemolysis assay on human erythrocytes. Phytochemical analysis by gas chromatography-mass spectrometry identified eucalyptol (33.1%), camphor (18.3%), and fenchone (15.6%) as major constituents. The test substance showed mainly fungicidal activity (MIC100 = 8 µg/mL; MFC = 16 µg/mL), including against two miconazole-resistant isolates of C. albicans. The effects of LD-EO were synergistic with those of miconazole and appeared not to involve damage to the fungal cell wall or plasma membrane. Its effectiveness in inhibiting biofilm formation was higher than the effect of disrupting preformed biofilm. Finally, the product exhibited low hemolytic activity at MIC. Based on the favorable and novel results described here, LD-EO could constitute a promising therapeutic alternative for oral candidiasis, including miconazole-resistant cases.

Coriandrum sativum L. essential oil obtained from organic culture shows antifungal activity against planktonic and multi-biofilm Candida.

This study aimed to analyze the phytochemical profile of essential oil obtained from the leaves of Coriandrum sativum L., and its antifungal activity against Candida spp. The research consisted of an in vitro study including collecting the vegetable product, analysis of its macronutrients, extraction, and chemical analysis of the essential oil, and assaying antifungal activity through minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), with growth inhibition kinetics, and the product's effects on multi-species Candida biofilm. Nitrogen (47.08 g Kg-1), phosphorus (5.3 g Kg-1) and potassium (50.46 g Kg-1) levels were within the normal range. The major constituents were octanal, decanal, dec-(2E)-enal, and dodecanal. The MIC and MFC of the product evaluated against 11 tested Candida strains ranged from 31.25 to 250 µg/mL. There was inhibition of fungal growth during 24 hours of exposure at the 3 concentrations tested (250, 125, and 62.5 µg/mL). The concentration of 80 mg/mL promoted the greatest reduction in multispecies biofilm (70% reduction in biofilm). Coriandrum sativum L. essential oil extract is principally constituted of alcohols and aldehydes and presents fungicidal activity against Candida spp. in its in planktonic and biofilm forms.