Gayan Wijesinghe - Area of Microbiology and Immunology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, SP, Brazil
Thaís Oliveira - Area of Microbiology and Immunology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, SP, Brazil
Flavia Maia - Area of Microbiology and Immunology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, SP, Brazil
Simone de Feiria - Area of Microbiology and Immunology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, SP, Brazil
Felipe Joia - Area of Microbiology and Immunology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, SP, Brazil
Janaina Barbosa - Area of Microbiology and Immunology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, SP, Brazil
Giovana Boni - Area of Microbiology and Immunology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, SP, Brazil
José Höfling - Area of Microbiology and Immunology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, SP, Brazil

Objective(s): The essential oil (EO) extracted from Cinnamomum verum leaves has been used as an antimicrobial agent for centuries. But its antifungal and antibiofilm efficacy is still not clearly studied. The objective of this research was to evaluate the in vitro antifungal and antibiofilm efficacy of C. verum leaf EO against C. albicans, C. tropicalis, and C. dubliniensis and the toxicity of EO using an in vitro model.Materials and Methods: The effect of EO vapor was evaluated using a microatmosphere technique. CLSI microdilution assay was employed in determining the Minimum Inhibitory (MIC) and Fungicidal Concentrations (MFC). Killing time was determined using a standard protocol. The effect of EO on established biofilms was quantified and visualized using XTT and Scanning Electron Microscopy (SEM), respectively. Post-exposure intracellular changes were visualized using Transmission Electron Microscopy (TEM). The toxicological assessment was carried out with the Human Keratinocyte cell line. The chemical composition of EO was evaluated using Gas Chromatography-Mass Spectrometry (GC-MS).Results: All test strains were susceptible to cinnamon oil vapor. EO exhibited MIC value ۱.۰ mg/ml and MFC value ۲.۰ mg/ml against test strains. The killing time of cinnamon oil was ۶ hr. Minimum Biofilm Inhibitory Concentration (MBIC۵۰) for established biofilms was Conclusion: C. verum EO is a potential alternative anti-candida agent with minimal toxicity on the human host.

Antifungal agent, Biofilms, Candida spp, Cinnamomum verum Essential oil