Efficacy of citronella and cinnamon essential oils on Candida albicans biofilms.
BACKGROUND
The discovery of new antimicrobials derived from plants could aid in the management of biofilm-associated infections, including denture-induced stomatitis (DS). DS is an oral infection caused by Candida biofilms on the surfaces of poorly cleansed dentures. Effective treatment of DS requires the use of an appropriate denture cleanser and preferably one that exhibits antimicrobial properties.


OBJECTIVE
This study aimed to evaluate the anti-Candida and anti-biofilm efficacy of two essential plant oils from Cymbopogon winterianus (citronella) and Cinnamon cassia (cinnamon).


METHODS
Minimum Inhibitory Concentrations (MICs) and Minimum Fungicidal Concentrations (MFCs) were determined by broth microdilution, whilst anti-biofilm activity was measured against mature (cultured for 72 h) biofilms on acrylic surfaces. Candida cell viability was assessed immediately (0 h) after treatment (T0) and 48 h after biofilm re-growth (T48). Biofilm structure was determined using Scanning Electron Microscopy (SEM) at T0 and T48.


RESULTS
The respective MICs of cinnamon and citronella oils were 65 and 250 μg/ml and these were also the MFC values. For anti-biofilm efficacy, both oils significantly (p < 0.05) reduced the number of viable micro-organisms and accumulation of biofilms at T0. However, at T48, there was no difference between treated and untreated biofilms.


CONCLUSIONS
It is concluded that citronella and cinnamon essential oils have potential for daily anti-candidal denture cleansing.
a Department of Restorative Dentistry , Araraquara Dental School, Univ. Estadual Paulista-UNESP , Araraquara , SP , Brazil ;
Leopoldina de Fátima Dantas de
Lde F
Almeida
b Department of Dentistry , School of Dentistry. Imperatriz Faculty (FACIMP) , Imperatriz , MA , Brazil ;
Jacqueline Felipe de
JF
Paula
b Department of Dentistry , School of Dentistry. Imperatriz Faculty (FACIMP) , Imperatriz , MA , Brazil ;
Rossana Vanessa Dantas de
RV
Almeida
c Oral and Biomedical Sciences , School of Dentistry, Cardiff University , Cardiff , Wales , UK ;
David Wynne
DW
Williams
d Department of Orthodontics and Paediatric Dentistry , Araraquara Dental School, Univ. Estadual Paulista-UNESP , Araraquara , SP , Brazil ;
Josimeri
J
Hebling
e Department of Dentistry , State University of Paraiba , Campina Grande , PB , Brazil.
Yuri Wanderley
YW
Cavalcanti
D000171:Acrolein / Q000031:analogs & derivatives / Q000494:pharmacology; D000180:Acrylic Resins / Q000737:chemistry; D000080462:Acyclic Monoterpenes; D000447:Aldehydes / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D002176:Candida albicans / Q000187:drug effects*; D027424:Cinnamomum; D031743:Cymbopogon; D044622:Dental Pellicle / Q000382:microbiology; D003820:Denture Cleansers; D006801:Humans; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D039821:Monoterpenes / Q000494:pharmacology; D009822:Oils, Volatile / Q000494:pharmacology*; D008517:Phytotherapy / Q000379:methods; D010938:Plant Oils / Q000494:pharmacology*; D011897:Random Allocation; D013499:Surface Properties; D013997:Time Factors
D000180:Acrylic Resins; D000080462:Acyclic Monoterpenes; D000447:Aldehydes; D000935:Antifungal Agents; D003820:Denture Cleansers; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; C488492:QC 20 (denture base resin); D000171:Acrolein; C007078:citronellol; C108217:citronellal; C076730:citronella oil; C012843:cinnamaldehyde
Anti-infective agents; Candida albicans; biofilm; denture stomatitis; phytotherapy