IADR Abstract Archives
Antifungal Potential of Essential Oils and Development of an Ex Vivo Model for Oral Candidosis
Objectives: This study has two main aims. Firstly, the antifungal activity of a range of essential oils (14), chlorhexidine and triclosan were evaluated against C. albicans under planktonic and biofilm conditions. Secondly, an ex vivo rodent mandible model to mimic oral candidosis was developed in order to investigate the antimicrobial properties of the successful compound.
Methods: Antifungal properties were determined using a microtitre plate assay. In vitro biofilms were constructed using 96-well plates and exposed to a range of antimicrobial concentrations. The minimum biofilm eradication concentrations (MBECs) were established by examining subsequent re-growth of biofilm cells. Results were compared with the minimum inhibitory concentrations (MICs) obtained for planktonic cells cultured in 96-wells plates. The ex vivo rodent mandible model was obtained by dissecting the mandible from a 28-day-old male Wistar rat and infecting it with C. albicans. Candida growth was monitored through histological examination and image analysis after incubation for 24 and 48 hours, whilst host tissue response was assessed by cytokine expression through RT-PCR.
Results: In the planktonic form, all the compounds tested showed Candida specific antimicrobial potential with MICs ranging from 0.002% (v/v) to 0.638% (v/v). There was also a noticeable increase in resistance in pre-formed biofilms (MBECs > 0.068% (v/v)). The infection of the rodent mandible showed Candida invasion of the gingiva and the release of pro-inflammatory cytokines (TNF, IL1, and IL6).
Conclusions: Despite an increase in resistance against pre-formed biofilms, this study showed that essential oils are promising agents to be used against oral candidosis, being able to inhibit Candida growth in the planktonic form. In addition, the development of an ex-vivo rodent mandible model allowed testing the antifungal properties of a variety of essential oils in a system that better mimics the in vivo conditions (e.g. tissue organization, penetration of the microorganisms into the tissues and host response).
Methods: Antifungal properties were determined using a microtitre plate assay. In vitro biofilms were constructed using 96-well plates and exposed to a range of antimicrobial concentrations. The minimum biofilm eradication concentrations (MBECs) were established by examining subsequent re-growth of biofilm cells. Results were compared with the minimum inhibitory concentrations (MICs) obtained for planktonic cells cultured in 96-wells plates. The ex vivo rodent mandible model was obtained by dissecting the mandible from a 28-day-old male Wistar rat and infecting it with C. albicans. Candida growth was monitored through histological examination and image analysis after incubation for 24 and 48 hours, whilst host tissue response was assessed by cytokine expression through RT-PCR.
Results: In the planktonic form, all the compounds tested showed Candida specific antimicrobial potential with MICs ranging from 0.002% (v/v) to 0.638% (v/v). There was also a noticeable increase in resistance in pre-formed biofilms (MBECs > 0.068% (v/v)). The infection of the rodent mandible showed Candida invasion of the gingiva and the release of pro-inflammatory cytokines (TNF, IL1, and IL6).
Conclusions: Despite an increase in resistance against pre-formed biofilms, this study showed that essential oils are promising agents to be used against oral candidosis, being able to inhibit Candida growth in the planktonic form. In addition, the development of an ex-vivo rodent mandible model allowed testing the antifungal properties of a variety of essential oils in a system that better mimics the in vivo conditions (e.g. tissue organization, penetration of the microorganisms into the tissues and host response).