Effect of Tyrosol on Candida Biofilm Formation

Objectives: Tyrosol is a Candida quorum-sensing molecule that participates in Candida albicans morphogenesis, but its role as an antibiofilm agent is not elucidated. This study aimed to test the effectiveness of tyrosol in inhibiting C. albicans and C. glabrata biofilm formation.
Methods: Acrylic resin (AR) and hydroxyapatite (HA) specimens were inserted into 24-well plates and inoculated with Candida strains (10⁷ cells/mL) for 2 h to promote adhesion cell to substrates. Next, tyrosol was diluted in artificial saliva at concentrations of 50, 100 and 200 mM, added to adhered cells and incubated at 37 ºC to allow biofilm formation. After 48 h, tyrosol efficacy was determined by total biofilm biomass quantification and by the metabolic activity (XTT). Chlorhexidine digluconate (CHG) was used as positive control. The data were analyzed statistically by two-way ANOVA and Holm-Sidak post-hoc test (α = 0.05).
Results: For C. albicans biofilms formed on AR, the exposure to CHG and tyrosol promoted significant reductions in total biomass ranging from 15.38 % to 30.76 %. When these biofilms were formed on HA, there were no decreases in biomass. Tyrosol was not able to reduce the C. glabrata biofilm biomass. Comparing the two types of substrates, it was observed higher total biomass on AR (p < 0.001) for C. albicans, and on HA for C. glabrata (p < 0.05). For two Candida strains, regardless of substrate, the treatment with CHG and tyrosol promoted significant reductions (p < 0.001) in the metabolic activity of biofilm cells, with reductions ranging from 22.64 % to 92.30 %.
Conclusions: These findings suggest that tyrosol has inhibitory effect on Candida biofilm formation and may contribute to the development of alternative therapies aimed at preventing Candida-associated denture stomatitis.