Inhibitory activity of hinokitiol against biofilm formation in fluconazole-resistant Candida species

PLoS One. 2017 Feb 2;12(2):e0171244. doi: 10.1371/journal.pone.0171244. eCollection 2017.

Abstract

The aim of this study was to investigate the ability of hinokitiol to inhibit the formation of Candida biofilms. Biofilm inhibition was evaluated by quantification of the biofilm metabolic activity with XTT assay. Hinokitiol efficiently prevented biofilm formation in both fluconazole-susceptible and fluconazole-resistant strains of Candida species. We determined the expression levels of specific genes previously implicated in biofilm development of C. albicans cells by real-time RT-PCR. The expression levels of genes associated with adhesion process, HWP1 and ALS3, were downregulated by hinokitiol. Transcript levels of UME6 and HGC1, responsible for long-term hyphal maintenance, were also decreased by hinokitiol. The expression level of CYR1, which encodes the component of signaling pathway of hyphal formation-cAMP-PKA was suppressed by hinokitiol. Its upstream general regulator RAS1 was also suppressed by hinokitiol. These results indicate that hinokitiol may have therapeutic potential in the treatment and prevention of biofilm-associated Candida infections.

MeSH terms

  • Antifungal Agents / pharmacology*
  • Biofilms / drug effects*
  • Candida / drug effects*
  • Candida albicans / drug effects
  • Candida glabrata / drug effects
  • Candida tropicalis / drug effects
  • Drug Resistance, Fungal
  • Fluconazole / pharmacology
  • Gene Expression Regulation, Fungal / drug effects
  • Microbial Sensitivity Tests
  • Monoterpenes / pharmacology*
  • Real-Time Polymerase Chain Reaction
  • Tropolone / analogs & derivatives*
  • Tropolone / pharmacology

Substances

  • Antifungal Agents
  • Monoterpenes
  • Tropolone
  • Fluconazole
  • beta-thujaplicin

Grants and funding

This research was supported by a grant from Korea University (K1508301).