title: The inhibitory activity of linalool against the filamentous growth and biofilm formation in Candida albicans.
abstract: Candida spp. are part of the natural human microbiota, but they also represent important opportunistic human pathogens. Biofilm-associated Candida albicans infections are clinically relevant due to their high levels of resistance to traditional antifungal agents. In this study, we investigated the ability of linalool to inhibit the formation of C. albicans biofilms and reduce existing C. albicans biofilms. Linalool exhibited antifungal activity against C. albicans ATCC 14053, with a minimum inhibitory concentration (MIC) of 8 mM. Sub-MIC concentrations of linalool also inhibited the formation of germ tubes and biofilms in that strain. The defective architecture composition of C. albicans biofilms exposed to linalool was characterized by scanning electron microscopy. The expression levels of the adhesin genes HWP1 and ALS3 were downregulated by linalool, as assessed by real-time RT-PCR. The expression levels of CYR1 and CPH1, which encode components of the cAMP-PKA and MAPK hyphal formation regulatory pathways, respectively, were also suppressed by linalool, as was the gene encoding their upstream regulator, Ras1. The expression levels of long-term hyphae maintenance associated genes, including UME6, HGC1, and EED1, were all suppressed by linalool. These results indicate that linalool may have therapeutic potential in the treatment of candidiasis associated with medical devices because it interferes with the morphological switch and biofilm formation of C. albicans.
authors.affiliation: Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chih-Chieh
authors.initials: CC
authors.lastname: Hsu
authors.forename: Wen-Lin
authors.initials: WL
authors.lastname: Lai
authors.forename: Kuei-Chin
authors.initials: KC
authors.lastname: Chuang
authors.forename: Meng-Hwan
authors.initials: MH
authors.lastname: Lee
authors.forename: Ying-Chieh
authors.initials: YC
authors.lastname: Tsai
mesh_terms: D000080462:Acyclic Monoterpenes; D000935:Antifungal Agents / Q000494:pharmacology*; D018441:Biofilms / Q000254:growth & development*; D002176:Candida albicans / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D015815:Cell Adhesion Molecules / Q000096:biosynthesis / Q000235:genetics; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics; D020869:Gene Expression Profiling; D025301:Hyphae / Q000187:drug effects / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D039821:Monoterpenes / Q000494:pharmacology*
chemical_list: C109455:ALA1 protein, Candida albicans; D000080462:Acyclic Monoterpenes; D000935:Antifungal Agents; D015815:Cell Adhesion Molecules; D005656:Fungal Proteins; D039821:Monoterpenes; C018584:linalool