Antibiofilm and Antihyphal Activities of Cedar Leaf Essential Oil, Camphor, and Fenchone Derivatives against Candida albicans

Abstract

<i>Candida albicans</i> can form biofilms composed of yeast, hyphal, and pseudohyphal elements, and <i>C. albicans</i> cells in the hyphal stage could be a virulence factor. The present study describes the chemical composition, antibiofilm, and antihyphal activities of cedar leaf essential oil (CLEO), which was found to possess remarkable antibiofilm activity against <i>C. albicans</i> but not to affect its planktonic cell growth. Nineteen components were identified in CLEO by gas chromatography/mass spectrometry, and phenolics were the main constituents. Of these, camphor, fenchone, fenchyl alcohol, α-thujone, and borneol significantly reduced <i>C. albicans</i> biofilm formation. Notably, treatments with CLEO, camphor, or fenchyl alcohol at 0.01% clearly inhibited hyphal formation, and this inhibition appeared to be largely responsible for their antibiofilm effects. Transcriptomic analyses indicated that camphor and fenchyl alcohol downregulated some hypha-specific and biofilm related genes (<i>ECE1, ECE2, RBT1</i>, and <i>EED1</i>). Furthermore, camphor and fenchyl alcohol reduced <i>C. albicans</i> virulence in a <i>Caenorhabditis elegans</i> nematode model. These results demonstrate CLEO, camphor, and fenchyl alcohol might be useful for controlling <i>C. albicans</i> infections.