Voriconazole inhibits melanization in Cryptococcus neoformans

Antimicrob Agents Chemother. 2007 Dec;51(12):4396-400. doi: 10.1128/AAC.00376-07. Epub 2007 Oct 8.

Abstract

Voriconazole is a triazole antifungal drug that inhibits ergosterol synthesis and has broad activity against yeast and molds. While studying the interaction of voriconazole and Cryptococcus neoformans, we noted that cells grown in the presence of subinhibitory concentrations of voriconazole reduced melanin pigmentation. We investigated this effect systematically by assessing melanin production in the presence of voriconazole, amphotericin B, caspofungin, itraconazole, and fluconazole. Only voriconazole impeded the formation of melanin at subinhibitory concentrations. Voriconazole did not affect the autopolymerization of l-dopa, and 0.5 MIC of voriconazole did affect the gene expression of C. neoformans. However, voriconazole inhibited the capacity of laccase to catalyze the formation of melanin. Hence, voriconazole affects melanization in C. neoformans by interacting directly with laccase, which may increase the efficacy of this potent antifungal against certain pigmented fungi.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antifungal Agents / pharmacology
  • Cell Line
  • Cryptococcus neoformans / drug effects*
  • Cryptococcus neoformans / genetics
  • Cryptococcus neoformans / metabolism
  • Fluconazole / pharmacology
  • Gene Expression Regulation, Fungal / drug effects
  • Laccase / genetics
  • Laccase / metabolism
  • Macrophages / drug effects
  • Macrophages / microbiology
  • Melanins / metabolism*
  • Mice
  • Microbial Sensitivity Tests
  • Phagocytosis / drug effects
  • Pyrimidines / pharmacology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Triazoles / pharmacology*
  • Voriconazole

Substances

  • Antifungal Agents
  • Melanins
  • Pyrimidines
  • Triazoles
  • Fluconazole
  • Laccase
  • Voriconazole