Novel antifungal activity of purpurin against Candida species in vitro.
The antifungal activity of purpurin (1,2,4-trihydroxy-9,10-anthraquinone), a natural red anthraquinone pigment in madder root (Rubia tinctorum L.), was evaluated by a broth microdilution assay against a total of 24 Candida isolates representing six species. The minimum inhibitory concentration (MIC) range of purpurin was 1.28-5.12 μg/ml. Mechanistic studies using the rhodamine 6G extrusion assay indicated that purpurin inhibited the energy-dependent efflux pumps of the Candida isolates in a dose-dependent manner. Furthermore, purpurin demonstrated a dose-dependent depolarization of mitochondrial membrane potential, one of the biochemical checkpoints regulating cell death in eukaryotic cells, suggesting a possible linkage between purpurin antifungal mechanism and Candida apoptosis.
Kang
Kai
K
Department of Biochemistry, The Chinese University of Hong Kong, Hong Kong, China.
Fong
Wing-Ping
WP
Tsang
Paul Wai-Kei
PW
D000880:Anthraquinones / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D008928:Mitochondria / Q000502:physiology
D000880:Anthraquinones; D000935:Antifungal Agents; C511975:purpurin anthraquinone