Plagiochin E, an antifungal active macrocyclic bis(bibenzyl), induced apoptosis in Candida albicans through a metacaspase-dependent apoptotic pathway

Biochim Biophys Acta. 2010 Apr;1800(4):439-47. doi: 10.1016/j.bbagen.2010.01.001. Epub 2010 Jan 11.


Background: Plagiochin E (PLE) is an antifungal active macrocyclic bis(bibenzyl) isolated from liverwort Marchantia polymorpha L. To elucidate the mechanism of action, previous studies revealed that the antifungal effect of PLE was associated with the accumulation of ROS, an important regulator of apoptosis in Candida albicans. The present study was designed to find whether PLE caused apoptosis in C. albicans.

Methods: We assayed the cell cycle by flow cytometry using PI staining, observed the ultrastructure by transmission electron microscopy, studied the nuclear fragmentation by DAPI staining, and investigated the exposure of phosphatidylserine at the outer layer of the cytoplasmic membrane by the FITC-annexin V staining. The effect of PLE on expression of CDC28, CLB2, and CLB4 was determined by RT-PCR. Besides, the activity of metacaspase was detected by FITC-VAD-FMK staining, and the release of cytochrome c from mitochondria was also determined. Furthermore, the effect of antioxidant L-cysteine on PLE-induced apoptosis in C. albicans was also investigated.

Results: Cells treated with PLE showed typical markers of apoptosis: G(2)/M cell cycle arrest, chromatin condensation, nuclear fragmentation, and phosphatidylserine exposure. The expression of CDC28, CLB2, and CLB4 was down-regulated by PLE, which may contribute to PLE-induced G(2)/M cell cycle arrest. Besides, PLE promoted the cytochrome c release and activated the metacaspase, which resulted in the yeast apoptosis. The addition of L-cysteine prevented PLE-induced nuclear fragmentation, phosphatidylserine exposure, and metacaspase activation, indicating the ROS was an important mediator of PLE-induced apoptosis.

Conclusions: PLE induced apoptosis in C. albicans through a metacaspase-dependent apoptotic pathway.

General significance: In this study, we reported for the first time that PLE induced apoptosis in C. albicans through activating the metacaspase. These results would conduce to elucidate its underlying antifungal mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Annexin A5 / drug effects
  • Annexin A5 / metabolism
  • Antifungal Agents / isolation & purification
  • Antifungal Agents / pharmacology*
  • Apoptosis / drug effects
  • Bridged-Ring Compounds / chemistry
  • Bridged-Ring Compounds / isolation & purification
  • Bridged-Ring Compounds / pharmacology*
  • Candida albicans / cytology
  • Candida albicans / drug effects*
  • Candida albicans / enzymology
  • Candida albicans / genetics
  • Caspase Inhibitors
  • Cell Cycle / drug effects
  • DNA Primers
  • Flow Cytometry
  • Macrocyclic Compounds / chemistry
  • Macrocyclic Compounds / isolation & purification
  • Macrocyclic Compounds / pharmacology*
  • Marchantia / chemistry
  • Models, Molecular
  • Molecular Conformation
  • Protease Inhibitors / pharmacology
  • RNA, Fungal / genetics
  • RNA, Fungal / isolation & purification
  • Reverse Transcriptase Polymerase Chain Reaction
  • Stilbenes / chemistry
  • Stilbenes / isolation & purification
  • Stilbenes / pharmacology*


  • Annexin A5
  • Antifungal Agents
  • Bridged-Ring Compounds
  • Caspase Inhibitors
  • DNA Primers
  • Macrocyclic Compounds
  • Protease Inhibitors
  • RNA, Fungal
  • Stilbenes
  • plagiochin E