Stimulation of autophagic activity in human glioma cells by anti-proliferative ardipusilloside I isolated from Ardisia pusilla

Life Sci. 2014 Aug 6;110(1):15-22. doi: 10.1016/j.lfs.2014.06.016. Epub 2014 Jun 28.


Aims: Ardipusilloside I (ADS-I), a triterpenoid saponin isolated from Ardisia pusilla A.DC (Myrsinaceae), has been recently tested for cancer treatment including brain cancer. However, the mechanism of its action remains elusive. The present study was to investigate the role of autophagy activation in the anti-tumor activities of ADS-I in human glioma cells.

Main methods: The tetrazolium dye (MTT) colorimetric assay was used for the measurement of cell proliferation in cultured glioma cells, transmission electron microscopy (TEM) for the examination of autophagic activity, flow cytometric analysis for the determination of cell cycle and apoptotic cells, and immunocytochemistry and Western blot for protein expression of microtubule-associated protein light-chain 3 (LC3) and Beclin 1.

Key findings: ADS-I significantly inhibited the proliferation of both U373 and T98G glioma cells in cultures in a dose-dependent manner. The cytotoxic activity of ADS-I against glioma cell growth was associated not only with the induction of cell cycle arrest at G2/M phase and cell apoptosis in flow cytometric analysis, but also with the activation of autophagy, indicated by the formation of autophagosomes and up-regulated expression of both autophagic protein Beclin 1 and LC3 in glioma cells. Additionally, the treatment with chloroquine, an autophagy inhibitor, reduced ADS-1-mediated cell death.

Significance: These data suggest that the anti-proliferative activity of ADS-I in human glioma cells is associated with the activation of autophagy in addition to cell cycle arrest and apoptosis, and the antagonistic effect of chloroquine suggests an important role of autophagy in ADS-I-mediated cell death against tumor growth.

Keywords: Apoptosis; Ardipusilloside I; Ardisia pusilla; Autophagy; Human glioblastoma; Natural compound; Triterpenoid saponin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents, Phytogenic / administration & dosage
  • Antineoplastic Agents, Phytogenic / isolation & purification
  • Antineoplastic Agents, Phytogenic / pharmacology
  • Apoptosis / drug effects
  • Apoptosis Regulatory Proteins / genetics
  • Ardisia / chemistry*
  • Autophagy / drug effects*
  • Beclin-1
  • Brain Neoplasms / drug therapy*
  • Brain Neoplasms / pathology
  • Cell Cycle / drug effects
  • Cell Cycle Checkpoints / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Chloroquine / pharmacology
  • Dose-Response Relationship, Drug
  • Flow Cytometry
  • Gene Expression Regulation, Neoplastic / drug effects
  • Glioma / drug therapy*
  • Glioma / pathology
  • Humans
  • Membrane Proteins / genetics
  • Oleanolic Acid / administration & dosage
  • Oleanolic Acid / analogs & derivatives*
  • Oleanolic Acid / isolation & purification
  • Oleanolic Acid / pharmacology
  • Saponins / administration & dosage
  • Saponins / isolation & purification
  • Saponins / pharmacology*


  • Antineoplastic Agents, Phytogenic
  • Apoptosis Regulatory Proteins
  • BECN1 protein, human
  • Beclin-1
  • Membrane Proteins
  • Saponins
  • ardipusilloside I
  • Oleanolic Acid
  • Chloroquine