Antitumor activity of water extract of a mushroom, Inonotus obliquus, against HT-29 human colon cancer cells

Phytother Res. 2009 Dec;23(12):1784-9. doi: 10.1002/ptr.2836.


In the current study, it was demonstrated that the hot water extract of I. obliquus (IOWE) exerts inhibitory activity against the proliferation of human colon cancer cells (HT-29). The inhibitory effect of IOWE on the growth of HT-29 cancer cells was evaluated by treating cells with IOWE at concentrations of 0.25, 0.5 and 1.0 mg/mL for 24 or 48 h. The IOWE inhibited cell growth in a dose-dependent manner, and this inhibition was accompanied by apoptotic cell death. The maximum inhibitory effect (56%) was observed when IOWE was treated at a concentration of 1.0 mg/mL for 48 h. The apoptotic effect of IOWE on HT-29 cells was also confirmed by flow cytometric analysis. In addition, the apoptotic cell percentage was closely associated with down-regulation of Bcl-2 and up-regulation of Bax and caspase-3. The results suggest that IOWE would be useful as an antitumor agent via the induction of apoptosis and inhibition of the growth of cancer cells through up-regulation of the expression of proapoptotic proteins and down-regulation of antiapoptotic proteins.

MeSH terms

  • Agaricales / chemistry*
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects*
  • Caspase 3 / metabolism
  • Cell Survival
  • Dose-Response Relationship, Drug
  • Gene Expression Regulation, Neoplastic
  • HT29 Cells
  • Humans
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • bcl-2-Associated X Protein / metabolism


  • Antineoplastic Agents
  • Proto-Oncogene Proteins c-bcl-2
  • bcl-2-Associated X Protein
  • Caspase 3