An aqueous polysaccharide extract from the edible mushroom Pleurotus ostreatus induces anti-proliferative and pro-apoptotic effects on HT-29 colon cancer cells

Cancer Lett. 2006 Nov 28;244(1):61-70. doi: 10.1016/j.canlet.2005.12.007. Epub 2006 Jan 18.


Anti-proliferative and pro-apoptotic activities of fractions of Pleurotus ostreatus were examined using HT-29 colon cancer cells in vitro. A hot-water-soluble fraction of the mycelium of the liquid cultured mushroom was partially isolated and chemically characterized as a low-molecular-weight alpha-glucan. HT-29 cells were exposed to the different isolates and significant inhibition of proliferation was obtained in a dose-dependent manner. Proliferation inhibition was shown to be the result of apoptotic induction because the pro-apoptotic molecules Bax and cytosolic cytochrome-c were upregulated. Fluorescence-activated cell sorter analyses of polysaccharide-treated HT-29 cells showed a high percentage of Annexin-positive cells. Here, we describe a newly identified low-molecular-weight alpha-glucan with promising anti-tumorigenic properties, and demonstrate its direct effect on colon cancer cell proliferation via induction of programmed cell death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Annexin A5 / metabolism
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects*
  • Cell Proliferation / drug effects*
  • Cytochromes c / metabolism
  • Cytosol / enzymology
  • Glucans / pharmacology*
  • HT29 Cells / drug effects
  • Humans
  • Molecular Weight
  • Plant Extracts / pharmacology*
  • Pleurotus / chemistry*
  • bcl-2-Associated X Protein / metabolism


  • Annexin A5
  • Antineoplastic Agents
  • Glucans
  • Plant Extracts
  • bcl-2-Associated X Protein
  • Cytochromes c