Prevention of the development of preneoplastic lesions, aberrant crypt foci, by a water-soluble extract from cultured medium of Ganoderma lucidum (Rei-shi) mycelia in male F344 rats

Oncol Rep. 2001 Nov-Dec;8(6):1341-5. doi: 10.3892/or.8.6.1341.


The modifying effects of a dietary water-soluble extract from cultured medium of Ganoderma lucidum (Rei-shi or Mannentake) mycelia (MAK) on the development of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) were investigated in male F344 rats. Rats were given subcutaneous injections of AOM (20 mg/kg body weight) once a week for three weeks to induce ACF and fed on diets containing 0, 1.25, 2.5 and 5.0% MAK for five weeks, starting one week before the first dose of carcinogen. MAK significantly and dose-dependently prevented the development of ACF, decreasing the total number of AC and inhibiting cyst formation. MAK (2.5 and 5.0%) also significantly reduced the longitudinal-cross section areas of colon epithelium. MAK in all doses significantly reduced the PCNA positive index, area of the germinal region and number of cells per half crypt. In an additional in vitro experiment, MAK inhibited anchorage-independent growth of several colon carcinoma cell lines. The present results thus indicate that dietary MAK could act as a preventive agent for colon carcinogenesis.

MeSH terms

  • Animals
  • Anticarcinogenic Agents / pharmacology*
  • Azoxymethane
  • Cell Division / drug effects
  • Colonic Neoplasms / chemically induced
  • Colonic Neoplasms / metabolism
  • Colonic Neoplasms / pathology
  • Colonic Neoplasms / prevention & control*
  • Culture Media
  • Male
  • Mycelium
  • Plant Extracts / pharmacology*
  • Precancerous Conditions / chemically induced
  • Precancerous Conditions / metabolism
  • Precancerous Conditions / pathology
  • Precancerous Conditions / prevention & control*
  • Proliferating Cell Nuclear Antigen / metabolism
  • Rats
  • Rats, Inbred F344
  • Reishi*
  • Tumor Cells, Cultured


  • Anticarcinogenic Agents
  • Culture Media
  • Plant Extracts
  • Proliferating Cell Nuclear Antigen
  • Azoxymethane