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.
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.
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Department of Environment and Mutation, Research Institute for Radiation Biology and Medicine, Hiroshima University, Minami-ku, Hiroshima 734-8553, Japan.
Uesaka
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Katoh
O
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Kyo
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Watanabe
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H
D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D001397:Azoxymethane; D002455:Cell Division / Q000187:drug effects; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D003470:Culture Media; D008297:Male; D025282:Mycelium; D010936:Plant Extracts / Q000494:pharmacology*; D011230:Precancerous Conditions / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D020940:Reishi; D014407:Tumor Cells, Cultured
D016588:Anticarcinogenic Agents; D003470:Culture Media; D010936:Plant Extracts; D018809:Proliferating Cell Nuclear Antigen; D001397:Azoxymethane