A water-soluble extract from cultured medium of Ganoderma lucidum (Rei-shi) mycelia suppresses azoxymethane-induction of colon cancers in male F344 rats.
The present study was designed to investigate the protective effect of a dietary water-soluble extract from cultured medium of Ganoderma lucidum (Rei-shi or Mannentake) mycelia (designated as MAK) on the induction and development of azoxymethane (AOM)-induced colon tumors in male F344/Du Crj rats. A total of 80 animals were divided into five groups at six weeks of age, groups 2, 3 and 4 being given weekly subcutaneous injections of AOM (15 mg/kg body weight) for the initial 3 weeks to induce colon tumors. Rats in group 1 and 5 were injected with the vehicle, 0.9% (w/v) saline, following the same schedule. Rats in groups 1, 2, 3, 4 and 5 were fed MF, MF, 1.25% MAK, 2.5% MAK and 2.5% MAK diets, respectively, starting 1 week before AOM treatment and throughout the six-month experimental period. There were no significant differences in number of ACF, total AC and AC per site among groups 2 to 4, but the tumor incidence was significantly lower, and tumor size was smaller in group 4 (AOM + 2.5% MAK) than in group 2 (AOM + MF). Additionally, beta-catenin positive tumor cell nuclei were significantly decreased in the MAK-fed rats (groups 3 and 4), which also demonstrated lowering of the PCNA labeling index and a shortened germinal region in the colon. The present results thus indicate that dietary MAK could act as a potent chemopreventive agent for colon carcinogenesis.
Lu
Huimei
H
Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima 734-8553, Japan.
Kyo
Eikai
E
Uesaka
Toshihiro
T
Katoh
Osamu
O
Watanabe
Hiromitsu
H
D000236:Adenoma / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D001397:Azoxymethane / Q000633:toxicity; D014408:Biomarkers, Tumor / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D003470:Culture Media; D007124:Immunoenzyme Techniques; D008297:Male; D025282:Mycelium; D010936:Plant Extracts / Q000494:pharmacology*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D020940:Reishi; D014407:Tumor Cells, Cultured
D016588:Anticarcinogenic Agents; D014408:Biomarkers, Tumor; D003470:Culture Media; D010936:Plant Extracts; D018809:Proliferating Cell Nuclear Antigen; D001397:Azoxymethane