Kashimoto Naoki, Hayama Minoru, Kamiya Kenji, Watanabe Hiromitsu
Department of Experimental Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima 734-8553, Japan.
Oncol Rep. 2006 Dec;16(6):1181-7.
A water-soluble extract from the culture medium of Ganoderma lucidum (Rei-shi) mycelia (MAK) has been shown to exert a potent chemopreventive effect. The present study was designed to investigate the effects of dietary MAK supplementation on the development of lung tumors initiated by N-nitrosobis (2-hydroxypropyl) amine (BHP) in male Slc:Wistar rats. A total of 77 animals, 6 weeks of age, were divided into 5 groups and given BHP (2,000 ppm) in their drinking water for 10 weeks. The normal controls were not supplied with BHP. After treatment with the carcinogen, the rats were fed a normal control MF solid diet, or the same diet containing MAK (1.25%, 2.5% or 5%) for 12 weeks. Macroscopically, all the doses of MAK reduced the number of nodules, and the effect of 5% MAK was found to be especially significant. Microscopically, an increase in the number of proliferating cell nuclear antigen (PCNA)-negative tumors and a decrease in the number of tumors strongly positive for PCNA were observed in the tissue sections from the rats that had received all the doses of MAK. The present results thus indicate that dietary supplementation with MAK inhibits the development of lung tumors, suggesting that MAK may be a potent chemopreventive agent against lung carcinogenesis.
灵芝菌丝体培养基的水溶性提取物（MAK）已被证明具有强大的化学预防作用。本研究旨在探讨膳食补充MAK对雄性Slc:Wistar大鼠由N-亚硝基双（2-羟丙基）胺（BHP）引发的肺肿瘤发生发展的影响。将总共77只6周龄的动物分为5组，在其饮用水中给予BHP（2000 ppm），持续10周。正常对照组不给予BHP。在用致癌物处理后，大鼠被喂食正常对照MF固体饲料，或含有MAK（1.25%、2.5%或5%）的相同饲料，持续12周。从宏观上看，所有剂量的MAK都减少了结节数量，发现5% MAK的效果尤为显著。从微观上看，在接受所有剂量MAK的大鼠的组织切片中，观察到增殖细胞核抗原（PCNA）阴性肿瘤数量增加，PCNA强阳性肿瘤数量减少。因此，目前的结果表明，膳食补充MAK可抑制肺肿瘤的发生发展，提示MAK可能是一种有效的抗肺癌化学预防剂。
