Ziliotto L, Barbisan L F, Rodrigues M A M
Department of Pathology, Botucatu Medical School, UNESP Sao Paulo State University, Botucatu, SP, Brazil.
Hum Exp Toxicol. 2008 Jun;27(6):505-11. doi: 10.1177/0960327108091862.
The mushroom Agaricus blazei (Ab) has been widely used in folk medicine to treat various diseases including cancer. No information is available on its possible protective effects on the development of colon cancer. The potential blocking effect of Ab intake on the initiation stage of colon carcinogenesis was investigated in a short-term (4-week) bioassay using aberrant crypt foci (ACF) as biomarker. Male Wistar rats were given four subcutaneous injections of the carcinogen 1,2-dimethylhydrazine (DMH, 40 mg/kg bw, twice a week), during 2 weeks to induce ACF. The diet containing Ab at 5% was given 2 weeks before and during carcinogen treatment to investigate the potential beneficial effects of this edible mushroom on DMH-induced ACF. All groups were killed at the end of the fourth week. The colons were analyzed for ACF formation in 1% methylene blue whole-mount preparations and for cell proliferation in histological sections immunohistochemically stained for the proliferating cell nuclear antigen (PCNA). All DMH-treated rats developed ACF mainly in the middle and distal colon. Agaricus blazei intake at 5% did not alter the number of ACF induced by DMH or the PCNA indices in the colonic mucosa. Thus, the results of the present study did not confirm a chemopreventive activity of Ab on the initiation stage of rat colon carcinogenesis.
姬松茸（Ab）已在民间医学中广泛用于治疗包括癌症在内的各种疾病。关于其对结肠癌发生可能的保护作用尚无相关信息。在一项为期4周的短期生物测定中，以异常隐窝灶（ACF）作为生物标志物，研究了摄入姬松茸对结肠癌发生起始阶段的潜在阻断作用。雄性Wistar大鼠在2周内接受4次皮下注射致癌物1,2 - 二甲基肼（DMH，40 mg/kg体重，每周两次）以诱导ACF形成。在致癌物处理前2周及处理期间给予含5%姬松茸的饮食，以研究这种食用菌对DMH诱导的ACF的潜在有益作用。在第四周结束时处死所有组。对结肠进行分析，在1%亚甲蓝全层制剂中检测ACF形成情况，并在免疫组织化学染色检测增殖细胞核抗原（PCNA）的组织切片中检测细胞增殖情况。所有接受DMH处理的大鼠主要在结肠中部和远端出现ACF。摄入5%的姬松茸并未改变DMH诱导的ACF数量或结肠黏膜中的PCNA指数。因此，本研究结果未证实姬松茸对大鼠结肠癌发生起始阶段具有化学预防活性。
