Bazo Ana Paula, Rodrigues Maria Aparecida Marchesan, Sforcin José Maurício, de Camargo João Lauro Viana, Ribeiro Lúcia Regina, Salvadori Daisy Maria Fávero
Departamento de Patologia, Faculdade de Medicina, UNESP, Botucatu, São Paulo, Brazil.
Teratog Carcinog Mutagen. 2002;22(3):183-94. doi: 10.1002/tcm.10011.
Propolis is a honeybee product with several biological and therapeutical properties. Its effect on the process of colon carcinogenesis and DNA damage were evaluated in the male Wistar rats using the aberrant crypt foci (ACF) assay and the comet assay, respectively. For both tests, animals were treated with the colon carcinogen 1,2 dimethylhydrazine (DMH, 40 mg/kg, s.c.) for 2 weeks (two injections/week) in order to induce both DNA damage and ACF. The animals were divided into groups that received propolis (ethanolic extract) at three different doses (10, 30, and 90 mg/kg b.w., by gavage), either simultaneously or after DMH treatment. For the comet assay, peripheral blood samples were collected 4 h after the last DMH treatment. All animals were sacrificed at the 5th week for evaluation of ACF. The results show that only the intermediate dose (30 mg/kg) of propolis, administered after DMH initiation, is significantly associated to a smaller number of aberrant crypts in the distal colon. No effect on DNA damage in peripheral blood cells, however, was verified by the comet assay. These data suggest that propolis has a protective influence on the process of colon carcinogenesis, suppressing the development of preneoplastic lesions, and probably exerts no protection against the initiation of carcinogenesis.
蜂胶是一种具有多种生物学和治疗特性的蜜蜂产品。分别使用异常隐窝灶（ACF）试验和彗星试验，在雄性Wistar大鼠中评估了其对结肠癌发生过程和DNA损伤的影响。对于这两项试验，动物用结肠致癌物1,2-二甲基肼（DMH，40mg/kg，皮下注射）处理2周（每周两次注射），以诱导DNA损伤和ACF。将动物分为几组，分别以三种不同剂量（10、30和九十mg/kg体重，经口灌胃）同时或在DMH处理后给予蜂胶（乙醇提取物）。对于彗星试验，在最后一次DMH处理后4小时采集外周血样本。所有动物在第5周处死以评估ACF。结果表明，仅在DMH开始后给予的中等剂量（30mg/kg）蜂胶与远端结肠中异常隐窝数量减少显著相关。然而，彗星试验未证实对外周血细胞DNA损伤有影响。这些数据表明，蜂胶对结肠癌发生过程具有保护作用，可抑制癌前病变的发展，并且可能对致癌作用的起始没有保护作用。
