Madrigal-Santillán E, Alvarez-González I, Márquez-Márquez R, Velázquez-Guadarrama N, Madrigal-Bujaidar E
Laboratorio de Genética, Escuela Nacional de Ciencias Biológicas, I.P.N, Sto. Tomás, Mexico.
Arch Environ Contam Toxicol. 2007 Oct;53(3):466-72. doi: 10.1007/s00244-006-0074-7. Epub 2007 Jul 26.
Aflatoxin B(1) (AFB(1)) is a potent mutagenic and carcinogenic agent found in numerous agricultural and dairy products consumed by humans. Therefore, we evaluated the capacity of mannan to cope with its genotoxic potential. We prepared a diet constituted of corn (90%) plus the recommended amount of other nutrients, as well as with the tested compounds (mannan and/or AFB(1)). Mice were fed this diet during 4 weeks as follows: one group with AFB(1)-contaminated corn (0.25 mg/kg of corn), three groups with mannan (50, 250, and 500 mg/kg of corn) plus AFB(1) (0.25 mg/kg), another group with only mannan (500 mg/kg), and the last group with an uncontaminated diet and no mannan added. We determined the weight, the micronucleated normochromatic erythrocyte rate (MNNE), the polychromatic/normochromatic index, and the sister chromatid exchange rate (SCE). We also examined the recovery response of mice during 4 additional weeks, when they were fed only the normal diet without AFB(1) or mannan. The results in the first period revealed the following: a) mice fed with mannan alone presented values in the range determined for the control group; b) mice fed AFB(1) had a significant weight decrease, as well as a significant increase in the rate of MNNE and SCE; and c) animals fed the combined regimen (AFB(1) plus mannan) presented a 25% weight increase with respect to the animals treated with AFB(1) alone, as well as a significant reduction in the level of MNNE and SCE with the two high doses tested. In the second (recovery) period, the control and the mannan fed groups maintained values similar to those exhibited in the previous phase, and the AFB(1) group as well as the groups fed the regimen combined with mannan showed an improvement in all evaluated parameters; the best response was that found in mice fed AFB(1) plus 500 mg/kg of mannan. Our study established an antigenotoxic effect of mannan that could be due to its adsorbent capacity.
黄曲霉毒素B1（AFB1）是一种在人类食用的众多农产品和乳制品中发现的强效诱变剂和致癌剂。因此，我们评估了甘露聚糖应对其遗传毒性潜力的能力。我们制备了一种由玉米（90%）加推荐量的其他营养素以及受试化合物（甘露聚糖和/或AFB1）组成的饮食。小鼠按如下方式喂食这种饮食4周：一组喂食受AFB1污染的玉米（0.25毫克/千克玉米），三组分别喂食甘露聚糖（50、250和500毫克/千克玉米）加AFB1（0.25毫克/千克），另一组仅喂食甘露聚糖（500毫克/千克），最后一组喂食未受污染且未添加甘露聚糖的饮食。我们测定了体重、微核正染红细胞率（MNNE）、嗜多染/正染指数和姐妹染色单体交换率（SCE）。我们还检查了小鼠在另外4周的恢复反应，在此期间它们仅喂食不含AFB1或甘露聚糖的正常饮食。第一阶段的结果显示如下：a）仅喂食甘露聚糖的小鼠呈现出在对照组确定的范围内的值；b）喂食AFB1的小鼠体重显著下降，同时MNNE和SCE率显著增加；c）喂食联合方案（AFB1加甘露聚糖）的动物相对于仅用AFB1处理的动物体重增加了25%，并且在测试的两个高剂量下MNNE和SCE水平显著降低。在第二（恢复）阶段，对照组和喂食甘露聚糖的组维持了与前一阶段相似的值，AFB1组以及喂食联合方案（AFB1加甘露聚糖）的组在所有评估参数上均有所改善；最佳反应是在喂食AFB1加500毫克/千克甘露聚糖的小鼠中发现的。我们的研究确定了甘露聚糖的抗遗传毒性作用，这可能归因于其吸附能力。
