Lemke S L, Mayura K, Reeves W R, Wang N, Fickey C, Phillips T D
Faculty of Toxicology (VAPH), College of Veterinary Medicine, Texas A & M University, College Station 77843-4458, USA.
J Toxicol Environ Health A. 2001 Feb 23;62(4):243-58. doi: 10.1080/009841001459405.
Previous studies with low-pH montmorillonite (LPHM) clay exchanged with alkylammonium compounds showed that these organo clays were quite effective in sorbing the estrogenic mycotoxin zearalenone (ZEN) from aqueous solution. The potential toxicity of these types of clays, in particular hexadecyltrimethylammonium (HDTMA) LPHM, led to the investigation of the sorption efficacy of clay exchanged with a less toxic primary amine analog, hexadecylamine (HDA). Isothermal analysis studies showed that HDA LPHM was able to bind ZEN, but less effectively than HDTMA LPHM as evidenced by a significantly lower Freundlich K (63,900 vs. 845). The in vivo effectiveness of these two clays to bind ZEN was tested utilizing the mouse uterine weight bioassay. At a dietary inclusion level of 0.25%, the clays did not have a negative impact on overall animal health as measured by final body weight; however, they did not protect the animals from the estrogenic effects induced by 35 mg ZEN/kg in the feed (i.e., the uterine weights were not reduced in comparison to ZEN alone). In fact, the HDTMA LPHM group showed an increase in uterine weight that was more than the ZEN treatment group. When the animals were fed 0.5% clay, both exchanged clays (i.e., HDTMA LPHM and HDA LPHM) resulted in decreased body weight gain. The uterine weights of ZEN-fed animals (either alone or in combination with clays) were not significantly different from each other. In contrast, the uterine:body weight ratio showed a dramatic increase in the groups fed exchanged clay + ZEN compared to ZEN alone. These results suggest that alkylamine groups may assist the transport or uptake of ZEN and result in an enhanced toxicity from contaminated feed. The findings from this study clearly demonstrate the need for careful testing of all mycotoxin-binding agents before their inclusion in the diet.
先前对与烷基铵化合物交换的低pH蒙脱石（LPHM）粘土的研究表明，这些有机粘土在从水溶液中吸附雌激素性霉菌毒素玉米赤霉烯酮（ZEN）方面相当有效。这些类型的粘土，特别是十六烷基三甲基铵（HDTMA）LPHM的潜在毒性，促使人们对与毒性较小的伯胺类似物十六胺（HDA）交换的粘土的吸附效果进行研究。等温分析研究表明，HDA LPHM能够结合ZEN，但效果不如HDTMA LPHM，Freundlich K值显著更低（63,900对845）证明了这一点。利用小鼠子宫重量生物测定法测试了这两种粘土在体内结合ZEN的有效性。在日粮添加水平为0.25%时，通过最终体重衡量，粘土对动物整体健康没有负面影响；然而，它们并不能保护动物免受饲料中35 mg ZEN/kg诱导的雌激素效应（即与单独使用ZEN相比，子宫重量没有降低）。事实上，HDTMA LPHM组的子宫重量增加幅度超过了ZEN处理组。当给动物喂食0.5%的粘土时，两种交换粘土（即HDTMA LPHM和HDA LPHM）都导致体重增加减少。喂食ZEN的动物（单独或与粘土组合）的子宫重量彼此之间没有显著差异。相比之下，与单独喂食ZEN相比，喂食交换粘土+ZEN的组的子宫与体重比显著增加。这些结果表明，烷基胺基团可能有助于ZEN的转运或吸收，并导致受污染饲料的毒性增强。这项研究的结果清楚地表明，在将所有霉菌毒素结合剂纳入日粮之前，需要进行仔细测试。
