Kobayashi Hironori, Suzuki Noriyuki, Ogra Yasumitsu
Laboratory of Toxicology and Environmental Health, Graduate School of Pharmaceutical Sciences, Chiba University, Chuo, Chiba 260-8675, Japan.
Toxicol Rep. 2018 Feb 2;5:220-223. doi: 10.1016/j.toxrep.2018.01.005. eCollection 2018.
Selenium (Se) is an essential element in animals but becomes severely toxic when the amount ingested exceeds the adequate intake level. It is known that the toxicological effects of Se are highly dependent on its chemical form. In this study, we evaluated the mutagenicity of nine naturally occurring Se compounds or the so-called bioselenocompounds, including selenite, selenate, selenocyanate, selenomethionine, selenocystine, -methylselenocysteine, selenohomolanthionine, -acetylgalactosamine-type selenosugar, and trimethylselenonium ion, by using the Ames test. typhimurium TA98, TA100, and TA1535 were used for the mutagenicity evaluation in the presence or absence of S9 mix, a metabolic activator. Only selenate showed weak mutagenicity even in the absence of S9 mix. None of the bioselenocompounds except selenate exhibited mutagenicity in all the strains tested in the presence or absence of S9 mix. Selenomethionine and selenocystine reduced the number of colonies in all the strains although no other selenoamino acids exerted the same effect. These results indicate that selenate directly or indirectly injures genome. Among the bioselenocompounds tested, selenomethionine and selenocystine show antibacterial activity, but the mechanism is unclear.
硒（Se）是动物体内的必需元素，但当摄入量超过适当摄入水平时会变得具有严重毒性。已知硒的毒理学效应高度依赖于其化学形式。在本研究中，我们通过艾姆斯试验评估了九种天然存在的硒化合物或所谓的生物硒化合物的致突变性，这些化合物包括亚硒酸盐、硒酸盐、硒氰酸盐、硒代蛋氨酸、硒代胱氨酸、γ-甲基硒代半胱氨酸、硒代高胱氨酸、N-乙酰半乳糖胺型硒糖和三甲基硒离子。鼠伤寒沙门氏菌TA98、TA100和TA1535用于在有无代谢激活剂S9混合物存在的情况下进行致突变性评估。即使在没有S9混合物的情况下，只有硒酸盐显示出微弱的致突变性。在有无S9混合物存在的情况下，除硒酸盐外，所有测试菌株中没有一种生物硒化合物表现出致突变性。硒代蛋氨酸和硒代胱氨酸减少了所有菌株中的菌落数，尽管其他硒代氨基酸没有产生相同的效果。这些结果表明，硒酸盐直接或间接损伤基因组。在所测试的生物硒化合物中，硒代蛋氨酸和硒代胱氨酸具有抗菌活性，但其机制尚不清楚。
