PDF(Pubmed)
Abstract：
Aflatoxin B1 (AFB1) is a highly hepatotoxic and carcinogenic mycotoxin produced by Aspergillus species. The compound is mainly metabolized in the liver and its metabolism varies between species. The present study quantified relevant AFB1- metabolites formed by mouse, rat, and human primary hepatocytes after treatment with 1 µM and 10 µM AFB1. The use of liquid chromatographic separation coupled with tandem mass spectrometric detection enabled the selective and sensitive determination of phase I and phase II metabolites of AFB1 over incubation times of up to 24 h. The binding of AFB1 to macromolecules was also considered. The fastest metabolism of AFB1 was observed in mouse hepatocytes which formed aflatoxin P1 as a major metabolite and also its glucuronidated form, while AFP1 occurred only in traces in the other species. Aflatoxin M1 was formed in all species and was, together with aflatoxin Q1 and aflatoxicol, the main metabolite in human cells. Effective epoxidation led to high amounts of DNA adducts already 30 min post-treatment, especially in rat hepatocytes. Lower levels of DNA adducts and fast DNA repair were found in mouse hepatocytes. Also, protein adducts arising from reactive intermediates were formed rapidly in all three species. Detoxification via glutathione conjugation and subsequent formation of the N-acetylcysteine derivative appeared to be similar in mice and in rats and strongly differed from human hepatocytes which did not form these metabolites at all. The use of qualitative reference material of a multitude of metabolites and the comparison of hepatocyte metabolism in three species using advanced methods enabled considerations on toxification and detoxification mechanisms of AFB1. In addition to glutathione conjugation, phase I metabolism is strongly involved in the detoxification of AFB1.
摘要：
黄曲霉毒素B1（AFB1）是由曲霉属物种产生的高度肝毒性和致癌的霉菌毒素。该化合物主要在肝脏中代谢并且其代谢在物种之间变化。本研究定量了小鼠形成的相关AFB1-代谢物，rat,用1µM和10µMAFB1处理后的人原代肝细胞。使用液相色谱分离与串联质谱检测相结合，可以在长达24小时的孵育时间内选择性和灵敏地测定AFB1的I相和II相代谢物。还考虑了AFB1与大分子的结合。在小鼠肝细胞中观察到AFB1的最快代谢，形成黄曲霉毒素P1作为主要代谢产物及其葡糖醛酸化形式，而AFP1仅在其他物种中出现痕迹。黄曲霉毒素M1在所有物种中都有形成，与黄曲霉毒素Q1和黄曲霉毒素一起，人体细胞中的主要代谢产物。有效的环氧化导致大量的DNA加合物已经30分钟后，尤其是在大鼠肝细胞中。在小鼠肝细胞中发现较低水平的DNA加合物和快速的DNA修复。此外，在所有三个物种中，由反应性中间体产生的蛋白质加合物迅速形成。通过谷胱甘肽缀合的解毒作用以及随后形成的N-乙酰半胱氨酸衍生物在小鼠和大鼠中似乎相似，并且与根本不形成这些代谢物的人肝细胞有很大不同。使用多种代谢物的定性参考材料以及使用先进方法比较三种物种的肝细胞代谢，可以考虑AFB1的毒性和解毒机制。除了谷胱甘肽缀合，I期代谢与AFB1的解毒密切相关。
