Sun Yuzhen, Liu Guangliang, Cai Yong
Institute of Environment and Health, Jianghan University, Wuhan 430056, China.
Institute of Environment and Health, Jianghan University, Wuhan 430056, China; Department of Chemistry and Biochemistry&Southeast Environmental Research Center, Florida International University, Miami, FL 33199, USA.
J Environ Sci (China). 2016 Nov;49:59-73. doi: 10.1016/j.jes.2016.08.016. Epub 2016 Oct 7.
Arsenic (As) is a notoriously toxic pollutant of health concern worldwide with potential risk of cancer induction, but meanwhile it is used as medicines for the treatment of different conditions including hematological cancers. Arsenic can undergo extensive metabolism in biological systems, and both toxicological and therapeutic effects of arsenic compounds are closely related to their metabolism. Recent studies have identified methylated thioarsenicals as a new class of arsenic metabolites in biological systems after exposure of inorganic and organic arsenicals, including arsenite, dimethylarsinic acid (DMA), dimethylarsinous glutathione (DMAGS), and arsenosugars. The increasing detection of thiolated arsenicals, including monomethylmonothioarsonic acid (MMMTA), dimethylmonothioarsinic acid (DMMTA) and its glutathione conjugate (DMMTAGS), and dimethyldithioarsinic acid (DMDTA) suggests that thioarsenicals may be important metabolites and play important roles in arsenic toxicity and therapeutic effects. Here we summarized the reported occurrence of thioarsenicals in biological systems, the possible formation pathways of thioarsenicals, and their toxicity, and discussed the biological implications of thioarsenicals on arsenic metabolism, toxicity, and therapeutic effects.
砷（As）是一种在全球范围内备受关注的剧毒污染物，具有诱发癌症的潜在风险，但与此同时，它也被用作治疗包括血液系统癌症在内的多种病症的药物。砷在生物系统中可经历广泛的代谢过程，砷化合物的毒理学和治疗效果均与其代谢密切相关。近期研究已确定，在接触无机和有机砷化合物（包括亚砷酸盐、二甲基砷酸（DMA）、二甲基亚砷酰谷胱甘肽（DMAGS）和砷糖）后，甲基化硫代砷化合物是生物系统中一类新的砷代谢产物。包括一甲基一硫代砷酸（MMMTA）、二甲基一硫代砷酸（DMMTA）及其谷胱甘肽共轭物（DMMTAGS）和二甲基二硫代砷酸（DMDTA）在内的硫醇化砷化合物的检测日益增多，这表明硫代砷化合物可能是重要的代谢产物，并在砷的毒性和治疗效果中发挥重要作用。在此，我们总结了生物系统中已报道的硫代砷化合物的存在情况、硫代砷化合物可能的形成途径及其毒性，并讨论了硫代砷化合物对砷代谢、毒性和治疗效果的生物学意义。
