Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA.
Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA; Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA.
Toxicology. 2021 Jun 15;457:152803. doi: 10.1016/j.tox.2021.152803. Epub 2021 Apr 24.
Exposure to arsenic (As) is a major public health concern globally. Inorganic As (InAs) undergoes hepatic methylation to form monomethyl (MMAs)- and dimethyl (DMAs)-arsenical species, facilitating urinary As elimination. MMAs is considerably more toxic than either InAs or DMAs, and a higher proportion of MMAs in urine has been associated with risk for a wide range of adverse health outcomes. Efficiency of As methylation differs substantially between species, between individuals, and across populations. One-carbon metabolism (OCM) is a biochemical pathway that provides methyl groups for the methylation of As, and is influenced by folate and other micronutrients, such as vitamin B, choline, betaine and creatine. A growing body of evidence has demonstrated that OCM-related micronutrients play a critical role in As methylation. This review will summarize observational epidemiological studies, interventions, and relevant experimental evidence examining the role that OCM-related micronutrients have on As methylation, toxicity of As, and risk for associated adverse health-related outcomes. There is fairly robust evidence supporting the impact of folate on As methylation, and some evidence from case-control studies indicating that folate nutritional status influences risk for As-induced skin lesions and bladder cancer. However, the potential for folate to be protective for other As-related health outcomes, and the potential beneficial effects of other OCM-related micronutrients on As methylation and risk for health outcomes are less well studied and warrant additional research.
砷（As）暴露是一个全球性的主要公共卫生问题。无机砷（InAs）在肝脏中经过甲基化形成一甲基（MMAs）和二甲基（DMAs）砷化物，促进了砷的尿液排泄。MMAs 的毒性远高于 InAs 或 DMAs，尿液中 MMAs 的比例较高与多种不良健康结果的风险相关。砷甲基化的效率在物种之间、个体之间和人群之间存在很大差异。一碳代谢（OCM）是提供甲基供砷甲基化的生化途径，受叶酸和其他微量营养素（如维生素 B、胆碱、甜菜碱和肌酸）的影响。越来越多的证据表明，OCM 相关的微量营养素在砷甲基化中起着关键作用。这篇综述将总结观察性流行病学研究、干预措施以及相关实验证据，探讨 OCM 相关微量营养素在砷甲基化、砷毒性和相关不良健康相关结局风险中的作用。有相当多的证据支持叶酸对砷甲基化的影响，一些病例对照研究的证据表明，叶酸营养状况影响砷诱导的皮肤损伤和膀胱癌的风险。然而，叶酸对其他与砷相关的健康结果是否具有保护作用，以及其他 OCM 相关微量营养素对砷甲基化和健康结果风险的潜在有益影响研究较少，值得进一步研究。
