海产品中的砷及其代谢机制的研究进展

海产品中的砷通过食物链富集的方式进入人体。海产品中检测出的砷形态有三价的亚砷酸盐(As(III))、五价的砷酸盐(As(V))、砷胆碱(As C)、砷甜菜碱(As B)、砷糖、砷脂等。各种形态的砷通过不同代谢途径产生不同的代谢产物,从而表现出不同的毒性。砷的形态主要是通过高效液相色谱与电感耦合等离子体质谱仪的联用(HPLC-ICP-MS)来测定的。有机砷中砷胆碱(As C)的代谢产物为砷甜菜碱(As B)和砷脂;砷甜菜碱(As B)经尿液直接排出;不同的砷脂代谢产物不一样;砷糖的代谢产物至少12种,最主要的是五价的二甲基砷酸盐(DMA(V))。无机砷(包括砷酸盐和亚砷酸盐)最后代谢产物为五价的二甲基砷酸盐(DMA(V))和三价的二甲基亚砷酸盐(DMA(III))。海产品经过不同烹调处理后,其总砷浓度或多或少都有增加,砷形态也有变化,部分加工会导致毒性增加。对于消费者来说,注意饮食习惯包括海产品摄入量,摄入间隔,日常营养元素摄入与烹调方式的选择等是预防过量摄入有毒砷形态的有效手段。

Research Progress on Arsenic Species in Seafood and Their Metabolic Mechanisms

Arsenic in seafood enters the human body by a process of food chain enrichment. The arsenic species detected in seafood include arsenide (As(III)), arsenate (As(V)), arsenocholine (AsC), arsenobetaine (AsB), arsenosugars, and arsenolipids. Arsenic species are metabolized through various pathways and result in different metabolites and toxicities. High-performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was used to analyze arsenic species in seafood. The metabolites of AsC, a type of organic arsenic, were mainly AsB and arsenolipids. AsB could be excreted through urine. Each arsenolipid has different metabolites. More than 12 arsenic species were found as metabolites of arsenosugars, of which dimethylarsinic acid (DMA(V)) was the most common. The pentavalent methylated DMA(V), and trivalent methylated DMA(III) were the final metabolites of inorganic arsenic species. Cooking methods affect the concentration of total arsenic and the form of arsenic. Some methods can result in increased toxicity. Therefore, to prevent excessive intake of toxic forms of arsenic, effective measures including reducing seafood intake, increasing intervals between seafood meals, daily intake of specific nutrients, and choosing optimal cooking methods, should be recommended to consumers.