Metabolism and Toxicity of Organic Arsenic Compounds in Marine Organisms

Abstract

The ingestion of finfish has been recommended as a preventive measure for lifestyle-related diseases, and marine algae are gaining attention as a source of dietary fiber and essential nutrients, including minerals. However, given the recognition of a potential for high arsenic levels in marine organisms, these dietary recommendations may have neglected the necessity of verifying the absence of health risk from the ingestion of arsenic in marine-derived foods. Under such circumstances, it is clear that the toxicological effects of both arsenosugars and arsenolipids, common in marine-derived materials, are important among organic arsenic (As) compounds. This includes the recent identification of thio-dimethylarsinic acid (thio-DMA) as an arsenosugar metabolite and the demonstration that it is more cytotoxic than even inorganic arsenic (III) which is considered highly toxic. Moreover, multiple studies have found arsenic-containing hydrocarbons (AsHCs), a group of arsenolipids produced by marine organisms, are strong neurotoxins. Similar to thio-DMA, AsHCs are equally or more toxic than inorganic arsenic. Thus, future efforts need to elucidate the biological and toxic effects of organic As compounds by evaluating next-generation effects and brain dysfunction caused by genotoxicity. Although arsenobetaine (AB) is the organic As compound with the highest probability of ingestion, the conclusion that AB is a nontoxic arsenical seems probable.