Biotransformation of Dietary Inorganic Arsenic in a Freshwater Fish Carassius auratus and the Unique Association between Arsenic Dimethylation and Oxidative Damage

Publication date: Available online 21 January 2020Source: Journal of Hazardous MaterialsAuthor(s): Di Cui, Peng Zhang, Haipu Li, Zhaoxue Zhang, Wenbao Luo, Zhaoguang YangAbstractThe metabolic process and toxicity mechanism of dietary inorganic arsenic (iAs) in freshwater fish remain unclear to date. The present study conducted two iAs [arsenate (As(V)) and arsenite (As(III))] dietary exposures in freshwater fish crucian carp (Carassius auratus). The fish were fed on As supplemented artificial diets at nominal concentrations of 50 and 100 μg As(III) or As(V) g-1 (dry weight) for 10 d and 20 d. We found that liver, kidney, spleen and intestine accumulate more As in As(V) feeding group than that in As(III), while the total As level in muscle were similar between As(V) and As(III) group at the end of exposure. Reduction of As(V) to As(III) and oxidation of As(III) to As(V) occurred in fish fed with As(V) and As(III), respectively, indicating that toxicity of iAs were likely elevated or reduced when iAs was absorbed by fish before entering into human body through diet. Biomethylation to monomethylarsonic acid and dimethylarsinic acid and transformation to arsenocholine and arsenobetaine were also found in the fish. The linear regression analysis showed a positive correlation between secondary methylation index and the malondialdehyde content in tissues, highlighting the vital role of arsenic dimethylation in the oxidative damages in fish.Graphical abstract
Source: Journal of Hazardous Materials - Category: Environmental Health Source Type: research