In Vitro Reduction of Arsenic Bioavailability Using Dietary Strategies

The main route of human exposure to inorganic arsenic (As) is through the consumption of food and water. Continued exposure to inorganic As [As(III) and As(V)] may cause a variety of diseases, including various types of cancer. The removal of As from these sources is complex, especially for food. One way to decrease As exposure could be by reducing intestinal absorption of it. The aim of this study is to seek dietary strategies (pure compounds, extracts, or supplements) that are capable of reducing the amount of As that is absorbed and reaches systemic circulation. Standard solutions of As(III) and As(V) and bioaccessible fractions of food samples with or without the dietary strategies to be tested were added to colon-derived human cells (NCM460 and HT-29MTX) to determine the apparent permeability (P_app) of As. Results show that transport across the intestinal monolayers is substantial, and the passage of As(III) (P_app = 4.2 × 10^-5 cm/s) is greater than that of As(V) (P_app = 2.4 × 10^-5 cm/s). Some of the treatments used (iron species, cysteine, grape extract) significantly reduce the transport of both inorganic As standards across the intestinal monolayer, thus decreasing absorption of them. In food samples, the effect of the dietary compounds on inorganic As bioavailability was also observed, especially in the cases of curcumin and cysteine. Compounds that proved effective in these in vitro assays could be the basis for intervention strategies aimed at reducing As toxicity in chronically exposed populations or regular consumers of food products with high As contents.