Modulation of genotoxicity and cytotoxicity by radish grown in metal-contaminated soils

Members of the Brassicaceae family are known for their anticarcinogenic and genetic material protective effects. However, many of the species of this family accumulate high amounts of metals, which is an undesirable feature. Radish (Raphanus sativus L.) has shown to accumulate metals in roots to a higher extent than others members of Brassicaceae. The main objectives of this work are (i) to study the distribution of the accumulated As, Pb and Cd in radish plants and (ii) to establish the genotoxic, antigenotoxic and cytotoxic activities of the root and shoot of this vegetable. Results indicate that (i) the shoots of radish accumulate higher concentrations of metal(oid)s than roots; (ii) the shoots were genotoxic at the different concentrations studied, with the root showing such genotoxic effect only at the highest concentration assayed; (iii) the antigenotoxic potential of radish is reduced in plants with high metal content and (iv) the tumouricide activities of the radish plants were negatively correlated to their metal(oid) contents. An interaction between metal(oid)s and the isotyocianates (hydrolysis products of the glucosinolates) contained in the radish is suggested as the main modulator agents of the genotoxic activity of the plants grown in contaminated soils with metal(oid)s.