Chronic toxicity of arsenic during Rhinella arenarum embryonic and larval development: potential biomarkers of oxidative stress and antioxidant response

BONGIOVANNI, GUILLERMINA; VENTURINO, ANDRÉS; MARDIROSIAN, MARIANA; LASCANO, CECILIA; BONGIOVANNI, GUILLERMINA; VENTURINO, ANDRÉS; MARDIROSIAN, MARIANA; LASCANO, CECILIA

ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY

SETAC PRESS

Año: 2017 vol. 36 p. 1614 - 1621

0730-7268

The Argentinean autochthonous toad Rhinella arenarum was selected to study the chronic toxicity of arsenic and the biochemical responses elicited by exposure to As in water during embryonic and larval development. A significant decrease in the total reactive antioxidant potential and in catalase activity was observed in individuals exposed chronically to sublethal concentrations of As, which is indicative of an oxidative stress situation. However, an antioxidant response was elicited during chronic exposure to As, as evidenced by the increase in endogenous reduced glutathione content and glutathione-related enzymatic activities such as glutathione -S-transferase and reductase. This protective response might prevent a deeper decline in the antioxidant system and further oxidative damage. Alternatively, it might be linked to As conjugation with reduced glutathione for its excretion. Considering the sustained increase in glutathione -S-transferase activity and the decrease in the total antioxidant reactive potential observed in this study, we propose them as good candidates to be used as biomarkers during As exposure. Interestingly, glutathione reductase activity was inhibited at a very low concentration of As considered safe for the aquatic life.