Combined administration of selenium and meso-2, 3-dimercaptosuccinic acid on arsenic mobilization and tissue oxidative stress in chronic arsenic-exposed male rats

Objective : The present study describes the effect of selenium either alone or in combination with meso-2, 3-dimercaptosuccinic acid (DMSA) against chronic arsenic poisoning in rats.
Materials and Methods : Male Wistar rats were exposed to 100 ppm sodium arsenite in drinking water for eight months and treated thereafter with DMSA (0.3 mmol/kg orally) either individually or in combination with selenium (Se, 6.3 or 12.6 µmol/kg, intraperitoneally) once daily for five days. The effects of these treatments in influencing the arsenic (As)-induced changes in heme synthesis, hepatic, renal or brain oxidative stress were evaluated along with the As concentration in blood and soft tissues.
Results : Exposure to As significantly altered biochemical parameters related to the heme synthesis pathway, blood and organ (liver, kidney and brain) oxidative stress while increasing body As burden in animals. Treatment with DMSA alone significantly reduced the adverse effects related to most of these biochemical parameters as well as the As concentration in blood and tissues. On the other hand, co-administration of Se with DMSA had only limited additional beneficial effects (particularly tissue oxidative stress) over the individual effect of DMSA.
Conclusion : The above results suggest that Se administration during chelation affected by other agents had some beneficial effects on oxidative stress with no major additional beneficial effect on arsenic depletion.

Keywords
Arsenic toxicity, chelating agent, oxidative stress, rats, selenium, combination therapy.