Effects of diphenyl diselenide diet on a model of mercury poisoning

This work investigated the preventive effect of diphenyl diselenide [(PhSe)₂] against the toxic effects of mercury in silver catfish (Rhamdia quelen). The animals were treated during 30 consecutive days with a (PhSe)₂ supplemented feed (3.0 mg kg^-1) or commercial feed. During the last 5 days the animals received a daily intraperitoneal dose of HgCl₂ (1.7 mg kg^-1) or Saline (0.9%). Twenty-four hours after the last HgCl₂ injection, the animals were euthanized by spinal cord section to biological material obtainment. Hepatic (AST and ALT) and renal (ammonia and creatinine) toxicity biomarkers, δ-ALA-D activity, TBARS, total and non-protein thiols levels and hepatic, renal and blood mercury (Hg) and zinc (Zn) content were evaluated. Considering renal parameters, HgCl₂ exposition increased serum creatinine levels and decreased δ-ALA-D activity, total and non-protein thiols and TBARS levels. HgCl₂ exposure also decreased blood δ-ALA-D activity. With exception of blood δ-ALA-D activity and total thiols levels, (PhSe)₂ supplementation partially prevented mercury induced alterations. Animals exposed to HgCl₂ presented an increase in liver and kidney Hg content and a decrease in liver and blood Zn content. The alteration in blood Zn content was partially prevented with (PhSe)₂ supplementation. With the exception of mercury and zinc content, no effects of HgCl₂ exposure on hepatic tissue were observed. These results show that (PhSe)₂ supplementation can represent a promising alternative to prevent the toxic effects presented by Hg exposure.