Bioaccumulation and Oxidative Stress Induced by Organometallic and Ionic Tin Compounds in Zebrafish (Danio rerio) Embryos.

Abstract

Tin, a heavy metal, in trace amounts is believed to play various roles in the biological development of fish, including involvement in cell structure, enzyme activities, and the metabolism of proteins and carbohydrates. Two endocrine-disrupting chemicals, Tributyltin (TBT) and Triphenyltin (TPT), are prevalent in aquatic environments. This study examines the bioaccumulation of these compounds and their impact on oxidative stress enzymes. Zebrafish embryos were used to assess the acute toxicity of TBT, TPT, and SnCl₂. Toxicity tests were conducted on fertilized eggs using different concentrations of TBT, TPT, and SnCl₂ (0, 1, 5, 10, 15, and 20 ng/L). The LC_{50, 96 h} values for TBT, TPT, and SnCl₂ in zebrafish embryos were 4.2, 8.7, and 12.56 ng/L, respectively. The study found an increase in the catalase (CAT) superoxide dismutase (SOD), and malondialdehyde (MDA) for TBT, TPT, and SnCl₂. Moreover, TBT showed higher bioaccumulation than other compounds. The mortality rate was higher in embryos exposed to TBT, suggesting that embryos are more susceptible to TBT and can induce oxidative stress and disrupt the antioxidant equilibrium..