Combined Effects of Arsenic and Cadmium With Selenium on Oxidative Stress Indicators in Goldfish: Implications for Veterinary Toxicology

BACKGROUND: The individual and combined effects of toxic heavy metals, including arsenic (As) and cadmium (Cd) and their interactions with selenium (Se), play a crucial role in modulating bioaccumulation patterns and oxidative stress responses in aquatic organisms. OBJECTIVES: This study aimed to evaluate the effects of As, Cd and Se, individually and in combination, on tissue metal accumulation and oxidative stress biomarkers in goldfish (Carassius auratus). METHODS: A total of 210 fish were randomly assigned to seven experimental groups with three replicates each and exposed to single or combined concentrations of As, Cd and Se via water for 14 days. At the end of the exposure period, tissue concentrations of metals were determined using inductively coupled plasma mass spectrometry (ICP-MS). Oxidative stress biomarkers, including malondialdehyde (MDA), catalase (CAT) and superoxide dismutase (SOD), were assessed using spectrophotometric methods and commercial assay kits. RESULTS AND CONCLUSIONS: Body weight increased in all treatment groups compared to initial values. Co-exposure to Se significantly reduced As accumulation, with tissue concentrations decreasing from 0.16 ± 0.02 mg/kg in the As group to 0.10 ± 0.009 mg/kg in the combined exposure groups (approximately 62 % reduction; p < 0.05). In contrast, Cd accumulation showed no significant difference between the Cd (1.06 ± 0.09 mg/kg) and Cd+Se (1.01 ± 0.07 mg/kg) groups (p > 0.05). A significant positive correlation was observed between As concentration and MDA levels across all groups, including the control (p < 0.01). Conversely, Se exhibited a negative correlation with MDA and a positive correlation with SOD, indicating its protective role against oxidative damage. Overall, the results demonstrate that combined exposure to heavy metals can produce variable toxicological interactions, ranging from antagonistic to potentially synergistic effects, depending on the type of metal and exposure conditions. These interactions are closely associated with oxidative stress responses, highlighting potential ecological risks to aquatic organisms and public health concerns associated with the consumption of contaminated fish.