Insights into the combined toxicity of copper and cadmium in zebrafish (Danio rerio) embryos and adults
Year: 2025
Type: article
Abstract: Metal pollution is a long-term environmental problem affecting the ecological integrity of different environmental compartments. Efforts have been made to investigate the mechanisms underlying the toxicological outcomes of metal pollution, but the key molecular and physiological events that contribute to understanding the mode of action related to mixed exposure scenarios are poorly documented and understood, especially when different life stages are included. In this study, zebrafish (Danio rerio) embryos and adults were used to investigate the responses to single and combined toxicity of Cu and Cd. The acute (10-day) toxicity of Cu in adult zebrafish is much higher compared to Cd with respective LC50/LC10 values of 216/91 µg/L (3.40/1.43 µM) and >2500/1750 µg/l (22.2/15.5 µM) in medium hard water. However, in combined Cu/Cd scenarios, the toxicity of the mixture becomes much stronger, indicative of a strong Cu/Cd toxicological interaction. Molecular and physiological responses were investigated during embryonic development and in adults using Cu and Cd concentrations in a combination resulting in a response close to the 10-day LC10 in the mixture (i.e. Cu 0.80 µM (50.8 µg/L and Cd 0.25 µM (28.1 µg/L). Developmental, morphological, and functional endpoints were evaluated in embryos at 96 hpf (hours post fertilisation). Metal accumulation and molecular responses related to oxidative stress, apoptosis, metal transport, and DNA repair were studied at both life stages to provide new insights into general and specific stress responses. The results show a strongly increased sensitivity of both embryos and adults simultaneously exposed to both metals. Underlying mechanisms activated during this combined exposure were related to DNA damage and oxidative stress. The degree of toxicity and underlying mode of action in adults showed organ specific differences. In addition, our data indicate that metal accumulation is not a strong indicator of toxicity, reflecting the importance of internal metal compartmentalization in toxicity.
Language: English
Subfield: Health, Toxicology and Mutagenesis
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,650
OpenAlex ID: W4410768425