LP-55 Potential Protective Effects of Calcined Mg-Al LDH Against Cadmium-Induced Toxicity in Danio rerio Early Developmental Stages

Layered double hydroxides (LDHs) are nanomaterials composed of positively charged mixed-metal hydroxide layers intercalated with anions and water molecules. Because of their ion-exchange capacity and adsorption capability, LDHs demonstrate promise in removing pollutants of the aquatic environment, including heavy metals. Cadmium is a metal posing a significant risk to aquatic organisms. This environmental pollutant primarily affects the nervous system. Our study evaluated the ability of calcined zinc-aluminium LDH-nitrate (c-Zn Al LDH-NO 3 ) and calcined magnesium-aluminium LDH-nitrate (c-Mg Al LDH-NO 3 ) to prevent cadmium-induced toxicity in early developmental stages of zebrafish ( Danio rerio ). We assessed mortality, malformations, and hatching rate after exposure of Danio rerio embryos and larvae to cadmium alone and in combination with 100 mg·l -1 c-Zn-Al LDH-NO 3 or c-Mg Al LDH-NO 3 following the OECD 236 guideline. The molecular changes in the DNA after 96 h were measured using a single-cell gel electrophoresis assay (comet assay). Cadmium exposure led to pericardial edema, impaired yolk sac absorption, and tail malformations. The hatching success was significantly decreased compared to untreated organisms. We also found significant DNA damage at LC 50 cadmium concentration. Co-exposure with c-Mg Al LDH-NO 3 reduced some of the cadmium effects, while c-Zn Al LDH-NO 3 did not induce similar protection. We found that c-Mg Al LDH-NO 3 is a potential protective material for reducing cadmium toxicity in aquatic environments. Further testing is needed to unveil why the other nanomaterial was not so effective.