Characterization of Green Synthesis VA-Pd/AC NPs and Evaluation of Their Neurotoxicity Using the Zebrafish Larvae

Abstract New strategies for fast, efficient and environmentally friendly approaches in nanoparticle (NP) synthesis have increased the interest in less toxic green synthesis products. In this study, VA-Pd / AC nanoparticles (NPs) were synthesized using palladium (Pd), activated carbon (AC) and Viscum album (VA) aqueous extract as stabilizer / reductant. Activated carbon in the synthesis stage was obtained using the Chenopodium album (CA) plant. The structural and morphological properties of VA-Pd / AC NPs were examined using TEM and XRD analyses. Zebrafish embryo and larvae were exposed to the produced VA-Pd / AC NPs at different concentrations (10, 50, 100 and 500 mg/L) for 96 h. Embryos/larvae were examined for survival rate, hatching and malformation during development. Morever, potential neurotoxic effects were assessed histopathologically and immunohistochemically using Caspase 3 and nNOS indicators. Although the hatching rate of VA-Pd / AC NP was 100% at all concentrations, the survival rate decreased in a dose dependent manner. Histopathological analyses revealed that 10 mg/L group looked similar to the control group, whereas necrotic degenerations were observed in the 50, 100 and 500 mg/L groups in a dose- dependent manner. In addition, Caspase 3 and nNOS expressions were evaluated as negative in the control and 10 mg/L groups in immunofluorescence staining. These results provide the evidence that 500 mg/L concentration of green synthesized VA-Pd/AC NPs from Viscum album (VA) and Chenopodium album (CA) plant induces neurotoxic and tetragenonic effect on zebrafish.