Assessing the impact of Ag-ZnO nanoparticle on the induction of oxidative stress, hematological, and molecular changes in zebrafish (Danio rerio) and McCoy fibroblast cell lines

Abstract

Silver nanoparticles (Ag-NPs) are renowned for their biological activity, while zinc oxide (ZnO) is a biocompatible metal oxide used in catalytic applications such as organic pollutant degradation and wastewater treatment. This study investigates the synthesis, characterization, and toxicological effects of silver-doped zinc oxide nanoparticles (Ag-ZnO NPs). Ag-ZnO NPs were synthesized with 3.0 mol% Ag(I) using the sol–gel method and characterized using X-ray diffraction (XRD), UV–Vis spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDX). Acute toxicity was evaluated in zebrafish (Danio rerio) embryos and adults, assessing mortality rates and hematological parameters. Additionally, the impact was also evaluated on enzymatic activity levels and the expression of proinflammatory cytokine genes. The cytotoxicity of Ag-ZnO NPs was also tested on McCoy fibroblast cells using the MTT assay. Acute toxicity tests in zebrafish embryos and larvae revealed a dose-dependent increase in mortality rates with rising Ag-ZnO NP concentrations. Hematological analysis showed a significant reduction in red blood cell (RBC) count and hemoglobin (Hb) levels, likely due to RBC lysis or impaired erythropoiesis. Elevated levels of superoxide dismutase (SOD), catalase (CAT), glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), acid phosphatase (ACP), and alkaline phosphatase (ALP) were observed in fish tissues, particularly indicating liver damage. Upregulation of proinflammatory cytokine genes (TNF-α, COX-2, and IL-10) was most pronounced in liver tissues. The MTT assay on McCoy fibroblast cells indicated that Ag-ZnO NPs induced cytotoxicity in a dose-dependent manner, with higher concentrations causing more significant cell damage. This study highlights the complex and dose-dependent effects of Ag-ZnO NPs on zebrafish physiology and McCoy fibroblast cell viability. The findings underscore the need for careful consideration of nanoparticle concentrations in applications to mitigate potential biological and environmental risks.