Zearalenone induced embryo and neurotoxicity in zebrafish model (Danio rerio): Role of oxidative stress revealed by a multi biomarker study

Abstract

In the present study, we evaluated the zearalenone induced adverse effects in zebrafish embryos using various endpoints like embryo toxicity, heart rate, oxidative stress indicators (reactive oxygen species (ROS), lipid peroxidation (LPO), Nitric oxide (NO)), antioxidant responses (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase enzyme (GST) and reduced glutathione (GSH), metabolic biomarkers (lactate dehydrogenase (LDH) and Nitric oxide (NO)), neurotoxicity (acetylcholinesterase (AChE)), genotoxicity (comet assay and acridine orange staining (AO)) and histological analysis. In this study, four concentrations 350, 550, 750 and 950 μg/L of ZEA were chosen based on LC10 and LC50 values of the previous report. The results shows that ZEA induces developmental defects like pericardial edema, hyperemia, yolk sac edema, spine curvature and reduction in heart rate from above 550 μg/L exposure and the severity was increased with concentration and time dependent manner. Significant induction in oxidative stress indices (ROS, LPO and NO), reduction in antioxidant defence system (SOD, CAT, GPx, GST and GSH) and changes in metabolic biomarkers (LDH and AP) were observed at higher ZEA exposed concentration. Neurotoxic effects of ZEA were observed with significant inhibition of AChE activity at higher exposure groups (750 and 950 μg/L). Moreover, we also noticed DNA damage, apoptosis and histological changes in the higher ZEA treatments at 96 h post fertilization (hpf) embryos. Hence, in the present study we concluded that oxidative stress is the main culprit in ZEA induced developmental, genotoxicity and neurotoxicity in zebrafish embryos.

Keywords: Antioxidant enzymes; Apoptosis; Histology; Oxidative stress; Zearalenone; Zebrafish embryos.