Abstract
2,4-Dichlorophenoxyacetic acid (2,4-D) is an herbicide widely used around the world. It has been detected in water samples, with a half-life ranging from 15 to 300 days depending on environmental conditions. This study aimed to assess the effects of short-term exposure to the herbicide 2,4-D on the liver of Danio rerio (zebrafish) through histopathological and histochemical analyses, as well as markers related to oxidative stress. The results revealed structural and vascular lesions in the livers of zebrafish across all groups exposed to 2,4-D (at concentrations of 0.03, 0.3 and 3.0 mg/L). Analysis of the Histopathological Alteration Index suggests severe (3.0 mg/L) or moderate (0.03 and 0.3 mg/L) liver impairment in zebrafish exposed to 2,4-D. Exposure to the herbicide also led to a reduction in acid polysaccharides (0.03 and 3.0 mg/L) and glutathione (GSH) levels (at concentrations of 0.03 and 3.0 mg/L), and increased levels of the oxidized glutathione (GSSG) (at concentrations of 0.03 and 0.3 mg/L). No significant changes in lipid peroxidation levels were observed. These findings suggest that just 7 days of exposure to permissible concentrations of 2,4-D (0.03 mg/L) or higher (0.3 and 3.0 mg/L) can have a detrimental impact on biochemical, histochemical, and histopathological parameters in the liver of adult zebrafish (Danio rerio).