Assessment of Oxidative Stress in Zebrafish (Danio rerio) Exposed to Fenvalerate: Analysis of Antioxidant Enzyme Gene Expression and Enzyme Activity

This study aimed to investigate the effects of fenvalerate treatment on the expression of sod1, cat, gstt1a, gpx1a, gsr , and g6pd genes, as well as the activities of SOD, CAT, GST, GPX, GR, and G6PD enzymes in zebrafish. The assessment of oxidative stress was conducted by analyzing liver and gill tissue samples. Both the concentration of fenvalerate (3.125 and 6.25 µg/L) and the duration of exposure influenced the changes observed in antioxidant enzyme activities and gene expression in zebrafish. The RT-PCR results indicated that the expression of these genes in fenvalerate-exposed zebrafish might function as an immediate response mechanism to chemical-induced stress. Furthermore, the activities of CAT, GST, and G6PD enzymes in both tissues exhibited an increase exposure to fenvalerate doses of 3.125 and 6.25 µg/L. The activities of CAT, GST, and G6PD enzymes in both liver and gill tissues demonstrated a decrease. However, prolonged exposure (over 72 hours) resulted in significantly higher MDA concentrations in the liver and gill tissues compared to the control sample. These findings contribute to our understanding of the role of antioxidant enzymes in oxidative stress and have practical implications for designing aquaculture selection programs to enhance stress tolerance in fish.