Toxicological Assessment and Potential Protective Effects of Brassica Macrocarpa Guss Leaf Extract Against Copper Sulphate-Induced Oxidative Stress in Zebrafish Embryos

Background: Oxidative stress is a key contributor to many chronic diseases. Natural biocompounds with antioxidant activity are of growing therapeutic interest. Brassica macrocarpa, a plant from the Brassicaceae family, has shown in vitro safety and antioxidant potential due to its rich content of glucosinolates and phenolics. However, in vivo, its effects remain poorly characterized. This study aimed to evaluate the in vivo safety and biological effects of Brassica macrocarpa leaf extract in zebrafish embryos and to assess its potential to counteract copper sulphate (CuSO4)-induced oxidative stress. Methods: Zebrafish embryos were exposed to Brassica macrocarpa extract at concentrations from 125 to 2000 µg/mL. Embryonic mortality and malformations were monitored daily to determine sub-lethal concentrations (125–500 µg/mL) for further behavioural and biochemical analysis. Antioxidant properties were tested in a CuSO4-induced oxidative stress model. Results: No teratogenic effects were observed over 96 h. Larvae showed normal swimming and no behavioural changes. Pre-treatment with the extract significantly reduced CuSO4-induced ROS and NO production, modulated antioxidant enzyme (SOD, CAT) activity, and lowered lipid peroxidation and protein oxidation, slightly affecting DNA damage. Conclusions: Brassica macrocarpa extract in vivo appears safe at sub-lethal doses and shows promising antioxidant effects, suggesting its potential role in managing oxidative stress-related conditions.