Propranolol hydrochloride induces neurodevelopmental toxicity and locomotor disorders in zebrafish larvae

Propranolol hydrochloride is the first-line drug for the clinical treatment of hypertension, arrhythmia, and other diseases. However, with the increasing use of this drug, its safety and environmental health have received more and more attention. In this study, aquatic vertebrate zebrafish were used as a model to study the toxic effects and mechanisms of propranolol hydrochloride. It was revealed that zebrafish larvae exposed to propranolol hydrochloride showed aberrant head nerve development and locomotor disorders. Additionally, exposure to propranolol hydrochloride could induce oxidative stress, alter the activities of AChE and ATPase, and disrupt the expression of genes involved in neurodevelopment and neurotransmitter pathways. More interestingly, the expression of Parkinson's disease-related genes was altered in zebrafish treated with propranolol hydrochloride. We detected the expression of genes related to the Wnt signaling pathway and found that their expression appeared to be down-regulated. The phenotype of nerve developmental defects and locomotor disorders can be effectively rescued by astaxanthin and Wnt activators. Collectively, the results suggest that propranolol hydrochloride may induce neurotoxicity and abnormal movement behavior with PD-like symptoms in zebrafish larvae.