A comprehensive evaluation of the effects and mechanisms of naringenin on zebrafish embryo development

Naringenin (NGN), a flavonoid widely utilized in agricultural and pharmaceutical applications, has increasingly become a source of environmental concern. This study systematically evaluated the developmental toxicity of NGN in zebrafish embryos. Our results showed that NGN exposure caused dose-dependent increases in embryonic mortality and induced a range of developmental malformations, including reduced body length, impaired eye and ear development, and cardiac dysfunction. Behavioral analyses revealed significant deficits in locomotor activity and sensory responses at concentrations of 5 and 10 mg/L. Molecular assessments via RT-qPCR demonstrated that NGN disrupted the expression of multiple genes critical for cardiac (kcnh2a, kcnh2b, hand2, has2, myh7, tnnt2a), otic (col2a1a, sox9a, sox9b), liver (hhex, leg1.1), visual (gnat1, gnat2), apoptotic (bax, casp9, casp3), and neurodevelopmental (pomca, bdnf, gfap, mbpa, s100b) pathways. Notably, NGN at 10 mg/L inhibited apoptosis and altered liver function, whereas a concentration of 15 mg/L promoted apoptosis, and these results suggest that NGN may interfere with the developmental processes of zebrafish embryos through different mechanisms at low and high concentrations, exhibiting a non-monotonic dose-response relationship. These findings highlight the potential ecological hazards of NGN contamination in aquatic environments, emphasizing the need for stricter management and further research into its long-term and combined effects with other pollutants. Our research offers new perspectives into the molecular and phenotypic mechanisms of NGN toxicity and underscores the importance of comprehensive risk assessment for emerging environmental contaminants.