Chronic exposure to low concentration of diflubenzuron and pyriproxyfen induces brain oxidative stress and inflammation and alters locomotion in zebrafish (Danio rerio)

• Published in: Environmental research 2025-01, Vol.264 (Pt 1), p.120278, Article 120278
• Main Authors: Teixeira, Júlia Robert de Sousa, Souza, Augusto Monteiro de, Macedo-Sampaio, João Vitor de, Tavares, Livia Alves de Macedo, Pereira, Bruno Fiorelini, Medeiros, Silvia Regina Batistuzzo de, Luchiari, Ana Carolina
• Format: Article
• Language: English
• Subjects: Animals; Behavior; Brain - drug effects; Brain - metabolism; Chronic exposure; Diflubenzuron - toxicity; Gene expression; Inflammation - chemically induced; Insecticides - toxicity; Locomotion - drug effects; Neurotoxicity; Oxidative Stress - drug effects; Pesticides; Pyridines - toxicity; Water Pollutants, Chemical - toxicity; Zebrafish
• ISSN: 0013-9351; 1096-0953; 1096-0953
• DOI: 10.1016/j.envres.2024.120278

Diflubenzuron (DFB1) and pyriproxyfen (PPF) are pesticides widely used in agriculture and urban environments to control insect actions. The aim of this study was to evaluate the effects of chronic 30-day exposure to DFB (0.025 and 0.125 mg/L) and PPF (0.379 and 0.758 mg/L) on the behavior of juvenile zebrafish (Danio rerio). Fish were exposed to insecticides from early stage (4 h post fertilization) to 30 days post fertilization (dpf). At 45 dpf, fish were evaluated in the novel tank test, social behavior test, and mirror aggressive test. Brain gene expression related to oxidative stress and inflammation was also evaluated. DFB reduced locomotor parameters in the novel tank and aggression tests, while it induced to hyperactivity in the social behavior test. PPF reduced anxiety-like behavior, measured by the time spent in risky areas of the novel tank, and reduced aggression against the mirror image. There was a significant reduction in mRNA levels of the nfe2l2 gene (∼0.54 fold downregulated) and increase in levels of cat (PPF ∼1.8 fold change), gsr (PPF ∼1.5 fold change), gpx1a (PPF ∼1.6 and DFB 1.1 fold change), tnf-α (PPF 1.9 and DFB 2.2 fold change), and il-6 (PPF ∼1.2 and DFB 2.3 fold change). These endpoints are indicative of the threatening effects of insecticides to aquatic organisms and the need for alternative methods to control pests by using less harmful and safer substances for animal and human well-being, as well as for the environment. [Display omitted] •Chronic low DFB exposure caused hypoactivity in anxiety and hyperactivity in social contexts.•Chronic low PPF exposure reduced anxiety-like behavior and aggressive interactions.•Behavior changes reflect brain condition with reduced nfe2l2 gene expression.•PPF exposure increased expression of peroxide-handling enzymes (cat, gsr, gpx1a).•DFB and PPF exposure increased pro-inflammatory gene expression (tnf-α, il-6).