Neurobehavioral effects of fungicides in zebrafish: a systematic review and meta-analysis

Abstract

With the aim of yielding high productivity levels, pesticides are widely used in global agriculture. Among them, fungicides are compounds intended to inhibit fungal proliferation in crops and seeds. Their application often leads to environmental contamination, with these chemicals persistently being detected in surface waters. This presence may threaten non-target organisms that dwell in the affected ecosystems, including humans. In toxicologic research, the zebrafish (Danio rerio) is the most used fish species to assess the potential effects of fungicide exposure, generating numerous and sometimes conflicting findings. We conducted a systematic review and meta-analysis aiming to synthesize the neurobehavioral effects of fungicides in zebrafish. The search was performed in three databases (PubMed, Scopus, and Web of Science) and the screening was based on a two-stage process guided by pre-defined inclusion/exclusion criteria. Qualitative and quantitative data, as well as reporting quality, were extracted from the included studies (n = 60). Meta-analyses were performed for the outcomes of distance traveled in larvae and adults, and spontaneous movements in embryos. We found an overall significant effect of fungicide exposure on distance, which was lower in exposed versus control groups (SMD -0.44 [-0.74; -0.13], p = 0.0055). No effect was observed for spontaneous movements. The overall heterogeneity for distance and spontaneous movements was considered high (I2 = 80%) and moderate (I2 = 74%), respectively. This can be explained by substantial methodological variation between protocols, whereas a poor reporting practice hinders the proper critical evaluation of the findings. However, a sensitivity analysis did not indicate any study skewing the meta-analyses. This review demonstrates the need for better-designed and reported experiments in this field. Highlights- We systematically reviewed the behavioral effects of fungicides in zebrafish - Fungicides decrease the distance traveled - Fungicide exposure has no significant effects on spontaneous movements - Moderate to high levels of heterogeneity were found - The results showed a need for better-designed studies with clarity of report