Pesticide effects on fish cholinesterase variability and mean activity: A meta-analytic review

• Published in: The Science of the total environment 2021-02, Vol.757, p.143829, Article 143829
• Main Authors: Santana, Manuela S., Sandrini-Neto, Leonardo, Di Domenico, Maikon, Prodocimo, Maritana Mela
• Format: Article
• Language: English
• Subjects: Acetylcholinesterase; Animals; Biomarker; Butyrylcholinesterase; Cholinesterase Inhibitors; Herbicides; Insecticides; Meta-analysis; Pesticides - toxicity; Reproducibility of Results; Systematic review
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.143829

Fish cholinesterases (ChEs) – like acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) – are common biomarkers of environmental contamination due to their sensitivity to a variety of toxicants. To understand pesticide effects on fish ChEs mean activity and variability, we conducted a systematic review and meta-analyses. Our goal was to verify (i) if brain and muscle ChEs responded differently to pesticide exposure; (ii) how fish size and life stage (i.e., juvenile and adult) influence ChEs variability and mean activity; (iii) what type of pesticides (i.e., herbicide, insecticide, and fungicide) has the strongest effect, and if the analytical-grade compounds differ from commercial formulations; (iv) if increasing concentrations combined with prolonged exposure leads to stronger ChEs inhibition; and (v) how each class of pesticide affects these enzymes. We validated ChEs reliability as biomarkers and identified factors influencing their response. Regardless of tissue, BChE response was more variable than AChE, and no difference between their average activity was detected. The size of juvenile fish is an important factor affecting ChEs mean activity and variability, whereas pesticide had no significant effect on adult fish ChEs. Insecticides were stronger inhibitors compared to herbicides and fungicides. Analytical-grade compounds decreased ChEs mean activity to a higher degree than commercial formulations. The combined effect of concentration and time was only significant for fungicides and insecticides. Among classes, organophosphorus insecticides had the strongest effect on ChEs, followed by carbamates, organochlorines, and pyrethroids. Organophosphorus herbicides and oxazolidinones were the only herbicides to decrease ChEs mean activity significantly, and their effects were similar from those of pyrethroids and organochlorines. Additionally, our results identified research gaps, such as the small number of studies on fungicides, neonicotinoids and other relevant pesticides. These findings suggest future directions, which might help researchers identify robust cause-effect relationships between fish ChEs and pesticides. [Display omitted] •We conducted a meta-analysis of pesticide effects on fish cholinesterases (ChEs).•Pesticides had an overall significant effect on fish ChEs means and variability.•BChE variability increases after exposure, implying biomarker sensitivity.•Length of juvenile fish significantly affects ChEs variability and activity.