Chronic environmentally relevant levels of simvastatin disrupt embryonic development, biochemical and molecular responses in zebrafish (Danio rerio)

This is the postprint (accepted manuscript) version of the article published in Aquatic Toxicology. https://doi.org/10.1016/j.aquatox.2018.05.014Simvastatin (SIM), a hypocholesterolaemic compound, is among the most prescribed pharmaceuticals for cardiovascular disease prevention worldwide. Several studies have shown that acute exposure to SIM causes multiple adverse effects in aquatic organisms. However, uncertainties still remain regarding the chronic effects of SIM in aquatic ecosystems. Therefore, the present study aimed to investigate the effects of SIM in the model freshwater teleost zebrafish (Danio rerio) following a chronic exposure (90 days) to environmentally relevant concentrations ranging from 8 ng/L to 1000 ng/L. This study used a multi-parameter approach integrating distinct ecologically-relevant endpoints, i.e. survival, growth, reproduction and embryonic development, with biochemical markers (cholesterol and triglycerides). Real Time PCR was used to analyse the transcription levels of key genes involved in the mevalonate pathway (hmgcra, cyp51, and dhcr7). Globally, SIM induced several effects that did not follow a dose-response relationship; embryonic development, biochemical and molecular markers, were significantly impacted in the lower concentrations, 8 ng/L, 40 ng/L and/or 200 ng/L, whereas no effects were recorded for the highest tested SIM levels (1000 ng/L). Taken together, these findings expand our understanding of statin effects in teleosts, demonstrating significant impacts at environmentally relevant concentrations and highlight the importance of addressing the effects of chemicals under chronic low-level concentrationsT. Neuparth was supported by the Postdoctoral fellowship SFRH/BPD/77912/2011 from Foundation of Science and Technology, Portugal. R. Montes, R. Rodil and J.B. Quintana acknowledge financial support from the Spanish “Agencia Estatal de Investigación” (project no. CTM2014-56628-C3-2-R), the Galician Council of Culture, Education and Universities (ED431C2017/36) and FEDER/ERDFS