Chronic environmentally relevant levels of Simvastatin induces non-monotonic responses in Zebrafish (Danio rerio)

Abstract

Simvastatin (SIM), a hypocholesterolaemic compound, is among the most prescribed pharmaceuticals for cardiovascular disease prevention worldwide. Several studies have shown that acute exposure to SIM is able to produce 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-parametric approach integrating distinct ecological-relevant endpoints, i.e. survival, growth, reproduction and embryonic development, with biochemical markers (cholesterol and triglycerides). Furthermore, 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 non-monotonic dose-responses; embryonic development, biochemical and molecular markers, were significantly impacted in the low-intermediate concentrations, 40 ng/L and 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 statins effects in teleosts, demonstrating significant impacts at environmentally relevant concentrations. The findings highlight the importance of addressing the effects of chemicals under chronic low-level concentrations.\n\nGraphical abstract\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=83 SRC=\"FIGDIR/small/289694v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (17K):\norg.highwire.dtl.DTLVardef@1922156org.highwire.dtl.DTLVardef@caad80org.highwire.dtl.DTLVardef@44c058org.highwire.dtl.DTLVardef@1afe60f_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LISeveral uncertainties exist regarding simvastatin mode of action in non-target organisms\nC_LIO_LIThis work integrates D. rerio multi-level responses after long-term exposure to simvastatin\nC_LIO_LISimvastatin impacted cholesterol/triglycerides levels and transcript levels of genes related to mevalonate pathway.\nC_LIO_LIParental exposure to simvastatin induced offspring embryonic malformations.\nC_LIO_LIEmbryonic abnormalities, biochemical and molecular data did follow a non-monotonic curve.\nC_LI