title: Effects of the UV-filter 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC) on expression of genes involved in hormonal pathways in fathead minnows (Pimephales promelas) and link to vitellogenin induction and histology.
abstract: UV-filters are increasingly used in cosmetics and in the protection of materials against UV-irradiation, and ultimately they reach aquatic systems. The lipophilic UV-filter 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC) belongs to one of the most frequently used UV-filters and accumulates in aquatic animals. Despite its ubiquitous presence in water and biota, very little is known about its potential hormonal effects on aquatic organisms. In our study, we evaluated the effects of measured water concentration of 5.4, 37.5, 244.5 and 394 μg/L EHMC on the expression of genes involved in hormonal pathways in the liver, testis and brain of male and female fathead minnows (Pimephales promelas). We compare the transcription profile with the plasma vitellogenin (VTG) content, secondary sex characteristics, and gonad histology. Transcripts of the androgen receptor (ar) were significantly down-regulated in the liver of females at 37.5, 244.5 μg/L and 394 μg/L EHMC. Additionally, the 3β-hydroxysteroid dehydrogenase (3β-HSD) transcript was significantly decreased in the liver of males at 37.5, 244.5 and 394 μg/L EHMC, and at 244.5 and 394 μg/L EHMC in females. The expressional changes were tissue-specific in most cases, being most significant in the liver. Vitellogenin plasma concentration was significantly increased at 244.5 μg/L EHMC in males. EHMC induced significant histological changes in testes and ovaries at 394 μg/L. Testes displayed a decrease in spermatocytes, and ovaries a decrease in previtellogenic oocytes. The induction of VTG plasma concentration and the histological changes in gonads suggest an estrogenic and/or antiandrogenic activity of EHMC. On the other hand, the gene expression profile shows an antiestrogenic (e.g.: down-regulation of esr1) activity of EHMC. In conclusion, our data demonstrate that EHMC displays low but multiple hormonal activities in fish.
authors.affiliation: University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Muttenz, Switzerland.
authors.forename: Verena
authors.initials: V
authors.lastname: Christen
authors.forename: Sara
authors.initials: S
authors.lastname: Zucchi
authors.forename: Karl
authors.initials: K
authors.lastname: Fent
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002934:Cinnamates / Q000633:toxicity*; D003530:Cyprinidae / Q000235:genetics* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D006066:Gonads / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D006728:Hormones / Q000235:genetics* / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D013473:Sunscreening Agents / Q000633:toxicity*; D014466:Ultraviolet Rays; D014819:Vitellogenins / Q000235:genetics* / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D002934:Cinnamates; D029941:Fish Proteins; D006728:Hormones; D013473:Sunscreening Agents; D014819:Vitellogenins; D014874:Water Pollutants, Chemical; C516303:ethylhexyl methoxycinnamate