Toxicological screening of imidazolium based ionic liquids

Sammanfattning: Ionic liquids are salts that are in liquid form at room temperature. These compounds have been suggested to be environmentally friendly and are proposed to be replacements for commercially available solvents used in laboratory operations today. There is an increasing interest in these compounds, but toxicological data of ionic liquids are still scarce. In this project five imidazolium based ionic liquids, 1-etyl-3-methylimidazolium, 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, 1-octyl-3-methylimidazolium and 1-decyl-3-methylimidazolium were evaluated based on responses on aryl hydrocarbon receptor (DR-Ecoscreen), Nrf2 activity (MCF732cARE), androgen receptor (AR-Ecoscreen) and estrogen receptor (VM7Luc4ER). This was done with an effect based in vitro approach using luciferase bioassays. The results show that imidazolium based ionic liquids have the ability to induce androgen and estrogen receptor activity. It is also shown that imidazolium based ionic liquids can act as antagonists on the androgen receptor. Imidazolium based ionic liquids does not seem cause oxidative stress and is shown to not interact with the aryl hydrocarbon receptor. The ability of 1-octyl-3-methylimidazolium and 1-decyl-3-methylimidazolium to pass the gastrointestinal tract was also tested in a modified transwell caco-2 permeability test, which resembled the human GI-tract. It was shown to be difficult to evaluate if 1-octyl-3-methylimidazolium and 1-decyl-3-methylimidazolium have the ability to pass through the GI-tract and antagonize on the androgen receptor. These results are important from both an environmental as well as human health point of view if imidazolium based ionic liquids are to be accidentally or intentionally release into the environment.