Effects Of Ionic Liquids On The Activity Of HepG2 In Human Hepatoma Cells And The Toxicity Of Zebrafish And Its Mechanism

Due to the excellent physical and chemical properties of Ionic Liquids?ILs?,they have been widely used in various industrial applications including heterogeneous catalysis,biocatalysis,electrochemistry and so on,which are considered as environment-tally benign solvent in the 21 st century.However,ILs have be released into the environment by accidental discharge inevitably with widely used today,which may pose a threat to biological organism and human health.Thus,the biological safety of Ionic Liquids and the unexpected health impacts to humans have become interesting points of researches.In the present study,the model animal zebrafish?Danio rerio?and human hepatoma G2?Hep G2?cells were choosed as subjects to study the toxic effects and mechanism of Ionic Liquids about 1-Butyl-3-methylimidazolium Tetrafluoroborate [BMIM]BF₄ and 1,3-di?9-chloromethyl anthracene?-3-methylimidazolium chloride [DENMIM]C l.The main results are summarized as follows:1.The MTT?3-?4,5-dimethyl-2-thiazolyl?-2,5-diphenyl-2-H-tetrazolium bromide?assays demonstrated that [BMIM]BF₄ inhibited the growth of Hep G2 cells in the concentration of 2.5,5,10 mM after 24 h exposure,indicating a significant cytotoxicity.[BMIM]BF₄ induced HepG2 cells to produce excessive amounts of hydroxyl radicals,superoxide anion and the total level of reactive oxygen species?ROS?,leading to cell oxidative damage.Genes of nox2 and nox4 were upregulated significantly with [BMIM]BF₄ treatment by means of real-time RT-PCR,NADPH oxidase was one of important sources of ROS,which suggested that they could be the key genes to induced excessive ROS in HepG2 cells.Thus,NADPH oxidase pathway would be one of the important pathways to produce excessive ROS in HepG2 cells after [BMIM]BF₄ treatment.2.In this paper,we use a fluorescent imidazolium salt to real-time visual detect the absorption,distribution and excretion of the [DENMIM]C l in early developmental zebrafish.As the results indicated,the fluorescence intensity was increased gradually in a time-dependent and dose-dependent manner.Fluorescence was predominantly distributed in liver and gastrointestinal tract such as stomach and intestine and then scattering in whole body with blood flow as time grew.Moreover,this study also found that fluorescence can be metabolized through digestive system and liver detoxification mechanisms by zebrafish larvae in the depuration stage.3.Zebrafish larvae were exposed to a series concentration of [BMIM]BF₄?0,5,10,20 and 40 mg/L?for 10 d,20 d and 30 d in order to study the the toxic effects and mechanism of [BMIM]BF₄ on zebrafish hypothalamus-pituitary-thyroid?HPT?axis.As the results showed,whole weight and body length of zebrafish were down obviously and condition factor?CF?was up after [BMIM]BF₄ exposure.Exposure to [BMIM]BF₄ led to the thyroid hormone disorder,which caused T4 level decreased but T3 level increased.Genes involved in the HPT axis expression were also analyzed.For example,the mRNA expressions of genes involved in thyroid hormone synthesis?crh,tsh,slc5 a,tg and tpo?were upregulated significantly with [BMIM]BF₄ treatment,which might be responsible for the decreased thyroxine T4 concentrations by feedback regulation.Besides,abnormal gene expression related to thyroid hormone metabolism?dio1 and ugt1ab?,transport?ttr?and thyroid hormone receptor?tr? and tr??further indicated that [BMIM]BF₄ can disturb the level of thyroid hormone,which finally influence normal physiology function of HPT axis in zebrafish larvae.