Toxicity and Mutagenicity of Upper Danube River Sediments Determined by Chemical Fractionation, the Danio Rerio Embryo Assay
Total Page:16
File Type:pdf, Size:1020Kb
Toxicity and Mutagenicity of Upper Danube River Sediments Determined by Chemical Fractionation, the Danio rerio Embryo Assay, the Ames Fluctuation Test and the H295R assay. A Thesis Submitted to the College of Graduate Studies and Research In Partial Fulfillment of the Requirements For the Degree of Master of Science In the Toxicology Graduate Program University of Saskatchewan Saskatoon By Eric Bertram Higley © Copyright Eric Bertram Higley, November, 2009. All rights reserved. Permission to Use In presenting this thesis in partial fulfilment of the requirements for a Postgraduate degree from the University of Saskatchewan, I agree that the Libraries of this University may make it freely available for inspection. I further agree that permission for copying of this thesis in any manner, in whole or in part, for scholarly purposes may be granted by the professor or professors who supervised my thesis work or, in their absence, by the Head of the Department or the Dean of the College in which my thesis work was done. It is understood that any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of Saskatchewan in any scholarly use which may be made of any material in my thesis. Requests for permission to copy or to make other use of material in this thesis in whole or part should be addressed to: Chair of the Toxicology Graduate Program Toxicology Centre University of Saskatchewan 44 Campus Drive Saskatoon, Saskatchewan S7N 5B3 i Abstract Declines in some fish populations in the upper Danube River, Germany, have been reported during the past decades despite extensive stocking efforts. Many theories exist for why such declines have occurred including habitat change, dams, invasive species, disease and pollution. One of the factors of concern in the Upper Danube River is pollution because a number of studies have shown that sediments collected from this area were acutely and/or chronically toxic to fish. Although it can be difficult to link bioassay results to direct effects on the population level, bioassays can give us insight into the potential of exposure of wildlife including fish to sediment. In combination with other researchers a large battery of sediment testing on the Upper Danube River is being performed. Testing includes sediment testing of estrogen receptor mediated processes, dioxin-like responses and genotoxic effects. In this study, four sediment extracts from the Upper Danube River in Germany were used with a novel fractionation technique to characterize the sediment extracts and fractions for their ability to disrupt steroidogenesis, for their mutagenic activities and their teratogenic effects. Fractionation of each of the four sediment samples was performed by separating compounds according to their polarity, planarity, and the size of the aromatic ring system in an on-line fractionation procedure on coupled high performance liquid chromatography columns. Mutagenic activity was measured in the raw sediment extracts and all 18 fractions using the Ames fluctuation assay and the Danio rerio embryo assay was used to assess lethal endpoints. Furthermore, disruptions of steroidogenesis were assessed by first establishing methods and a proof of concept of the H295R assay by exposing H295R cells to 7 model chemicals and measuring changes from a control in estradiol, ii testosterone and aromatase activity. Once methods were established all sediments and their fractions were analyzed using the Assay. Specifically, in the Danio rerio assay, two raw sediment extracts killed 100% of Danio rerio embryos at a concentration of 33.3 mg sediment equivalents (SEQ)/ml, but none of the 18 fractions of these samples produced any measured toxicity at a concentration of 100 mg SEQ/ml. In the Ames fluctuation assay, significant mutagenic activity was measured in raw sediment extracts and in the fractions. Fraction 10 produced a significant mutagenic response in all sediment samples measured only in S9 bio-activated samples. Furthermore, fraction 15 produced a significant mutagenic response in all sediment samples measured only in non bio-activated samples. All raw extracts tested in the H295R assay caused an increase in estradiol production up to 4-fold from controls. Testosterone production increased slightly from controls in only two of the raw extract samples. Of the 18 fractions, fractions 7, 10 and 15 increased estradiol in at least three of the samples studied (Sigmaringen2006, Opfingen2006, Lauchert2006 and Lauchert2004). Furthermore, fraction 7 significantly decreased testosterone production compared to controls in three of the four sediment samples. Taken as a whole, these results show the value of using multiple bioassays and fractionation to characterize sediments that covers a variety of different biological endpoints. This study also demonstrates the usefulness of the H295R assay when combined with a new fraction technique to assess endocrine disrupting chemicals in sediment samples. iii Acknowledgements I would like to thank my advisors Prof. John P. Giesy and Dr. Markus Hecker for their guidance and encouragement and for financial support throughout my Masters program. I would also like to thank my other committee members Dr. Michael Pietrock and Prof. Douglas A. Holdway. A special thanks to Prof. Henner Hollert and all the members of his lab at RWTH University Aachen, Germany. Last but not least I would like to thank all my friends and family for there support in the lab and outside the lab. Also, Thanks to everyone in the Toxicology Centre!!! iv List of Abbreviations AMAC Accelerated Membrane-Assisted Clean-up AMG Aminoglutethimide BpA Bisphenol A CN Cyanopropyl silica d Day DCM Dichloromethane DEPH Bis(2-ethylhexyl)phthalate DMSO Dimethyl sulfoxide dw Dry weight E2 17β-Estradiol EDA Effect-directed analysis EDC Endocrine Disrupting Chemical EE2 17α-Ethinylestradiol ELISA Enzyme-linked immunosorbent assay ER Estrogen Receptor FOR Forskolin GC-MS Gas chromatography- mass spectrometry h Hour Hx Hexane KET Ketoconazole Lau2006 Lauchert sediment sampled in 2006 Lau2004 Lauchert sediment sampled in 2004 LET Letrozole mo Month NO Nitrohenylpropyl silica NP Nonylphenol OECD Organization for Economic Cooperation and Development Opf2006 Oepfingen sediment sampled in 2006 PAH Polyaromatic hydrocarbon PCB Polychlorinated biphenyl v PCN Polychlorinated naphthalene PCDD/F Polychlorinated dibenzodioxin/ furan PGC Porous graphitized carbon PRO Prochloraz PrCo Procedural Control PC Positive Control SC Solvent Control SEQ Sediment Equivalents Sig2006 Sigmaringen sediment sampled in 2006 T Testosterone ww Wet weight YES Yeast Estrogen Screen YAS Yeast Androgen Screen vi TABLE OF CONTENTS Page ABSTRACT………………………………………………………………………… ii ACKNOWLEDGEMENTS………………………………………………………... iv LIST OF ABBREVIATIONS……………………………………………………… v 1.0 GENERAL INTRODUCTION………………………………………………… 1 1.1 Introduction………………………………………………………………….. 1 1.2 Contaminants and the Danube River…………………………………………. 4 1.3 Objectives……………………………………………………………………. 7 1.3.1 Objective #1: Proof of concept of the H295R Assay…………………... 8 1.3.2 Objective #2: Endocrine Disrupting Activities………………………… 8 1.3.3 Objective #3: Teratogenic Activities…………………………………... 9 1.3.4 Objective #4: Mutagenic activities…………………………………….. 10 1.4 Methods……………………………………………………………………… 10 1.4.1 Sampling………………………………………………………………. 10 1.4.2 H295R Assay………………………………………………………….. 11 1.4.3 Danio rerio Embryo Assay……………………………………………. 12 1.4.4 Ames Fluctuation Assay………………………………………………. 14 2.0 DIFFERENTIAL ASSESSMENT OF CHEMICAL EFFECTS ON AROMATASE ACTIVITY, AND E2 AND TESTOSTERONE PRODUCTION USING THE H295R CELL LINE………………………………………………………………………….. 16 2.1 Abstract…………………………………………………………………….. 16 2.2 Introduction…………………………………………………………………. 18 2.3 Materials and Methods……………………………………………………… 21 2.3.1 Test Chemicals………………………………………………………….. 21 2.3.2 Cell Culture………………..……………………………………………. 21 2.3.3 Experimental Design…………………………………………………… 22 2.3.4 Aromatase Activity Measurements…………………………………….. 23 2.3.5 Quantification of Hormones……………………………………………. 24 2.3.6 Statistical Analysis……………………………………………………… 25 2.4 Results……………………………………………………………………….. 25 2.4.1 General Inducers……………………………………………………….. 25 2.4.2 Potent Inhibitors……………………………………………………….... 29 2.4.3 Weak Aromatase Inhibitors…………………………………………….. 31 2.5 Discussion…………………………………………………………………… 35 2.5.1 General Inducers……………………………………………………….. 35 2.5.2 Potent Inhibitors………………………………………………………… 36 2.5.3 Other effectors………………………………………………………….. 39 2.5.4 Predictability of aromatase activity for E2 and T……………………… 41 2.5.5 Conclusions…………………………………………………………….. 42 vii 3.0 EFFECTS OF UPPER DANUBE RIVER SEDIMENTS ON STERIODOGENESIS USING A COMBINATION OF CHEMICAL FRACTIONATION AND THE H295R ASSAY ……………………………………………………………………………... 44 3.1 Abstract……………………………………………………………………... 44 3.2 Introduction…………………………………………………………………. 45 3.3 Materials and Methods……………………………………………………… 48 3.3.1 Sampling………….…………………………………………………… 48 3.3.2 Soxhlet-extraction of Sediment Samples………………………..……. 49 3.3.3 Accelerated Membrane–Assisted Clean-up of Sediment Extracts……. 50 3.3.4 Fractionation……………………………..…………………………….. 51 3.3.5 H295R Steriodogenesis Assay…………………………………………. 53 3.3.6 Statistical Analysis…………………………………………………….. 54 3.4 Results……………………………………………………………………….. 55 3.4.1 Raw Sediment Extracts……..………………………………………….. 55 3.4.1.1 Cytotoxicity………………………………………………………. 55 3.4.1.2 Estradiol………………………………………………………….