Effects of Complementary and Alternative Medicines (CAM) on the Metabolism and Transport of Anticancer Drugs KIM MOOIMAN Cover design: Kim Mooiman Lay-out & printing: Optima Grafische Communicatie, Rotterdam, The Netherlands Mooiman, K.D. Effects of Complementary and Alternative Medicines (CAM) on the Metabolism and Transport of Anticancer Drugs ISBN/EAN: 978-94-6169-457-7 © 2013 Kim Mooiman Effects of Complementary and Alternative Medicines (CAM) on the Metabolism and Transport of Anticancer Drugs Effecten van complementaire en alternatieve geneesmiddelen op het metabolisme en transport van oncolytica (met een samenvatting in het Nederlands) PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit Utrecht op gezag van de rector magnificus, prof. dr. G.J. van der Zwaan, ingevolge het besluit van het college voor promoties in het openbaar te verdedigen op woensdag 18 december 2013 des middags te 2.30 uur door Kim Delia Mooiman geboren op 22 mei 1986 te Woerden Promotoren: Prof. dr. J.H.M. Schellens Prof. dr. J.H. Beijnen Co-promotor: Dr. ir. I. Meijerman The research described in this thesis was performed at the Department of Pharmaceuti- cal Sciences, Division of Pharmacoepidemiology & Clinical Pharmacology of the Utrecht University in Utrecht, The Netherlands. Furthermore, part of the research was performed at the Department of Clinical Pharmacology of the Netherlands Cancer Institute in Amsterdam, and at the Department of Pharmacy and Pharmacology of the Slotervaart Hospital in Amsterdam, The Netherlands. Financial support by the Utrecht Institute for Pharmaceutical Sciences (UIPS), The Neth- erlands Laboratory for Anticancer Drug Formulation (NLADF), Shimadzu Benelux B.V. and the Dutch Cancer Society for the publication of this thesis is gratefully acknowledged. The Dutch Cancer Society funded the research published in this thesis under grant agree- ment UU 2007-3795. CONTENTS Chapter 1 Introduction 1.1 General introduction 11 1.2 Relevance of in vitro and clinical data for predicting CYP3A4- 21 mediated herb-drug interactions in cancer patients Chapter 2 Effects of CAM on CYP3A4- and CYP2C9-mediated metabolism of anticancer drugs 2.1 The effect of complementary and alternative medicines (CAM) 51 on CYP3A4-mediated metabolism of three different substrates: 7-benzyloxy-4-trifluoromethylcoumarin (BFC), midazolam and docetaxel 2.2 Development and validation of a LC-MS/MS method for the in 71 vitro analysis of 1-hydroxymidazolam in human liver microsomes: application for determining CYP3A4 inhibition in complex matrix mixtures 2.3 The effect of complementary and alternative medicines (CAM) on 91 CYP2C9 activity Chapter 3 Nuclear receptor-mediated inhibition of CYP3A4 induction 3.1 Evaluation of a reporter gene assay as suitable in vitro system to 111 screen for novel PXR antagonists 3.2 Milk thistle’s active components silybin and iso-silybin: Novel 131 inhibitors of PXR-mediated CYP3A4 induction Chapter 4 Effects of CAM on P-gp and BCRP mediated transport of anticancer drugs 4.1 The effect of complementary and alternative medicines (CAM) on 161 P-gp and BCRP mediated transport of topotecan and imatinib Chapter 5 Effects of Chinese herbal medicines (CHM) on CYP3A4- mediated metabolism of anticancer drugs 5.1 Effect of Chinese herbs on CYP3A4 activity and expression in vitro 185 5.2 Letter to the editor regarding ‘A prospective, controlled study of 201 botanical compound mixture LCS101 for chemotherapy-induced hematological complications in breast cancer’ by Yaal-Hahoshen et al. (The Oncologist 2011; 16; 1197-1202) Chapter 6 Conclusions and perspectives 207 Chapter 7 In short Summary 216 Nederlandse samenvatting 220 Chapter 8 Appendix Dankwoord 226 List of co-authors 232 List of publications 236 About the author 238 CHAPTER 1 INTRODUCTION 1.1 GENERAL INTRODUCTION General introduction 13 Cancer is often treated with multiple anticancer drugs or hormonal agents in combina- tion with supplemental therapies to prevent or treat side effects 1. In addition, cancer patients often use complementary and alternative medicines (CAM) for various reasons such as reducing side effects of chemotherapy, improving their quality of life and slowing the progression of cancer 2, 3. The most popular CAM among cancer patients are herbal supplements such as milk thistle, St. John’s wort and Echinacea; and dietary supplements such as β-carotene and vitamins 2, 4, 5. In general, the use of CAM is con- sidered safe for patients. However, the concomitant use of anticancer drugs and CAM could result in serious safety problems: undertreatment or increased toxicities. These safety problems are mainly caused by pharmacokinetic interactions. Almost all pharmacokinetic interactions between CAM and anticancer drugs involve cy- tochrome P450 (CYP) metabolizing enzymes and drug efflux transporters. Major players in the metabolism and elimination of anticancer drugs are the metabolizing enzymes CYP3A4, CYP2C9 and the drug efflux transporters P-glycoprotein (P-gp; ABCB1) and Breast Cancer Resistance Protein (BCRP; ABCG2) 6-9. Both inhibition and induction of these enzymes and transporters by CAM could easily result in altered plasma levels of anticancer drugs and subsequently serious safety problems due to their narrow thera- peutic windows. Clinically relevant pharmacokinetic interactions between St. John’s wort and the anti- cancer drugs irinotecan 10 and imatinib 11, 12 have already been reported. However, clini- cal pharmacokinetic interactions between other CAM and anticancer drugs are less well documented. Consequently, for the majority of CAM it is unknown whether concomitant use with anticancer drugs is safe. To address this issue it is crucial to expand our knowl- edge of the effects of CAM on the metabolism and transport of anticancer drugs. In literature, several in vitro studies have been performed to determine the effects of CAM on the expression and activity of CYP enzymes and drug efflux transporters. However, the effect of each CAM was often separately determined in differentin vitro studies. Due to differences in the phytochemical content of CAM products, equipment and person- nel, it is not possible to compare the potency of multiple CAM to affect the metabolism and transport of anticancer drugs from the different in vitro studies. Furthermore, the majority of the in vitro studies assessed the effects of CAM by using one substrate while it has been recommended to use multiple substrates 13, 14. In these published studies predominantly model substrates have been used and relevant oncolytic substrates were not or scarcely included. However, depending on the substrate used, a compound can significantly differ in its potency to influence the activity of CYP enzymes and drug efflux transporters. 14 Chapter 1.1 Therefore, this thesis focuses on the in vitro potency of the following CAM to affect the metabolism and transport of multiple substrates, in particular anticancer drugs: β-carotene, Echinacea (Echinacea purpurea), garlic (Allium sativum), green tea (Camellia sinensis), Ginkgo biloba, ginseng (Eleutherococcus senticosus), grape seed (Vitis vinifera), milk thistle (Silybum marianum), saw palmetto (Serenoa serrulata), St. John’s wort (Hy- pericum perforatum), valerian (Valeriana officinalis), vitamin B6, B12 and C. This selection is based on the frequency of use by cancer patients and the potential to interact with anticancer drugs 2-5, 15. Ultimately, the obtained in vitro results are useful as first indica- tion for clinical trials to establish the clinical relevance of potential CAM-anticancer drug interactions. Since there are large interspecies differences between animals with regard to the regula- tion of CYP enzymes and drug transporter expression and activity, in vitro studies are currently one of the best tools to predict clinical pharmacokinetic interactions between CAM and anticancer drugs. It is therefore important to determine the extrapolatability of in vitro data to the clinic. To address this issue in Chapter 1.2 the in vitro and clinical effects of St. John’s wort, milk thistle, garlic and ginseng on CYP3A4 have been com- pared. The selection of these CAM was based on the availability of clinical studies that used the model CYP3A4 substrate midazolam and anticancer drugs, which are scarcely used as CYP3A4 substrates. Chapter 2 focuses on the pharmacokinetic interactions between CAM and anticancer drugs on the level of drug metabolism. The two major enzymes that are involved in the metabolism of anticancer drugs are CYP3A4 and CYP2C9. The inhibiting effects of CAM on CYP3A4-mediated metabolism of 7-benzyloxy-4-trifluoromethyl-coumarin (BFC) (fluorescent CYP3A4 substrate), midazolam (CYP3A4 model substrate) and docetaxel (CYP3A4 metabolized anticancer drug) are described in Chapter 2.1. To sup- port this in vitro study, an analytical assay based on liquid-chromatography coupled to tandem mass spectrometry (LC-MS/MS) has been developed and validated to quantify 1-hydroxymidazolam, the major metabolite of midazolam (Chapter 2.2). In Chapter 2.3 the inhibiting effects of CAM on CYP2C9-mediated metabolism of 7-methoxy-4-triflu- oromethylcoumarine (MFC) (fluorescent CYP2C9 substrate) and tolbutamide (CYP2C9 model substrate) are discussed. Besides inhibition of CYP enzymes, the induction of these enzymes can also have serious consequences for cancer patients. Plasma levels of anticancer drugs might decrease, subsequently resulting in a reduced therapeutic efficacy of chemotherapy. Chapter 3 focuses on the induction