Sun Huimin. / Thesis submitted in: December 2002. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 77-89). / Abstracts in English and Chinese. / TITLE PAGE --- p.i / ACKNOWLEDGEMENTS --- p.ii / ABSTRACT --- p.iii / ABSTRACT IN CHINESE --- p.v / LIST OF PUBLICATIONS --- p.vii / ABBREVIATIONS --- p.viii / TABLE OF CONTENTS --- p.ix / Chapter CHAPTER 1. --- General Introduction --- p.1 / Chapter 1.1 --- Current Status of Herbal Product Use --- p.1 / Chapter 1.2 --- Herb-drug interactions --- p.2 / Chapter 1.2.1. --- Mechanisms of herb-drug interaction --- p.3 / Chapter 1.2.2. --- Pharmacodynamic interaction --- p.3 / Chapter 1.2.3. --- Pharmacokinetic interaction --- p.4 / Chapter 1.2.4. --- Herb-drug interaction involving drug metabolizing enzymes --- p.5 / Chapter 1.3 --- Methodologies for studying herb-drug interactions involving CYP enzymes --- p.7 / Chapter 1.3.1. --- Animal studies (Ex vivo approach) --- p.7 / Chapter 1.3.2. --- In vitro inhibition/induction studies --- p.8 / Chapter 1.3.3. --- Clinical studies --- p.9 / Chapter CHAPTER 2. --- Effect of flavonoid-containing herbs on CYP 450 enzyme activities: a screening study in rat --- p.11 / Chapter 2.1 --- Introduction --- p.11 / Chapter 2.2 --- Materials and Methods --- p.12 / Chapter 2.2.1. --- Chemicals --- p.12 / Chapter 2.2.2. --- Herbs --- p.12 / Chapter 2.2.3. --- Preparation of herbal extracts --- p.13 / Chapter 2.2.3.1. --- Preparation of Green Tea extract --- p.13 / Chapter 2.2.3.2. --- Preparation of Decaffeinated Green Tea (DGT) and its extracts --- p.13 / Chapter 2.2.3.3. --- "Preparation of extracts of Huang Qin, Ge Gen and Huai Mi" --- p.14 / Chapter 2.2.3.4. --- Preparation of Ginkgo biloba extract suspension --- p.14 / Chapter 2.2.4. --- Animal treatment --- p.14 / Chapter 2.2.5. --- Preparation of rat liver microsomes --- p.15 / Chapter 2.2.6. --- Determination of protein content of liver microsomes --- p.16 / Chapter 2.2.7. --- Determination of microsomal CYP content --- p.17 / Chapter 2.2.8. --- Statistical analysis --- p.19 / Chapter 2.3 --- Results --- p.19 / Chapter 2.4 --- Discussion --- p.24 / Chapter 2.5 --- Conclusion --- p.25 / Chapter CHAPTER 3 --- Rationale of the clinical study --- p.26 / Chapter CHAPTER 4 --- Development of HPLC methods for simultaneous determination of multiple probe drugs and their metabolites in human plasma or urine --- p.30 / Chapter 4.1 --- Introduction --- p.30 / Chapter 4.2 --- Materials and Methods --- p.33 / Chapter 4.2.1. --- Chemicals and reagents --- p.33 / Chapter 4.2.2. --- Preparation of stock and working solutions --- p.33 / Chapter 4.2.3. --- Equipment and chromatographic conditions --- p.34 / Chapter 4.2.4. --- Treatment of plasma and urine samples with β-glucuronidase --- p.35 / Chapter 4.2.5. --- Extraction procedures --- p.36 / Chapter 4.2.6. --- Preparation of working solutions for calibration curve --- p.37 / Chapter 4.3 --- Results --- p.39 / Chapter 4.3.1. --- Separation of the analytes --- p.39 / Chapter 4.3.2. --- Calibration and linearity --- p.39 / Chapter 4.3.3. --- Sensitivity --- p.39 / Chapter 4.3.4 --- Accuracy and precision --- p.50 / Chapter 4.4 --- Discussion --- p.52 / Chapter 4.5 --- Conclusions --- p.53 / Chapter CHAPTER 5 --- Stability study of probe drugs --- p.54 / Chapter 5.1 --- Introduction --- p.54 / Chapter 5.2 --- Materials and Methods --- p.54 / Chapter 5.2.1. --- Preparation of standard solutions of probe drugs --- p.54 / Chapter 5.2.2. --- Preparation of stability study mediums --- p.54 / Chapter 5.2.2.1. --- Gastric juice (pH=1.2) --- p.54 / Chapter 5.2.2.2. --- Intestine fluid (pH=6.8) --- p.54 / Chapter 5.2.2.3. --- Human plasma (pH=7.4) --- p.55 / Chapter 5.2.2.4. --- Phosphate buffer (pH=7.4) --- p.55 / Chapter 5.2.3. --- Incubation --- p.55 / Chapter 5.2.4. --- Determination of probe drug concentrations in incubation samples --- p.56 / Chapter 5.3 --- Results --- p.57 / Chapter 5.4 --- Discussion --- p.59 / Chapter 5.5 --- Conclusion --- p.59 / Chapter CHAPTER 6 --- Effect of the extract of Ginkgo biloba leaf (761) on CYP isozymes in human subjects --- p.60 / Chapter 6.1 --- Introduction --- p.60 / Chapter 6.2 --- Materials and Methods --- p.60 / Chapter 6.2.1. --- Drugs --- p.60 / Chapter 6.2.2. --- Subjects --- p.61 / Chapter 6.2.3. --- Study design --- p.62 / Chapter 6.2.4. --- Determination of probe drugs/metabolites in the plasma and urine --- p.63 / Chapter 6.2.5. --- Data analysis --- p.65 / Chapter 6.2.6. --- Statistical analysis --- p.66 / Chapter 6.3 --- Results --- p.66 / Chapter 6.3.1. --- Effect of EGb761on CYP1A2 activity --- p.66 / Chapter 6.3.2. --- Effect of EGb761on CYP2E1 activity --- p.67 / Chapter 6.3.3. --- Effect of EGb761 on CYP450 3A activity --- p.68 / Chapter 6.3.4. --- Effect of EGb761 on NAT2 activity --- p.69 / Chapter 6.3.5. --- Effect of EGb761 on CYP2D6 activity --- p.70 / Chapter 6.3.6. --- Effects of EGb761 on CYP2C19 activity --- p.71 / Chapter 6.4 --- Discussion --- p.72 / Chapter 6.5 --- Conclusion --- p.76 / References --- p.77 / Appendix --- p.90