by Chan Hoi Tak. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 129-137). / Abstracts in English and Chinese. / Acknowledgment --- p.i / Abstract --- p.ii / Abstract (Chinese Version) --- p.iv / Abbreviations --- p.vi / Contents --- p.viii / Chapter CHAPTER ONE --- INTRODUCTION --- p.1 / Chapter 1.1 --- Aflatoxins --- p.1 / Chapter 1.1.1 --- AFB1 Metabolism --- p.5 / Chapter 1.1.2 --- Bioactivation --- p.5 / Chapter 1.1.3 --- Detoxification --- p.8 / Chapter 1.1.4 --- Toxicity of AFB1 --- p.9 / Chapter 1.2 --- Licorice Plants --- p.11 / Chapter 1.2.1 --- Glycyrrhizic Acid (GA) --- p.13 / Chapter 1.2.2 --- Metabolism of GA --- p.16 / Chapter 1.2.3 --- Adverse Effects of GA --- p.19 / Chapter 1.3 --- Aim of Research --- p.19 / Chapter CHAPTER TWO --- MATERIALS AND METHODS --- p.21 / Chapter 2.1 --- Cell cultures --- p.21 / Chapter 2.1.1 --- Isolation of splenocytes --- p.21 / Chapter 2.1.2 --- Culture of cell lines --- p.22 / Chapter 2.1.3 --- Trypsinziation of cells --- p.22 / Chapter 2.2 --- Preparation of drugs --- p.23 / Chapter 2.2.1 --- Preparation of commercially available chemicals for cell culture --- p.23 / Chapter 2.2.2 --- Preparation of Licorice extracts for cell culture --- p.23 / Chapter 2.2.3 --- Preparation of chemicals for enzymatic reaction --- p.24 / Chapter 2.3 --- Cytotoxicity assay Methods --- p.24 / Chapter 2.3.1 --- MTT assay --- p.25 / Chapter 2.3.2 --- Neutral red assay --- p.25 / Chapter 2.4 --- Cytotoxicity Assay --- p.32 / Chapter 2.5 --- Chemoprotection assay --- p.32 / Chapter 2.5.1 --- Direct addition of drugs --- p.33 / Chapter 2.5.2 --- Pretreatment of cells --- p.33 / Chapter 2.5.3 --- Culture of cells with drugs --- p.34 / Chapter 2.6 --- Preparation of enzymes --- p.36 / Chapter 2.6.1 --- Preparation of cells --- p.36 / Chapter 2.6.2 --- Pretreatment of rat microsomes --- p.36 / Chapter 2.7 --- Bradford Assay --- p.37 / Chapter 2.8 --- Alkoxyresorufin O-Dealkylase assay --- p.39 / Chapter 2.8.1 --- Effects of AFB1 on P450 --- p.44 / Chapter 2.8.2 --- Effects of drugs on P450 --- p.44 / Chapter 2.9 --- Glutathione-S-transferase assay --- p.44 / Chapter 2.9.1 --- GST assay in rat microsomal fractions --- p.48 / Chapter 2.9.1.1 --- Effects of AFB1 on GST --- p.48 / Chapter 2.9.1.2 --- Effects of drugs on GST --- p.48 / Chapter 2.9.2 --- GST assay in crude fractions from cells --- p.48 / Chapter 2.9.2.1 --- Direct addition effects of drugs on GST --- p.48 / Chapter 2.9.2.2 --- Effects of drug-containing medium on GST --- p.49 / RESULTS / Chapter CHAPTER THREE --- CELL CULTURES --- p.50 / Chapter 3.1 --- Cytotoxicity assay --- p.51 / Chapter 3.1.1 --- Cytotoxicity of AFB1 --- p.51 / Chapter 3.1.1.1 --- Cytotoxicity of AFB1 to splenocytes --- p.51 / Chapter 3.1.1.2 --- Cytotoxicity of AFB1 to cell lines --- p.57 / Chapter 3.1.2 --- Cytotoxicity of drugs to cell lines --- p.62 / Chapter 3.2 --- Chemoprotection assay --- p.73 / Chapter 3.2.1 --- Direct addition of drugs --- p.73 / Chapter 3.2.2 --- Pretreatment of cells with drugs --- p.78 / Chapter 3.2.3 --- Culture of cells with drugs --- p.83 / Chapter CHAPTER FOUR --- ENZYMATIC ASSAYS --- p.87 / Chapter 4.1 --- Alkoxyresorufin O-dealkylase assay --- p.88 / Chapter 4.1.1 --- Effects of AFB1 on P450s --- p.88 / Chapter 4.1.2 --- Effects of GA on P450s --- p.92 / Chapter 4.1.3 --- Effects of EX on P450s --- p.95 / Chapter 4.2 --- Glutathione -S- transferase assay --- p.98 / Chapter 4.2.1 --- Effects of drugs on GST in cells --- p.100 / Chapter 4.2.2 --- Effects of AFB1 and drugs on GST from rats --- p.108 / Chapter 4.2.2.1 --- Effects of AFB1 on GST from rats --- p.108 / Chapter 4.2.2.2 --- Effects of drugs on GST from rats --- p.112 / Chapter CHAPTER FIVE --- DISCUSSION --- p.115 / Chapter 5.1 --- Cytotoxicity of AFB1 --- p.118 / Chapter 5.2 --- "Cytotoxicity of EX, GA and AA" --- p.119 / Chapter 5.3 --- Chemoprotection of GA and EX on AFB1 cytotoxicity --- p.121 / Chapter 5.4 --- Effects of GA and EX on enzymes involved in AFB1 metabolism --- p.123 / REFERENCES --- p.129