Thesis (M. Sc.)--University of Hong Kong, 1969. / Offprints of An examination of the Euphorbiaceae of Hong Kong, pts. III and VI, by W.H. Hui and the author in pocket. Typewritten.

Thesis (Ph. D.)--University of Hong Kong, 1976. / 8 articles in pocket.

published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--Michigan State University. Dept. of Food Science and Human Nutrition, 2008. / Title from PDF t.p. (viewed on Mar. 27, 2009). Includes bibliographical references. Also issued in print.

Thesis (Ph. D.)--New York University, 1929. / Bibliography: p. 787, 235.

Thesis (M.Phil. Chemistry)--University of Waikato, 2006. / Author held a Georgetti scholarship. Includes bibliographical references (leaves 89-99). Also available via the World Wide Web.

Human gut harbors 100 trillion microbial organisms that is intrinsically linked to individual’s health and diseases, including cancer. Food fiber and phytochemicals such as polyphenols are considered as prebiotic-like dietary modifiers. They can influence the gut microbial communities, and in turn to modulate disease outcome and drug responses of the host. Saponins belong to a family of phytochemicals commonly found in many medicinal and edible plants. Herbal saponins have raised keen interest among scientists for their health-promoting effects, but have not been investigated for their potential as prebiotics. Gynostemma pentaphyllum (Gp) is riched in triterpenoid saponins and has been consumed in China and other part of the world as an herbal tea and as a folk medicine. In our lab, we have demonstrated that Gp possesses strong anticancer and anti-inflammatory effects. Whether Gp possesses prebiotic property and whether gut microbiota plays any part of the anticancer effect of Gp are the questions addressed in the present study. Thus, we hypothesized that Gp saponins (GpS) might modulate the gut microbiota, which in turn enhance its anticancer activities. In the study, the gut microbiome analysis were carried out using two main techniques, neamly the enterobacterial repetitive intergenic consensus (ERIC-PCR) and 16S pyrosequencing approaches. Both xenograft nude mice and Apcmin/+ mice were employed as the animal models to investigate the interaction between the herbal saponins and the gut microbiota in the host. Athymic nude mice have been employed for tumorigenic research for decades, however, the relationships between the gut microbiome and host’s response to the grafted tumors and drug treatments are unexplored. For the first part of the thesis, we investigated the relationship between the gut microbiota and grafted tumor in the nude mice under the treatment of Gp saponins. Partial least squared discriminant analysis (PLS-DA) of ERIC-PCR data showed that the microbiota profile of xenograft nude mice departed from that of the nonxenograft mice. However, prolonged treatment of GpS seems to realign the fecal microbiota with the pretreatment control. Pyrosequencing data reiterated the differences in fecal microbiome between the nonxenograft and xenograft animals. GpS treatment had a much stronger impact on the phylotypes of the xenograft than the nonxenograft mice. In addition, GpS treatment markedly induced the relative abundance of Clostridium cocleatum and Bacteroides acidifaciens, for which the beneficial effects on the host have been well documented. ApcMin/+ colorectal cancer mouse model was further employed for the investigation of the association of the gut microbiota and cancer occurred inside the gut, which was a more direct site to interact with the gut microbiota. In the ApcMin/+ mouse model, we found distinct difference of fecal microbiome between the ApcMin/+ and the wild-type littermates. GpS treatment significantly reduced the number of intestinal polyps. GpS also increased the ratio of Bacteroidetes/Firmicutes and reduced the sulfate- and sulfur-reducing bacteria lineage and potential opportunistic pathogens, which might cause certain deleterious effects to the host. The impact of GpS on the gut mucosal environment was also examined. We found GpS treatment improved the gut barrier function by increasing the numbers of Paneth cells, goblet cells, up-regulating the expression of E-cadherin and down-regulating the expression of N-cadherin in the intestine. In addition, GpS treatment down-regulated the protein expression of beta-catenin and p-STAT3. Furthermore, higher levels of anti-inflammatory and tissue repair-related cytokines as well as Arginase I, but lower level of iNOS expression were found in GpS-treated ApcMin/+ mice, indicating increased anti-inflammatory macrophage phenotype M2 (associated with tissue repair) and reduced proinflammatory phenotype M1. Furthermore, in addition to GpS, other herbal saponins also showed prebiotic-like effects in C57BL/6 mice. In summary, this study provides first hand evidence for the impact of herbal saponins on the gut microbial ecosystem and new insight into mechanisms responsible, at least in part, for the activities of GpS. We demonstrate that tumor growth induce intestinal dysbiosis. GpS treatment can inhibit tumor progression and concurrently alter the microbiome by increasing symbionts and/or decreasing pathobionts, which may contribute to its chemopreventive effect against tumorigenesis. Herbal saponins showing prebiotic-like effects may be used for improving the health of the host by manipulation of the gut microbiota.

Wong Pak Ki. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 86-88). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iv / Dedication --- p.v / Table of Contents --- p.vi / List of Abbreviations --- p.ix / List of Appendices --- p.xi / List of Figures --- p.xiv / List of Tables --- p.xx / Chapter Chapter 1: --- Introduction --- p.1 / Chapter 1.1 --- Ginseng and Ginsenosides --- p.1 / Chapter 1.2 --- Instrumental Analysis of Ginsenosides --- p.6 / Chapter 1.2.1 --- Thin Layer Chromatography --- p.6 / Chapter 1.2.2 --- Infrared Spectroscopy --- p.7 / Chapter 1.2.3 --- Colorimetry --- p.7 / Chapter 1.2.4 --- Gas Chromatography --- p.7 / Chapter 1.2.5 --- High Performance Liquid Chromatography --- p.8 / Chapter 1.3 --- Objective of the Study --- p.9 / Chapter Chapter 2: --- Experimental --- p.13 / Chapter 2.1 --- History of Electrophoresis and Capillary Electrophoresis --- p.13 / Chapter 2.1.1 --- Electroosmotic Flow (EOF) --- p.14 / Chapter 2.1.2 --- Electrophoretic Migration --- p.18 / Chapter 2.2 --- Reagents and Materials --- p.20 / Chapter 2.2.1 --- Reagents and Glassware --- p.20 / Chapter 2.2.2 --- Instrumentation --- p.20 / Chapter 2.2.3 --- Preparation of Solutions and Wavelength Selection --- p.22 / Chapter 2.2 --- Procedures --- p.23 / Chapter Chapter 3: --- Results and Discussions --- p.24 / Chapter 3.1 --- Initial Selection of the Running Electrolyte --- p.24 / Chapter 3.2 --- Inclusion Additives in the Aqueous Buffer Solution --- p.29 / Chapter 3.2.1 --- Reasons for Addition of Buffer Additives --- p.29 / Chapter 3.2.1.1 --- Cyclodextrin --- p.29 / Chapter 3.3 --- Addition of Surfactants --- p.33 / Chapter 3.3.1 --- Sodium Dodecyl Sulfate (SDS) --- p.35 / Chapter 3.3.2 --- Sodium Cholate --- p.41 / Chapter 3.4 --- Addition of Organic Modifier --- p.43 / Chapter 3.5 --- Effect of pH --- p.46 / Chapter 3.6 --- Effect of the Concentration of the Borate/Phosphate Solution --- p.51 / Chapter 3.7 --- Effect of Capillaries with Different Inner Diameters (I.D.) --- p.54 / Chapter 3.7.1 --- Effect of pH --- p.54 / Chapter 3.7.2 --- Effect of the Buffer Concentration --- p.60 / Chapter 3.7.3 --- Comparison of Migration Time between Capillaries of 50μm and 75μm Inner Diameter --- p.62 / Chapter 3.8 --- Optimization of Other Experimental Parameters --- p.66 / Chapter 3.8.1 --- Applied Voltage --- p.66 / Chapter 3.8.2 --- The Time of Injection --- p.68 / Chapter 3.8.3 --- The Operating Temperature --- p.70 / Chapter 3.9 --- Intra-day and Inter-day Reproducibility --- p.72 / Chapter 3.10 --- Quantitative Analysis of the Ginsenosides --- p.74 / Chapter 3.11 --- Application of the Developed Methodology --- p.78 / Chapter 3.11.1 --- Experimental Procedures --- p.79 / Chapter Chapter 4: --- Conclusion --- p.83 / References --- p.86 / Appendices --- p.89

by Cheung Yuen-Nei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 194-208). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Abstract --- p.ii / 摘要 --- p.iv / Contents --- p.vi / List of Figures --- p.xii / List of Tables --- p.xv / Abbreviations --- p.xvi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1 --- Introduction --- p.2 / Chapter 1.1 --- Characteristic of Saponins --- p.3 / Chapter 1.1.1 --- Occurrence of Saponins --- p.3 / Chapter 1.1.2 --- General Properties of Saponins --- p.3 / Chapter 1.1.2.1 --- Emulsifying Agents --- p.3 / Chapter 1.2.2.2 --- Forming Complex with Cholesterol --- p.4 / Chapter 1.1.2.3 --- Hemolytic Property --- p.4 / Chapter 1.1.3 --- Structure of Saponins --- p.5 / Chapter 1.1.3.1 --- Categories of Saponins --- p.5 / Chapter 1.1.3.1.1 --- Triterpene Saponins --- p.5 / Chapter 1.1.3.1.2 --- Steroid Saponins --- p.5 / Chapter 1.1.3.2 --- Monodesmosidic and Bidesmosidic Saponins --- p.7 / Chapter 1.1.4 --- Biological and Pharmacological Properties of Saponins --- p.9 / Chapter 1.1.4.1 --- Anti-microbial Activity --- p.9 / Chapter 1.1.4.1.1 --- Anti-fungal Activities --- p.9 / Chapter 1.1.4.1.2 --- Anti-bacterial Activities --- p.10 / Chapter 1.1.4.1.3 --- Anti-viral Activities --- p.10 / Chapter 1.1.4.2 --- Insecticidal Activity --- p.10 / Chapter 1.1.4.3 --- Molluscicidal Activity --- p.10 / Chapter 1.1.4.4 --- Hypocholesterolemic Activity --- p.11 / Chapter 1.1.4.5 --- Anti-ulcer Activity --- p.11 / Chapter 1.1.4.6 --- Contraceptive Activity --- p.12 / Chapter 1.1.4.7 --- Immunomodulatory Activities --- p.12 / Chapter 1.1.4.7.1 --- Direct Immunostimulation --- p.12 / Chapter 1.1.4.7.2 --- Acting as Immuno-adjuvants --- p.13 / Chapter 1.1.4.8 --- Anti-tumor Activity --- p.14 / Chapter 1.1.4.8.1 --- Anti-carcinogenesis --- p.15 / Chapter 1.1.4.8.2 --- Suppression of Tumor Growth --- p.16 / Chapter 1.1.5 --- Anti-tumor Activity of Steroid Saponins --- p.18 / Chapter 1.1.5.1 --- Diosgenin Steroid Saponin --- p.18 / Chapter 1.1.5.2 --- Hong Kong Compounds --- p.18 / Chapter 1.1.5.3 --- Hong Kong18 --- p.21 / Chapter 1.2 --- Human Hepatocellular Carcinoma (HCC) --- p.24 / Chapter 1.2.1 --- The Incidence of Liver Cancer --- p.24 / Chapter 1.2.2 --- Classification of Liver Cancer --- p.24 / Chapter 1.2.3 --- Human Hepatocellular Carcinoma Cell Lines --- p.25 / Chapter 1.2.3.1 --- Human Hepatocellular Carcinoma Cell Line HepG2 --- p.25 / Chapter 1.2.3.2 --- Multidrug Resistant Human Hepatocellular Carcinoma Cell Line R-HepG2 --- p.27 / Chapter 1.2.3.2.1 --- Mechanisms of Multidrug Resistance --- p.28 / Chapter 1.2.3.2.2 --- Structure and Characteristics of P-glycoprotein --- p.29 / Chapter 1.2.3.2.3 --- Methods in Dealing with P-glycoprotein Over-expressed MDR Cells --- p.31 / Chapter 1.3 --- Objectives of the Project --- p.32 / Chapter 1.3.1 --- Study of the Anti-tumor Activities of Hong Kong 18 on Human Hepatocellular Carcinoma Cell Line HepG2 and Unravel the Underlying Mechanisms --- p.32 / Chapter 1.3.2 --- Study of the Anti-tumor Activities of Hong Kong 18on Multidrug Resistant Human Hepatocellular Carcinoma Cell Line R-HepG2 and Unravel the Underlying Mechanisms --- p.32 / Chapter Chapter 2 --- Materials and Methods --- p.33 / Chapter 2.1 --- Materials --- p.34 / Chapter 2.1.1 --- Cell Culture --- p.34 / Chapter 2.1.1.1 --- Cell Lines --- p.34 / Chapter 2.1.1.2 --- Culture Media --- p.35 / Chapter 2.1.2 --- Reagents and Buffers --- p.36 / Chapter 2.1.2.1 --- Phosphate Buffered Saline (PBS) --- p.36 / Chapter 2.1.2.2 --- Reagents and Buffers for DNA Fragmentation --- p.36 / Chapter 2.1.2.3 --- Reagents and Buffers for Western Analysis --- p.37 / Chapter 2.1.2.4 --- Reagents and Buffer for Caspases Activities --- p.39 / Chapter 2.1.2.5 --- Fluorescent Dyes used for Flow Cytometry --- p.39 / Chapter 2.1.3 --- Chemicals --- p.39 / Chapter 2.2 --- Methods --- p.46 / Chapter 2.2.1 --- MTT Assay --- p.46 / Chapter 2.2.2 --- Determination of Cell Viability --- p.46 / Chapter 2.2.3 --- Purification of Macrophages from balb/c Mice --- p.47 / Chapter 2.2.4 --- Hemolysis Assay --- p.47 / Chapter 2.2.5 --- In vivo Studies of the Toxicity of HK18 --- p.48 / Chapter 2.2.6 --- DNA Fragmentation Assay --- p.50 / Chapter 2.2.7 --- Detection of Apoptotic and Necrotic / Late Apoptotic Cells Death by Flow Cytometry with Annexin V-FITC / PI --- p.51 / Chapter 2.2.8 --- Detection of Mitochondrial Membrane Potential by JC-1 Fluorescent Dye --- p.52 / Chapter 2.2.9 --- Detection of Intracellular Ca Level by Flow Cytometry with Fluo-3 Fluorescent Dye --- p.52 / Chapter 2.2.10 --- Detection of Intracellular Hydrogen Peroxide Level by Flow Cytometry with DCF Fluorescence Dye --- p.53 / Chapter 2.2.11 --- Simultaneous Detection of Mitochondrial Membrane Potential and Intracellular Ca2+ or Mitochondrial Membrane Potential and Intracellular Hydrogen Peroxide --- p.54 / Chapter 2.2.12 --- Western Analysis --- p.55 / Chapter 2.2.12.1 --- Total Protein Extraction --- p.55 / Chapter 2.2.12.2 --- Extraction of Cytosolic Proteins --- p.59 / Chapter 2.2.13 --- Determination of Caspases Enzymatic Activity --- p.63 / Chapter 2.2.14 --- Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) --- p.67 / Chapter 2.2.14.1 --- RNA Extraction by TRIzol Reagent --- p.67 / Chapter 2.2.14.2 --- Reverse Transcription --- p.68 / Chapter 2.2.14.3 --- Polymerase Chain Reaction --- p.68 / Chapter 2.3 --- Statistic Analysis --- p.71 / Chapter Chapter 3 --- Cytotoxicity of HK18 --- p.72 / Chapter 3.1 --- Cytotoxicity of HK18 on HepG2 Cells --- p.73 / Chapter 3.1.1 --- Study of the Cytotoxic Activity of HK18 on HepG2 Cells by MTT Assay --- p.73 / Chapter 3.1.2 --- Study of the Cytotoxic Activity of HK18 on HepG2 Cells by Tryphan Blue Exclusion Assay --- p.76 / Chapter 3.2 --- Cytotoxicity of HK18 on R-HepG2 Cells --- p.78 / Chapter 3.2.1 --- Study of the Cytotoxic Activity of HK18 on R-HepG2 Cells by MTT Assay --- p.78 / Chapter 3.2.2 --- Study of the Cytotoxic Activity of HK18 on R-HepG2 Cells by Tryphan Blue Exclusion Assay --- p.81 / Chapter 3.3 --- Cytotoxicity of HK18 on Macrophages --- p.83 / Chapter 3.4 --- Hemolytic Activity of HK18 --- p.85 / Chapter 3.5 --- In vivo Study of the Toxicity of HK18 --- p.87 / Chapter Chapter 4 --- Mechanistic Study of HK18 on HepG2 Cells --- p.90 / Chapter 4.1 --- Hallmarks of Apoptosis Induced by HK18 on HepG2 Cells --- p.91 / Chapter 4.1.1 --- Induction of Phosphatidylserine Externalization by HK18 on HepG2 Cells --- p.91 / Chapter 4.1.2 --- Induction of DNA Fragmentation by HK18 of HepG2 Cells --- p.97 / Chapter 4.2 --- Study of the Underlying Mechanisms of HK18 Induced Apoptosis in HepG2 Cells --- p.99 / Chapter 4.2.1 --- The Role of Mitochondria in HK18 Induced Apoptosis of HepG2 Cells --- p.99 / Chapter 4.2.1.1 --- HK18 Induced Mitochondrial Membrane Depolarization in HepG2 Cells --- p.101 / Chapter 4.2.1.2 --- Addition of Bongkrekic Acid Reduced HK18 Cytotoxicity on HepG2 Cells --- p.105 / Chapter 4.2.1.3 --- Elevation of Intracellular Hydrogen Peroxide Level in HK18 Treated HepG2 Cells --- p.108 / Chapter 4.2.1.4 --- Elevation of Intracellular Ca2+ Level in HK18 Treated HepG2 Cells --- p.114 / Chapter 4.2.1.5 --- HK18 Induced Cytochrome c and AIF Released from Mitochondria of HepG2 Cells --- p.120 / Chapter 4.3 --- Downstream Biochemical Changes Induced by HK18 on HepG2 Cells --- p.123 / Chapter 4.3.1 --- Activation of Caspase 3 of HepG2 Cells by HK18 as Demonstrated by Western Blot --- p.123 / Chapter 4.3.2 --- Induction of Caspases Activities of HepG2 Cells by HK18 as Demonstrated by Enzymatic Activity Assays --- p.125 / Chapter 4.4 --- Down-regulation of Anti-apoptotic Bcl-2 Family Members of HepG2 Cells by HK18 --- p.129 / Chapter Chapter 5 --- Mechanistic Study of HK18 on R-HepG2 Cells --- p.133 / Chapter 5.1 --- Hallmarks of Apoptosis Induced by HK18 on R-HepG2 Cells --- p.134 / Chapter 5.1.1 --- Induction of Phosphatidylserine Externalization by HK18 on R-HepG2 Cells --- p.134 / Chapter 5.1.2 --- Induction of DNA Fragmentation by HK18 of R-HepG2 Cells --- p.137 / Chapter 5.2 --- Study of the Underlying Mechanisms of HK18 Induced Apoptosis in R-HepG2 Cells --- p.139 / Chapter 5.2.1 --- The Role of Mitochondria in HK18 Induced Apoptosis of R-HepG2 Cells --- p.139 / Chapter 5.2.1.1 --- HK18 Induced Mitochondrial Membrane Depolarization in R-HepG2 Cells --- p.139 / Chapter 5.2.1.2 --- Addition of Bongkrekic Acid Reduced HK18 Cytotoxicity on R-HepG2 Cells --- p.142 / Chapter 5.2.1.3 --- Elevation of Intracellular Hydrogen Peroxide Level in HK18 Treated R-HepG2 Cells --- p.144 / Chapter 5.2.1.4 --- Elevation of Intracellular Ca2+ Level in HK18 Treated R-HepG2 Cells --- p.146 / Chapter 5.3 --- Downstream Biochemical Changes Induced by HK18 on R-HepG2 Cells --- p.148 / Chapter 5.3.1 --- Activation of Caspase 3 of R-HepG2 Cells by HK18 as Demonstrated by Western Blot --- p.148 / Chapter 5.3.2 --- Induction of Caspases Activation of R-HepG2 Cells by HK18 as Demonstrated by Enzymatic Activity Assays --- p.150 / Chapter 5.4 --- Down-regulation of the Anti-apoptotic Bcl-2 Protein of R-HepG2 Cells by HK18 --- p.154 / Chapter 5.5 --- HK18 was Not a Substrate of P-glycoprotein Contents --- p.156 / Chapter Chapter 6 --- Discussion --- p.158 / Chapter 6.1 --- Cytotoxicity of HK18 --- p.159 / Chapter 6.1.1 --- HK18 was Cytotoxic to the Human Hepatocellular Carcinoma Cell Line HepG2 and Multidrug Resistant Human Hepatocellular Carcinoma Cell Line R-HepG2 --- p.159 / Chapter 6.1.2 --- Study of the Toxicity of HK18 --- p.160 / Chapter 6.2 --- Mechanistic Studies of the Cytotoxic Effects of HK18 on HepG2 Cells --- p.161 / Chapter 6.2.1 --- Apoptotic Cell Death Induction of HK18 on HepG2 Cells --- p.161 / Chapter 6.2.2 --- Studies of the Underlying Mechanisms of HK18 Induced Apoptosis of HepG2 Cells --- p.162 / Chapter 6.3 --- Mechanistic Studies of the Cytotoxic Effects of HK18 on R-HepG2 Cells --- p.181 / Chapter 6.3.1 --- Apoptotic Cell Death Induction of HK18 on R-HepG2 Cells --- p.181 / Chapter 6.3.2 --- Studies of the Underlying Mechanisms of HK18 Induced Apoptosis of HepG2 Cells --- p.181 / Chapter Chapter 7 --- Future Perspectives --- p.190 / Chapter Chapter 8 --- References --- p.193

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xvi, 105 p.; also includes graphics (some col.) Includes bibliographical references (p. 95-105). Available online via OhioLINK's ETD Center