Cheung Sao Fong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves xxiv-xxxvii). / Abstracts in English and Chinese. / Examination Committee List --- p.i / Declaration --- p.ii / Acknowledgements --- p.iii / Abstract --- p.v / Abstract in Chinese --- p.viii / List of Figures and Tables --- p.x / List of Abbreviations --- p.xix / Table of Content --- p.xxiii / Chapter Chapter 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Human Liver Cancer --- p.1 / Chapter 1.1.1 --- Incidence of Hepatocellular Carcinoma --- p.1 / Chapter 1.1.2 --- Causes and Symptoms of Hepatocellular Carcinoma --- p.4 / Chapter 1.1.3 --- Treatment Options for Hepatocellular Carcinoma --- p.4 / Chapter 1.1.4 --- Multi-drug Resistance --- p.5 / Chapter 1.1.4.1 --- Mechanisms of Multi-drug Resistance --- p.5 / Chapter 1.2 --- Traditional Chinese Medicine --- p.10 / Chapter 1.2.1 --- Sophora flavescens and Radix Sophorae --- p.10 / Chapter 1.2.2 --- Flavonoid and its Sub-classification --- p.13 / Chapter 1.2.3 --- Flavonoid and Human Health --- p.15 / Chapter 1.3 --- Cell Death --- p.17 / Chapter 1.3.1 --- Necrosis --- p.17 / Chapter 1.3.2 --- Apoptosis --- p.17 / Chapter 1.3.3 --- Signaling Pathways in Apoptosis --- p.18 / Chapter 1.3.3.1 --- Extrinsic (Death Receptor-mediated) Pathway --- p.20 / Chapter 1.3.3.2 --- Intrinsic (Mitochondrial) Pathway --- p.21 / Chapter 1.3.3.3 --- Cysteine Aspartatic Acid Proteases --- p.21 / Chapter 1.4 --- Research Objective (s) --- p.22 / Chapter Chapter 2 --- MATERIALS AND METHODS --- p.23 / Chapter 2.1 --- Materials --- p.23 / Chapter 2.1.1 --- Cell Lines --- p.23 / Chapter 2.1.1.1 --- HepG2 --- p.24 / Chapter 2.1.1.2 --- RHepG2 --- p.24 / Chapter 2.1.1.3 --- WRL-68 --- p.25 / Chapter 2.1.2 --- Culture Media --- p.26 / Chapter 2.1.2.1 --- Rosewell Park Memorial Institute( RPMl) 1640 Medium --- p.26 / Chapter 2.1.2.2 --- Dulbecco's Modified Eagle's Medium (DMEM) --- p.26 / Chapter 2.1.3 --- Animals --- p.27 / Chapter 2.2 --- Traditional Chinese Medicines and Conventional Anti-cancer Drugs --- p.27 / Chapter 2.3 --- Antibodies --- p.29 / Chapter 2.4 --- Chemicals --- p.30 / Chapter 2.5 --- Reagents and Buffers --- p.34 / Chapter 2.5.1 --- Reagents for Silica Gel Column Chromatography --- p.34 / Chapter 2.5.2 --- Buffers for Common Use --- p.34 / Chapter 2.5.3 --- Reagents for Cell Viability Assay --- p.35 / Chapter 2.5.4 --- Reagents and Buffers for Typical Apoptosis Experiments --- p.35 / Chapter 2.5.4.1 --- Cell Cycle Analysis --- p.35 / Chapter 2.5.4.2 --- Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick End Labeling (TUNEL) Assay --- p.35 / Chapter 2.5.4.3 --- DNA Fragmentation Detection --- p.35 / Chapter 2.5.5 --- Reagents and Buffers for Western Blot Study --- p.36 / Chapter 2.5.5.1 --- Whole-cell Protein Extraction --- p.38 / Chapter 2.5.5.2 --- Mitochondrial and Cytosolic Fraction Protein Extraction --- p.38 / Chapter 2.5.6 --- Reagents and Buffers for Mitochondrial Transmembrane Potential Depolarization Measurement --- p.39 / Chapter 2.5.7 --- Reagents and Buffers for in vivo Animal Study --- p.39 / Chapter 2.5.8 --- Reagents and Buffers for Two-Dimensional Gel Electrophoresis --- p.40 / Chapter 2.5.8.1 --- Sample Preparation --- p.40 / Chapter 2.5.8.2 --- First Dimension Gel Electrophoresis - Isoelectric Focusing (IEF) --- p.40 / Chapter 2.5.8.3 --- Second Dimension Gel 日ectrophoresis - SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE) --- p.40 / Chapter 2.5.8.4 --- Silver Staining --- p.41 / Chapter 2.5.9 --- Reagents for Mass Spectrometry Preparation --- p.42 / Chapter 2.5.9.1 --- Destaining --- p.42 / Chapter 2.5.9.2 --- Trypsin Digestion --- p.42 / Chapter 2.5.9.3 --- Desalting of Peptide Mixture --- p.43 / Chapter 2.5.10 --- Reagents and Buffers for Real-Time PCR --- p.43 / Chapter 2.6 --- Methods --- p.44 / Chapter 2.6.1 --- Isolation of Bioactive Constituents by Silica Gel Column Chromatography --- p.44 / Chapter 2.6.2 --- Cell Viability Assay --- p.45 / Chapter 2.6.3 --- Typical Apoptosis Experiments --- p.45 / Chapter 2.6.3.1 --- Cell Cycle Analysis --- p.46 / Chapter 2.6.3.2 --- Annexin V-FITC/ PI Staining Experiment --- p.47 / Chapter 2.6.3.3 --- Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick End Labeling (TUNEL) Assay --- p.48 / Chapter 2.6.3.4 --- DNA Fragmentation Reaction --- p.48 / Chapter 2.6.4 --- Western Blot Study --- p.49 / Chapter 2.6.4.1 --- Whole-cell Protein Extraction --- p.49 / Chapter 2.6.4.2 --- Mitochondrial and Cytosolic Fraction Protein Extraction --- p.50 / Chapter 2.6.5 --- Caspase Activity Determination --- p.54 / Chapter 2.6.6 --- Mitochondrial Transmembrane Potential Depolarization Measurement --- p.55 / Chapter 2.6.7 --- in vivo Animal Study --- p.56 / Chapter 2.6.8 --- Two-Dimensional Gel Electrophoresis --- p.58 / Chapter 2.6.8.1 --- Sample Preparation --- p.58 / Chapter 2.6.8.2 --- First Dimension Electrophoresis - Isoelectric Focusing (IEF) --- p.59 / Chapter 2.6.8.3 --- Second Dimension Electrophoresis - SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE) --- p.60 / Chapter 2.6.8.4 --- Silver Staining --- p.61 / Chapter 2.6.9 --- Mass Spectrometry Preparation --- p.63 / Chapter 2.6.9.1 --- Destaining and Trypsin Digestion --- p.63 / Chapter 2.6.9.2 --- Peptide Extraction --- p.63 / Chapter 2.6.9.3 --- Desalting of Peptide Mixture --- p.64 / Chapter 2.6.10 --- Real-Time PCR --- p.65 / Chapter 2.6.11 --- Cellular Glutathione Level Detection --- p.69 / Chapter 2.7 --- Statistical Analysis --- p.70 / Chapter Chapter 3 --- RESULTS AND DISCUSSIONS - CYTOTOXICITY OF FLAVONOIDS ISOLATED FROM RADIX SOPHORAE --- p.72 / Chapter 3.1 --- Screening of Cytotoxic Flavonoids from Radix Sophorae --- p.72 / Chapter 3.2 --- Cytotoxicity of Leachianone A on Human Hepatoma Cell Lines --- p.74 / Chapter 3.3 --- Cytotoxicity of Leachianone A on Human Normal Liver Cell Line --- p.77 / Chapter 3.4 --- Cytotoxicity of Sophoraflavone J on Human Hepatoma Cell Line --- p.79 / Chapter 3.5 --- Cytotoxicity of Sophoraflavone J on Human Normal Liver Cell Line --- p.79 / Chapter 3.6 --- Cytotoxicities of Cisplatin and Taxol on Human Hepatoma as well as Normal Liver Cell Lines --- p.81 / Chapter 3.7 --- Conclusion --- p.86 / Chapter Chapter 4 --- "RESULTS AND DISCUSSIONS - MECHANISTIC STUDY OF LEACHIANONE A-INDUCED CELL DEATH IN HEPATOMA CELLS, HepG2 and RHepG2" --- p.88 / Chapter 4.1 --- Promotion of Cell Cycle Arrest --- p.88 / Chapter 4.2 --- Induction of Apoptosis as Evidenced by Phosphatidylserine Externalization and DNA Fragmentation --- p.93 / Chapter 4.2.1 --- Occurrence of Phosphatidylserine Externalization --- p.94 / Chapter 4.2.2 --- DNA Fragmentation Detection --- p.99 / Chapter 4.2.2.1 --- Terminal Deoxynucleotidyl Transferase(TdT)-mediated dUTP Nick End Labeling (TUNEL) Assay --- p.99 / Chapter 4.2.2.2 --- DNA Laddering Pattern in Agarose Gel Electrophoresis --- p.103 / Chapter 4.3 --- Recruitment of Multiple Signaling Pathways in Leachianone A-induced Apoptosis --- p.105 / Chapter 4.3.1 --- "Activation of Caspases-3, -8, and -9" --- p.105 / Chapter 4.3.2 --- Altered Expressions of Bcl-2 Family Proteins --- p.112 / Chapter 4.3.3 --- Loss of Mitochondrial Membrane Potential --- p.115 / Chapter 4.4 --- in vivo Tumor Growth Inhibition in HepG2-bearing Nude Mice --- p.121 / Chapter 4.5 --- Conclusion --- p.127 / Chapter Chapter 5 --- RESULTS AND DISCUSSIONS - MECHANISTIC STUDY OF SOPHORAFLAVONE J-INDUCED CELL DEATH IN HEPATOMA CELLS HepG2 --- p.132 / Chapter 5.1 --- Execution of Cellular Apoptosis --- p.133 / Chapter 5.2 --- Involvement of Multiple Signaling Pathways in Sophoraflavone J-induced Apoptosis --- p.138 / Chapter 5.3 --- Differential Proteomes of Control and Sophoraflavone J-treated HepG2 Cells --- p.148 / Chapter 5.4 --- Conclusion --- p.167 / Chapter Chapter 6 --- OVERALL CONCLUSION AND FUTURE PERSPECTIVES --- p.169 / References --- p.xxiv

Po Lai See. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 142-152). / Abstracts in English and Chinese. / TITLE PAGE --- p.p.1 / ACKNOWLEGDEMENTS --- p.p.2 / ABSTRACT --- p.p.3 / 摘要 --- p.p.6 / TABLE OF CONTENTS --- p.p.9 / LIST OF FIGURES AND TABLES --- p.p.16 / Chapter CHAPTER 1 --- GENERAL INTRODUCTION / Chapter 1.1 --- Estrogen and Estrogen Receptors and its Action --- p.p.18 / Chapter 1.1.1 --- Estrogen --- p.p.19 / Chapter 1.1.2 --- Estrogen Receptors --- p.p.19 / Chapter 1.1.3 --- Structural Differences between ERa and ERp --- p.p.21 / Chapter 1.1.4 --- Functional Differences --- p.p.22 / Chapter 1.1.5 --- Effects of Selective Estrogen Receptor Modulators --- p.p.22 / Chapter 1.1.6 --- Estrogen works --- p.p.23 / Chapter 1.1.7 --- Estrogen Receptors and Breast Cancer --- p.p.24 / Chapter 1.2 --- Flavonoids： Properties and Biological Activities --- p.p.25 / Chapter 1.2.1 --- Chemical Structure and Classification of flavonoids --- p.p.25 / Chapter 1.2.2 --- Biological Properties and Action Mechanism of Flavonoids… --- p.p.27 / Chapter 1.2.3 --- Flavonoids and breast cancer prevention --- p.p.27 / Chapter 1.3 --- Aims and Scopes of Investigation --- p.p.29 / Chapter CHAPTER 2 --- MATERIALS AND METHODS / Chapter 2.1 --- Chemicals --- p.p.30 / Chapter 2.1.1 --- Flavonoids --- p.p.30 / Chapter 2.1.2 --- Plasmids --- p.p.30 / Chapter 2.2 --- Mammalian cell culture --- p.p.31 / Chapter 2.2.1 --- Maintenance of cells --- p.p.31 / Chapter 2.2.2 --- Preparation of cell stock --- p.p.32 / Chapter 2.2.3 --- Cell recovery from liquid nitrogen stock --- p.p.32 / Chapter 2.3 --- Identification of estrogenic activity in flavonoids --- p.p.33 / Chapter 2.3.1 --- Steady Glo Luciferase Assay --- p.p.33 / Chapter 2.3.2 --- The Biorad Protein Assay kit (a modified Bradford method). --- p.p.33 / Chapter 2.4 --- Viability Assay --- p.p.34 / Chapter 2.5 --- ERE Luciferase reporter gene assay --- p.p.35 / Chapter 2.5.1 --- Transient transfect ion of cell using lipofectamine PLUS reagent --- p.p.36 / Chapter 2.5.2 --- Dual Luciferase Assay --- p.p.37 / Chapter 2.6 --- ERα competitive binding ASSAY --- p.p.37 / Chapter 2.7 --- Apoptotic death assay --- p.p.38 / Chapter 2.8 --- Semi-quantitative RT-PCR Assay --- p.p.40 / Chapter 2.8.1 --- "Isolation of RNA using TRIzol® Reagent (Life Technology,USA) " --- p.p.40 / Chapter 2.8.2 --- Quantitation of RNA --- p.p.41 / Chapter 2.8.3 --- First strand cDNA synthesis --- p.p.41 / Chapter 2.8.4 --- PCR reactions --- p.p.43 / Chapter 2.9 --- Flow Cytometry Analysis --- p.p.43 / Chapter 2.10 --- Total triglyceride and cholesterol measurement --- p.p.44 / Chapter 2.10.1 --- Determination of the total cholesterol --- p.p.45 / Chapter 2.10.2 --- Determination of the total triglyceride --- p.p.46 / Chapter 2.11 --- Manipulation of DNA and RNA --- p.p.46 / Chapter 2.11.1 --- Transformation of DH5α --- p.p.46 / Chapter 2.11.2 --- Mini preparation of plasmid DNA --- p.p.47 / Chapter 2.11.3 --- Preparation of plasmid DNA using QIAGEN-tip 100 midi-prep kit --- p.p.48 / Chapter 2.11.4 --- Preparation of plasmid DNA using QIAGEN-tip 10000 Giga-prep kit --- p.p.49 / Chapter 2.11.5 --- Ethanol preparation of DNA and RNA --- p.p.50 / Chapter 2.11.6 --- Agarose gel electrophoresis of DNA --- p.p.51 / Chapter 2.12 --- Statistical methods --- p.p.52 / Chapter CHAPTER 3 --- Estrogenic and antiproliferative activities on MCF-7 breast cancer cells by flavonoids / Chapter 3.1 --- Introduction --- p.p.53 / Chapter 3.2 --- Results --- p.p.56 / Screening of phytoestrogens for estrogenic activities on MELN cells --- p.p.56 / Cell proliferation activity of phytoestrogens on MCF-7 and MDA-MA231 cells --- p.p.59 / Estrogenic and antiestrogenic activity of phytoestrogens on ERα or erβ transfected hepg2 cells --- p.p.64 / Chapter 3.3 --- Discussion --- p.p.73 / Chapter Chapter 4 --- interaction of baicalein with estrogen receptors / Chapter 4.1 --- Introduction --- p.p.76 / Chapter 4.2 --- Results --- p.p.78 / Estrogen receptor competition assay --- p.p.78 / ERE-Luciferase gene reporter assay --- p.p.82 / Chapter 4.3 --- Discussion --- p.p.88 / Chapter Chapter 5 --- baicalein and genistein display differential actions on er transactivation / Chapter 5.1 --- Introduction --- p.p.90 / Chapter 5.2 --- Results --- p.p.92 / Estrogenic and antiestrogenic activities of genistein and baicalein on ER transactivation --- p.p.92 / Chapter 5.3 --- Discussion --- p.p.105 / Chapter CHAPTER 6 --- APOPTOTIC EFFECTS OF BAICALEIN ON MCF-7 AND MDA-MB-231 CELL LINES / Chapter 6.1 --- Introduction --- p.p.107 / Chapter 6.2 --- Results --- p.p.111 / ER POSITIVE MCF-7 AND ER NEGATIVE MDA-MB-231 cell death assay --- p.p.111 / "Bcl-2, Bax and PS2 mRNA expression " --- p.p.116 / Arrest at sub G1 phase of MCF-7 by baicalein --- p.p.124 / Chapter 6.3 --- Discussion --- p.p.127 / Chapter CHAPTER 7 --- BAICALEIN CAN REDUCE INTRACELLULAR cholesterol and triglceride / Chapter 5.1 --- Introduction --- p.p.129 / Chapter 5.2 --- Results --- p.p.130 / Baicalein has beneficial effect on lipid metabolism --- p.p.130 / Chapter 5.3 --- Discussion --- p.p.139 / Chapter chapter 8 --- Summary --- p.p.140 / BIBLIOGRAPHY --- p.p.142 / APPENDIX 1 ABBREVIATIONS --- p.p.153 / APPENDIX 2 PRIMER LISTS --- p.p.156 / APPENDIX 3 REAGENTS AND BUFFERS --- p.p.157

Orientadores: Hiroshi Aoyama / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-19T03:25:44Z (GMT). No. of bitstreams: 1 Camargo_CamiladeAndrade_D.pdf: 5871656 bytes, checksum: 08f82cc2064fb3997898335664c62806 (MD5) Previous issue date: 2011 / Resumo: Atualmente o câncer é um problema de saúde pública mundial, em virtude do aumento de sua incidência. A anorexia e a perda de peso involuntária são comuns em pacientes oncológicos. Esta condição, também conhecida como caquexia, afeta a capacidade funcional, a resposta ao tratamento, a qualidade de vida e a sobrevida do paciente. Estima-se que aproximadamente dois milhões de pessoas no mundo morrem anualmente devido às conseqüências da via câncer/caquexia. O modelo estudado neste trabalho é o carcinossarcoma de Walker 256 (W256), que tem como característica principal o desenvolvimento da caquexia nos animais portadores, devido ao seu comportamento biológico agressivo, crescimento invasivo e alto potencial de metástase. Os flavonóides, fitocompostos polifenólicos encontrados em plantas, apresentam diversas atividades biológicas, principalmente, devido as suas propriedades antioxidantes e habilidades em modular diversas enzimas ou receptores celulares. Estes compostos possuem efeitos protetores contra doenças relacionadas ao sistema cardiovascular, certas etiologias de câncer, doenças provocadas pela fotossensibilidade e envelhecimento, dentre outras. A proposta do presente estudo foi avaliar os efeitos dos flavonóides quercetina, narigina, morina e do composto acetoxi DMU (um derivado sintético do resveratrol e do DMU-212), na prevenção/atenuação da caquexia e inibição do crescimento do tumor em ratos portadores de W256, num estudo pré-clínico. Ratos machos sadios foram inoculados subcutaneamente, no flanco direito, com as células tumorais e tratados com diferentes doses dos compostos (10, 25 e 35mg/kg), via intraperitoneal, 5 dias consecutivos por semana, durante 50 dias ou até o óbito. A administração de 10mg/kg de quercetina e de 25mg/kg de narigina, morina e do composto acetoxi DMU inibiram cerca de 50% o crescimento do tumor (ED50) quando comparado com os animais controle inoculados com tumor, sem tratamento (grupo Tumor). A ED50 para os tratamentos com quercetina, narigina, morina e acetoxi DMU foi responsável por um aumento de 30, 70, 60 e 70%, respectivamente, na sobrevida dos ratos tratados (p < 0,05) em contraste aos 100% de mortalidade observada no grupo Tumor. Outra conseqüência da administração da ED50 foi a ocorrência de regressão tumoral em 2, 5, 2 e 3 animais, respectivamente, para os tratamentos com quercetina, narigina, morina e acetoxi DMU (n=10). O tratamento com os compostos também foi eficiente em manter os níveis das citocinas TNF-? e IL-6 (no tecido hepático e tumoral do hospedeiro), mediadores do processo caquético, semelhantes aos encontrados nos ratos controle sem tumor (grupo Controle). Já os ratos do grupo Tumor apresentaram altos níveis destas citocinas, tanto nas amostras de fígado como nas de tumor. Os tratamentos promoveram também um alto potencial anti-angiogênico, mostrado através da diminuição na expressão de VEGF e nas atividades das MMP-2 presentes nas amostras de fígado e tumor. Os níveis de VEGF encontrados nos fígados dos ratos do grupo Tumor foram significantemente maiores que os do grupo Controle. Outro efeito do tratamento com os compostos foi uma diminuição significativa na expressão da proteína tirosina fosfatase de baixa massa molecular (nas amostras de fígado e tumor), que havia sido super-expressa em animais do grupo Tumor. As análises dos pesos dos testículos e órgãos reprodutivos acessórios (epidídimo, vesícula seminal, glândula de coagulação e próstata) foram feitas para os animais tratados com narigina e acetoxi DMU. Os resultados indicaram uma redução significativa nos órgãos dos animais do grupo Tumor em comparação com o grupo Controle. Pelo contrário, o tratamento terapêutico de ratos com tumor com a narigina e o acetoxi DMU se mostrou eficaz em proteger a morfologia destes órgãos e inibir esta redução. De acordo com os resultados obtidos, o melhor tratamento foi obtido com o acetoxi DMU. Os resultados obtidos neste trabalho confirmam o efeito dos flavonóides e de acetoxi DMU em diminuir os sintomas da caquexia no modelo tumoral utilizado para experimentação e em inibir o crescimento tumoral, contribuindo, assim, para uma melhor compreensão da ação in vivo destes compostos, tanto no organismo sadio como na presença do tumor / Abstract: Currently, cancer is a public health problem worldwide in virtue of the increase in incidence. Anorexia and involuntary weight loss are common in cancer patients. This condition, also known as cachexia, affects the functional capacity, response to treatment, quality of life and patient survival. It is estimated that approximately two million people worldwide die annually because of cancer cachexia consequences. In this work the Walker 256 carcinosarcoma (W256) is used as an experimental model to establish cancer cachexia in infected animals. Furthermore, it presents an aggressive biological behavior, local invasive growth and high metastasis potential. Flavonoids are polyphenolic compounds with several biological activities mainly due to its antioxidant properties and ability to modulate several enzymes or cellular receptors. These characteristics are associated with the protective effect attributed to these compounds against cardiovascular system diseases, some causes of cancer, diseases caused by photosensitivity and aging, among other. The aim of this study was to evaluate the effects of the flavonoids quercetin, naringin and morin and the compound acetoxy DMU (a synthetic derivative of resveratrol and DMU-212) in the cachexia prevention/attenuation and inhibition of tumor growth in rats bearing W256, in a preclinical study. Healthy male rats were inoculated with tumor cells and treated with different doses of quercetin, naringin, morin and acetoxy DMU (10, 25 and 35mg/kg) intraperitoneally administered, 5 consecutive times a week, during 50 days or until death. The administration of 10 mg/kg quercetin and 25mg/kg naringin, morin and acetoxy DMU inhibited about 50% of tumor growth (ED50) compared with Tumor group (untreated). The ED50 values for the treatment with quercetin, naringin, morin and acetoxy DMU were responsible for a survival increase about 30, 50, 40 and 60%, respectively, in contrast to 100% mortality observed in the tumor group. Another consequence of the ED50 administration was the tumor regression in 2, 5, 2 and 3 animals, respectively, for treatment with quercetin, naringin, morin and acetoxy DMU (n=10). The effect of treatment with these compounds on cytokines mediators of the cachectic process (in liver and tumor tissue) was efficient in maintaining the TNF-? and IL-6 levels similar to those found in control rats (Control group). Tumor group presented high levels of these cytokines in both liver and tumor samples. The treatments also promoted a high potential anti-angiogenic, shown by the decrease in VEGF expression and MMP-2 activity of liver and tumor samples. The VEGF levels found in Tumor group (liver samples) were significantly higher than the Control group. Another effect of treatment with the compounds was a significant decrease in the low molecular weight protein tyrosine phosphatase expression (in liver and tumor tissue), which had been over-expressed in Tumor group. Analyses of testes and accessory reproductive organs weights (epididymis, seminal vesicle, coagulating gland and prostate) were made for animals treated with narigina and acetoxy DMU. The results indicated a significant reduction in Tumor group organs compared with the Control group. On the other hand, the naringin and acetoxi DMU therapeutic treatments of rats with tumor have been proven effective in protecting the morphology of these organs and inhibiting its reduction. According to the results, the best treatment was obtained with the acetoxy DMU. The results of this work confirm the effect of these flavonoids and acetoxi DMU on reducing the cachexia symptoms and tumor growth inhibition, contributing to a better understanding of the action of these compounds in vivo, both in healthy and in tumor organisms / Doutorado / Bioquimica / Doutor em Biologia Funcional e Molecular

Baicalein is known to be a potent antifungal agent and induces programmed cell death in Candida albicans. In the present study, we found that baicalein also inhibited the growth of C. krusei isolates. The minimal inhibitory concentrations of baicalein against eight C. krusei isolates were 1.35--2.70 microg/ml. One-hour exposure to baicalein elicited a consistent and moderate post-antifungal effect on the C. krusei isolates. Further flow cytometric study demonstrated a depolarization of mitochondrial membrane potential. However, both the levels of reactive oxygen species and DNA fragmentation were not significantly changed after baicalein treatment in C. krusei. It can be concluded that the antifungal activity of baicalein was mitochondria-dependent in both C. krusei and C. albicans, but the antifungal mechanism was different. Reactive oxygen species may not play a direct role and baicalein does not initiate programmed cell death or apoptosis in C. krusei. The structure-activity relationship study showed that the three hydroxyl groups in baicalein were essential for its antifungal potency. / Candidiasis has become a serious infection with very high mortality and morbidity in the world if not providing effective treatments. However, due to clinical limitation and resistance of the current antifungal agents, there is an urgent need to search for novel antifungals. In this study, after screening a compound library (n=400) for antifungal activity, three members (metergoline, purpurin and baicalein) were chosen for further study. Their antifungal characteristics and the antifungal mechanisms were investigated. / Metergoline, a serotonin receptor antagonist, was found to have potent antifungal activity against the intrinsically fluconazole-resistant human fungal pathogen Candida krusei. The minimal inhibitory concentration and minimal fungicidal concentration of metergoline against C. krusei were 4 microg/ml and 8 microg/ml respectively. Metergoline induced post-antifungal effect. Significant synergism was found in combination of metergoline with amphotericin B by a checkerboard assay, which may be due to the perturbation of cell permeability and increase in the intracellular accumulation of antifungal agents. Metergoline also inhibited extracellular phospholipase production in C. krusei. To gain insights into the mechanisms, intracellular changes that accompany apoptosis were examined by flow cytometry and spectrophotometry. The results showed an increase in the level of reactive oxygen species, depolarization of mitochondrial membrane potential, phosphatidylserine externalization, and positive terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labelling in the metergoline-treated C. krusei . Taken together, we conclude that metergoline may promote apoptosis in C. krusei through reactive oxygen species production and perturbation in mitochondrial homeostasis, implying its antifungal potential to treat candidiasis. / The antifungal activity of purpurin, a natural red anthraquinone pigment in madder root (Rubia tinctorum L.), was evaluated against Candida isolates by a broth microdilution assay. The minimal inhibitory concentrations of purpurin against Candida species isolates were 1.28--5.12 microg/ml. Mechanistic studies indicated that purpurin inhibited energy-dependent efflux pumps of Candida isolates. Furthermore, purpurin demonstrated a depolarization of mitochondrial membrane potential, suggesting a possible linkage of the antifungal mechanism of purpurin to Candida apoptosis. / Kang, Kai. / Adviser: Fong Wing Ping. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 98-123). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.