Thesis (M.Sc. (Microbiology)) -- University of Limpopo, 2023 / Plants are not only an important source of medicines, but also play a significant role in drug development for the treatment of diseases such as Tuberculosis (TB). TB is a pulmonary disease that is caused by Mycobacterium tuberculosis complex. The aim of the study is to identify and characterise antimycobacterial compounds from Dombeya rotundifolia. The plant was collected from the University of Limpopo, dried and ground into fine powder. Extraction was done using different solvents that differ in polarity. The plant was screened and analysed for phytochemicals. Three major phytochemicals were quantified using reagent assays and analysed using standard curves. The antioxidant activity of the plant was determined using 2,2-Diphenyl-1- picrylhydrazyl (DPPH) and ferric reducing power assay. The antibacterial activity of the plant extracts was tested against Mycobacterium smegmatis using bioautography and serial microplate broth dilution assay. The antibiofilm activity of the plant extracts were evaluated using crystal violet assay. The anti-inflammatory activity of the plant was determined using egg albumin protein denaturation assay. The cytotoxic effects of the extracts were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on THP-1 cell line. The antimycobacterial compounds were isolated and purified using bioassay-guided assay incorporated with column chromatography and preparative TLC. The isolated compounds were analysed and identified using nuclear magnetic resonance spectroscopy (NMR). The results obtained in this study showed that water was the best extractant, extracting 57.6 mg of the plant material, followed by methanol with 38.1 mg and hexane as the least extractant with 12.4 mg. In the phytochemical analysis of TLC plates, there was a separation of compounds in all the mobile systems, and a clear separation of compounds was observed in the BEA mobile system, followed by the EMW system. The plant has all major phytochemicals that are needed for drug development. The plant extracts had antioxidant activity, which was confirmed by the quantitative assays. The high inhibitory activity of the extracts was indicated by low MIC values that inhibited the bacterial growth. The butanol extract had the lowest MIC value (0.13 mg/mL). The plant extracts were able to prevent the formation of biofilm at different concentrations. The plant was proven to have anti-inflammatory properties by having a high inhibition capacity to prevent protein denaturation. The cytotoxicity results showed that the plant was toxic to the cells. The isolated antimycobacterial compounds were identified as Eicosanoic acid and Docosanoic. They have moderate activity with the MIC value of 0.25 mg/mL. The study indicated that the isolated compounds have antimycobacterial activity, which showed that the plant has a potential to treat TB or symptoms related to TB. However, further studies are needed to evaluate their toxic effects before use. / The National Research Foundation (NRF)

No description available.

T2DM is a chronic disease characterized by postprandial hyperglycemia. One of the therapeutic approaches to attenuate hyperglycemia is to inhibit intestinal ɑ-glucosidase enzyme and/or suppress glucose transporters that regulate intestinal glucose transporters such as SGLT1 & GLUT2. Berries rich in polyphenol antioxidants have various health benefits. Although the antidiabetic effects of various berry extracts or berry mixture in pre-clinical and clinical studies, the underlying pathways at the molecular level is still unclear. In this study, we investigated antioxidant and antidiabetic effects of selected berry extracts by determining free radical scavenging activates, Caco-2 intestinal ɑ-glucosidase activity, glucose uptake and the gene expression of ɑ-glucosidase and glucose transporters in Caco-2 cells. Total phenolic contents of berry extracts varied from 28.55 ± 0.06 to 56.15 ± 1.08 gallic acid equivalent (GAE μg/mL) and correlated with antioxidant capacities. Both cranberry extract (CBE) and blackberry extract (BBE) at 200 μg/mL concentration significantly decreased glucose uptake in Caco-2 cells. While mRNA expression and activity of ɑ-glucosidase were inhibited by CBE and BBE, mRNA expression of SGLT1 and GLUT2 was only inhibited by CBE. Moreover, CBE and BBE significantly decreased glucose uptake in the presence of sucrose and AS. Our data suggest that CBE and BBE have different molecular mechanisms in suppressing hyperglycemia and their effects are mediated by inhibiting carbohydrate digestion and absorption.

In the preparation of tannin extract from chestnut wood chips there is present in the extract, along with the tannin, certain insoluble non-tannin constituents. If allowed to remain in the extract, these materials make the tanning solution unsuitable for use in the manufacture of leather. To accomplish the separation of the non-tannin constituents from the tannin, the Lead Corporation of Lynchburg, Virginia, now employs a process of concentration and mechanical settling. For the past twenty years the company has been engaged in research to develop a better process. The investigations have been concentrated mainly on the idea of varied forms of mechanical separation. So far no solution to the problem has been found, thereby giving rise to the opinion that perhaps mechanical separation is the wrong approach to the problem. In a preliminary study of this problem 6), research work has been done at V.P.I. using several new approaches, the most important of these being electrophoresis and adsorption. Of these two procedures, adsorption save indications of having the greater potentialities. The following thesis will deal with additional research work using coals of varying grades as an adsorbing medium. The American Viscose Company of Roanoke, Virginia has installed units for clarifying the spinning bath solutions. The units incorporate coal as an adsorbing medium. The process is extremely successful and therefore strengthens the belief that it may be applicable to the clarification of tannin extract solutions. Adsorption methods are often applied industrially to remove impurities, especially if they are present in low concentrations. Small amounts of impurities often interfere with processes such as crystallization, filtration, and distillation, but by the application of adsorption the impurities may be separated and the fault corrected. Often times adsorbents are used to recover valuable constituents, which otherwise would be lost completely or require for more costly processing. Separation by adsorption is made possible because of the fact that different materials differ in the degree to which they are adsorbed by a given adsorbent. The object of the research work is to investigate the possibility of developing an economically feasible process, based on adsorption, using coal as the adsorbent, for the separation of the insoluble non-tannin constituents present in a fresh tannin extract. / Master of Science

The following study was conducted to investigate the antibacterial and feed additive potential of medicinal plants. Ethanol extracts of different medicinal plants including Curcuma longa (Turmeric), Zingiber officinale (Ginger), Piper nigrum (Black Pepper), Cinnamomum cassia (Cinnamon), Thymus vulgaris (Thyme), Laurus nobilis (Bay leaf), and Syzgium aromaticum (Clove) were tested using the disc diffusion method for their antimicrobial activity against the common poultry pathogens E. coli, S. typhimurium, E. faecium, and E. faecalis. Cinnamon extract (CE), at 130 mg/disk, exhibited antibacterial activity against E. coli, S. typhimurium, and E. faecalis. Thyme extract (TE), at 30 mg/disk, exhibited antibacterial activity against E. coli, E. faecium, and E. faecalis while the remaining medicinal plants extracts showed no activity. The minimum inhibitory concentration (MIC) of the cinnamon and thyme ranged from 31.25 to 250 mg/ml by the dilution method. From this in vitro antibacterial study, cinnamon and thyme were selected for a 21-d feeding trial in broilers to study their influence on feed consumption, body weight gain, and feed conversion. There were 6 dietary treatments groups: 1) negative control (NC) containing no plant extracts or antibiotic, 2) positive control (PC) containing BMD (bacitracin) at 50g/ton of feed, 3) Diet 1 plus low level of cinnamon extract (LCE) at 290 gm/100 kg of feed, 4) Diet 1 plus high level of cinnamon extract (HCE) at 580 gm/ 100 kg of feed, 5) Diet 1 plus low level of thyme extract (LTE) at 290 gm/100kg of feed, and 6) Diet 6 plus high level of thyme extract (HTE) at 580 gm/100 kg of feed. No significant changes in body weight gain were observed with the cinnamon extracts compared to the NC or PC at 7, 14, or 21 d. The HTE reduced body weight gain compare to the NC and PC at 7, 14, and 21 d (P < 0.02). No difference in feed efficiency was observed with any of the treatments except LCE which reduced feed efficiency compared to other treatments. No difference in feed consumption was found among any of the treatments. These results suggest that cinnamon and thyme have antibacterial activity in vitro, and thyme has an activity that reduces body weight. Since cinnamon caused no significant change in body weight gain compared to positive or negative controls, it warrants further study as a substitute for antibiotics in the diet. / Master of Science

Yes / This study describes the screening of 13 commercially-available plant extracts for pharmacological activity modulating vascular function using an endothelial cell model. A French maritime pine bark extract (FMPBE) was found to have the greatest effect upon nitric oxide availability in control (181% ± 36% of untreated cells) and dysfunctional cells (132% ± 8% of untreated control cells). In healthy volunteers, the FMPBE increased plasma nitrite concentrations 8 h post-consumption compared to baseline (baseline corrected median 1.71 ± 0.38 (25% IQR) and 4.76 (75% IQR) µM, p < 0.05). This was followed by a placebo-controlled, healthy volunteer study, which showed no effects on plasma nitrite. It was confirmed that different batches of extract had been used in the healthy volunteer studies, and this second batch lacked bioactivity, assessed using the in vitro model. No difference in plasma catechin levels was seen at 8 h following supplementation between the studies (252 ± 194 nM versus 50 ± 64 nM, p > 0.05), however HPLC-UV fingerprinting showed that the new batch had a 5-15% in major constituents (including procyanidins A2, B1 and B2) compared to the original batch. This research describes a robust mechanism for screening bioactive extracts for vascular effects. It also highlights batch variability as a significant limitation when using complex extracts for pharmacological activity, and suggests the use of in vitro systems as a tool to identify this problem in future studies.

Wong Chun-kwan. / Thesis submitted in: December 1999. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 127-137). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgments --- p.viii / Tables of Contents --- p.ix / List of Figures --- p.xv / List of Tables --- p.xxvi / Chapter Chapter 1: --- INTRODUCTION --- p.1 / Chapter Chapter 2: --- LITERATURE REVIEW --- p.8 / Chapter 2.1 --- Toxicology --- p.8 / Chapter 2.1.1 --- Acute toxicity test --- p.8 / Chapter 2.1.2 --- Biochemical Analysis --- p.9 / Chapter 2.1.3 --- Organ weights --- p.10 / Chapter 2.2 --- Histology --- p.11 / Chapter 2.2.1 --- Light Microscope --- p.11 / Chapter 2.2.2 --- Electron Microscopy --- p.11 / Chapter 2.3 --- Tissue injury --- p.12 / Chapter 2.3.1 --- Free-radical mechanisms --- p.12 / Chapter 2.3.2 --- Lipid peroxidation --- p.13 / Chapter 2.4 --- Carbon tetrachloride (CC14) --- p.14 / Chapter 2.4.1 --- Mechanisms of carbon tetrachloride toxicity --- p.15 / Chapter 2.5 --- Trichloroethylene (TCE) --- p.18 / Chapter 2.5.1 --- Mechanisms of trichloroethylene toxicity --- p.21 / Chapter 2.6 --- Dimethyl sulfoxide (DMSO) --- p.25 / Chapter 2.7 --- N-acetylcysteine (NAC) --- p.27 / Chapter Chapter 3: --- MATERIALS AND METHODS --- p.28 / Chapter 3.1 --- Materials --- p.28 / Chapter 3.2 --- Methods --- p.31 / Chapter 3.2.1 --- Acute hepatotoxicity test on aqueous seaweed extracts --- p.31 / Chapter 3.2.1.1 --- Preparation of aqueous extracts of seaweed --- p.31 / Chapter 3.2.1.2 --- Experimental protocol --- p.31 / Chapter 3.2.1.3 --- Biochemical assays --- p.32 / Chapter 3.2.1.4 --- Organ weights --- p.36 / Chapter 3.2.1.5 --- Histopathological examination --- p.36 / Chapter 3.2.1.6 --- Statistical analysis --- p.36 / Chapter 3.2.2 --- Curative and preventive tests of seaweed aqueous extracts against the CCl4-induced hepatotoxicity --- p.37 / Chapter 3.2.2.1 --- Preparation of aqueous extracts of seaweed --- p.37 / Chapter 3.2.2.2 --- Experimental protocol --- p.37 / Chapter 3.2.2.3 --- Biochemical assays --- p.39 / Chapter 3.2.2.4 --- Organ weights --- p.39 / Chapter 3.2.2.5 --- Histopathological examination --- p.40 / Chapter 3.2.2.6 --- Statistical analysis --- p.41 / Chapter 3.2.3 --- Acute hepatotoxicity test of TCE in rats by oral and intraperitoneal routes --- p.42 / Chapter 3.2.3.1 --- Experimental protocol --- p.42 / Chapter 3.2.3.2 --- Biochemical assays --- p.43 / Chapter 3.2.3.3 --- Organ weights --- p.43 / Chapter 3.2.3.4 --- Histopathological examination --- p.44 / Chapter 3.2.3.5 --- Statistical analysis --- p.44 / Chapter 3.2.4 --- Curative and preventive tests of seaweed aqueous extracts against the TCE effective dose-induced toxicity --- p.44 / Chapter 3.2.4.1 --- Preparation of aqueous extracts of seaweed --- p.44 / Chapter 3.2.4.2 --- Experimental protocol --- p.45 / Chapter 3.2.4.3 --- Biochemical assays --- p.46 / Chapter 3.2.4.4 --- Organ weights --- p.46 / Chapter 3.2.4.5 --- Histopathological examination --- p.46 / Chapter 3.2.5 --- Antidotal effects of dimethyl sulfoxide (DMSO) and N-acetylcysteine (NAC) against CC14- and TCE- induced poisoning in rats --- p.47 / Chapter 3.2.5.1 --- Experimental protocol --- p.47 / Chapter 3.2.5.2 --- Biochemical assays --- p.48 / Chapter 3.2.5.3 --- Organ weights --- p.48 / Chapter 3.2.5.4 --- Histopathological examination --- p.49 / Chapter 3.2.6 --- Hepatoprotective effect of seaweeds' methanol extract against CC14- and TCE-induced poisoning in rats --- p.49 / Chapter 3.2.6.1 --- Preparation of methanol extracts of seaweed --- p.49 / Chapter 3.2.6.2 --- Experimental protocol --- p.50 / Chapter 3.2.6.3 --- Biochemical assays --- p.52 / Chapter 3.2.6.4 --- Organ weights --- p.52 / Chapter 3.2.6.5 --- Histopathological examination --- p.53 / Chapter Chapter 4 --- RESULTS --- p.54 / Chapter 4.1 --- Acute hepatotoxicity test on aqueous seaweed extracts --- p.54 / Chapter 4.1.1 --- The biochemical assays of the serum transaminase activity --- p.54 / Chapter 4.1.2 --- The organ weight (Aqueous seaweed crude extracts) --- p.56 / Chapter 4.2 --- Curative and preventive tests of seaweed aqueous extracts against the CCl4-induced hepatotoxicity --- p.58 / Chapter 4.2.1 --- The biochemical assays of the serum transaminase activity (Curative) --- p.58 / Chapter 4.2.2 --- The organ weight (Curative) --- p.60 / Chapter 4.2.3 --- The biochemical assays of the serum transaminase activity (Preventive) --- p.62 / Chapter 4.2.4 --- The organ weight (Preventive) --- p.64 / Chapter 4.3 --- Acute hepatotoxicity test of TCE in rats by oral and intraperitoneal routes --- p.66 / Chapter 4.3.1 --- Oral route --- p.66 / Chapter 4.3.1.1 --- One-time oral route --- p.66 / Chapter 4.3.1.2 --- Two-time oral route --- p.66 / Chapter 4.3.2 --- Intraperitoneal route --- p.66 / Chapter 4.3.3 --- Time course of the effective dose of 20% TCE in i.p. route --- p.67 / Chapter 4.4 --- Curative and preventive tests of seaweed aqueous extracts against the TCE effective dose-induced toxicity --- p.12 / Chapter 4.4.1 --- The biochemical assays of the serum transaminase activity (Curative) --- p.72 / Chapter 4.4.2 --- The organ weight (Curative) --- p.74 / Chapter 4.4.3 --- The biochemical assays of the serum transaminase activity (Preventive) --- p.76 / Chapter 4.4.4 --- The organ weight (Preventive) --- p.78 / Chapter 4.5 --- Antidotal effects of dimethyl sulfoxide (DMSO) and N-acetylcysteine (NAC) against CC14- and TCE-induced poisoning in rats --- p.80 / Chapter 4.5.1 --- The biochemical assays of the serum transaminase activity (Curative) --- p.80 / Chapter 4.5.2 --- The organ weight (Curative) --- p.82 / Chapter 4.5.3 --- The biochemical assays of the serum transaminase activity (Preventive) --- p.84 / Chapter 4.5.4 --- The organ weight (Preventive) --- p.86 / Chapter 4.6 --- Hepatoprotective effect of methanol extract of seaweed against CC14- and TCE-induced poisoning in rats --- p.88 / Chapter 4.6.1 --- The biochemical assays of the serum transaminase activity (Curative) --- p.88 / Chapter 4.6.2 --- The organ weight (Curative) --- p.89 / Chapter 4.7 --- Histopathological examinations --- p.90 / Chapter 4.7.1 --- Acute hepatotoxicity test on aqueous seaweed extracts --- p.91 / Chapter 4.7.2 --- Curative and preventive tests of seaweed aqueous extracts against the CC14-induced hepatotoxicity --- p.92 / Chapter 4.7.3 --- Acute hepatotoxicity test of TCE in rats by oral and intraperitoneal routes --- p.99 / Chapter 4.7.4 --- Curative and preventive tests of seaweed aqueous extracts against the TCE effective dose-induced toxicity --- p.100 / Chapter 4.7.5 --- Antidotal effects of dimethyl sulfoxide (DMSO) and N-acetylcysteine (NAC) against CC14- and TCE-induced poisoning in rats --- p.100 / Chapter 4.7.6 --- Hepatoprotective effect of methanol extract of seaweed against CC14- and TCE-induced poisoning in rats --- p.102 / Chapter Chapter 5 --- DISCUSSION --- p.106 / Chapter Chapter 6 --- CONCLUSION --- p.124 / REFERENCES --- p.127 / APPENDIX --- p.138

Wong Sze Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 124-144). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Cancer treatment and potential novel antitumor agents --- p.1 / Chapter 1.2 --- History of mushroom polysaccharides in medical uses --- p.1 / Chapter 1.3 --- Life cycle of mushroom --- p.3 / Chapter 1.4 --- Classification of antitumor mushroom polysaccharides --- p.5 / Chapter 1.4.1 --- (3-glucans --- p.5 / Chapter 1.4.2 --- Heteropolysaccharides --- p.7 / Chapter 1.4.3 --- Polysaccharide-protein complexes --- p.7 / Chapter 1.5 --- Structure-activity relationship of mushroom polysaccharides --- p.8 / Chapter 1.5.1 --- Lentinan as typical example --- p.9 / Chapter 1.5.2 --- Molecular weight --- p.10 / Chapter 1.5.3 --- Conformation --- p.10 / Chapter 1.5.4 --- Chemical modification --- p.11 / Chapter 1.5.5 --- Degree of branching --- p.13 / Chapter 1.6 --- Antitumor mushroom polysaccharides obtained from different developmental stages --- p.17 / Chapter 1.7 --- Mechanisms of in vitro antitumor activity of mushroom polysaccharides: cell cycle arrest and apoptotic induction --- p.20 / Chapter 1.7.1 --- Cell cycle regulation --- p.21 / Chapter 1.7.2 --- Induction of apoptosis --- p.24 / Chapter 1.8 --- The novel strategies for cancer treatment --- p.27 / Chapter 1.9 --- Literature Review on Pleurotus tuber-regium --- p.30 / Chapter 1.10 --- Objectives --- p.33 / Chapter Chapter 2 --- Materials and Methods --- p.35 / Chapter 2.1 --- Materials --- p.35 / Chapter 2.1.1 --- Assay kits --- p.35 / Chapter 2.1.2 --- Mushroom samples --- p.35 / Chapter 2.1.3 --- Cell lines and their subculture --- p.36 / Chapter 2.1.4 --- Antibodies --- p.37 / Chapter 2.2 --- Extraction of mushroom polysaccharides --- p.38 / Chapter 2.2.1 --- Hot-water extracts from mushroom fruiting body --- p.38 / Chapter 2.2.2 --- Hot-water extracts from mushroom mycelia --- p.38 / Chapter 2.2.3 --- Exo-polysaccharides from submerged fermentation medium --- p.39 / Chapter 2.3 --- Chemical and physio-chemical composition of PTR extracts --- p.41 / Chapter 2.3.1 --- Neutral monosaccharides --- p.41 / Chapter 2.3.1.1 --- Acid Depolymerization --- p.41 / Chapter 2.3.1.2 --- Neutral sugar derivatization --- p.42 / Chapter 2.3.1.3 --- Determination of neutral sugar composition by GC- --- p.43 / Chapter 2.3.2 --- Uronic acid (acidic monosaccharides) content --- p.45 / Chapter 2.3.3 --- Total carbohydrate content --- p.46 / Chapter 2.3.4 --- Protein content --- p.46 / Chapter 2.3.5 --- Molecular weight and the homogeneity --- p.47 / Chapter 2.4 --- In vitro growth inhibitory effects --- p.48 / Chapter 2.4.1 --- Trypan blue dye exclusion method --- p.48 / Chapter 2.4.2 --- "Colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay" --- p.49 / Chapter 2.5 --- In vitro cell proliferation assay --- p.50 / Chapter 2.6 --- Cell-cycle analysis --- p.51 / Chapter 2.7 --- Apoptotic determination --- p.52 / Chapter 2.8 --- Expression of proteins involved in apoptosis and cell-cycle --- p.52 / Chapter 2.8.1 --- Preparation of cell lysates --- p.53 / Chapter 2.8.2 --- Determination of protein concentrations --- p.53 / Chapter 2.8.3 --- Western blot --- p.54 / Chapter 2.9 --- Statistics --- p.57 / Chapter Chapter 3 --- Results and Discussion --- p.58 / Chapter 3.1 --- Yield of extract samples isolated from different developmental stages of PTR --- p.58 / Chapter 3.2 --- Chemical characteristics of hot-water extracts isolated from different stages of PTR --- p.60 / Chapter 3.2.1 --- The total carbohydrate and protein content of PTR extracts- --- p.60 / Chapter 3.2.2 --- The monosaccharide composition of PTR extracts --- p.62 / Chapter 3.3 --- Molecular weight distribution of PTR extracts --- p.64 / Chapter 3.4 --- Chemical characterization of PTR extracts --- p.69 / Chapter 3.5 --- Cytotoxic effect of PTR extracts on various cell line in vitro --- p.71 / Chapter 3.5.1 --- Effect of PTR extracts on HL-60 cell viability --- p.71 / Chapter 3.5.2 --- Effect of PTR extracts on K562 cell viability --- p.74 / Chapter 3.5.3 --- Effect of PTR extracts on MCF-7 cell proliferation --- p.76 / Chapter 3.5.4 --- Effect of PTR extracts on HepG2 cell proliferation --- p.76 / Chapter 3.5.5 --- Effect of PTR extracts on normal cell proliferation --- p.78 / Chapter 3.6 --- Effect of PTR extracts on the proliferation rate of various cell lines in vitro --- p.78 / Chapter 3.6.1 --- Effect of PTR extracts on HL-60 cell proliferation --- p.79 / Chapter 3.6.2 --- Effect of PTR extracts on K562 cell proliferation --- p.79 / Chapter 3.6.3 --- Effect of PTR extracts on MCF-7 cell proliferation --- p.80 / Chapter 3.6.4 --- Effect of PTR extracts on HepG2 cell proliferation --- p.80 / Chapter 3.6.5 --- Effect of PTR extracts on normal cell proliferation --- p.84 / Chapter 3.7 --- Summary of the cytotoxic and antiproliferative activities exhibited by PTR extracts --- p.84 / Chapter 3.8 --- Analysis of the effect of PTR extracts on the cell-cycle phases of HL-60 and K562 cells --- p.87 / Chapter 3.8.1 --- Effect of CEP on cell-cycle phases of HL-60 and K562 cells --- p.87 / Chapter 3.8.2 --- Effect of EDP on cell-cycle phases of HL-60 and K562 cells --- p.92 / Chapter 3.8.3 --- Effect of HWE1 on cell-cycle phases of HL-60 and K562 cells --- p.95 / Chapter 3.8.4 --- Effect of HWE2 on cell-cycle phases of HL-60 and K562 cells --- p.98 / Chapter 3.8.5 --- Effect of HWE3 on cell-cycle phases of HL-60 and K562 cells --- p.102 / Chapter 3.8.6 --- Summary --- p.105 / Chapter 3.9 --- The effect of PTR extracts on expression of cellular proteins involved in cell-cycle control and apoptotic pathway in HL-60 cells --- p.106 / Chapter 3.9.1 --- Expression of Bcl-2 and Bax proteins in HL-60 cells treated with PTR extracts --- p.106 / Chapter 3.9.2 --- Expression of cyclins and Cdks in HL-60 cells by PTR extracts --- p.115 / Chapter 3.9.3 --- The plausible antiproliferative mechanism(s) involved in PTR extracts on HL-60 cells --- p.117 / Chapter Chapter 4 --- Conclusions and Future works --- p.120 / Chapter 4.1 --- Conclusions --- p.120 / Chapter 4.2 --- Future works --- p.122 / References --- p.124 / Related Publications --- p.144

肝癌是造成癌症相關死亡的主要原因之一。而常規化療受耐藥性的發展和各種副作用的限制。由於無毒性和鲜明的生物药物能力，從蘑菇提取的代謝物在癌症治療中獲得更多的注意和关注。我們以前的研究已經證明來自平菇香菇多醣蛋白複合物的抗癌作用。本研究的目的是探討一種含有多醣蛋白複合物的秀珍菇（PP）熱水提取物在肝癌細胞中抗癌活性的分子機制。 / 我們的研究結果表明，用PP处理过的肝癌細胞，不僅顯著的显示出降低的體外腫瘤細胞的增殖和侵襲，也增強化療藥物順鉑的藥物敏感性。無論是口服和腹腔注射都顯著抑制移植免疫BALB / c裸小鼠的腫瘤生長。同时，PP也能在體外和體內实验顯著抑制PI3K/Akt信號通路在肝癌細胞。有趣的是，当过表达AKT时，Myr-AKT，PP的這種抑制癌细胞生长的效果有减弱的趋势，同时也反映在PP对癌细胞侵襲抑制的作用上。印跡和酶聯免疫吸附試驗結果表明，在PP处理过的肝癌細胞中，血管內皮生長因子（VEGF）的表達和分泌減少了。此外， rhVEGF的加入减弱了 PP对PI3K/Akt通路和肝癌细胞表型的抑製作用。 / 我們的研究結果表明，PP能在體外和體內试验中抑制肝癌細胞增殖，侵襲和耐藥性，通过抑制分泌血管內皮生長因子誘導PI3K/Akt的信號通路。這項研究表明了PP的潛在治療肝癌的治療意義。 / Liver cancer or hepatocellular carcinoma is one of the leading causes of cancer-related deaths. Conventional chemotherapies are limited by the development of drug resistance and various side effects. Because of its non-toxicity and potent biopharmacological activity, metabolites derived from mushrooms have received more attention in cancer therapy. Our previous studies have demonstrated the anti-cancer effects of polysaccharide-protein complexes derived from the Pleurotus mushrooms. The aim of this study was to investigate the underlying molecular mechanism of the anti-cancer activity of a hot water extract containing a polysaccharide-protein complex isolated from Pleurotus pulmonarius (PP) in liver cancer cells. / Our results indicated that exposure of liver cancer cells to PP not only significantly reduced the in vitro cancer cell proliferation and invasion but also enhanced the drug-sensitivity to the chemotherapeutic drug Cisplatin. Both oral administration and intraperitoneal injection of PP significantly inhibited the tumor growth in xenograft BALB/c nude mice. PP triggered a marked suppression of the PI3K/AKT signaling pathway in liver cancer cells in vitro and in vivo, and overexpression of the constitutively active form of AKT, Myr-AKT, abrogated this effect and the inhibited proliferation and invasion by PP. Both western blot and ELISA results showed that PP-treated liver cancer cells had reduced expression and secretion of vascular endothelial growth factor (VEGF). Addition of recombinant human VEGF attenuated the inhibitory effects of PP on PI3K/AKT pathway and the cancer phenotypes. / Our results demonstrated that PP suppressed the proliferation, invasion, and drug-resistance of liver cancer cells in vitro and in vivo, mediated by the inhibition of autocrine VEGF-induced PI3K/AKT signaling pathway. All these results suggest the potential therapeutic implication of PP in the treatment of human liver cancer. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Xu, Wenwen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 83-99). / Abstracts also in Chinese. / Thesis Committee --- p.i / English Abstract --- p.ii / Chinese Abstract --- p.iv / Acknowledgements --- p.v / List of Tables --- p.vi / List of Figures --- p.vii / Abbreviations --- p.x / Content page --- p.xiv / Chapter Chapter 1 --- Literature Review --- p.1 / Chapter 1.1 --- Mushroom as functional foods --- p.1 / Chapter 1.1.1 --- Introduction of functional food --- p.1 / Chapter 1.1.2 --- Functional food and cancer --- p.1 / Chapter 1.1.3 --- Edible Mushroom as functional food --- p.4 / Chapter 1.1.4 --- Pleurotus pulmonarius and its function --- p.7 / Chapter 1.2 --- Hepatocellular carcinoma --- p.9 / Chapter 1.2.1 --- Liver and hepatocellular carcinoma --- p.9 / Chapter 1.2.2 --- Carcinogenesis of liver cancer --- p.12 / Chapter 1.2.2.1 --- Hallmarks of cancer --- p.12 / Chapter 1.2.2.2 --- Cell cycle --- p.13 / Chapter 1.2.2.3 --- Apoptosis --- p.15 / Chapter 1.2.2.4 --- Angiogenesis --- p.17 / Chapter 1.2.2.5 --- Invasion and metastasis --- p.19 / Chapter 1.2.2.6 --- Drug resistance --- p.21 / Chapter 1.2.3 --- The role of PI3K/AKT pathway --- p.23 / Chapter 1.2.4 --- The role of growth factor Vascular endothelial growth factor (VEGF) in HCC --- p.25 / Chapter 1.3 --- Research objectives --- p.27 / Chapter 1.3.1 --- Hypothesis and objectives --- p.27 / Chapter 1.3.2 --- Experimental design --- p.28 / Chapter Chaper 2 --- Materials and Methods --- p.29 / Chapter 2.1 --- Materials --- p.29 / Chapter 2.1.1 --- Mushroom Pleurotus pulmonarius --- p.29 / Chapter 2.1.2 --- Drugs and cell lines --- p.29 / Chapter 2.1.3 --- Antibodies list --- p.30 / Chapter 2.1.4 --- Animal models --- p.32 / Chapter 2.2 --- Sample preparation and structure investigation --- p.32 / Chapter 2.2.1 --- Polysaccharide extraction from mushroom --- p.32 / Chapter 2.2.2 --- Endotoxin test --- p.32 / Chapter 2.2.3 --- Determination of monosaccharide profile by gas chromatography and mass spectrometry (GC/MS) --- p.33 / Chapter 2.2.3.1 --- Sample preparation for gas chromatography analysis --- p.33 / Chapter 2.2.3.1.1 --- Acid depolymerisation --- p.33 / Chapter 2.2.3.1.2 --- Neutral sugar derivatization --- p.33 / Chapter 2.2.3.1.3 --- External monosaccharide standard preparation --- p.34 / Chapter 2.2.3.2 --- Gas chromatography-mass spectrometry (GC/MS) --- p.34 / Chapter 2.2.4 --- Determination of total sugar by phenol-sulfuric acid method (Dubois, 1956) --- p.36 / Chapter 2.2.5 --- Determination of protein content by Lowry-Folin method (Lowry et al.,1951) --- p.37 / Chapter 2.3 --- Biological assays --- p.38 / Chapter 2.3.1 --- In vitro assays --- p.38 / Chapter 2.3.1.1 --- MTT assay --- p.38 / Chapter 2.3.1.2 --- Colony formation assay --- p.38 / Chapter 2.3.1.3 --- Plasmid transfection --- p.39 / Chapter 2.3.1.4 --- In vitro cell invasion assay --- p.39 / Chapter 2.3.1.5 --- Cell cycle analysis --- p.39 / Chapter 2.3.1.6 --- Western blot analysis --- p.40 / Chapter 2.3.1.7 --- VEGF ELISA Kit --- p.42 / Chapter 2.3.2 --- In vivo assays --- p.43 / Chapter 2.3.2.1 --- Tumor xenograft nude mouse model --- p.43 / Chapter 2.3.2.2 --- Immunohistochemistry --- p.45 / Chapter 2.3.2.3 --- H&Estaining --- p.45 / Chapter 2.3.3 --- Statistical analysis --- p.45 / Chapter Chaper 3 --- Results and discussion --- p.46 / Chapter 3.1 --- The yield and chemical characteristic of PP --- p.46 / Chapter 3.1.1 --- The yield of PP from mushroom Pleurotus pulmonarius --- p.46 / Chapter 3.1.2 --- Total carbohydrate and protein content --- p.47 / Chapter 3.1.3 --- Monosaccharide composition by GC-MS --- p.48 / Chapter 3.2 --- Toxicity of the PP water by Limulus amebocyte lysate (LAL) test --- p.48 / Chapter 3.2.1 --- Limulus amebocyte lysate (LAL) test --- p.48 / Chapter 3.3 --- Effects of PP on the proliferation of liver cancer cell lines --- p.50 / Chapter 3.3.1 --- MTT assay --- p.50 / Chapter 3.3.2 --- Colony-formation assay --- p.51 / Chapter 3.3.3 --- Cytotoxic effects of PP against normal liver cell --- p.52 / Chapter 3.3.4 --- The anti-proliferative effect of PP on other cancer types --- p.53 / Chapter 3.3.5 --- Cell cycle analysis by flow cytometry of PP treated liver cancer cells --- p.54 / Chapter 3.3.6 --- Protein expression by western blot analysis of P treated liver cancer cells --- p.56 / Chapter 3.4 --- Anti-cancer effect of PP on liver cancer cells through inactivation of PI3K/AKT signaling pathway --- p.57 / Chapter 3.4.1 --- Effect of PP on inactivation of PI3K/AKT pathway --- p.57 / Chapter 3.4.2 --- The abrogated inhibitory effect of PP on Huh7 with overexpression of AKT. --- p.59 / Chapter 3.4.3 --- The abrogated inhibitory effect of PP on PI3K/AKT signal pathway with overexpression of the constitutively active form of AKT, Myr-AKT --- p.60 / Chapter 3.5 --- Inhibition of VEGF expression and secretion by PP --- p.62 / Chapter 3.5.1 --- ELISA result of PP on VEGF secretion --- p.62 / Chapter 3.5.2 --- The attenuated inhibitory effect of PP on cell proliferation with addition of rhVEGF --- p.63 / Chapter 3.5.3 --- The attenuated inhibitory effect of PP on PI3K/AKT signal pathway with addition of rhVEGF --- p.64 / Chapter 3.6 --- Effect of PP on enhancing the chemosensitivity of liver cancer cells to Cisplatin --- p.66 / Chapter 3.6.1 --- Synergistic effect of PP with cisplatin (DDP) in liver cancer cells --- p.66 / Chapter 3.6.2 --- The abrogated drug-resistant effect by PP by overexpression of the constitutively active form of AKT, Myr-AKT --- p.67 / Chapter 3.6.3 --- The abrogated drug-resistant effect of PP with addition of rhVEGF --- p.68 / Chapter 3.7 --- The anti-invasive potential of PP on liver cancer cells. --- p.69 / Chapter 3.7.1 --- Boyden chamber assay --- p.69 / Chapter 3.7.2 --- The attenuated anti-invasive effect of PP on liver cancer cells with overexpression of constitutively activated AKT --- p.71 / Chapter 3.7.3 --- The attenuated anti-invasive effect of PP on liver cancer cells with addition of rhVEGF --- p.72 / Chapter 3.8 --- The anti-tumor effect of PP in vivo --- p.73 / Chapter 3.8.1 --- The anti-tumor effect of PP by using tumor xenograft model --- p.73 / Chapter 3.8.2 --- Body weight of nude mice treated with PP --- p.75 / Chapter 3.8.3 --- Harmful effect of PP on nude mice --- p.76 / Chapter 3.8.4 --- Immunohistochemist analysis of mice tumor xenograft treated with PP --- p.77 / Chapter 3.8.5 --- Western blot anaylysis using the tumor tissues harvested from mice xenograftes treated with PP --- p.78 / Chapter Chapter 4 --- Conclusion and future Plan --- p.81 / Reference --- p.83 / Related Publication List --- p.100

Chau, Hiu Yan Anita. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 109-122). / Abstracts in English and Chinese. / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Introduction on mushroom life cycle --- p.1 / Chapter 1.2 --- Introduction of mushroom sclerotium --- p.2 / Chapter 1.3 --- Different extraction methods of mushroom polysaccharides --- p.3 / Chapter 1.4 --- Bioactivities of mushroom polysaccharides and factors affecting their biological activities --- p.4 / Chapter 1.4.1 --- Molecular weight --- p.4 / Chapter 1.4.2 --- Linkages --- p.5 / Chapter 1.4.3 --- Branching rate --- p.5 / Chapter 1.4.4 --- Conformation --- p.6 / Chapter 1.5 --- Mechanisms for antitumor activites of mushrooms polysaccharides.… --- p.7 / Chapter 1.5.1 --- Cancer-preventing activity --- p.7 / Chapter 1.5.2 --- Immuno-enhancing activity (BRM) --- p.8 / Chapter 1.5.3 --- Direct tumor inhibition activity --- p.8 / Chapter 1.6 --- Cell cycle regulation and induction of apoptosis --- p.9 / Chapter 1.6.1 --- The cell cycle machinery --- p.9 / Chapter 1.6.2 --- Cell cycle arrest and regulation --- p.11 / Chapter 1.6.3 --- Apoptosis and regulation --- p.13 / Chapter 1.7 --- Literature review on Pleurotus tuber-regium --- p.16 / Chapter 1.7.1 --- Introduction of Pleurotus tuber-regium --- p.16 / Chapter 1.7.2 --- Antitumor effect of mushroom polysaccharides isolated from different developmental stages of Pleurotus tuber-regium --- p.17 / Chapter 1.7.2.1 --- Sclerotium --- p.17 / Chapter 1.7.2.2 --- Mycelium --- p.19 / Chapter 1.7.2.3 --- Culture medium --- p.19 / Chapter 1.7.2.4 --- Fruiting body --- p.20 / Chapter 1.8 --- Literature review on Size reduction process --- p.21 / Chapter 1.8.1 --- Introduction of micron technology --- p.21 / Chapter 1.8.1.1 --- Ball milling --- p.21 / Chapter 1.8.1.2 --- Jet milling --- p.22 / Chapter 1.8.1.3 --- High-pressure micronizing --- p.22 / Chapter 1.8.1.4 --- Oscillatory milling --- p.23 / Chapter 1.8.2 --- Effect of particle sizes on physicochemical properties and biological activities of plant materials --- p.23 / Chapter 1.8.2.1 --- Physicochemical properties --- p.24 / Chapter 1.8.2.2 --- Biochemical activities --- p.24 / Chapter 1.9 --- Objectives --- p.26 / Chapter Chapter 2. --- Materials and methods --- p.28 / Chapter 2.1 --- Materials --- p.28 / Chapter 2.1.1 --- Mushroom sclerotia --- p.28 / Chapter 2.1.2 --- Micronisation --- p.29 / Chapter 2.1.3 --- Cell lines --- p.31 / Chapter 2.1.4 --- Antibodies --- p.33 / Chapter 2.1.5 --- Animal model --- p.33 / Chapter 2.2 --- Methods --- p.34 / Chapter 2.2.1 --- Micronisation --- p.34 / Chapter 2.2.2 --- Hot water extraction for mushroom sclerotia --- p.35 / Chapter 2.2.3 --- Measurement of monosaccharide profile --- p.36 / Chapter 2.2.3.1 --- Acid deploymerisation --- p.36 / Chapter 2.2.3.2 --- Neutral sugar derivatization --- p.36 / Chapter 2.2.3.3 --- Gas chromatography (GC) --- p.37 / Chapter 2.2.4 --- Total sugar content by Phenol-sulphuric acid Method --- p.38 / Chapter 2.2.5 --- Acidic sugar content by measuring uronic acid content --- p.39 / Chapter 2.2.6 --- Protein content by Lowry-Folin Method --- p.40 / Chapter 2.2.7 --- Size exclusion chromatography by high pressure liquid chromatograhy (HPLC) --- p.41 / Chapter 2.2.8 --- In vitro antitumor assay --- p.41 / Chapter 2.2.8.1 --- Trypan blue exclusion assay --- p.42 / Chapter 2.2.8.2 --- MTT Assay --- p.42 / Chapter 2.2.9 --- Cell cycle analysis by Flow Cytometry --- p.43 / Chapter 2.2.10 --- Protein expression involved in apoptosis --- p.45 / Chapter 2.2.10.1 --- Cell lysates preparation --- p.45 / Chapter 2.2.10.2 --- Determination of protein concentrations --- p.46 / Chapter 2.2.10.3 --- Western blot --- p.46 / Chapter 2.2.11 --- In vivo antitumor assay --- p.50 / Chapter 2.2.11.1 --- BALB/c mice --- p.50 / Chapter 2.2.11.2 --- Athymic nude mice --- p.50 / Chapter 2.2.12 --- Statistical methods --- p.51 / Chapter Chapter 3 --- Results and Discussion --- p.52 / Chapter 3.1 --- Yield of hot water-soluble extracts from Pleurotus tuber-regium --- p.52 / Chapter 3.2 --- Chemical composition of hot water-soluble extracts from PTR --- p.56 / Chapter 3.2.1 --- Total carbohydrate content --- p.56 / Chapter 3.2.2 --- Uronic acid content --- p.57 / Chapter 3.2.3 --- Protein content --- p.58 / Chapter 3.3 --- Monosaccharide profiles of hot water-soluble extracts from PTR by gas chromatography (GC) --- p.61 / Chapter 3.4 --- Molecular weight profile of hot water-soluble extracts from PTR by size exclusion chromatography (SEC) --- p.64 / Chapter 3.5 --- Antitumor effects of mushroom sclerotial polysaccharides --- p.72 / Chapter 3.5.1 --- In vitro antiproliferation study --- p.72 / Chapter 3.5.1.1 --- In vitro antiproliferation study by HL-60 --- p.72 / Chapter 3.5.1.2 --- In vitro antiproliferation study by THP-1 --- p.75 / Chapter 3.5.1.3 --- In vitro antiproliferation study by MCF-7 --- p.77 / Chapter 3.5.1.4 --- In vitro antiproliferation study by K562 --- p.77 / Chapter 3.5.1.5 --- In vitro antiproliferation study by SI80 --- p.79 / Chapter 3.5.1.6 --- In vitro antiproliferation study by normal cells --- p.79 / Chapter 3.5.1.7 --- Dose-response relationship between hot water-soluble extract from PTR and tumor cell inhibition --- p.80 / Chapter 3.5.2 --- In vivo antitumor study --- p.83 / Chapter 3.5.2.1 --- BALB/c mice --- p.83 / Chapter 3.5.2.2 --- Athymic nude mice --- p.84 / Chapter 3.6 --- Flow cytometric analysis of tumor cells treated by various hot wter-soluble extracts from PTR --- p.88 / Chapter 3.6.1 --- Antiproliferative effect of various hot water-soluble extracts from 10PTR on HL-60 --- p.88 / Chapter 3.6.2 --- Antiproliferative effect of various hot water-soluble extracts from 10PTR on THP-1 --- p.93 / Chapter 3.7 --- Effects of various hot water-soluble extracts from 10PTR on expression of Bcl-2 and Bax proteins in HL-60 cells --- p.99 / Chapter 3.8 --- "Correlation between particle size, structure and antitumor activity of mushroom sclerotial extracts" --- p.101 / Chapter Chapter 4. --- Conclusions and Future Works --- p.105 / List of References --- p.109 / Related Publications --- p.123