39 research outputs found

    Sulfated galactans from red seaweed Gracilaria fisheri target epidermal growth factor receptor (EGFR) and inhibit cholangiocarcinoma cells (CCA) proliferation

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    Cholangiocarcinoma (CCA) is increasing in incidence worldwide and is resistant to chemotherapeutic agents, making treatment of CCA a major challenge. Previous studies reported that natural sulfated polysaccharides (SPs) disrupted growth factor receptor activation in cancer cells. The present study, therefore, aimed at investigating the anti-proliferation effect of sulfated galactans (SG) isolated from the red seaweed Gracilaria fisheri (G. fisheri) on CCA cell lines. Direct binding activity of SG to CCA cells, epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) were determined. The effect of SG on proliferation of CCA cells was investigated. Cell cycle analyses and expression of signaling molecules associated with proliferation were also determined. The results demonstrated that SG bound directly to EGFR. SG inhibited proliferation of various CCA cell lines by inhibiting EGFR and extracellular signal-regulated kinases (ERK) phosphorylation, and inhibited EGF-induced increased cell proliferation. Cell cycle analyses showed that SG induced cell cycle arrest at the G0/G1 phase, down-regulated cell cycle genes and proteins (cyclin-D, cyclin-E, Cdk-4, Cdk-2), and up-regulated the tumor suppressor protein P53 and the cyclin-dependent kinase inhibitor P21. Taken together, these data demonstrate that SG from G. fisheri inhibited proliferation of CCA cells, and its mechanism of inhibition is mediated, to some extent, by inhibitory effects on EGFR activation and EGFR/ERK signaling pathway. SG presents a potential EGFR targeted molecule, which may be further clinically developed in a combination therapy for CCA treatment

    A Critical Study of Thailand's Higher Education Reforms: The culture of borrowing

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    This book offers a critical examination of contemporary higher education reforms in Thailand situated in the broader historical, socio-economic and political changes. Through a qualitative case study with three methods of inquiry, this book explores why different 'global education policies' such quasi-privatisation, internationalization, as quality assessment (QA) have resonated in Thailand higher education sector. Grounded in policy borrowing and lending, this book uses the politics, economics and culture of borrowing to analyse major reforms in Thailand for the past one hundred years. It is argued that historical legacy, policy contexts and belief systems of policy elites play pivotal roles in facilitating policy changes or the lack thereof. While historical analysis elucidates that the Thai state has always been an active borrower of western ideas, the perseverance of the 'Thai-ness' discourse has often been used to suggest its so-called independence and idiosyncrasy. This in-depth analysis of the Thai case aims to contribute to the critical studies in Asian education, comparative higher education, policy borrowing and lending and Thai studies. The Culture of Borrowing intensively studies the policy appropriation in the Thai education system by analysing: • Selective Borrowing and the Historical Development of Thai Higher Education • The Asian Economic Crisis as Window of Opportunity: Autonomous University • Internationalization of Teaching: Quantitative and Qualitative Challenges • The Emergence of Quality Policies and their Rationales • The Intended and Unintended Consequences of Quality Policies This book will appeal to researchers in Education, particularly to scholars studying educational policies within the context of tertiary education. It will also interest scholars specialising in Asian and South-east Asian Studies

    Towards the stereoselective synthesis of bicyclic and tricyclic alkaloid natural products

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    In this thesis we discuss the stereoselective synthesis of natural products containing bicyclic heterocycle with a bridgehead nitrogen atom. The unique structural feature of this core skeleton has inspired interest regarding to their stereochemistry and biological properties.DOCTOR OF PHILOSOPHY (SPMS

    Kaempferol Addition Increases the Antimalarial Activity of Artesunate in Experimental Mice

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    Kaempferol (KMF) is a member of flavonol widely found in tea, broccoli, apples, strawberries, and beans. It has been demonstrated to present several pharmacological properties with potent antimalarial activity against Plasmodium berghei-infected mice. Hence, the search for a safe and new antimalarial compound with combinations to delay the development of resistance was the aim of this study. Thus, the therapeutic effect of the combination of KMF and artesunate (ART) in P. berghei-infected mice was evaluated. Combination of KMF and ART in P. berghei ANKA- (PbANKA-) infected ICR mice in a fixed-ratio combination (1 : 1) and fractions of their median effective dose (ED50) was also investigated using the standard 4-day suppressive test. The ED50 levels of KMF and ART in mice infected with PbANKA were 20.06 ± 2.65 and 6.06 ± 1.33 mg/kg, respectively. Moreover, KMF showed promising synergistic combination with ART at the doses of their ED50 and fixed-ratio combination (1 : 1) of their ED50 of 1/2 with combination index (CI) values of 0.86 and 0.47, respectively. Additionally, KMF, ART, and its combination at the doses of their ED50 and fixed-ratio combination (1 : 1) of their ED50 of 1/2 also presented significantly (P<0.001) prolonged mean survival time (MST). The findings of this study showed that a combination of KMF and ART enhanced the antimalarial activity of ART and prolonged MST. This study supports the basis for the selection of KMF as a prospective compound for further consideration as a partner drug for ART
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