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1.
Int J Mol Sci ; 25(14)2024 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-39063200

RESUMO

While BCR::ABL1 tyrosine kinase inhibitors have transformed the treatment paradigm for chronic myeloid leukemia (CML), disease progression and treatment resistance due to BCR::ABL1-dependent and BCR::ABL1-independent mechanisms remain a therapeutic challenge. Natural compounds derived from plants have significantly contributed to cancer pharmacotherapy. This study investigated the efficacy of an active component of Leea indica, a local medicinal plant, in CML. Using high-performance liquid chromatography-electrospray ionization-mass spectrometry, a chemical constituent from L. indica extract was isolated and identified as gallic acid. Commercially obtained gallic acid was used as a chemical standard. Gallic acid from L. indica inhibited proliferation and induced apoptosis in CML cell lines, as did the chemical standard. Furthermore, gallic acid induced apoptosis and decreased the colony formation of primary CML CD34+ cells. The combination of isolated gallic acid or its chemical standard with BCR::ABL1 tyrosine kinase inhibitors resulted in a significantly greater inhibition of colony formation and cell growth compared to a single drug alone. Mechanistically, CML cells treated with gallic acid exhibited the disruption of multiple oncogenic pathways including ERK/MAPK, FLT3 and JAK/STAT, as well as impaired mitochondrial respiration. Rescue studies showed that gallic acid is significantly less effective in inducing apoptosis in mitochondrial respiration-deficient ρ0 cells compared to wildtype cells, suggesting that the action of gallic acid is largely through the inhibition of mitochondrial respiration. Our findings highlight the therapeutic potential of L. indica in CML and suggest that gallic acid may be a promising lead chemical constituent for further development for CML treatment.


Assuntos
Apoptose , Proliferação de Células , Proteínas de Fusão bcr-abl , Ácido Gálico , Leucemia Mielogênica Crônica BCR-ABL Positiva , Mitocôndrias , Inibidores de Proteínas Quinases , Transdução de Sinais , Ácido Gálico/farmacologia , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Proteínas de Fusão bcr-abl/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Transdução de Sinais/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Linhagem Celular Tumoral
2.
Int J Mol Sci ; 22(10)2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-34063491

RESUMO

Phosphodiesterases (PDEs) hydrolyze cyclic nucleotides to modulate multiple signaling events in cells. PDEs are recognized to actively associate with cyclic nucleotide receptors (protein kinases, PKs) in larger macromolecular assemblies referred to as signalosomes. Complexation of PDEs with PKs generates an expanded active site that enhances PDE activity. This facilitates signalosome-associated PDEs to preferentially catalyze active hydrolysis of cyclic nucleotides bound to PKs and aid in signal termination. PDEs are important drug targets, and current strategies for inhibitor discovery are based entirely on targeting conserved PDE catalytic domains. This often results in inhibitors with cross-reactivity amongst closely related PDEs and attendant unwanted side effects. Here, our approach targeted PDE-PK complexes as they would occur in signalosomes, thereby offering greater specificity. Our developed fluorescence polarization assay was adapted to identify inhibitors that block cyclic nucleotide pockets in PDE-PK complexes in one mode and disrupt protein-protein interactions between PDEs and PKs in a second mode. We tested this approach with three different systems-cAMP-specific PDE8-PKAR, cGMP-specific PDE5-PKG, and dual-specificity RegA-RD complexes-and ranked inhibitors according to their inhibition potency. Targeting PDE-PK complexes offers biochemical tools for describing the exquisite specificity of cyclic nucleotide signaling networks in cells.


Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores de Fosfodiesterase/farmacologia , Extratos Vegetais/farmacologia , Proteínas Quinases/metabolismo , 3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Domínio Catalítico , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Polarização de Fluorescência , Terapia de Alvo Molecular , Complexos Multiproteicos/metabolismo , Nucleotídeos Cíclicos/metabolismo , Diester Fosfórico Hidrolases/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Especificidade por Substrato
3.
Molecules ; 24(4)2019 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-30781458

RESUMO

Leea indica (Vitaceae) is a Southeast Asian medicinal plant. In this study, an ethyl acetate fraction of L. indica leaves was studied for its phytoconstituents using high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-microTOF-Q-MS/MS) analysis. A total of 31 compounds of different classes, including benzoic acid derivatives, phenolics, flavonoids, catechins, dihydrochalcones, coumarins, megastigmanes, and oxylipins were identified using LC-MS/MS. Among them, six compounds including gallic acid, methyl gallate, (-)-epigallocatechin-3-O-gallate, myricetin-3-O-rhamnoside, quercetin-3-O-rhamnoside, and 4',6'-dihydroxy-4-methoxydihydrochalcone 2'-O-ß-d-glucopyranoside were isolated and identified by NMR analysis. The LC-MS/MS analysis led to the tentative identification of three novel dihydrochalcones namely 4',6'-dihydroxy-4-methoxydihydrochalcone 2'-O-rutinoside, 4',6'-dihydroxy-4-methoxydihydrochalcone 2'-O-glucosylpentoside and 4',6'-dihydroxy-4-methoxydihydrochalcone 2'-O-(3″-O-galloyl)-ß-d-glucopyranoside. The structural identification of novel dihydrochalcones was based on the basic skeleton of the isolated dihydrochalcone, 4',6'-dihydroxy-4-methoxydihydrochalcone 2'-O-ß-d-glucopyranoside and characteristic LC-MS/MS fragmentation patterns. This is the first comprehensive analysis for the identification of compounds from L. indica using LC-MS. A total 24 compounds including three new dihydrochalcones were identified for the first time from the genus Leea.


Assuntos
Cromatografia Líquida de Alta Pressão , Magnoliopsida/química , Compostos Fitoquímicos/química , Extratos Vegetais/química , Folhas de Planta/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Estrutura Molecular , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos
4.
Int Immunol ; 27(12): 621-32, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26138671

RESUMO

Selected cytotoxic chemicals can provoke the immune system to recognize and destroy malignant tumors. Most of the studies on immunogenic cell death are focused on the signals that operate on a series of receptors expressed by dendritic cells to induce tumor antigen-specific T-cell responses. Here, we explored the effects of oxaliplatin, an immunogenic cell death inducer, on the induction of stress ligands and promotion of natural killer (NK) cell-mediated cytotoxicity in human ovarian cancer cells. The results indicated that treatment of tumor cells with oxaliplatin induced the production of type I interferons and chemokines and enhanced the expression of major histocompatibility complex class I-related chains (MIC) A/B, UL16-binding protein (ULBP)-3, CD155 and TNF-related apoptosis-inducing ligand (TRAIL)-R1/R2. Furthermore, oxaliplatin but not cisplatin treatment enhanced susceptibility of ovarian cancer cells to NK cell-mediated cytolysis. In addition, activated NK cells completely abrogated the growth of cancer cells that were pretreated with oxaliplatin. However, cancer cells pretreated with the same concentration of oxaliplatin alone were capable of potentiating regrowth over a period of time. These results suggest an advantage in combining oxaliplatin and NK cell-based therapy in the treatment of ovarian cancer. Further investigation on such potential combination therapy is warranted.


Assuntos
Antineoplásicos/farmacologia , Imunoterapia Adotiva , Células Matadoras Naturais/efeitos dos fármacos , Compostos Organoplatínicos/farmacologia , Neoplasias Ovarianas/terapia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Terapia Combinada , Citotoxicidade Imunológica , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/transplante , Neoplasias Ovarianas/imunologia , Oxaliplatina , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Receptores Virais/genética , Receptores Virais/metabolismo , Estresse Fisiológico/efeitos dos fármacos
5.
Rapid Commun Mass Spectrom ; 27(12): 1380-4, 2013 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-23681816

RESUMO

RATIONALE: One new phosphodiesterase type 5 (PDE-V) inhibitor, propoxyphenyl homohydroxysildenafil (PP-HHS), has been isolated from one health supplement, and analyzed using high-resolution Orbitrap mass spectrometry. High-resolution mass spectrometry (HRMS) is useful to elucidate unknown substances at low concentrations. METHODS: Two isolated compounds, propoxyphenyl thiohomohydroxysildenafil (PP-THHS) and propoxyphenyl homohydroxysildenafil (PP-HHS), were infused into the Thermo Fischer Scientific LTQ Orbitrap XL™ hybrid FTMS system at a flow rate of 3 µL per min. The high-resolution MS(2) spectra were acquired using different high-energy collision dissolution (HCD) mode; 40 V for PPT-HHS and 45 V for PP-HHS. The accurate mass measurement was assisted with the aid of Mass Frontier software, version 5.0. RESULTS: The fragmentation pattern of PP-HHS in the MS(2) spectrum is very similar to that of PP-THHS except the product ions at m/z 519, 501, 325, 299 and 283 are less than PP-THHS by 16 m/z units. This is a result of the replacement of sulfur atom by oxygen at the thiolactam moiety. All the mass errors are below 5.0 ppm. CONCLUSIONS: High-resolution Orbitrap mass spectrometry is an alternative method to determine unknown compounds like PDE-V inhibitor analogues unambiguously by analyzing the product ions at high mass accuracy. PP-HHS is an unapproved drug and no pharmacological study has been reported. Hence, it could be harmful to unknowing consumers with undesirable side effects.


Assuntos
Espectrometria de Massas/métodos , Piperazinas/química , Sulfonas/química , Espectrometria de Massas/instrumentação , Estrutura Molecular , Peso Molecular , Purinas/química , Citrato de Sildenafila
6.
Anal Bioanal Chem ; 405(13): 4443-50, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22825675

RESUMO

A sildenafil analogue was detected in a functional coffee sample labelled to have male sexual performance enhancement effects. This analogue was isolated and purified by flash chromatography and preparative high-performance liquid chromatography. Its structure was elucidated using high-resolution mass spectrometry; electrospray ionization-tandem mass spectrometry; and nuclear magnetic resonance spectroscopy, ultraviolet spectroscopy, and infrared spectroscopy. Compared with sildenafil, instead of an N-methylpiperazinyl moiety, ring opening of the piperazine ring with the loss of a carbon atom resulted in a substituted benzenesulfonamide. The chemical name of this analogue is N-[2-(dimethylamino)ethyl]-4-ethoxy-3-(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)benzenesulfonamide. It is named descarbonsildenafil because it has one less carbon atom when compared with sildenafil.


Assuntos
Café/química , Piperazinas/química , Extratos Vegetais/química , Sulfonamidas/química , Sulfonas/química , Vasodilatadores/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas/métodos , Estrutura Molecular , Piperazinas/isolamento & purificação , Purinas/química , Purinas/isolamento & purificação , Citrato de Sildenafila , Sulfonamidas/isolamento & purificação , Sulfonas/isolamento & purificação , Vasodilatadores/isolamento & purificação
7.
BMC Complement Med Ther ; 23(1): 79, 2023 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-36899361

RESUMO

BACKGROUND: The rich biodiversity of medicinal plants and their importance as sources of novel therapeutics and lead compounds warrant further research. Despite advances in debulking surgery and chemotherapy, the risks of recurrence of ovarian cancer and resistance to therapy are significant and the clinical outcomes of ovarian cancer remain poor or even incurable. OBJECTIVE: This study aims to investigate the effects of leaf extracts from a medicinal plant Leea indica and its selected phytoconstituents on human ovarian cancer cells and in combination with oxaliplatin and natural killer (NK) cells. METHODS: Fresh, healthy leaves of L. indica were harvested and extracted in 70% methanol by maceration. The crude extract was partitioned with n-hexane, dichloromethane and ethyl acetate. Selected extracts and compounds were analyzed for their effects on cell viability of human ovarian cancer cells, NK cell cytotoxicity, and stress ligands expression for NK cell receptors. They were also evaluated for their effects on TNF-α and IL-1ß production by enzyme-linked immunosorbent assay in lipopolysaccharide-stimulated human U937 macrophages. RESULTS: Leaf extracts of L. indica increased the susceptibility of human ovarian tumor cells to NK cell-mediated cytotoxicity. Treatment of cancer cells with methyl gallate but not gallic acid upregulated the expression of stress ligands. Tumor cells pretreated with combination of methyl gallate and low concentration of oxaliplatin displayed increased levels of stress ligands expression and concomitantly enhanced susceptibility to NK cell-mediated cytolysis. Further, NK cells completely abrogated the growth of methyl gallate-pretreated ovarian cancer cells. The leaf extracts suppressed TNF-α and IL-1ß production in human U937 macrophages. Methyl gallate was more potent than gallic acid in down-regulating these cytokine levels. CONCLUSIONS: We demonstrated for the first time that leaf extracts of L. indica and its phytoconstituent methyl gallate enhanced the susceptibility of ovarian tumor cells to NK cell cytolysis. These results suggest that the combined effect of methyl gallate, oxaliplatin and NK cells in ovarian cancer cells warrants further investigation, for example for refractory ovarian cancer. Our work is a step towards better scientific understanding of the traditional anticancer use of L. indica.


Assuntos
Neoplasias Ovarianas , Plantas Medicinais , Feminino , Humanos , Extratos Vegetais/farmacologia , Oxaliplatina/farmacologia , Fator de Necrose Tumoral alfa , Células Matadoras Naturais
8.
J Sep Sci ; 35(1): 53-9, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22127806

RESUMO

Conventional methods of drug discovery from natural products include bioassay-guided fractionation, which is tedious and has low efficiency. The aim of this work is to develop a platform method to rapidly identify bioactive compounds from crude plant extracts and their partially purified fractions using multivariate data analysis (MVDA). Soxhlet extraction and liquid-liquid fractionation were used to prepare different extracts and fractions from the leaves of a medicinal plant, Ardisia elliptica. The extracts and fractions were analysed chemically using GC-MS, and their ability to inhibit platelet aggregation was investigated. Two MVDA methods were developed and optimised to analyse the results. In the first method, compounds with the highest contribution scores for biological activity calculated by different models were listed as potential antiplatelet compounds. For the second MVDA method, a correlation of the concentrations of constituents and biological activities in the various extracts and fractions for each compound was done. Compounds with the highest correlation coefficients were identified as potential antiplatelet compounds. One of the predicted components was isolated, purified and confirmed to possess antiplatelet effects. This platform method can be developed and optimised for other plant extracts and biological activities, thus reducing time and cost of drug discovery while improving efficiency.


Assuntos
Ardisia/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Ácido Oleanólico/análogos & derivados , Extratos Vegetais/química , Plantas Medicinais/química , Feminino , Humanos , Masculino , Análise Multivariada , Ácido Oleanólico/química , Ácido Oleanólico/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta/química , Agregação Plaquetária/efeitos dos fármacos
9.
Sex Med Rev ; 9(4): 568-592, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33277212

RESUMO

INTRODUCTION: Erectile dysfunction is the persistent or recurrent inability to achieve or maintain an erection sufficient for intercourse. Despite various treatment options, not all patients respond adequately and their usefulness is limited by adverse effects and cost. Botanical medicine and natural products have been and continue to be invaluable and untapped sources of new drugs, including potentially those to treat erectile dysfunction. OBJECTIVES: To review the current literature on botanical medicine traditionally used as aphrodisiacs and treatment of erectile dysfunction, in particular, scientific and clinical investigations that have been performed, possible active phytoconstituents, and mechanisms of action and to identify gaps in current knowledge to better guide future research efforts. METHODS: A comprehensive literature search was conducted via PubMed, Scopus, Science Direct, and Web of Science on English publications, using various keywords, for example, "herb", "natural product", combined with "erectile dysfunction", "aphrodisiac", and "sexual performance". RESULTS: 369 relevant articles studying medicinal plants used for erectile dysfunction were analyzed. A total of 718 plants from 145 families and 499 genera were reported to be used traditionally as aphrodisiacs and treatment of erectile dysfunction. Top plants used include Pausinystalia johimbe, Lepidium meyenii, and Panax ginseng. Different plant parts are used, with roots being the most common. Less than half of these plants have been evaluated scientifically, using various research methodologies. Clinical trials conducted were collated. Current scientific investigation shows mixed results about their usefulness in enhancing sexual performance. A limited number of studies have attempted to elucidate the mechanisms of action of these medicinal plants. CONCLUSION: A comprehensive literature review on botanical medicine and natural products used for treatment of erectile dysfunction was successfully conducted. Although medicinal plants serve as a potential source of lead compounds for erectile dysfunction drugs, further studies are warranted to further evaluate their efficacy and safety. SinVJ-E, Anand GS, Koh H-L. Botanical Medicine and Natural Products Used for Erectile Dysfunction. Sex Med Rev 2021;9:568-592.


Assuntos
Afrodisíacos , Produtos Biológicos , Disfunção Erétil , Plantas Medicinais , Afrodisíacos/uso terapêutico , Produtos Biológicos/uso terapêutico , Disfunção Erétil/tratamento farmacológico , Humanos , Ereção Peniana
10.
Acupunct Med ; 39(6): 629-636, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34049443

RESUMO

BACKGROUND: Conventional therapy may be inadequate for many patients with axial spondyloarthritis (axSpA). Traditional Chinese medicine (TCM) may be a viable alternative, but its effectiveness for axSpA is unknown. We are currently conducting a pragmatic randomised controlled trial (RCT) to investigate the effectiveness of a TCM collaborative model of care (TCMCMC), which combines usual rheumatologic care with acupuncture for patients with axSpA. This nested qualitative sub-study aims to identify facilitators of and barriers to the implementation of the TCMCMC. METHODS: We conducted individual in-depth interviews with participants who had completed the acupuncture regimen to elicit opinions on the facilitators of and barriers to the implementation of the TCMCMC. The interviews were transcribed and analysed using thematic analysis. RESULTS: Twelve participants were included, with data saturation occurring after 10 interviews. The analysis revealed both a number of important 'facilitators' and 'barriers'. Facilitators to the implementation of the TCMCMC included effectiveness of TCM to relieve symptoms, inadequacy of conventional treatment and positive social perceptions of TCM. Barriers included scepticism towards TCM, inability of TCM to provide instant relief, needle-related discomfort, variable effectiveness of TCM influenced by physicians' skills and experience and the high cost of TCM. Recommendations to overcome barriers included further patient education about TCM. CONCLUSION: Policymakers should take into account the various feasibility factors identified in this study when developing and implementing a TCMCMC. TRIAL REGISTRATION NUMBER: NCT03420404 (ClinicalTrials.gov).


Assuntos
Terapia por Acupuntura , Espondilartrite/terapia , Adulto , Idoso , Feminino , Humanos , Masculino , Medicina Tradicional Chinesa , Pessoa de Meia-Idade , Pesquisa Qualitativa , Resultado do Tratamento , Adulto Jovem
11.
Indian J Exp Biol ; 48(3): 275-9, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21046981

RESUMO

Ardisia elliptica Thunberg (Myrsinaceae) is a medicinal plant traditionally used for alleviating chest pains, treatment of fever, diarrhoea, liver poisoning and parturition complications. The objectives of the study were to investigate the effect of A. elliptica on collagen induced platelet aggregation and to isolate and purify potential antiplatelet components. Fresh A. elliptica leaves were extracted using methanol (70% v/v) by Soxhlet extraction and the extract was analysed for its inhibition of collagen-induced platelet aggregation. Inhibition of platelet aggregation was assessed by incubating the extracts with rabbit blood and collagen in a whole blood aggregometer and measuring the impedance. The leaf extract was found to inhibit platelet aggregation with an IC50 value of 167 microg/ml. Using bioassay guided fractionation, beta-amyrin was isolated and purified. The IC50 value of beta-amyrin was found to be 4.5 microg/ml (10.5 microM) while that of aspirin was found to be 11 microg/ml (62.7 microM), indicating that beta-amyrin was six times as active as aspirin in inhibiting platelet aggregation. This paper is the first report that beta-amyrin isolated from A. elliptica is more potent than aspirin in inhibiting collagen-induced platelet aggregation. In conclusion, A. elliptica leaves were found to inhibit collagen-induced platelet aggregation and one of the bioactive components responsible for the observed effect was determined to be beta-amyrin.


Assuntos
Ardisia/química , Aspirina/farmacologia , Ácido Oleanólico/análogos & derivados , Agregação Plaquetária/efeitos dos fármacos , Animais , Colágeno/farmacologia , Relação Dose-Resposta a Droga , Masculino , Ácido Oleanólico/isolamento & purificação , Ácido Oleanólico/farmacologia , Folhas de Planta/química , Inibidores da Agregação Plaquetária/farmacologia , Coelhos
12.
BMC Complement Med Ther ; 20(1): 335, 2020 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-33167947

RESUMO

BACKGROUND: Medical professionalism is important for establishing public trust in doctors. Its definition is culture-sensitive. However, no research has explored medical professionalism in Traditional Chinese Medicine (TCM) practitioners. This study aims to (a) establish the domains of professionalism in TCM practitioners in Singapore, and to (b) compare the domains of professionalism of practitioners trained in TCM and practitioners trained in conventional medicine. METHODS: Data for this qualitative study was collected through in-depth interviews (IDIs) with TCM practitioners. IDIs were audio-recorded and transcribed verbatim. Thematic analysis was conducted by two independent coders using the Professionalism Mini-Evaluation Exercise (P-MEX) as a framework. The domains of professionalism in TCM and conventional medicine were then compared, using data from a similar study on professionalism in practitioners trained in conventional medicine. RESULTS: A total of 27 TCM practitioners (40.7% male) participated in this study. The four domains of professionalism in the P-MEX, namely doctor-patient relationship skills, reflective skills, time management and inter-professional relationship skills, and two new sub-domains, "communicated effectively with patient" and "demonstrated understanding and integrated with conventional medicine", were relevant to TCM practitioners. This is largely similar to that of practitioners trained in conventional medicine, with a few differences, including "ensured continuity of care" and "used health resources appropriately". CONCLUSION: The domains of professionalism in TCM practitioners were established and they are similar to that of practitioners trained in conventional medicine. This study is the first to define medical professionalism in TCM practitioners. Findings will provide guidance on the education of professionalism in TCM practitioners.


Assuntos
Medicina Tradicional Chinesa , Relações Médico-Paciente , Profissionalismo , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Singapura , Gerenciamento do Tempo
13.
BMC Complement Med Ther ; 20(1): 91, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32188443

RESUMO

BACKGROUND: Dysregulation of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) form the basis of immune-mediated inflammatory diseases. Vitex trifolia L. is a medicinal plant growing in countries such as China, India, Australia and Singapore. Its dried ripe fruits are documented in Traditional Chinese Medicine to treat ailments like rhinitis and dizziness. Its leaves are used traditionally to treat inflammation-related conditions like rheumatic pain. OBJECTIVE: This study aimed to investigate the effects of V. trifolia leaf extracts prepared by different extraction methods (Soxhlet, ultrasonication, and maceration) in various solvents on cytokine production in human U937 macrophages, and identify phytoconstituents from the most active leaf extract. METHODS: Fresh leaves of V. trifolia were extracted using Soxhlet, ultrasonication, and maceration in hexane, dichloromethane, methanol, ethanol or water. Each extract was evaluated for its effects on TNF-α and IL-1ß cytokine production by enzyme-linked immunosorbent assay in lipopolysaccharide-stimulated human U937 macrophages. The most active extract was analyzed and further purified by different chemical and spectroscopic techniques. RESULTS: Amongst 14 different leaf extracts investigated, extracts prepared by ultrasonication in dichloromethane and maceration in ethanol were most active in inhibiting TNF-α and IL-1ß production in human U937 macrophages. Further purification led to the isolation of artemetin, casticin, vitexilactone and maslinic acid, and their effects on TNF-α and IL-1ß production were evaluated. We report for the first time that artemetin suppressed TNF-α and IL-1ß production. Gas chromatography-mass spectrometry analyses revealed the presence of eight other compounds. To the best of our knowledge, this is the first report of butylated hydroxytoluene, 2,4-di-tert-butylphenol, campesterol and maslinic acid in V. trifolia leaf extracts. CONCLUSIONS: In conclusion, leaf extracts of V. trifolia obtained using different solvents and extraction methods were successfully investigated for their effects on cytokine production in human U937 macrophages. The findings provide scientific evidence for the traditional use of V. trifolia leaves (a sustainable resource) and highlight the importance of conservation of medicinal plants as resources for drug discovery. Our results together with others suggest further investigation on V. trifolia and constituents to develop novel treatment strategies in immune-mediated inflammatory conditions is warranted.


Assuntos
Interleucina-1beta/metabolismo , Macrófagos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Vitex/química , Humanos , Extratos Vegetais/química , Folhas de Planta/química , Singapura , Células U937
14.
Int J Rheum Dis ; 23(3): 334-341, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31903711

RESUMO

OBJECTIVE: To estimate the economic annual direct and indirect costs of axial spondyloarthritis (axSpA) in Singapore, and to identify factors associated with these costs. METHODS: A retrospective, cross-sectional, Institutional Review Board-approved study was conducted. A questionnaire was administered to the patients between 2013 and 2016 from the Singapore General Hospital (SGH) spondyloarthritis registry. Direct medical costs and indirect costs were estimated using the SGH database and the human capital approach respectively. Multivariate analyses using generalized linear model with gamma distribution and a log-linked function was conducted to identify factors associated with these total, direct and indirect costs. All costs were adjusted to 2017 using the Singapore Consumer Price Index and converted to 2017 US dollars (USD) by purchasing power parity. RESULTS: A total of 135 consecutive patients were included in the study, with a mean age of 40.4 ± 13.2 years. The overall annual total economic cost to society was around USD 74 790 820, with annual direct cost being the main component of total cost (90.8%). Annual direct cost was around USD 67 931 457, while annual indirect cost was around USD 6 855 951. Presence of extra-spinal symptoms (ever) was associated with an increase in total and direct costs. Higher education level and Patient Global Assessment were associated with an increase in indirect costs. Lack of employment was associated with a decrease in indirect costs. CONCLUSION: The disease burden of axSpA in Singapore is not trivial given that the disease is relatively common. This highlights the need for measures to accommodate patients with axSpA economically in Singapore.


Assuntos
Antirreumáticos/economia , Antirreumáticos/uso terapêutico , Custos de Medicamentos , Espondilartrite/tratamento farmacológico , Espondilartrite/economia , Adulto , Estudos Transversais , Feminino , Gastos em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Estudos Retrospectivos , Singapura/epidemiologia , Fatores Socioeconômicos , Espondilartrite/diagnóstico , Espondilartrite/epidemiologia , Fatores de Tempo , Resultado do Tratamento
15.
Phytochem Anal ; 20(4): 293-7, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19402186

RESUMO

INTRODUCTION: Simple and robust atomic absorption spectrometry (AAS) analytical methods were developed to determine the contents of arsenic (As), lead (Pb) and mercury (Hg) contained in Chinese herbal medicine products or Chinese proprietary medicine. OBJECTIVE: To develop AAS analytical methods to determine the contents of the toxic heavy metals in herbal medicine, and thus monitor them according to the regulated content limits to ensure the quality and safety of herbal products. METHODOLOGY: A flow injection-mercury hydride system technique was used for the quantitation of As and Hg, and a graphite furnace technique was used for the analysis of Pb. Limits of detection (LOD) for the three toxic heavy metals were found to be 0.3 ppb for As, 0.1 ppb for Pb and 0.5 ppb for Hg. Eight samples of 'Yin Qiao Jie Du' tablets available on the market were selected as the model herbal medicine for analysis. CONCLUSION: The developed analytical methods are sensitive enough to detect these heavy metals to meet regulated guidelines. No trace amounts of Hg were found in the test samples due to the fact that the Hg level is less than the LOD. However, variable amounts of As (135.0-5349.3 ppb) and Pb (22.5-968.3 ppb) were found in all products.


Assuntos
Medicamentos de Ervas Chinesas/química , Análise de Injeção de Fluxo , Compostos de Mercúrio/química , Metais Pesados/química , Espectrofotometria Atômica , Astato/química , Contaminação de Medicamentos , Grafite , Chumbo/química , Mercúrio/química
16.
Int J Rheum Dis ; 22(12): 2206-2212, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31721427

RESUMO

INTRODUCTION: The Ankylosing Spondylitis Disease Activity Score with C-reactive protein (ASDAS-CRP) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) are commonly used instruments for measuring disease activity. However, few studies have assessed their psychometric properties in patients with axial spondyloarthritis (axSpA). We aimed to assess the validity and reliability of ASDAS-CRP and BASDAI in patients with axSpA in Singapore. METHODS: Cross-sectional data from 280 patients with axSpA from a dedicated axSpA clinic in a Singapore tertiary referral hospital from 2011 to 2019 were used. Internal consistency was assessed using Cronbach's alpha. Construct validity was assessed through 12 a priori hypotheses by correlation of overall ASDAS-CRP and BASDAI score with other patient-reported outcomes measures (PROMs). Structural validity was evaluated via confirmatory factor analysis using maximum-likelihood method, where Comparative Fit Index (CFI) >0.95, Tucker-Lewis Index (TLI) >0.95, Root Mean Square Error of Approximation (RMSEA) <0.06 and Standardized Root Mean Residuals (SRMR) <0.08 were indicative of good fit. RESULTS: Among 280 patients (78.2% Male; 92.5% Chinese), ASDAS-CRP showed poor internal consistency of 0.33, while BASDAI showed high internal consistency of 0.87. Convergent and divergent construct validity were demonstrated by fulfillment of 11 out of 12 a priori hypotheses when ASDAS-CRP and BASDAI were compared with other PROMs. Our proposed ASDAS-CRP and BASDAI model showed good fit for a 1-factor structure respectively (CFI = 0.993, TLI = 0.984, RMSEA = 0.036, SRMR = 0.026 for ASDAS-CRP; CFI = 0.993, TLI = 0.985, RMSEA = 0.057, SRMR = 0.022 for BASDAI), demonstrating structural validity. CONCLUSION: This study supports the use of both ASDAS-CRP and BASDAI in measuring disease activity in patients with axSpA in Singapore.


Assuntos
Proteína C-Reativa/análise , Indicadores Básicos de Saúde , Mediadores da Inflamação/sangue , Espondilite Anquilosante/diagnóstico , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Estudos Transversais , Feminino , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Singapura , Espondilite Anquilosante/sangue , Espondilite Anquilosante/imunologia , Adulto Jovem
17.
J Ethnopharmacol ; 235: 75-87, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-30599223

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: The extensive biodiversity of plants in Southeast Asia and inadequate research hitherto warrant a continued investigation into medicinal plants. On the basis of a careful review of fresh medicinal plant usage to treat cancer from previous ethnobotanical interviews in Singapore and from the traditional uses of the indigenous plants, fresh leaves of seven locally grown medicinal plant species were evaluated for anti-proliferative activity. AIM OF THE STUDY: To evaluate the anti-proliferative activity of local medicinal plant species Clausena lansium Skeels, Clinacanthus nutans (Burm. f.) Lindau, Leea indica (Burm. f.) Merr., Pereskia bleo (Kunth) DC., Strobilanthes crispus (L.) Blume, Vernonia amygdalina Delile and Vitex trifolia L. MATERIALS AND METHOD: Fresh, healthy and mature leaves of the seven medicinal plants were harvested from various locations in Singapore and Malaysia for Soxhlet, ultrasonication and maceration extractions in three different solvents (water, ethanol and methanol). Cell proliferation assay using water soluble tetrazolium salt (WST-1) assay was performed on twelve human cancer cell lines derived from breast (MDA-MB-231, T47D), cervical (C33A), colon (HCT116), leukemia (U937), liver (HepG2, SNU-182, SNU-449), ovarian (OVCAR-5, PA-1, SK-OV-3) and uterine (MES-SA/DX5) cancer. RESULTS: A total of 37 fresh leaf extracts from seven medicinal plants were evaluated for their anti-tumour activities in twelve human cancer cell lines. Of these, the extracts of C. lansium, L. indica, P. bleo, S. crispus, V. amygdalina and V. trifolia exhibited promising anti-proliferative activity against multiple cancer cell lines. Further investigation of selected promising leaf extracts indicated that maceration methanolic extract of L. indica was most effective overall against majority of the cancer cell lines, with best IC50 values of 31.5 ±â€¯11.4 µg/mL, 37.5 ±â€¯0.7 µg/mL and 43.0 ±â€¯6.2 µg/mL in cervical C33A, liver SNU-449, and ovarian PA-1 cancer cell lines, respectively. CONCLUSION: The results of this study provide new scientific evidence for the traditional use of local medicinal plant species C. lansium, L . indica, P. bleo, S. crispus, V. amygdalina and V. trifolia in cancer treatment. These results highlight the importance of the upkeep of these indigenous plants in modern society and their relevance as resources for drug discovery.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Neoplasias/tratamento farmacológico , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , Etnobotânica , Humanos , Malásia , Medicina Tradicional do Leste Asiático/métodos , Neoplasias/patologia , Singapura
18.
Trials ; 20(1): 46, 2019 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-30642381

RESUMO

BACKGROUND: Axial spondyloarthritis (AxSpA) is a chronic disease which results in fatigue, pain, and reduced quality of life (QoL). Traditional Chinese medicine (TCM), especially acupuncture, has shown promise in managing pain. Although a TCM collaborative model of care (TCMCMC) has been studied in cancer, there are no randomized controlled trials investigating TCM in AxSpA. Therefore, we will conduct a pragmatic trial to determine the clinical effectiveness, safety, and cost-effectiveness of TCMCMC for patients with AxSpA. We define TCMCMC as standard TCM history taking and physical examination, acupuncture, and TCM non-pharmacological advice and communications with rheumatologists in addition to usual rheumatologic care. The purpose of this paper is to describe the rationale for and methodology of this trial. METHODS/DESIGN: This pragmatic randomized controlled trial will recruit 160 patients who are diagnosed with AxSpA and have inadequate response to non-steroidal anti-inflammatory drugs (NSAIDs). Simple randomization to usual rheumatologic care or the intervention (TCMCMC) with a 1:1 allocation ratio will be used. Ten 30-min acupuncture sessions will be provided to patients assigned to the TCMCMC arm. All participants will continue to receive usual rheumatologic care. The primary endpoint - spinal pain - will be evaluated at week 6. Secondary endpoints include clinical, quality of life, and economic outcome measures. Patients will be followed up for up to 52 weeks, and adverse events will be documented. DISCUSSION: This trial may provide evidence regarding the clinical effectiveness, safety, and cost-effectiveness of a TCMCMC for patients with AxSpA. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03420404 . Registered on 14 February 2018.


Assuntos
Dor nas Costas/terapia , Comunicação Interdisciplinar , Medicina Tradicional Chinesa/métodos , Reumatologistas , Espondiloartropatias/terapia , Terapia por Acupuntura , Dor nas Costas/diagnóstico , Dor nas Costas/economia , Dor nas Costas/fisiopatologia , Análise Custo-Benefício , Feminino , Custos de Cuidados de Saúde , Humanos , Masculino , Anamnese , Medicina Tradicional Chinesa/efeitos adversos , Medicina Tradicional Chinesa/economia , Equipe de Assistência ao Paciente , Exame Físico , Ensaios Clínicos Pragmáticos como Assunto , Reumatologistas/economia , Singapura , Espondiloartropatias/diagnóstico , Espondiloartropatias/economia , Espondiloartropatias/fisiopatologia , Fatores de Tempo , Resultado do Tratamento
19.
Acta Pharmacol Sin ; 29(9): 1137-40, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18718183

RESUMO

AIM: Panax notoginseng is a cultivated ginseng species highly valued for its various pharmacological activities mostly associated with triterpenoid saponin glycosides. It would be of great interest to understand biodiversity in this ginseng species after its long history of domestication. METHODS: We collected 92 random sampled 3-year-old P notoginseng plants from 4 counties of Wenshan prefecture in Yunnan province, China and documented their morphological features of plant height, stem color, number of leaves/leaflets and dry weight of tap root. Their genetic diversity was evaluated by fluorescent amplified fragment length polymorphism (fAFLP) analysis. RESULTS: Among the samples collected, variable morphological features were observed. For these 4 populations (Zhulijie, Shangliuhe, Bazai and Jinbuhuan) analyzed by fAFLP, percentage of polymorphic bands among the total number of 582 discrete bands were 74.05%, 45.36%, 38.83% and 51.89% respectively. Mean genetic heterozygosity were 0.166, 0.093, 0.094 and 0.125. On the other hand, Nei genetic distances among populations were all <0.03. Further analysis of molecular variance (AMOVA) attributed most (93.5%) genetic diversity to within population variation. Principal coordinates analysis (PCA) did not group any population distinctively. CONCLUSION: This domesticated ginseng species still maintains a fair level of biodiversity and this conclusion is consistent with the local practice of non-selective collection of seeds for next season planting. There was no genetic drift in populations. Biodiversity of P notoginseng can be exploited to improve this important herb through breeding. Two possible strategies include inbreeding for pure lines and hybrid breeding with genetic divergent parents for hybrid vigor.


Assuntos
Panax notoginseng/química , Panax notoginseng/genética , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Análise de Variância , Biodiversidade , DNA de Plantas/biossíntese , DNA de Plantas/genética , Panax notoginseng/anatomia & histologia , Folhas de Planta/química
20.
J Pharm Biomed Anal ; 47(2): 255-9, 2008 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-18280079

RESUMO

A sample labeled to be a natural herbal supplement for the enhancement of sexual function, was sent to Health Sciences Authority (HSA) of Singapore for testing. An unknown compound was detected and isolated from the product. The structure of the unknown compound was identified using LC-UV, high-resolution MS, ESI-MS/MS, IR, and NMR. The compound was characterized as a phosphodiesterase-5 (PDE-5) inhibitor, benzamidenafil. This is the first report of benzamidenafil, representing a new class of PDE-5 inhibitors, as an adulterant of a dietary supplement.


Assuntos
Benzamidas/química , Suplementos Nutricionais/análise , Contaminação de Alimentos , Inibidores de Fosfodiesterase/análise , Inibidores de Fosfodiesterase/classificação , Benzamidas/análise , Cromatografia Líquida , Disfunção Erétil/dietoterapia , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Espectrometria de Massas , Estrutura Molecular , Inibidores de Fosfodiesterase/química , Singapura
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