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1.
Lett Appl Microbiol ; 76(1)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36688778

RESUMO

Extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases (AmpCs)-producing Enterobacteriaceae have been increasingly reported and imposing significant threat to public. Livestock production industry might be the important source for clinically important ESBL-producing Enterobacteriaceae. This study aims to investigate the resistance profile, phenotypic ESBL production, beta-lactamase genes, virulence factors, and plasmid replicon types among 59 Enterobacteriaceae strains isolated from poultry faecal samples in Malaysia's commercial poultry farm. There were 38.7% and 32.3% of Escherichia coli resistant to cefotaxime and cefoxitin, respectively, while Klebsiellaspp. demonstrated resistance rate of 52.6% to both mentioned antimicrobials. Majority of the E. coli isolates carried blaTEM and blaCMY-2 group. blaSHV was the most prevalent gene detected in Klebsiellaspp., followed by blaDHA and blaTEM. Resistance to extended spectrum cephalosporin in our isolates was primarily mediated by plasmid mediated AmpC beta-lactamase such as CMY-2 group and DHA enzyme. The CTX-M genes were found in two ESBL-producing E. coli. IncF, IncI1, and IncN plasmids were most frequently detected in E. coli and Klebsiellaspp. The virulence factor, including EAST1 and pAA were identified at low frequency. This study highlights the poultry as a reservoir of resistance and virulence determinants and prevalence of plasmids in Enterobacteriaceae might drive their dissemination.


Assuntos
Infecções por Escherichia coli , Escherichia coli , Animais , Escherichia coli/genética , Aves Domésticas , Infecções por Escherichia coli/veterinária , Fazendas , Enterobacteriaceae/genética , Malásia , Proteínas de Bactérias/genética , beta-Lactamases/genética , Plasmídeos , Antibacterianos
2.
Anticancer Agents Med Chem ; 23(7): 817-831, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36380402

RESUMO

AIMS: The aim of this study was to sensitize the resistant breast adenocarcinoma cells towards Tumour Necrosis Factor-related Apoptosis-inducing Ligand (TRAIL)-induced apoptosis. BACKGROUND: Breast cancer is a heterogeneous disease involving complex mechanisms. TRAIL is a potential anticancer candidate for targeted treatment due to its selective killing effects on neoplastic cells. Nonetheless, resistance occurs in many cancers either intrinsically or after multiple treatments. OBJECTIVE: Therefore, this research investigated whether the combination of Trichostatin A (TSA) and Zebularine (Zeb) (TZ) followed by TRAIL (TZT) could sensitize the human breast adenocarcinoma cells towards apoptosis. METHODS: The breast adenocarcinoma cells, MDA-MB-231, MCF-7 and E-MDA-MB-231 (E-cadherin re-expressed MDA-MB-231) were treated with TSA, Zeb, TZ, TRAIL and TZT. The cells were subjected to hematoxylin and eosin (H & E) staining and FITC-Annexin V/Propidium Iodide apoptosis detection prior to proteome profiling. RESULTS: Based on morphological observation, apoptosis was induced in all cells treated with all treatment regimens though it was more evident for the TZT-treated cells. In the apoptosis detection analysis, TZ increased early apoptosis significantly in MDA-MB-231 and MCF-7 while TRAIL induced late apoptosis significantly in E-MDA-MB-231. Based on the proteome profiling on MDA-MB-231, TRAIL R2 and Fas expression was increased. For E-MDA-MB- 231, down-regulation of catalase, paraoxonase-2 (PON2), clusterin, an inhibitor of apoptosis proteins (IAPs) and cell stress proteins validated the notion that E-cadherin re-expression enhances TZT anti-cancer efficacy. Similar trend was observed in MCF-7 whereby TZT treatment down-regulated the anti-apoptotic catalase and PON2, increased the proapoptotic, B cell lymphoma 2 (Bcl-2)-associated agonist of cell death (Bad) and Bcl-2-associated X (Bax), second mitochondria-derived activator of caspase (SMAC) and HtrA serine peptidase 2 (HTRA2) as well as TRAIL receptors (TRAIL R1 and TRAIL R2). CONCLUSION: TZ treatment serves as an efficient treatment regimen for MDA-MB-231 and MCF-7, while TRAIL serves as a better treatment option for E-MDA-MB-231. Therefore, future studies on E-cadherin's positive regulatory role in TRAIL-induced apoptosis are warranted.


Assuntos
Adenocarcinoma , Neoplasias da Mama , Humanos , Feminino , Catalase , Ligantes , Proteoma/farmacologia , Linhagem Celular Tumoral , Apoptose , Neoplasias da Mama/patologia , Fator de Necrose Tumoral alfa , Proteínas Inibidoras de Apoptose , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Caderinas , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia
3.
Phytochemistry ; 193: 112988, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34717280

RESUMO

Four undescribed cucurbitacins, designated as petiolaticins A-D, and four known cucurbitacins were isolated from the bark and leaves of Elaeocarpus petiolatus (Jack) Wall. Their chemical structures were elucidated based on detailed analyses of the NMR and MS data. The absolute configuration of petiolaticin A was also determined by X-ray diffraction analysis. Petiolaticin A represents a cucurbitacin derivative incorporating a 3,4-epoxyfuranyl-bearing side chain, while petiolaticin B possesses a furopyranyl unit fused to the tetracyclic cucurbitane core structure. Petiolaticins A, B, and D were evaluated in vitro against a panel of human breast, pancreatic, and colorectal cancer cell lines. Petiolaticin A exhibited the greatest cytotoxicity against the MDA-MB-468, MDA-MB-231, MCF-7, and SW48 cell lines (IC50 7.4, 9.2, 9.3, and 4.6 µM, respectively). Additionally, petiolaticin D, 16α,23α-epoxy-3ß,20ß-dihydroxy-10αH,23ßH-cucurbit-5,24-dien-11-one, and 16α,23α-epoxy-3ß,20ß-dihydroxy-10αH,23ßH-cucurbit-5,24-dien-11-one 3-O-ß-D-glucopyranoside were tested for their ability to inhibit cell entry of a pseudotyped virus bearing the hemagglutinin envelope protein of a highly pathogenic avian influenza virus. Petiolaticin D showed the highest inhibition (44.3%), followed by 16α,23α-epoxy-3ß,20ß-dihydroxy-10αH,23ßH-cucurbit-5,24-dien-11-one (21.0%), and 16α,23α-epoxy-3ß,20ß-dihydroxy-10αH,23ßH-cucurbit-5,24-dien-11-one 3-O-ß-D-glucopyranoside showed limited inhibition (9.0%). These preliminary biological assays have demonstrated that petiolaticins A and D possess anticancer and antiviral properties, respectively, which warrant for further investigations.


Assuntos
Elaeocarpaceae , Triterpenos , Animais , Cucurbitacinas , Estrutura Molecular , Extratos Vegetais , Folhas de Planta , Triterpenos/farmacologia , Pseudotipagem Viral
4.
Sci Rep ; 11(1): 22536, 2021 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-34795382

RESUMO

Graphene-based materials have gained remarkable attention in numerous disciplines owing to their unique electrochemical properties. Out of various hybridized nanocomposites, graphene-zirconia nanocomposite (GZ) was distinctive due to its biocompatibility. Zirconia nanoparticles serve as spacers that reduce the stacking of graphene and improve the electrochemical performance of the material. Considering that lungs and skin suffer the greatest exposure to nanoparticles, this study aimed to evaluate the cytotoxicity of the as-synthesized GZ nanocomposites on MRC5 (lung cells) and HaCaT (skin cells) via morphological observation and cell viability assay using 3-(4,5 dimethylthiazol-2-yl)-(2,5-diphenyltetrazolium bromide) tetrazolium (MTT). GZ-treated cells showed a comparable proliferation rate and morphology with untreated cells under microscopic evaluation. Based on MTT results, the IC50 values of GZ were > 500 µg/ml for MRC5 and HaCaT cells. The excellent biocompatibility was the supremacy of GZ over other nanocomposites applied as electrode materials in biosensors. GZ was functionalized with biolinker for the detection of carcinoembryonic antigen (CEA). The proposed immunosensor exhibited good responses towards CEA detection, with a 4.25 pg/ml LOD and correlation coefficient of R2 = 0.99 within a linear working range from 0.01 to 10 ng/ml. The performance of the immunosensor to detect CEA present in human serum was also evaluated. Good recovery of CEA was found, suggesting that the proposed immunosensor possess a high affinity to CEA even in a complex biological matrix, rendering it a promising sensing platform for real sample analysis and open a new way for the detection of cancer-associated proteins.


Assuntos
Materiais Biocompatíveis/química , Técnicas Biossensoriais/métodos , Grafite/química , Nanocompostos/química , Zircônio/química , Antígeno Carcinoembrionário/sangue , Linhagem Celular Tumoral , Sobrevivência Celular , Eletroquímica , Humanos , Concentração Inibidora 50 , Limite de Detecção , Sais de Tetrazólio/química , Tiazóis/química
5.
Analyst ; 146(6): 2009-2018, 2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33523052

RESUMO

The envelope glycoprotein domain III (EDIII) of dengue virus (DENV) has been recognised as the antigenic region responsible for receptor binding. In the present work, we have proposed a novel immunosensor constructed on a graphene-coated screen-printed carbon electrode (SPCE) using plant-derived EDIII as the probe antigen to target DENV IgG antibodies. The developed immunosensor demonstrated high sensitivity towards DENV IgG within a wide linear working range (125-2000 ng mL-1) under the optimised sensing conditions. The limit of detection was determined to be 22.5 ng mL-1. The immunosensor also showed high specificity towards DENV IgG, capable of differentiating DENV IgG from the antibodies of other infectious diseases including the similarly structured Zika virus (ZIKV). The ability of the immunosensor to detect dengue antibodies in serum samples was also verified by conducting tests on mouse serum samples. The proposed immunosensor was able to provide a binary (positive/negative) response towards the serum samples comparable to the conventional enzyme-linked immunosorbent assay (ELISA), indicating promising potential for realistic applications.


Assuntos
Técnicas Biossensoriais , Vírus da Dengue , Dengue , Grafite , Infecção por Zika virus , Zika virus , Animais , Anticorpos Antivirais , Dengue/diagnóstico , Ensaio de Imunoadsorção Enzimática , Glicoproteínas , Imunoensaio , Camundongos
6.
Biosens Bioelectron ; 176: 112895, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33358432

RESUMO

This study reports on the development of a novel impedimetric immunosensor design using plant-derived antigenic glycoprotein for the detection of dengue virus (DENV) IgG antibodies. The electrochemical immunosensor platform was constructed using screen-printed carbon electrode (SPCE) modified with graphene/titanium dioxide (G/TiO2) nanocomposite to improve the electrode in terms electrochemical performance and specific surface area. A plant-derived dengue envelope domain III (EDIII) protein was used as the antigenic probe protein in this immunosensing strategy. Under optimised sensing conditions, the immunosensor demonstrated high sensitivity towards DENV IgG in a wide linear working range (62.5-2000 ng/mL), with a limit of detection of 2.81 ng/mL. The immunosensor showed high specificity for discriminating DENV IgG against antibodies of other infectious disease, including the closely related Zika virus (ZIKV). The reliability of the immunosensor in serological diagnosis was verified by challenging the immunosensor against serum samples, compared to conventional enzyme-linked immunosorbent assay (ELISA). As shown by its remarkable performance throughout the study, the devised immunosensor is proposed as a reliable and practical diagnostic tool for the serological detection of dengue in realistic applications.


Assuntos
Técnicas Biossensoriais , Vírus da Dengue , Dengue , Grafite , Infecção por Zika virus , Zika virus , Anticorpos Antivirais , Dengue/diagnóstico , Humanos , Imunoensaio , Reprodutibilidade dos Testes , Titânio
7.
Front Plant Sci ; 12: 769855, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35095950

RESUMO

Fusarium oxysporum f. sp. cubense tropical race 4 (FocTR4) is a destructive necrotrophic fungal pathogen afflicting global banana production. Infection process involves the activation of programmed cell death (PCD). In this study, seven Musa acuminata vacuolar processing enzyme (MaVPE1-MaVPE7) genes associated with PCD were successfully identified. Phylogenetic analysis and tissue-specific expression categorized these MaVPEs into the seed and vegetative types. FocTR4 infection induced the majority of MaVPE expressions in the susceptible cultivar "Berangan" as compared to the resistant cultivar "Jari Buaya." Consistently, upon FocTR4 infection, high caspase-1 activity was detected in the susceptible cultivar, while low level of caspase-1 activity was recorded in the resistant cultivar. Furthermore, inhibition of MaVPE activities via caspase-1 inhibitor in the susceptible cultivar reduced tonoplast rupture, decreased lesion formation, and enhanced stress tolerance against FocTR4 infection. Additionally, the Arabidopsis VPE-null mutant exhibited higher tolerance to FocTR4 infection, indicated by reduced sporulation rate, low levels of H2O2 content, and high levels of cell viability. Comparative proteomic profiling analysis revealed increase in the abundance of cysteine proteinase in the inoculated susceptible cultivar, as opposed to cysteine proteinase inhibitors in the resistant cultivar. In conclusion, the increase in vacuolar processing enzyme (VPE)-mediated PCD played a crucial role in modulating susceptibility response during compatible interaction, which facilitated FocTR4 colonization in the host.

9.
Int J Mol Sci ; 21(15)2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32708043

RESUMO

An ideal scaffold should be biocompatible, having appropriate microstructure, excellent mechanical strength yet degrades. Chitosan exhibits most of these exceptional properties, but it is always associated with sub-optimal cytocompatibility. This study aimed to incorporate graphene oxide at wt % of 0, 2, 4, and 6 into chitosan matrix via direct blending of chitosan solution and graphene oxide, freezing, and freeze drying. Cell fixation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, alkaline phosphatase colorimetric assays were conducted to assess cell adhesion, proliferation, and early differentiation of MG63 on chitosan-graphene oxide scaffolds respectively. The presence of alkaline phosphatase, an early osteoblast differentiation marker, was further detected in chitosan-graphene oxide scaffolds using western blot. These results strongly supported that chitosan scaffolds loaded with graphene oxide at 2 wt % mediated cell adhesion, proliferation, and early differentiation due to the presence of oxygen-containing functional groups of graphene oxide. Therefore, chitosan scaffolds loaded with graphene oxide at 2 wt % showed the potential to be developed into functional bone scaffolds.


Assuntos
Materiais Biocompatíveis/química , Proliferação de Células/efeitos dos fármacos , Quitosana/química , Grafite/química , Osteogênese/efeitos dos fármacos , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Fosfatase Alcalina/metabolismo , Adesão Celular/efeitos dos fármacos , Glutaral/química , Humanos , Microscopia Eletrônica de Varredura , Osteoblastos/metabolismo
10.
Crit Rev Oncol Hematol ; 143: 81-94, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561055

RESUMO

Apoptosis is an ordered and orchestrated cellular process that occurs in physiological and pathological conditions. Resistance to apoptosis is a hallmark of virtually all malignancies. Despite being a cause of pathological conditions, apoptosis could be a promising target in cancer treatment. Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), also known as Apo-2 ligand (Apo2L), is a member of TNF cytokine superfamily. It is a potent anti-cancer agent owing to its specific targeting towards cancerous cells, while sparing normal cells, to induce apoptosis. However, resistance occurs either intrinsically or after multiple treatments which may explain why cancer therapy fails. This review summarizes the apoptotic mechanisms via extrinsic and intrinsic apoptotic pathways, as well as the apoptotic resistance mechanisms. It also reviews the current clinically tested recombinant human TRAIL (rhTRAIL) and TRAIL receptor agonists (TRAs) against TRAIL-Receptors, TRAIL-R1 and TRAIL-R2, in which the outcomes of the clinical trials have not been satisfactory. Finally, this review discusses the current strategies in overcoming resistance to TRAIL-induced apoptosis in pre-clinical and clinical settings.


Assuntos
Neoplasias/tratamento farmacológico , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/agonistas , Ligante Indutor de Apoptose Relacionado a TNF/uso terapêutico , Apoptose/efeitos dos fármacos , Humanos , Neoplasias/metabolismo , Ensaios Clínicos Controlados Aleatórios como Assunto , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Receptores Chamariz do Fator de Necrose Tumoral/agonistas
11.
BMC Complement Altern Med ; 19(1): 169, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291936

RESUMO

BACKGROUND: Garcinia species contain bioactive compounds such as flavonoids, xanthones, triterpernoids, and benzophenones with antibacterial, antifungal, anti-inflammatory, and antioxidant activities. In addition, many of these compounds show interesting biological properties such as anti-human immunodeficiency virus activity. Garcinia parvifolia is used in traditional medicine. Currently, the antiviral activity of G. parvifolia is not known. METHODS: This study was conducted to determine the effects of ethyl acetate (45 L Ea), ethanol (45 L Et), and hexane (45 L H) leaf extracts of G. parvifolia on the infectivity of pseudorabies virus (PrV) in Vero cells. The antiviral effects of the extracts were determined by cytopathic effect (CPE), inhibition, attachment, and virucidal assays. RESULTS: The 50% cytotoxicity concentration (CC50) values obtained were 237.5, 555.0, and < 1.25 µg/mL for 45 L Ea, 45 L Et, and 45 L H, respectively. The 45 L Ea showed the greatest viral inhibition potency of 75% at 125 µg/mL. Both 45 L Ea and 45 l Et caused 100% residual viral inhibition at 250 µg/mL. The selectivity index values for 45 L Ea, 45 L Et, and 45 L H were 2.65, 1.75, and 0.10 showing that 45 L Ea had the greatest antiviral activity among the three extracts. CONCLUSION: This study showed that ethyl acetate is the best solvent to be used to obtain extract from G. parvifolia leaves with potent antiviral activities.


Assuntos
Antivirais/farmacologia , Garcinia/química , Herpesvirus Suídeo 1/efeitos dos fármacos , Extratos Vegetais/farmacologia , Acetatos , Animais , Antivirais/isolamento & purificação , Antivirais/toxicidade , Chlorocebus aethiops , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Células Vero , Ensaio de Placa Viral
12.
Lipids ; 54(6-7): 369-379, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31124166

RESUMO

Dysregulated hepatic gluconeogenesis is a hallmark of insulin resistance and type 2 diabetes mellitus (T2DM). Although existing drugs have been proven to improve gluconeogenesis, achieving this objective with functional food is of interest, especially using conjugated linoleic acid (CLA) found in dairy products. Both cis-9, trans-11 (c9,t11) and trans-10, cis-12 (t10,c12) isomers of CLA were tested in human (HepG2) and rat (H4IIE) hepatocytes for their potential effects on gluconeogenesis. The hepatocytes exposed for 24 h with 20 µM of c9,t11-CLA had attenuated the gluconeogenesis in both HepG2 and H4IIE by 62.5% and 80.1%, respectively. In contrast, t10,c12-CLA had no effect. Of note, in HepG2 cells, the exposure of c9,t11-CLA decreased the transcription of gluconeogenic enzymes, cytosolic phosphoenolpyruvate carboxykinase (PCK1) by 87.7%, and glucose-6-phosphatase catalytic subunit (G6PC) by 38.0%, while t10,c12-CLA increased the expression of G6PC, suggesting the isomer-specific effects of CLA on hepatic glucose production. In HepG2, the peroxisome proliferator-activated receptor (PPAR) agonist, rosiglitazone, reduced the glucose production by 72.9%. However, co-administration of c9,t11-CLA and rosiglitazone neither exacerbated nor attenuated the efficacy of rosiglitazone to inhibit glucose production; meanwhile, t10,c12-CLA abrogated the efficacy of rosiglitazone. Paradoxically, PPARγ antagonist GW 9662 also led to 70.2% reduction of glucose production and near undetectable PCK1 expression by abrogating CLA actions. Together, while the precise mechanisms by which CLA isomers modulate hepatic gluconeogenesis directly or via PPAR warrant further investigation, our findings establish that c9,t11-CLA suppresses gluconeogenesis by decreasing PEPCK on hepatocytes.


Assuntos
Glucose/biossíntese , Hepatócitos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Ácidos Linoleicos Conjugados/farmacologia , Fosfoenolpiruvato Carboxiquinase (GTP)/antagonistas & inibidores , Animais , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Gluconeogênese/efeitos dos fármacos , Gluconeogênese/genética , Células Hep G2 , Hepatócitos/química , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Ácidos Linoleicos Conjugados/química , Fosfoenolpiruvato Carboxiquinase (GTP)/genética , Fosfoenolpiruvato Carboxiquinase (GTP)/metabolismo , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estereoisomerismo , Relação Estrutura-Atividade
13.
J Mater Sci Mater Med ; 30(6): 62, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31127374

RESUMO

This study aimed to explore a potential use of fish scale-derived gelatin nanofibrous scaffolds (GNS) in tissue engineering due to their biological and economical merits. Extraction of gelatin was achieved via decalcification, sonication and lyophilization of mixed fish scales. To fabricate nano-scale architecture of scaffolds analogous to natural extracellular matrix, gelatin was rendered into nanofibrous matrices through 6-h electrospinning, resulting in the average diameter of 48 ± 12 nm. In order to improve the water-resistant ability while retaining their biocompatibility, GNS were physically crosslinked with ultraviolet (UV) irradiation for 5 min (UGN5), 10 min (UGN10) and 20 min (UGN20). On average, the diameter of nanofibers increased by 3 folds after crosslinking, however, Fourier transform infrared spectroscopy analysis confirmed that no major alterations occurred in the functional groups of gelatin. A degradation assay showed that UGN5 and UGN10 scaffolds remained in minimum essential medium for 14 days, while UGN20 scaffolds degraded completely after 10 days. All UGN scaffolds promoted adhesion and proliferation of human keratinocytes, HaCaT, without causing an apparent cytotoxicity. UGN5 scaffolds were shown to stimulate a better growth of HaCaT cells compared to other scaffolds upon 1 day of incubation, whereas UGN20 had a long-term effect on cells exhibiting 25% higher cell proliferation than positive control after 7 days. In the wound scratch assay, UGN5 scaffolds induced a rapid cell migration closing up to 79% of an artificial wound within 24 h. The current findings provide a new insight of UGN scaffolds to serve as wound dressings in the future. In the wound scratch assay, UGN5 induced a rapid cell migration closing up to 79% of an artificial wound within 24 h.


Assuntos
Escamas de Animais/química , Gelatina/química , Nanofibras/química , Engenharia Tecidual/métodos , Animais , Materiais Biocompatíveis , Adesão Celular , Linhagem Celular Tumoral , Proliferação de Células , Reagentes de Ligações Cruzadas/química , Eletroquímica , Matriz Extracelular , Fibroblastos/citologia , Peixes , Humanos , Queratinócitos/citologia , Teste de Materiais , Especificidade da Espécie , Espectroscopia de Infravermelho com Transformada de Fourier , Alicerces Teciduais , Raios Ultravioleta , Água/química , Cicatrização
14.
Front Plant Sci ; 10: 455, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31057572

RESUMO

Dengue fever is currently ranked as the top emerging tropical disease, driven by increased global travel, urbanization, and poor hygiene conditions as well as global warming effects which facilitate the spread of Aedes mosquitoes beyond their current distribution. Today, more than 100 countries are affected most of which are tropical Asian and Latin American nations with limited access to medical care. Hence, the development of a dengue vaccine that is dually cost-effective and able to confer a comprehensive protection is ultimately needed. In this study, a consensus sequence of the antigenic dengue viral glycoprotein domain III (cEDIII) was used aiming to provide comprehensive coverage against all four circulating dengue viral serotypes and potential clade replacement event. Utilizing hepatitis B tandem core technology, the cEDIII sequence was inserted into the immunodominant c/e1 loop region so that it could be displayed on the spike structures of assembled particles. The tandem core particles displaying cEDIII epitopes (tHBcAg-cEDIII) were successfully produced in Nicotiana benthamiana via Agrobacterium-mediated transient expression strategy to give a protein of ∼54 kDa, detected in both soluble and insoluble fractions of plant extracts. The assembled tHBcAg-cEDIII virus-like particles (VLPs) were also visualized from transmission electron microscopy. These VLPs had diameters that range from 32 to 35 nm, presenting an apparent size increment as compared to tHBcAg control particles without cEDIII display (namely tEL). Mice immunized with tHBcAg-cEDIII VLPs showed a positive seroconversion to cEDIII antigen, thereby signifying that the assembled tHBcAg-cEDIII VLPs have successfully displayed cEDIII antigen to the immune system. If it is proven to be successful, tHBcAg-cEDIII has the potential to be developed as a cost-effective vaccine candidate that confers a simultaneous protection against all four infecting dengue viral serotypes.

15.
Int J Mol Sci ; 20(2)2019 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-30654580

RESUMO

Malignancy often arises from sophisticated defects in the intricate molecular mechanisms of cells, rendering a complicated molecular ground to effectively target cancers. Resistance toward cell death and enhancement of cell survival are the common adaptations in cancer due to its infinite proliferative capacity. Existing cancer treatment strategies that target a single molecular pathway or cancer hallmark fail to fully resolve the problem. Hence, multitargeted anticancer agents that can concurrently target cell death and survival pathways are seen as a promising alternative to treat cancer. Tocotrienols, a minor constituent of the vitamin E family that have previously been reported to induce various cell death mechanisms and target several key survival pathways, could be an effective anticancer agent. This review puts forward the potential application of tocotrienols as an anticancer treatment from a perspective of influencing the life or death decision of cancer cells. The cell death mechanisms elicited by tocotrienols, particularly apoptosis and autophagy, are highlighted. The influences of several cell survival signaling pathways in shaping cancer cell death, particularly NF-κB, PI3K/Akt, MAPK, and Wnt, are also reviewed. This review may stimulate further mechanistic researches and foster clinical applications of tocotrienols via rational drug designs.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias/patologia , Tocotrienóis/farmacologia , Animais , Autofagia/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Humanos
16.
Trop Life Sci Res ; 29(1): 229-238, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29644026

RESUMO

Recent studies suggested that combined treatment approaches can be used to improve anticancer potency and circumvent the limitations of high-dose tocotrienols administration. Acalypha wilkesiana is a medicinal plant that has been used as an adjunct treatment for cancers in traditional medicine. Herein, the effects of single and combined treatments of ß-, γ- and δ-tocotrienols and ethyl acetate extract (9EA) of Acalypha wilkesiana on lung (A549) and brain (U87MG) cancer cells were investigated. γ- and δ-tocotrienols exhibited higher potent antiproliferative effects against A549 (12.1 µg/ml and 13.6 µg/ml) and U87MG cells (3.3 µg/ml and 5.2 µg/ml) compared to ß-tocotrienols (9.4 µg/ml and 92.4 µg/ml), respectively. Whereas, 9EA induced potent antiproliferative effects against U87MG cells only (2.0 µg/ml). Combined treatments of tocotrienols and 9EA induced a synergistic growth inhibition with up to 8.4-fold reduction in potent doses of ß-, γ- and δ-tocotrienols on A549 cells. Apoptotic features were also evidenced on A549 cells receiving single and combined treatments. The synergism may greatly improve the therapeutic outcome for lung cancer.

17.
Polymers (Basel) ; 10(2)2018 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30966168

RESUMO

At present, polyhydroxyalkanoates (PHAs) have been considered as a promising alternative to conventional plastics due to their diverse variability in structure and rapid biodegradation. To ensure cost competitiveness in the market, thermoseparating aqueous two-phase extraction (ATPE) with the advantages of being mild and environmental-friendly was suggested as the primary isolation and purification tool for PHAs. Utilizing two-level full factorial design, this work studied the influence and interaction between four independent variables on the partitioning behavior of PHAs. Based on the experimental results, feed forward neural network (FFNN) was used to develop an empirical model of PHAs based on the ATPE thermoseparating input-output parameter. In this case, bootstrap resampling technique was used to generate more data. At the conditions of 15 wt % phosphate salt, 18 wt % ethylene oxide⁻propylene oxide (EOPO), and pH 10 without the addition of NaCl, the purification and recovery of PHAs achieved a highest yield of 93.9%. Overall, the statistical analysis demonstrated that the phosphate concentration and thermoseparating polymer concentration were the most significant parameters due to their individual influence and synergistic interaction between them on all the response variables. The final results of the FFNN model showed the ability of the model to seamlessly generalize the relationship between the input⁻output of the process.

18.
J Mater Chem B ; 6(8): 1195-1206, 2018 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32254180

RESUMO

Highly sensitive and selective immunosensors that can detect disease biomarkers at ultra-low levels in early stages are urgently needed to reduce mortality risks. A facile and efficient approach using sonochemical-assisted solvent graphene exfoliation and a hydrothermal synthesis method has been used to prepare graphene/titanium dioxide (G/TiO2) nanocomposites. Nanocomposites containing different ratios of graphene and TiO2 precursors were prepared to determine the optimum composition of G/TiO2 that has the highest conductivity and electrocatalytic properties. Characterisation methods such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and high resolution TEM (HRTEM) were used to study the crystallinity, surface characteristics, elemental composition, and morphology of the synthesised nanocomposites. The synthesised materials were also confirmed via Raman spectroscopy. Using ferricyanide as the redox active probe, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses indicated that 1 : 8 ratio of G/TiO2 exhibited the best current response and the lowest charge transfer resistance (Rct) of 1525 Ω. The potential of G/TiO2 for electrochemical sensing application was investigated using hydrogen peroxide (H2O2), a by-product of most enzymatic processes, as the analyte of interest. The sensitivity of the sensor towards H2O2 was 0.557 µA mM-1, with a limit of detection (LOD) at 56.89 µM. An in vitro cell proliferation assay was carried out to investigate the biocompatibility of the nanocomposites. The half-maximal inhibitory concentration (IC50) values obtained were >500 µg ml-1 for human lung fibroblasts (MRC5) and 5-25 µg ml-1 for human skin cells (HaCat).

19.
Curr Opin Virol ; 26: 81-89, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28800551

RESUMO

Production of proteins in plants for human health applications has become an attractive strategy attributed by their potentials for low-cost production, increased safety due to the lack of human or animal pathogens, scalability and ability to produce complex proteins. A major milestone for plant-based protein production for use in human health was achieved when Protalix BioTherapeutics produced taliglucerase alfa (Elelyso®) in suspension cultures of a transgenic carrot cell line for the treatment of patients with Gaucher's disease, was approved by the USA Food and Drug Administration in 2012. In this review, we are highlighting various approaches for plant-based production of proteins and recent progress in the development of plant-made therapeutics and biologics for the prevention and treatment of human diseases.


Assuntos
Produtos Biológicos/metabolismo , Vetores Genéticos , Vírus de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/virologia , Proteínas Recombinantes/metabolismo , Biotecnologia/métodos , Humanos , Proteínas Recombinantes/genética , Tecnologia Farmacêutica/métodos
20.
Phytomedicine ; 30: 74-84, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28545672

RESUMO

BACKGROUND: γ-Tocotrienol, a vitamin E isomer possesses pronounced in vitro anticancer activities. However, the in vivo potency has been limited by hardly achievable therapeutic levels owing to inefficient high-dose oral delivery which leads to subsequent metabolic degradation. Jerantinine A, an Aspidosperma alkaloid, originally isolated from Tabernaemontana corymbosa, has proved to possess interesting anticancer activities. However, jerantinine A also induces toxicity to non-cancerous cells. PURPOSE: We adopted a combinatorial approach with the joint application of γ-tocotrienol and jerantinine A at lower concentrations in order to minimize toxicity towards non-cancerous cells while improving the potency on brain cancer cells. METHODS: The antiproliferative potency of individual γ-tocotrienol and jerantinine A as well as combined in low-concentration was firstly evaluated on U87MG cancer and MRC5 normal cells. Morphological changes, DNA damage patterns, cell cycle arrests and the effects of individual and combined low-concentration compounds on microtubules were then investigated. Finally, the potential roles of caspase enzymes and apoptosis-related proteins in mediating the apoptotic mechanisms were investigated using apoptosis antibody array, ELISA and Western blotting analysis. RESULTS: Combinatorial study between γ-tocotrienol at a concentration range (0-24µg/ml) and fixed IC20 concentration of jerantinine A (0.16µg/ml) induced a potent antiproliferative effect on U87MG cells and led to a reduction on the new half maximal inhibitory concentration of γ-tocotrienol (i.e.tIC50=1.29µg/ml) as compared to that of individual γ-tocotrienol (i.e. IC50=3.17µg/ml). A reduction on undesirable toxicity to MRC5 normal cells was also observed. G0/G1 cell cycle arrest was evident on U87MG cells receiving IC50 of individual γ-tocotrienol and combined low-concentration compounds (1.29µg/ml γ-tocotrienol + 0.16µg/ml jerantinine A), whereas, a profound G2/M arrest was evident on cells treated with IC50 of individual jerantinine A. Additionally, individual jerantinine A and combined compounds (except individual γ-tocotrienol) caused a disruption of microtubule networks triggering Fas- and p53-induced apoptosis mediated via the death receptor and mitochondrial pathways. CONCLUSIONS: These findings demonstrated that the combined use of lower concentrations of γ-tocotrienol and jerantinine A induced potent cytotoxic effects on U87MG cancer cells resulting in a reduction on the required individual concentrations and thereby minimizing toxicity of jerantinine A towards non-cancerous MRC5 cells as well as probably overcoming the high-dose limiting application of γ-tocotrienol. The multi-targeted mechanisms of action of the combination approach have shown a therapeutic potential against brain cancer in vitro and therefore, further in vivo investigations using a suitable animal model should be the way forward.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Encefálicas/tratamento farmacológico , Antineoplásicos Fitogênicos/administração & dosagem , Proteínas Reguladoras de Apoptose/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Caspases/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromanos/administração & dosagem , Cromanos/efeitos adversos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Humanos , Alcaloides Indólicos/administração & dosagem , Concentração Inibidora 50 , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Vitamina E/administração & dosagem , Vitamina E/efeitos adversos , Vitamina E/análogos & derivados
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