• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 106
  • 51
  • 13
  • 12
  • 5
  • 4
  • 4
  • 2
  • 1
  • 1
  • Tagged with
  • 232
  • 96
  • 23
  • 21
  • 20
  • 20
  • 19
  • 17
  • 17
  • 16
  • 16
  • 15
  • 15
  • 14
  • 14
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Synaptic remodeling after cortical injury: effects of neuroinflammatory modulation

Zhou, Yuxin 07 December 2020 (has links)
The brain is capable of plasticity, so that the structural and functional loss that are caused by cortical injury may recover. Neuroinflammatory response can greatly influence post-injury recovery by modulating synaptic plasticity. In our previous work, mesenchymal derived exosomes were found to promote functional recovery by converting microglia from a pro-inflammatory state to an anti-inflammatory state in aged rhesus monkeys after cortical injury in the primary motor cortex. In the present project, we demonstrated the effects of exosomes on synaptic changes and synapse-microglia interactions after lesion in the same monkeys. To further investigate the effects of modulating neuroinflammation on synaptic changes after injury, we also investigated dietary curcumin, an anti-inflammatory substance, in a separate group of monkeys. Both treatments showed an effect as neuroinflammatory modulators that reduced the density of microglial markers, Iba- 1/P2RY12. However, the cortical injury induced synaptic loss was reversed by the exosome treatment, whereas the other anti-inflammatory treatment, curcumin, did not show the same effect. Our results are consistent with previous study that cortical injury induced synaptic loss and microglia activation. Exosomes can both reduce inflammation and synapse loss after injury, but curcumin only showed anti-inflammatory effects. Overall, these data suggested that exosomes and curcumin had different mechanisms of how to modulate inflammation and synaptic properties to promote recovery after cortical injury.
52

Prevention and treatment of colorectal cancer with turmeric and its main active constituent, curcumin

Luers, Erin Conner 12 July 2018 (has links)
PROBLEM: Colorectal cancer (CRC) is a top three leading cause of death among western countries. Epidemiological evidence shows a positive correlation between western diet, which consists of high-fat, meat and processed foods. Positive correlations indicate that diets high in fruits and vegetables could greatly decrease risk of CRC. Specifically the ubiquitous spice, turmeric, and its main active constituent have been broadly researched to determine its efficacy in the treatment and prevention of CRC. RESULTS: Curcumin proves to be effective in the treatment and prevention of CRC. It acts as a chemosensitizer for chemotherapeutics which increases their effectiveness especially against chemoresistant CRC cell lines. In many in vitro studies curcumin has inhibited critical pathways involved in CRC progression such as Wnt/β-catenin and sonic hedgehog pathway. Curcumin can also act as a ligand for VDR, which is significant because high vitamin D intake is associated with a decreased risk of CRC. In vivo, curcumin has minimized tumor growth in animal models. In clinical trials curcumin proves to be a naturally derived, non-toxic agent. CONCLUSION: Curcumin and turmeric should be further studied for its use against CRC, specifically its use in nanotechnology and NDDS as either a stand-alone nutraceutical or a chemosensitizer. Additionally, it would likely be advantageous to prescribe turmeric in the diet in combination with black pepper, heat, and oil (which increases its bioavailability) in patients at high risk of developing CRC.
53

Combination treatment with highly bioavailable curcumin and NQO1 inhibitor exhibits potent antitumor effects on esophageal squamous cell carcinoma / 生物学的利用能が高いクルクミンとNQO1阻害剤の併用投与は食道扁平上皮癌に対し強い抗腫瘍効果を示す

Mizumoto, Ayaka 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医科学) / 甲第21699号 / 医科博第103号 / 新制||医科||7(附属図書館) / 京都大学大学院医学研究科医科学専攻 / (主査)教授 妹尾 浩, 教授 渡邊 直樹, 教授 松原 和夫 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
54

An Automated Study of Antioxidant Potentials of Polar Extract of Turmeric as Influenced by Ultraviolet Radiation

Alawadi, Nagham Salah 07 May 2016 (has links)
Turmeric polar extract (TPE) was obtained by dielectric-precipitation of turmeric slurry and found to contain three proteins with two in the 10-11 KDa range being dominant. Antioxidative activity and persistence (AP) of TPE (5%, w/v) respectively showed 87% and 85% greater generation of alkoxy- and peroxyl radicals compared the non-redox-active buffer alone showing significant (p<0.05) pro-oxidative behavior. Conversely, purified curcumin (CU) (0.1% w/v) was dramatically antioxidative with AA and AP values of 2,828 and 1,129%, respectively, compared to the blank. However, a combination of the two at the same concentration dropped these values to 590 and 389%, respectively, reflecting dramatic dampening of the efficacy of CU. Ultraviolet radiation significantly modulated the efficacy of CU where UVB (300 nm) exposure gave the highest enhancement when limited to five min. Data showed that turmeric contains highly pro-oxidant polar proteins that significantly dramatically diminishes the beneficial antioxidative efficacy of its principal phytochemical, CU.
55

The Effect Of Curcumin (Curcuma Longa) On Biofilm Formation And Surface Proteins Of Listeria Monocytogenes

Ruengvisesh, Songsirin 01 January 2012 (has links) (PDF)
The food-borne pathogen Listeria monocytogenes can attach to the environmental surfaces and develop biofilm which can cause food contamination in the food industries. Sortase A and surface proteins are involved in biofilm and virulence of L. monocytogenes. Curcumin was reported to inhibit sortase A and biofilm in gram positive bacteria. The overall objective of this study was to observe the effect of curcumin (Curcuma longa) on the biofilm formation and surface proteins of L. monocytogenes. The antibiofilm effect of curcumin against the strain LM21 (wild type) and s22-11G (sortase A defective mutant) was studied using the microtiter plate assay. No significant differences between the growth of the wild type and the sortase A defective mutant were observed at sub-inhibitory concentrations of curcumin. However, a greater biofilm reduction was observed in the strain s22-11G. The effect of curcumin from two different manufacturers on the wild type was also compared by the microtiter plate assay. Both curcumin did not exhibit statistically different effect on the growth of the wild type. However, a greater biofilm inhibitory effect was observed in one curcumin. The HPLC results suggested that curcumin with the greater antibiofilm activity contained higher amount of curcumin which was reported to be the most potent curcuminoid compound in curcumin. Three different protein extraction methods were evaluated and the most efficient method was used for 2D-GE. When cells were grown in the presence of curcumin, 5 proteins, 16 proteins and 4 proteins were up-regulated, down-regulated and absent, respectively in L. monocytogenes LM21. The influence of the enzyme sortase A upon surface protein expression was evaluated by comparing proteins expressed by wildtype L. monocytogenes LM21 to that of the sortase A mutant, s22-11G. In strain s22-11G, 2 proteins, 8 proteins and 3 proteins were up-regulated, down-regulated and absent in comparison to wildype LM21. The exact information of these differentially expressed proteins still need to be identified by mass spectrometry.
56

Encapsulation of Curcumin in O/w Nanoemulsions and Its Bioaccessibility After In Vitro Digestion

Ahmed, Kashif 01 January 2010 (has links) (PDF)
The functional ingredient curcumin has a variety of biological and pharmacological actions, such as anti-tumor, anti-inflammatory, anti-virus, anti-oxidant, and anti-HIV properties coupled with low toxicity. However, curcumin possesses low bioavailability due to its poor solubility in water. The purpose of this study was to investigate the impact of different lipid-based formulations of curcumin on in vitro solubilization and bioaccessibility. Oils representing LCT, MCT, LCT:SCT mix and SCT were used to prepare O/W (nano)emulsions with droplet sizes as low as 174 nm. An in vitro digestion model simulating the small intestine milieu in the fasted and fed state was used to characterize rate, extent, and particle size associated with emulsion digestion. Rate and extent were oil dependent, but not particle size. SCT emulsions digested at the fastest initial rate, but MCT emulsions were digested to the largest extent. Bioaccessibility, a precursor to eventual bioavailability, was determined after digestion using a curcumin:lipid content dependent and independent method. MCT produced the highest bioaccessibility of curcumin for each method. Nanoemulsion digestion and bioaccessibility results were compared to conventional emulsions because an appropriate comparison was needed to determine the merits of the nanoemulsion delivery system. There was no significant difference in particle size and bioaccessibility between the conventional and nanoemulsions.
57

Polymorphs of Curcumin and Its Cocrystals With Cinnamic Acid

Rathi, N., Paradkar, Anant R, Gaikar, V.G. 21 March 2019 (has links)
Yes / We report formation of polymorphs and new eutectics and cocrystals of curcumin, a sparingly water-soluble active component in turmeric, structurally similar to cinnamic acid. The curcumin polymorphs were formed using liquid antisolvent precipitation, where acetone acted as a solvent and water was used as the antisolvent. The metastable form 2 of curcumin was successfully prepared in varied morphology over a wide range of solvent-to-antisolvent ratio and under acidic pH conditions. We also report formation of new eutectics and cocrystals of curcumin with cinnamic acid acting as a coformer. The binary phase diagrams were studied using differential scanning calorimetry and predicted formation of the eutectics at the curcumin mole fraction of 0.15 and 0.33, whereas a cocrystal was formed at 0.3 mole fraction of curcumin in the curcumin–cinnamic acid mixture. The formation of the cocrystal was supported with X-ray powder diffraction, the enthalpy of fusion values, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The hydrogen bond interaction between curcumin and cinnamic acid was predicted from Fourier-transform infrared spectra, individually optimized curcumin and cinnamic acid structures by quantum mechanical calculations using Gaussian-09 and their respective unit cell packing structures.
58

Experimentelle Therapie eines transgenen Tiermodells der Charcot-Marie-Tooth-Krankheit mit Meriva-Curcumin und Cholesterol / Experimental study of a transgenetic CMT-animal model using Meriva-Curcumin and Cholesterol

Yildiz, Anna Dilan 19 June 2017 (has links)
No description available.
59

Efeitos de solventes nos espectros de absorção e emissão da Dimethoxy Curcumin / Solvent Effects on Absorption and Emission Spectra of Dimethoxy Curcumin

Ramos, Tárcius Nascimento 07 April 2015 (has links)
A Curcumin há muito tempo é utilizada como condimento, colorífico e na medicina tradicional asiática. Conhecida como açafrão-da-índia, recentemente tem chamado a atenção devido ao grande potencial medicinal. Surgiram trabalhos principalmente sobre seus supostos efeitos benignos no tratamento de câncer e Alzheimer porém não limitados a estas enfermidades. Na tentativa de otimizar as propriedades medicinais surgiu a Dimethoxy Curcumin, um composto sintético que apresenta maior citotoxicidade e estabilidade biológica que a Curcumin. A maioria das reações químicas e biológicas ocorrem em soluções e os efeitos dos solventes são de extrema importância e complexidade. Neste trabalho nós estudamos os efeitos dos solventes ciclohexano e acetonitrila nos espectros de absorção e emissão da Dimethoxy Curcumin. Consideramos a contribuição de diferentes isômeros e estados excitados usando a Teoria do Funcional Densidade Dependente do Tempo (TD-DFT) utilizando a aproximação Modelo Contínuo Polarizável para o solvente. Nós observamos que as energias de emissão dos estados singletos sofrem um deslocamento para o vermelho enquanto que os estados tripletos sofrem um deslocamento para o azul. Respondemos estas questões analisando a variação do momento de dipolo durante a transição. Neste trabalho encontramos boa concordância com os valores experimentais dos espectros de absorção, emissão, deslocamento espectral e deslocamento Stokes. / The Curcumin has long been used as a condiment, pigment and in the traditional Asian medicine. Known as turmeric, recently has attracted attention because of the large medical potential. Several studies were made mainly about the supposed benign effects in the treatment of cancer and Alzheimer but not limited to these diseases. Attempt to optimize their medicinal properties there appeared the Dimethoxy Curcumin, a synthetic compound that has a higher cytotoxicity and biological stability than Curcumin. Most of the chemical and biological reactions occur in solutions and the solvent effects are of great importance and complexity. In the present work, we study the effects of the solvents cyclohexane and acetonitrile in the absorption and emission spectra of Dimethoxy Curcumin. We consider the contribution of various isomers and excited states using the Time Dependent Density Functional Theory (TD-DFT) with the Polarizable Continuum Model (PCM) approximation for the solvent. We observe that the emission energy of the singlet states are red shifted while the triplet states are blue shifted. We address this by analyzing the dipole moment variation after the transition. We find good agreement with the experimental values for the absorption, emission, spectral shift and Stokes shift
60

Die Hemmung der Bildung des Interleukin-1-Rezeptorkomplexes als redoxregulierter antiinflammatorischer Mechanismus / The inhibition of the Interleukin-1 receptor complex formation as a redox regulated antiinflammatory mechanism

Jurrmann, Nadine January 2006 (has links)
Das proinflammatorische Zytokin Interleukin-1 (IL-1) spielt eine zentrale Rolle bei Entzündungen und Infektionen. Die zellulären Antworten von IL-1 werden über den IL-1-Rezeptor Typ I (IL-1RI) vermittelt. Adapterproteine und die IL-1RI-assoziierte Kinase IRAK werden nach Ligandenbindung an den Rezeptor rekrutiert. Nach ihrer Phosphorylierung dissoziiert die IRAK vom IL-1RI-Komplex und aktiviert weitere Kinasen, was letztendlich zur Aktivierung von NF-κB und zur Induktion der Transkription von Genen führt. Für eine adäquate Immunantwort ist ein intrazellulärer reduzierter Status von Proteinthiolen essentiell. Vorausgegangene Untersuchungen an der murinen Thymomzelllinie EL-4 zeigten, dass die IL-1-Signalkaskade durch thiolmodifizierende Substanzen wie Menadion (MD) oder Phenylarsinoxid (PAO) gehemmt wird. Eine IL-1-abhängige Aktivierung von IL-1RI-assoziierte Kinasen oder NF-κB fand nicht mehr statt.<br><br> Ziele dieser Arbeit waren: (i) mögliche Proteine, die für den Angriff von thiolmodifizierenden Agenzien ein Ziel sein könnten, zu identifizieren und (ii) den Einfluss nahrungsrelevanter und redoxaktiver Substanzen auf frühe Ereignisse der IL-1-Signaltransduktion wie der Bildung des IL-1RI-Komplexes zu untersuchen. Als Zellmodell wurden EL-4-Zellen mit stabil überexprimierter IRAK (EL-4<sup>IRAK</sup>) verwendet. Um die Bildung des IL-1RI-Komplexes, anschließende Phosphorylierungsereignisse und somit Kinase-Aktivitäten nachzuweisen, wurden Co-Präzipitations-Experimente und <i>in vitro</i> Kinase Tests durchgeführt. Die Markierung von Proteinthiolen erfolgte mit dem thiolspezifischen Reagenz Iodoacetyl-[<sup>125</sup>I]-Iodotyrosin ([<sup>125</sup>I]-IAIT).<br><br> Die Vorbehandlung von EL-4<sup>IRAK</sup>-Zellen mit MD oder PAO führte zu einer Hemmung der Rekrutierung der IRAK an den IL-1RI und der anschließenden Phosphorylierungen. Zur Identifikation weiterer IL-1RI-assoziierter Proteine wurden IL-1RI-Immunpräzipitate zweidimensional aufgetrennt, Colloidal-Coomassie gefärbte Proteinspots ausgeschnitten und anschließend massenspektrometrisch mittels ESI-Q-TOF analysiert. Bei der Analyse wurden Proteine des Cytoskeletts wie z. B. Actin identifiziert.<br><br> In Analogie zu den synthetischen Substanzen MD und PAO wurden nahrungsrelevante und redoxaktive Substanzen wie Curcumin (Gelbwurz) und Sulforaphan (Broccoli) eingesetzt, um zu untersuchen, ob sie bereits früh die IL-1-Signaltransduktion beeinflussen. Bislang sind antiinflammatorische Effekte dieser beiden Nahrungsinhaltsstoffe nur auf der Ebene der Zytokin-vermittelten Aktivierung von NF-κB beschrieben. Sowohl Curcumin als auch Sulforaphan blockierten konzentrationsabhängig die Assoziation der IRAK an den IL-1RI in EL-4<sup>IRAK</sup>-Zellen, wobei beide Substanzen unterschiedlich wirkten. Curcumin beeinflusste die IRAK-Aktivierung durch direkte Modifikation von Thiolen der IRAK ohne die Bindung von IL-1 mit dem IL-1RI zu beeinträchtigen. Sulforaphan hingegen induzierte auf mRNA- und Proteinebene die Expression von Tollip, welches durch PCR bzw. Western Blot nachgewiesen wurde. Tollip, ein negativer Regulator in TLR/IL-1RI-Signalkaskaden, könnte somit nach Induktion die IRAK-Aktivierung unterdrücken. Die Sulforaphan-abhängige Induktion der Tollip-Expression erfolgte jedoch nicht über Nrf2 und "antioxidant response element" (ARE)-regulierte Transkription, obwohl Sulforaphan ein bekannter Nrf2-Aktivator ist.<br><br> Diese Ergebnisse veranschaulichen, dass die IRAK ein redoxsensitives Protein ist und für die Bildung des IL-1RI-Komplexes reduzierte Proteinthiole eine Voraussetzung sind. Der Angriffspunkt für die antiinflammatorische Wirkung der beiden Nahrungsbestandteile Curcumin und Sulforaphan ist die Bildung des IL-1RI-Komplexes als ein frühes Ereignis in der IL-1-Signalkaskade. Die Hemmung dieses Prozesses würde die in der Literatur beobachteten Inhibitionen der abwärts liegenden Signale wie die Aktivierung von NF-κB und die Induktion proinflammatorischer Proteine erklären. / The pro-inflammatory cytokine Interleukin-1 (IL-1) generates cellular responses in infection and inflammation. Effects of IL-1 are mediated by the IL-1-receptor type I (IL-1RI). Following ligand binding the IL-1RI-associated kinase IRAK is recruited to the IL-1RI. After phosphorylation and dissociation of IRAK from the receptor different adapter proteins and kinases are activated finally leading to translocation of NF-κB into the nucleus and induction of gene expression. An intracellular reduced state of cysteine residues (thiols) of proteins is necessary for an appropriate IL-1 response. It was shown recently, that preincubation of murine thymoma EL-4 cells with the thiol modifying agents menadione (MD) or phenylarsine oxide (PAO) completely abolished e. g. the IL-1-induced activation of NF-κB. <br><br> The question to answer therefore was: (i) what are the proteins requiring free thiols and (ii) is the complex formation also influenced by dietary compounds exhibiting anti-inflammatory effects and being able to react with thiols in proteins. As a model the EL-4-cell line stably overexpressing IRAK (EL-4<sup>IRAK</sup>) was used. Recruitment of IRAK was followed by its co-precipitation with the IL-1RI by means of Western blotting with an IRAK antibody. IRAK phosphorylation was demonstrated by in vitro kinase assays with the co-precipitates. Free thiols of IL-1RI complex-associated proteins were made visible by Iodo-acetyl-[<sup>125</sup>I]-Iodotyrosine ([<sup>125</sup>I]-IAIT). <br><br> By combining these methods with pretreatment of cells with MD or PAO, inhibition of recruitment of IRAK was identified as the first step in the IL-1 signaling cascade sensitive to thiol modification. To detect further redox-sensitive IL-1RI-associated proteins, receptor immunoprecipitates were separated by two dimensional gel electrophoresis and protein spots were analyzed by ESI-Q-TOF. In this way proteins of the cytoskeleton, including actin, were identified. <br><br> In addition to the synthetical compounds MD or PAO the effects of dietary agents were investigated on the IL-1 signaling pathway. Curcumin as a component of turmeric and sulforaphane from broccoli have been described to be redox-active and anti-inflammatory by an impairment of late events in IL-1- and Toll-like receptor (TLR) signaling. Increasing doses of curcumin and sulforaphane blocked the recruitment of IRAK to the IL-1RI in EL-4<sup>IRAK</sup> cells, but these dietary compounds acted by different mechanisms. Curcumin exerted this inhibition not due to an interference with ligand binding to the receptor, it rather modified protein thiols of IRAK. In contrast, sulforaphane had an indirect effect by an induction of Tollip expression, as shown by mRNA (PCR) and protein (Western blot) analysis. Tollip is known as a negative regulator of IL-1- and TLR-mediated signaling and enhanced expression of Tollip mediated by sulforaphane might therefore inhibit IRAK activation. The induction of Tollip expression was not initiated by Nrf2 and antioxidant response element (ARE)-regulated transcription, which is known to be activated by sulforaphane. <br><br> These results demonstrate that IRAK is a redox-sensitive protein and the complex formation requires a reduced state of proteins involved. Curcumin and sulforaphane act anti-inflammatory by blocking IL-1 signaling pathway at the most early step, explaining its inhibitory effect on further downstream events in pro-inflammatory pathways.

Page generated in 0.016 seconds