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  • 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.
171

Role of Non-coding RNAs in chemotherapeutic treatments / Ruolo dei Non coding RNAs nei trattamenti chemioterapici

Vannini, Ivan <1975> 14 April 2015 (has links)
The transcribed ultraconserved regions (T-UCRs) are a group of long non-coding RNAs involved in human carcinogenesis. The factors regulating the expression of T-UCRs and their mechanism of action in human cancers are unknown. In this work it was shown that high expression of uc.339 associates with lower survival in 204 non-small cell lung cancer (NSCLC) patients. Moreover, it was shown that uc.339 found up-regulated in archival NSCLC samples, acts as a decoy RNA for miR-339-3p, -663-3p and -95-5p. So, Cyclin E2, a direct target of three microRNAs is up-regulated, inducing cancer growth and migration. Evidence of this mechanism was provided from cell lines and primary samples confirming that TP53 directly regulates uc.339. These results support a key role for uc.339 in lung cancer.
172

Characterization of the Caspr2 and NLGN2 ligands: a proteomic and biochemical approach

Vincelli, Gabriele <1985> January 1900 (has links)
Autism Spectrum Disorder (ASD) is a range of early-onset conditions classified as neurodevelopmental disorders, characterized by deficits in social interactions and communication, as well as by restricted interest and repetitive behaviors. Among the proteins associated with this spectrum of disease there are Caspr2, α-NRXN1, NLGN1-4. Caspr2 is involved in the clustering of K+ channels at the juxtaparanodes, where it is proposed to bind TAG-1. Recent works reported a synaptic localization of Caspr2, but little is know on its role in this compartment. NRXNs and their ligand NLGNs, instead, have a well-defined role in the formation and maintenance of synapses. Among the neuroligins, NLGN2 binds NRXNs with the lowest affinity, suggesting that it could have other not yet characterized ligands. The aim of this work was to better characterize the binding of Caspr2 to TAG-1 and to identify new potential binding partner for Caspr2 and NLGN2. Unexpectedly, using Isothermal Titration Calorimetry and co-immunoprecipitation experiments the direct association of the first two proteins could not be verified and the results indicate that the first evidences reporting it were biased by false-positive artifacts. These findings, together with the uncharacterized synaptic localization of Caspr2, made the identification of new potential binding partners for this protein necessary. To find new proteins that associate with Caspr2 and NLGN2, affinity chromatography in tandem with mass spectrometry experiments were performed. Interestingly, about 25 new potential partners were found for these two proteins and NLGN1, that was originally included as a control: 5 of those, namely SFRP1, CLU, APOE, CNTN1 and TNR, were selected for further investigations. Only the association of CLU to NLGN2 was confirmed. In the future, screenings of the remaining candidates have to be carried out and the functional role for the proposed NLGN2-CLU complex has to be studied.
173

La ricerca traslazionale in farmacologia gastroenterologica / Translational research in Pharmacology applied to Gastroenterology

Dothel, Giovanni <1982> 14 April 2015 (has links)
Il presente studio si concentra sull’analisi degli aspetti traslazionali nella ricerca farmacologica applicata alla Gastroenterologia. La trattazione si articola in due parti: una prima elaborazione teorica, che permette di inquadrare nel contesto della ricerca traslazionale il razionale scientifico ed etico alla base delle attività sperimentali eseguite durante il triennio; una seconda parte, nella quale si riportano i metodi, i risultati e le osservazioni conclusive derivanti dallo studio sperimentale. Nella prima parte vengono analizzate alcune caratteristiche delle procedure, adottate nella ricerca in ambito farmacologico gastrointestinale, che permettono di ottenere un dato verosimile derivabile da modelli diversi rispetto all’organismo umano. Sono inclusi nella trattazione gli aspetti etici dell’utilizzo di alcuni modelli animali di patologie intestinali organiche e funzionali in relazione al loro grado di predittività rispetto alla realtà sperimentale clinica. Nella seconda parte della trattazione, viene presentato uno studio esplorativo tissutale multicentrico sul ruolo del sistema oppioide e cannabinoide nella sindrome dell’intestino irritabile (IBS). Obiettivo dello studio è la valutazione dell’espressione e la localizzazione del recettore oppioide µ (µOR), del suo ligando β endorfina (β-END) e del recettore cannabinoide 2 (CB2) nei pazienti con IBS ad alvo costipato (IBS-C) e diarroico (IBS-D), ed in soggetti sani (HC). I dati ottenuti indicano un’implicazione del sistema oppioide e cannabinoide nella risposta immune alterata riscontrata nei pazienti con IBS ed in particolare nel sottogruppo IBS-C. La presente trattazione suggerisce come la creazione di nuovi sistemi di indagine sempre più validi da un punto di vista traslazionale possa dipendere, almeno in parte, dalla capacità di integrare realtà disciplinari, tecnologie ed esperienze metodologiche diverse nel contesto della ricerca in campo biomedico e farmacologico ed in particolare tramite un mutuo scambio di informazioni tra realtà clinica e ricerca di base / The present study focuses on the analysis of translational issues of pharmacological research applied to Gastroenterology. The dissertation is divided in two parts: the first one consists in a theroethical elaboration allowing to contextualize - within the framework of translational research - the scientific and ethical rationale underlying the experimental activity carried out over the last three years. The second part deals with the methods, the results and the conclusive observations deriving from the experimental study presented. In the first part some features of the procedures adopted in the field of pharmacology applied to gastroenterology are presented. These allow to obtain a reliable data deriving from models other than human one. This section also addresses the ethical issues concerning the use of animal models of both organic and functional intestinal pathologies. Such issues are put in relation to the level of predicitivity peculiar to the model and related to the research. In the second part of the dissertation the author presents a multicenter study about the role of the opioid and cannabinoid system in the irritable bowel syndrome (IBS). The aim of the study is the assessment of the expression of µ opioid receptor (µOR), of its ligand β-endorphin (β-END) and the cannabinoid receptor 2 (CB2) in IBS patients with either constipation (IBS-C) or diarrhea (IBS-D) compared to healthy controls (HC). The data obtained suggest that the opioid and cannabinoid systems contribute to the abnormal immune response detected in IBS patients, particularly in IBS-C. The present dissertation suggests how the creation of innovative research methodologies ever more effective from a translational standpoint may depend, at least in part, from the ability to integrate different research areas, technologies and methodological expertise in the context of biomedical and pharmacological research, especially through the mutual exchange of information between clinical and basic research.
174

Evaluation of Tumor M2 Pyruvate Kinase and Endocannabinoid System Expression in Colorectal Preneoplastic and Neoplastic Lesions: Possible Use for non Invasive Diagnosis

Zaccaro, Cristina <1987> 03 May 2016 (has links)
Colorectal cancer (CRC) is a multistep process that goes through adenoma-carcinoma sequence. Many forms of CRC may be prevented by routine control, which can detect precancerous neoplasm before they undergo malignant transformation (123). For this reasons we hypothesized that a combination of simple faecal tests, may help to identify patients with higher risk of adenomas and/or CRC. The aim of this study is to clarify whether FOBT, enzyme Tumor M2-PK and endocannabinoid system molecules (CB1, CB2, FAAH), could represent diagnostic non-invasive markers, alone or in combination, for early diagnosis of CRC and its precancerous lesions. In a pivotal study we analyzed a selected population, using i-FOBT and quantitative ELISA stool test for t-M2-PK detection. i-FOBT showed the highest specificity and PPV (88.8% and 52.7% respectively); M2-PK had the best sensitivity (87.2%); the best results it obtained with combination tests; in fact if our patients had been subjected only to the i-FOBT test, 33 high risk adenoma and 14 CRC would not have been diagnosed. Supported by these findings, we analyzed a consecutive population: patients with both positive tests have only 31.6% risk of developing CRC; in contrast, patients negative to both markers, cancer risk was less than 2% (VPN 98.5%). We confirmed, also with immuoistochemistry, that increase of tumour M2-PK in patients with CRC, as well as in stool samples, is correlated with pre neoplastic stages. To investigate the expression of endocannabinoid system in CRC, CB1, CB2 and FAAH markers were studied immunochemically in different stages and normal tissue. CB receptors and their ligands, as well as FAAH inhibitions, showed to have a protective role in colorectal cancer. They, in combination with other markers (such as t-M2-PK and FOBT), could be indicated to develop a non-invasive test for an early diagnosis of cancerous and pre-cancerous colorectal lesions.
175

Caratterizzazione di un nuovo modello di NAFLD e valutazione del potenziale effetto antisteatotico di estratti vegetali / Characterization of a new model of NAFLD and evaluation of the potential antisteatotic effect of plant extracts

Vornoli, Andrea <1986> January 1900 (has links)
Nella presente tesi, abbiamo caratterizzato un modello di ratto trattato con dieta iperlipidica e streptozotocina (D), utilizzato per valutare i potenziali effetti anti-steatotici di una miscela contenente 5 estratti vegetali (caigua, soia, erba medica, carciofo e riso rosso fermentato) somministrata a due differenti dosaggi (0,3 [A] e 1 mg/Kg [B]) e confrontata con il controllo positivo eugenolo (E) ed il veicolo di somministrazione latte di soia (M). I valori concernenti colesterolo, LDL, glucosio, ALT ed il contenuto di lipidi nel tessuto epatico sono risultati aumentati in D, A ed M, rispetto ai CTR, e ripristinati significativamente in B ed E. Le attività marcatrici del CYP2E1 (p-nitrofenolo idrossilasi ed anilina-idrossilasi) e le analisi di Western blotting per le proteine CYP2E1 e CYP4A hanno evidenziato una significativa induzione su D, A ed M ed un parziale ripristino dei valori di controllo in B. Dal dosaggio del GSH e della carbonilazione delle proteine è stata evidenziata la presenza di stress ossidativo nei ratti iperlipidici, significativamente ridotta nel B. La presenza del colesterolo nella dieta iperlipidica è stata determinante per la significativa riduzione dei geni HMGCR ed LDLr. Dall’analisi di geni coinvolti nell’infiammazione e nello stress mitocondriale si è evidenziato un significativo aumento nei gruppi D, A e M rispetto al CTR, mentre una significativa riduzione si è osservata in B ed E. Per estendere la caratterizzazione del ratto HFD/STZ, in un nuovo esperimento abbiamo analizzato geni chiave del metabolismo del colesterolo e del trasporto degli acidi biliari. Abbiamo osservato un’induzione dei geni responsabili della formazione dell’acido colico CYP7A1 e CYP8B1, ma non di quelli dell’acido chenodeossicolico CYP27A1 e CYP7B1. Inoltre è emersa una diminuita espressione di SHP (gene chiave per l’inibizione feedback del CYP7A1 e del CYP8B1) e dei geni responsabili del trasporto degli acidi biliari, del colesterolo, e della fosfatidilcolina. / In this thesis, we characterized a rat model treated with a high fat diet and low dose of streptozotocin (HFD/STZ, D), to evaluate the anti-steatotic effects of a 5 plant extracts mixture (caigua, soybean, alfalfa, artichoke and fermented red rice) administered at two different doses (0.3 [A] and 1 mg/kg [B]) and compared to the positive control eugenol (E) and the vehicle soy milk (M) administration. Cholesterol, LDL, glucose and ALT blood parameters values and liver lipids content were increased in D, A and M, with the respect to CTR, and significantly recovered in B and E. CYP2E1 specific activities (p-nitrophenol hydroxylase and aniline hydroxylase) and Western blot analysis for CYP2E1 and CYP4A proteins were induced in D, A and M, and partially restored in B. GSH and protein carbonylation analysis highlighted, compared to CTR, the presence of oxidative stress in HFD/STZ rats, which was significantly reduced in B. The analysis of genes involved in inflammation (IL6, TNFα) and mitochondrial stress revealed a significant increase in A, D, M groups, but not in E and B. The presence of 2% of cholesterol in the high fat diet determined a significant reduction of HMGCR and LDLr transcripts. To extend the characterization of our steatotic rat model, we analyzed key genes of cholesterol metabolism and bile acids transporters in a new experiment. It was observed an induction of CYP7A1 and CYP8B1 genes responsible for the formation of cholic acid (CA), but not of CYP27A1 and CYP7B1, which lead to chenodeoxycholic acid (CDCA). In addition, we observed a decreased expression of FXR-regulated SHP (the key gene for the feedback CYP7A1 and CYP8B1 inhibition) and of the genes responsible for the transport of bile acids (NTCP, MRP2/4, OATP1A1, OATP1B2, BSEP), cholesterol (ABCG5), and phosphatidylcholine (MDR3).
176

Effetti della Vitamina E sul metabolismo degli xenobiotici e sull'omeostasi ossidoriduttiva / Effects of Vitamin E on carcinogen metabolizing enzymes and redox homeostasis

Vivarelli, Fabio <1985> January 1900 (has links)
Negli ultimi decenni, in virtù delle eccellenti proprietà antiossidanti della vitamina E (VE), la possibile associazione tra questa e la riduzione dell’incidenza di patologie neoplastiche è stata studiata mediante numerosi trial clinici. I risultati sono però ambigui e l’impiego della VE come agente chemiopreventivo su larga scala è oggi più che mai al centro del dibattito scientifico. Il Selenium and Vitamin E Cancer Prevention Trial (SELECT) ha addirittura evidenziato un rischio d’incidenza più alto per il cancro alla prostata nel gruppo d’intervento in cui è stata somministrata la VE. Tuttavia, il meccanismo d’azione non è noto. Poiché la VE induce l’espressione di alcune isoforme del P450 nel fegato e poichè tale induzione è associata ad un aumento della produzione di specie reattive centrate sull’ossigeno, ci siamo posti il problema di come un’eventuale up-regulation a livello prostatico avrebbe potuto generare uno stress ossidativo responsabile del fenomeno di cui sopra. Il presente lavoro ha mostrato come la VE provochi una marcata induzione delle isoforme CY1A1, CYP1A2, e CYP1B1/2 nel rene e nella prostata di ratto trattato i.p. con VE (100 o 200 mg/kg p.c. per sette o quattordici giorni consecutivi), e nel rene una generale inattivazione degli enzimi post-ossidativi GST e UDPGT ed una riduzione della potenzialità antiossidante. La spettroscopia EPR abbinata alla tecnica radical trapping ha rilevato una generazione anomala di radicali liberi in entrambi i tessuti. I risultati sono stati confermati in vitro in cellule epiteliali di prostata umana RWPE-1 esposte alla VE. Insieme ad un aumento dell’espressione genica (mRNA) di differenti CYPs, è stato osservato un incremento di radicali liberi e della prostaglandina E2 (PGE2) rispetto al controllo. Lo studio indica che la VE induce la superfamiglia CYP e uno stress ossidativo a livello prostatico (co-cancerogenesi) e può contribuire a spiegare i risultati inaspettati del trial SELECT. / Several meta-analysis and randomized clinical trials have seriously questioned chemoprevention based on vitamins including vitamin E (VE). Recently, the Selenium and Vitamin E Cancer Prevention Trial (SELECT) has pointed out an increased risk for prostate cancer among VE long–term users. However, to date, the mechanism underlying these findings still remain unknown. Evidence from both in vitro and in vivo models reported how VE might increase the expression of hepatic cytochrome P450 (CYP). Induction may increase the biotransformation of ubiquitous pre-carcinogens and trigger an over-production of oxygen centred radicals (ROS) in the target tissue. We apotheosized that if such phenomenon occured also in the prostate, it could contribute to explain the SELECT unexpected data. Male Sprague-Dawley rats were daily treated i.p. with either 100 or 200 mg/kg b.w. for 7 or 14 consecutive days. A powerful booster effect of various CYP isoforms such as CY1A1, CYP1A2, and CYP1B1/2, coupled with a marked free radical over-generation were recorded in renal and prostate tissues. VE treatment led to a wide down-regulation of antioxidant (catalase, NAD(P)H:quinone reductase) and phase II enzymes (glutathione S-transferase, UDP-glucuronosyl transferase capability. Results observed in the in vivo study were consistent with those obtained by the use of a RWPE-1 human prostate cell based model. Compared to the control RWPE-1, cells exposed to VE reported a general CYP up-regulation associated with a higher content of free radicals. Interestingly, VE treatment also induced the cyclooxygenase (COX-2) expression with a consequently increased of the prostaglandin E2 levels. The present study suggests that VE can act as a co-carcinogen and pro-oxidant agent. If such epigenetic mechanisms occur in human, may contribute to explain the harmful outcomes raised up from the SELECT study.
177

Epigenetic changes promoting HeLa cell apoptosis are linked to valproic acid-induced down-regulation of REST and its corepressor CoREST

Khodeneva, Natalya <1988> January 1900 (has links)
REST (RE-1 silencing transcription factor, or NRSF –neuron-restrictive silencing factor) binds to a conserved RE-1 motif present in the promoter region of regulated genes and represses their transcription in neuronal and non-neuronal cells (Bruce et al., 2004). REST recruits corepressors (CoREST, mSin3a) and multiple chromatin modifying enzymes (HDAC1/2, demethylase LSD1 and methyltransferase G9a), causing chromatin compaction and altering gene expression by changing epigenetic tagets (Ballas et al., 2005). REST contributes to orchestrate the epigenetic regulation of target genes through several miRNAs including miR-9/9*, miR-29a, miR-124a, miR-218 and others (Wu and Xie, 2006). My thesis has ascertained an anti-tumor properties of transcription factor REST on a model of cervical adenocarcinoma where class I histone deacetylase (HDAC) inhibitor: valproic acid (VPA) down-regulates REST and its corepressors CoREST and HDAC1 at mRNA and protein level. These effects are related to a potent effect on cell apoptosis, possibly mediated by miR-9 overexpression as consequence of REST and CoREST down-regulation. I report the presence of a double-negative feedback loop between REST and miR-9 in HeLa cell line: in absence of REST, miR-9 levels substantially increase while miR-9 overexpression promotes REST down-regulation. Interestingly, I have observed that REST is sufficient to induce a noteworthy chromatin remodeling in HeLa cells. HeLa cell apoptosis induced by these events, involves mitochondrial control of apoptosis signaling pathways, particularly Bcl-2 family gene BAX. In conclusion, the present study aims to contribute to a more accurate comprehension of the processes responsible for REST activity in a model of epithelial cervical adenocarcinoma, and relevant for a detailed knowledge of important events causing oncogenesis. Moreover, considering the crucial role of epigenetic regulation of gene transcription in the etiology of many pathological conditions, any further knowledge in this field could find important and innovative pharmacological applications.
178

Chronic Obstructive Pulmonary Disease: Genetic Polymorphisms and Intermediary Metabolism Alterations

Consolini, Nicola <1984> January 1900 (has links)
Chronic obstructive pulmonary disease (COPD) is a multifactorial disease characterized by airflow obstruction that is usually progressive and associated with an abnormal inflammatory response of the lungs to noxious particles and gases. Cigarette smoke (CS) is the main risk factor, but only a small proportion of smokers (15-20%) develop symptomatic disease, this suggests that there are individual susceptibility factors involved in disease onset and progression. Considering the impact of environmental and genetic risk factors in COPD, this dissertation sought to uncover genetic susceptibility biomarkers in a population affected by COPD and explore tissue metabolic alterations induced by chronic CS exposure in a mouse model. A case-control study was carried on in a COPD population, aiming to investigate whether polymorphisms of microsomal epoxide hydrolase (EPHX1) gene, and related phenotypes, had any bearing on individual susceptibility to COPD onset and severity. DNA of COPD patients and controls was genotyped for functional polymorphisms of EPHX1 gene (exon 3 Tyr113His, exon 4 His139Arg), and haplotype analysis was performed using PCR-RFLP and PCR-RT techniques. The statistical analysis did not show any significant result about the potential relationship between analyzed SNPs, related phenotypes, and COPD risk and severity. Stable isotope-resolved metabolomics approach was used to study glycolytic pathway alterations induced by chronic CS exposure in lung and liver tissue of an emphysema mouse model. C57BL/6J mice, after CS exposure, were injected via IP injection with glucose tracer containing carbon stable isotope - 13C6-glucose – then, tissues were collected and the incorporation of 13C into metabolites was monitored by mass spectrometry and nuclear magnetic resonance spettroscopy. Lung tissue analyses did not reveal any significant alteration in lung tissue glycolysis of mice exposed to CS. On the other hand, CS may contribute to dysregulated glycolysis, PPP, glycogen synthesis and utilization, in emphysema mouse model liver tissue.
179

Síntese e atividade antifúngica de derivados ftalimídicos ligados a triazóis

ESPÍRITO SANTO FILHO, Albérico Real do 10 February 2015 (has links)
Submitted by Fernanda Rodrigues de Lima (fernanda.rlima@ufpe.br) on 2018-11-06T19:43:59Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Albérico Real do Espírito Santo Filho.pdf: 1868427 bytes, checksum: dc46833dccb7787924921cd0a9aa4bb3 (MD5) / Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2019-01-25T14:39:18Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Albérico Real do Espírito Santo Filho.pdf: 1868427 bytes, checksum: dc46833dccb7787924921cd0a9aa4bb3 (MD5) / Made available in DSpace on 2019-01-25T14:39:18Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Albérico Real do Espírito Santo Filho.pdf: 1868427 bytes, checksum: dc46833dccb7787924921cd0a9aa4bb3 (MD5) Previous issue date: 2015-02-10 / CNPq / FACEPE / CAPES / Os antibióticos e antifúngicos estão incluídos entre os fármacos mais indiscriminadamente utilizados, contribuindo para o crescimento de resistência bacteriana e fúngica, o que provoca uma diminuição da ação antimicrobiana. Esta resistência estimula a pesquisa de novos compostos que apresentem efeitos antimicrobianos, sejam eles compostos naturais obtidos de plantas, de outros organismos ou compostos sintéticos obtidos através de modificações especificas de moléculas quimicamente conhecidas, tornando-as biologicamente mais ativas, como, por exemplo, as imidas cíclicas. Por esta razão, o objetivo deste estudo foi sintetizar e avaliar a atividade antimicrobiana de novos derivados de ftalimidas ligadas a 1,2,3-triazóis. Os compostos foram sintetizados através da reação entre N-2-(azidaetil) ftalimida com cadeia alifática n=2 e alcino aromático. Essa reação foi processada na presença de iodeto de cobre (CuI), trietilamina, dimetilformamida (DMF) à temperatura de 25⁰C, sob energia de ultrassom, baseada na click chemistry. O screening antimicrobiano foi realizado através do teste de difusão em Agar, utilizando bactérias (Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae, Pseudomonas aeruginosa e Salmonella enteritidis) da Coleção de Culturas de Microrganismos do Departamento de Antibióticos/UFPE, os fungos leveduriformes foram do gênero Candida (C. krusei, C. albicans, C. pelliculosa, C. glabrata e C. parapsilosis) os filamentosos (Aspergillus flavus, A. fumigatus, A. niger, Fusarium lateritium, F. solani, F. oxysporum, F. verticillioides, Metarhizium anisopliae, Colletotrichum gloeosporioides, Microsporum gypseum, M. canis, Trichophyton rubrum, T. tonsurans) da Micoteca do Departamento de Micologia/UFPE. Aos discos de papel foram adicionados 50 μL da nova ftalamida (0,6 mg/disco), e em seguida foram colocados em placas de Petri previamente inoculadas com cada microrganismo teste, em meio Agar Nutriente para bactérias a 37⁰C e Agar Sabouraud para fungos a 30⁰C. O experimento foi realizado em duplicata. Os resultados foram avaliados através do diâmetro do halo (mm) de inibição e estão representados como média aritmética. A análise quantitativa foi determinada através da CMI em meio Sabouraud, a anfotericina B foi utilizada como droga padrão. A CMF foi determinada após o 6º dia, As microplacas foram submetidas ao leitor de Elisa com comprimento de onda entre 492 nm e 630 nm, em seguida coradas com Resazurina. Os compostos não foram ativos para as bactérias, bem como para as espécies de C. glabrata, A. niger, F. oxysporum, F. solani. Os maiores halos de inibição foram obtidos nos fungos filamentosos tratados com as novas ftalimidas 1a e 2a, com destaque para ftalimida 2a que mostrou os halos mais expressivos (33–65 mm), inibindo 14 dos 18 fungos testados. A CMI da nova ftalimida 2a variou entre 5 – 20 μg/mL. A nova ftalimida 2a demonstrou ter potente atividade antifúngica podendo servir como protótipo para novas drogas. / Antibiotics and antifungals are included among the most used drugs indiscriminately. This fact contributing to the growth of bacterial or fungal resistance, which causes a decrease in antimicrobial action. This resistance encourages the search for new compounds having antimicrobial effects, like that natural compounds obtained from plants, other organisms or synthetic compounds obtained by chemical modifications of known specific molecules, making them more biologically active, for example, cyclic imides. For this reason, the aim of this study was to synthesize and evaluate the antimicrobial activity of new derivatives of phthalimides connected to 1,2,3- triazoles. Compounds were synthesized by the reaction of N-2- (azidaetil) phthalimide with n=2 aliphatic chain and aromatic alkyne. This reaction was worked in the presence of copper iodide (CuI), triethylamine, dimethylformamide (DMF) the temperature of 25 °C, under ultrasonic energy, based on click chemistry. The antimicrobial screening was performed using the agar diffusion test using bacteria (Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella enteritidis) of Microorganisms Culture Collection of the Department of Antibiotics / UFPE, the yeasts were Candida genus (C. krusei, C. albicans, C. pelliculosa, C. glabrata and C. parapsilosis) and filamentous (Aspergillus flavus, A. fumigatus, A. niger, Fusarium lateritium, F. solani, F. oxysporum, F. verticillioides, Metarhizium anisopliae, Colletotrichum gloeosporioides, Microsporum gypseum, M . canis, Trichophyton rubrum, T. tonsurans) the mycology department/UFPE. The paper discs were added 50 μL of the new phthalimide (0.6 mg/disc), then were placed on inoculated Petri dishes each test microorganism in Nutrient Agar for bacteria to 37 ⁰C and Sabouraud agar medium for fungi 30 ⁰C. The experiment was performed in duplicate. The results were evaluated through the inhibition zone diameter and are represented as the arithmetic mean. Quantitative analysis was determined through the MIC in Sabouraud broth, amphotericin B was used as the standard drug. The CMF was determined after the 6º day. The microplates were subjected to ELISA reader at a wavelength between 492 nm and 630 nm then stained with Resazurin. The compounds were not active for bacterias, as well as C. glabrata, A. niger, F. oxysporum, F. solani. More was observed inhibition zones in three of the five selected yeasts. However the best inhibition zones were obtained in filamentous fungi with the phthalimides 1a e 2a. Where the new phthalimide 2a showed the most significant halos (33 – 65 mm ), inhibiting 14 of the 18 tested fungi. MIC The new phthalimide 2a ranged from 5-20 μg/mL. The new phthalimide 2a shown to have potent antifungal activity may serve as a prototype for new drugs.
180

Estudo da atividade citotÃxica de compostos obtidos do extrato acetÃnico das folhas de Annona muricata L. por fracionamento bioguiado

Francisco StefÃnio Barreto 24 January 2014 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O cÃncer à uma complexa doenÃa de origem genÃtica, resultante de mutaÃÃes em proto-oncogenes e/ou genes supressores tumorais. à considerada uma das principais causas de morte por doenÃa no mundo. Estudos preliminares com o extrato acetÃnico e compostos isolados da espÃcie Annona muricata evidenciaram o seu potencial antitumoral. Annona muricata L. (Annonaceae) à popularmente conhecida como gravioleira; possui ampla distribuiÃÃo, principalmente em regiÃes tropicais. No Brasil, a espÃcie à utilizada como analgÃsico, hipoglicemiante, anti-inflamatÃrio, antitÃrmico, hepatoprotetor, antinevrÃlgico, antiparasitÃrio e antirreumÃtico. O presente trabalho descreve o isolamento de uma acetogenina, denominada anonacina, com anel mono-tetrahidrofurano, fÃrmula molecular C35H64O7 e massa de 596 u.m.a à partir do extrato acetÃnico das folhas da referida espÃcie, atravÃs de prospecÃÃo quÃmica bioguiada pela citotoxicidade usando o ensaio do MTT. Todas as fraÃÃes obtidas e a acetogenina isolada na prospecÃÃo apresentaram potencial citotÃxico nas linhagens tumorais testadas. Os valores de concentraÃÃo inibitÃria mÃdia dessa acetogenina, apresentaram-se na ordem de nano-molar. O ensaio de citotoxicidade mostrou que esse composto apresenta atividade antiproliferativa frente à todas as linhagens tumorais testadas, com CI50 variando de 3.280 nM a 1,56 nM em HL-60 e HCT-116, respectivamente apÃs 72 horas de incubaÃÃo, onde a substÃncia foi mais ativa frente Ãs linhagens HCT-116, OVCAR-8, SF-295 e PC-3M. Essa acetogenina nÃo foi capaz de inibir a proliferaÃÃo de cÃlulas mononucleares do sangue perifÃrico, embora tenha apresentado efeito hemolÃtico em eritrÃcitos de camundongos. A acetogenina AMFA-4, em linhagem de cÃlula de cÃncer colorretal, apresentou efeito citotÃxico dependente da dose e do tempo de incubaÃÃo, sendo capaz de alterar o nÃmero de cÃlulas viÃveis e nÃo-viÃveis apÃs 48 e 72 h de exposiÃÃo. Nesses dois tempos de incubaÃÃo, essa molÃcula foi capaz de alterar a morfologia das cÃlulas HCT-116, onde a mesma teve aumento do nÃcleo e citoplasma e aspecto fusiforme. O presente trabalho mostrou que o extrato acetÃnico das folhas de A. muricata à uma fonte promissora para obtenÃÃo de compostos pertencentes a classe das acetogeninas com atividade citotÃxica relevante em cÃlulas tumorais de origem humana. / Cancer is a complex disease of genetic origin, resulting from mutations in proto-oncogenes and / or tumor suppressor genes. It is considered one of the major causes of death in the world. Preliminary studies with the acetone extract and isolated compounds from the Annona muricata species demonstrated their antitumor potential. Annona muricata L. (Annonaceae), popularly known as soursop, has wide distribution, mainly in the tropical regions. In Brazil, the species is widely used as analgesic, hypoglycemic, anti-inflammatory, antipyretic, hepatoprotective, anti-neuralgic, anti-parasitic and anti-rheumatic. This study reports the isolation of an acetogenin, called Annonacin, with a mono-tetrahydrofuran ring, the molecular formula: C35H64O7 and a mass of 596 u.m.a from the acetone extract of Annona muricata leaves through a bioguided chemical prospecting by cytotoxicity using the MTT assay. All the obtained fractions and the isolated acetogenin showed a cytotoxic potential in the tested tumor cell lines. The values of the mean inhibitory concentration of this acetogenin, had an order of nano-molar. The cytotoxicity assay demonstrated that the compound has anti-proliferative activity against all the tested tumor cell lines, with an IC50 ranging from 3.280 nM to 1.56 nM in HL-60 and HCT-116, respectively, after 72 hours of incubation, where the substance was most active against the following tumor cell lines: HCT-116, OVCAR-8, SF-295 and PC-3M. This acetogenin was not able to inhibit the proliferation of normal peripheral blood cells, although it showed a hemolytic effect on mice erythrocytes. The Annonacin, in a colorectal cancer cell line, showed a cytotoxic effect strongly related to the dose and incubation time, being able to change the number of viable and non-viable cells after 48 and 72 h of exposure. In both incubation times, this molecule was able to modify the HCT-116 cell morphology, where it had an increase on the cytoplasm and nucleus size, besides a fusiform appearance. This study showed that the acetone extract from the A. muricata leaves is a promising source for obtaining compounds belonging to the acetogenins class with significant cytotoxic activity on tumor cells of human origin.

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