Uranium decontamination gains a great importance with the spread of nuclear waste in both soil and water systems across the planet. All known remediation methods of uranium can be exclusively based either on synthetic materials with high adsorbent power and known physical chemistry or life organisms by which the uranium eventually accumulated inside their tissues. In the present thesis, it was attempted to design a rational approach for uranyl removal primarily from waters using the reducing potential of quercetin, which is a plant-derived small organic molecules, along with its photochemical activities. Such approach, which is neither a fully synthetic nor an organism-based approach, was chosen here to avoid disadvantages with both traditional strategies. Here, complexation experiments were designed to assess the use of uranyl-quercetin complexes for the photoreduction of water-soluble U(VI) to insoluble U(IV) by comparing absorption properties of uranyl-quercetin complexes in acetone, water, and hydrophobic bilayer lipid vesicles. The UV-vis data show that uranyl quercetin complex can form in both hydrophobic and hydrophilic environments. In both cases the B-ring band in quercetin structure becomes reduced, red shifted and a pronounced absorption arises in the 400-500 nm range. Such data suggests that U(VI) binds at the 3-OH and 4-carbonyl of ring C of quercetin. Interestingly, the results of UV-Vis spectroscopy part hint at a crucial role of a stable or transiently ionized hydroxyl for the efficient uranyl-dependent photodegradation of quercetin. FTIR spectroscopy absorption changes further demonstrates that the UV-vis-spectroscopic changes are indeed accompanied by changes in the chemical structure of the complex as expected for a uranyl-dependent photodegradation. IR data thus suggest that U(VI) becomes reduced by the photoreaction, rather than merely changing its coordination shell. The frequency shifts in the C=C and C=O absorption range on the other hand are consistent with changes in force constants rather than bond breakage. Upon illumination condition, uranyl quercetin complex in water forms a dark precipitate. Uranyl precipitation and the disappearance of U(VI) IR absorption bands upon illumination further demonstrate that uranyl acts as a redox partner rather than a catalyst in the photoreaction of quercetin. The formation of uranyl-quercetin complexes in the presence of lipidic phases has been addressed experimentally. The complex is partitioned into the hydrophilic/hydrophobic interface of liposomes. Its electronic absorption properties are influenced by the degree of hydrophobicity provided by the adjacent lipid headgroups. The preference of quercetin to associate with hydrophobic microenvironments can thus be exploited to transfer uranyl to the lipid water biomolecular interface. Illumination of the uranyl-quercetin complex in the presence of different liposomes has been performed in this study for the first time, to the best of my knowledge. The data provide evidence that again uranyl is a redox partner for the photodegradation of quercetin also in this microenvironment. Uranyl in an oxidation state smaller than VI is unsoluble in water. Therefore, its quercetin-mediated photoreduaction of uranium provides a method to transfer soluble uranium to the liposome and stabilize the reduced photoproduct. Thereby, uranyl could be removed from solution in an insoluble form using cheap natural compounds. The binding site assignment of uranyl-quercetin complex in acetone have been verified here using NMR spectra and DFT theory. NMR Spectra showed that the observations of broadened and narrow bands in the NMR spectra of quercetin, upon complexation with uranyl, support an intramolecular exchange or site exchange within the quercetin molecule. Moreover, the complexation takes place around the carbonyl group with U(VI) exhibiting two possibly coordination modes, involving the carbonyl and the adjacent O(H) groups. This has been also confirmed from the DFT calculations. Finally, interaction experiments of uranyl-quercetin complex with DNA have been performed to assess an alternative uranyl-trapping and photoreduction system. The data show that consecutive addition of quercetin and uranyl destabilizes DNA. However, a preformed uranyl quercetin complex has very little effect on DNA structure. On the other hand, quercetin and uranyl appear to bind to DNA as a preformed complex in the loop portion of hairpin DNA. Therefore, also HP DNA is expected to be a suitable but less effective trapping system for the uranyl quercetin complex and its potential photoproducts.

Universiẗat, Diss., 2001--Münster (Westfalen).

The effects of three oral dosages (0.4 mg, 0.8 mg, and 1.6 mg) of quercetin on Colon-25 tumors implanted in Balb-c mice were studied. The data in this study show that: (1) certain dosages of quercetin in alcohol solutions, reduces the weight, and size of implanted Colon-25 tumors in Balb-c mice, (2) these same dosages of quercetin all produce a profound neutrophilia combined with a significant lymphopenia at day 20 post-implantation, and (3) there was relatively little evidence of histological changes in the quercetin-treated tumor section which would indicate that the action(s) of quercetin is primarily at the subcellular level probably within the nuclei of the tumor cells.

Doctor of Philosophy / Department of Chemistry / Duy H. Hua / The first chapter of the thesis involves the design, synthesis, and anti-influenza activity of quercetin derivatives. Influenza viruses are important pathogens that cause respiratory infections in humans and animals. In addition to vaccination, antiviral drugs against influenza virus play a significant role in controlling viral infections by reducing disease progression and virus transmission. Plant derived polyphenols are associated with antioxidant activity, anti-carcinogenic, and cardio- and neuro-protective actions. Some polyphenols, such as resveratrol and epigallocatechin gallate (EGCG), showed significant anti-influenza activity in vitro. The antiviral effects of isoquercetin were greater than that of quercetin with lower IC[subscript]5[subscript]0 values and higher in vitro therapeutic index. Various phenolic esters, alkoxy and aminoalkoxy derivatives of quercetin were synthesized by functionalization of C3, C3’, and C5 hydroxyl groups. Antiviral activities of these synthesized compounds were tested against influenza virus (porcine H1N1 strain). Quercetin-3-gallate which is structurally similar to EGCG showed greater antiviral activity among the synthesized compounds. Its antiviral activity was comparable to that of EGCG with better in vitro therapeutic index. Second chapter in the thesis involves the progress towards the synthesis of mini graphenes like hexa-peri-benzocoronene cyclophane (HBCC). Bilayered graphenes are highly conducting materials with potential application in electronic devices and in lithium ion batteries. Despite great potential, bilayer graphenes with defined distance between the two layers have not been achieved through chemical synthesis. Chemical synthesis of hexa-peri-benzocorenene cyclophane (HBCC) from commercially available p-xylene was carried out. Final product, presumably compound 90 (the structure has not been completely characterized), is insoluble in all tested solvents including aqueous acids and organic solvents such as DMSO, DMF, benzene, 1,2-dichlorobenzene, dichloromethane, THF, hexanes and diethyl ether. The insoluble nature of the final product restricted the analysis to UV-visible spectroscopy. Synthesis of soluble analog incorporating the long chain ether groups is being investigated in Dr. Hua’s laboratory.

O aumento da incidência de câncer tem sido expressivo nas ultimas décadas na população mundial, sendo confirmada segundo previsões de entidades nacionais e internacionais da área da saúde. O surgimento do câncer é influenciado predominantemente por fatores genéticos e ambientais, sendo manifestado com mais intensidade na população adulta. As principais modalidades para tratamento do câncer (radioterapia, quimioterapia e cirurgia) podem ser usadas individualmente ou em combinação, dependendo do tipo de câncer. Entre as modalidades citadas, a radioterapia é aquela com maior abrangência no tratamento de pacientes, tendo associado um efeito colateral denominado radiodermite que possui graus de severidade que variam de um simples eritema até radionecrose. As manifestações da radiodermite poderão ocorrer durante o tratamento ou após as seções de radioterapia, ambas as situações terão grande relevância na qualidade de vida do paciente e no custo social. Uma das terapias alternativas estudadas para atenuar a radionecrose é a aplicação cutânea de quercetina. Para avaliar a efetividade desta atenuação foi elaborado um modelo animal de radionecrose a ser utilizado em ratos Wistar. Após estudos in vitro, foi possível determinar as concentrações e momento de aplicação da quercetina, redundo o número de animais a serem utilizados nos experimentos in vivo. Com a aplicação tópica de 250 mol/L de quercetina, uma hora antes da irradiação gama com dose de 85 Gy, foi possível minimizar os efeitos secundários da radiação, evitando a formação de radionecrose e uma tendência de atenuar a área da ferida nos animais estudados, em comparação aos animais irradiados sem a aplicação da mesma. / The increased incidence of cancer has been significant in recent decades in the world population, as confirmed by national and international institutions in the health area. The emergence of cancer is influenced, predominantly by genetic and environmental factors, being manifested more in the adult population. The main modalities for cancer treatment (radiotherapy, chemotherapy and surgery) may be used separately or in combination, depending on the type of cancer. Among the methods mentioned, radiation therapy is the one more broadly used for the treatment of patients, having an associated side effect called radiodermatitis, which has degrees of severity ranging from simple erythema to radionecrosis. The manifestation of radiodermatitis may occur during the treatment or after the radiotherapy sessions: both situations have great relevance in the patient\'s quality of life and social costs. One of the studied alternative therapies for attenuating the radionecrosis is the quercetin cutaneous application. One of the alternative therapies, studied to mitigate or eliminate the radionecrosis, is based on the topical application of quercetin. To evaluate the effectiveness of this mitigation, an animal model of radionecrosis was developed, to be used in Wistar rats. After in vitro studies, the quercetin concentrations and time of application were determined, reducing the number of animals, when in vivo experiments are carried out. With the topical application of 250 mol/L of quercetin, one hour prior to gamma irradiation, at a dose of 85 Gy, the side effects of radiation were minimized, avoiding the formation of radionecrosis. There was, also, a tendency to attenuate the wound area in the studied animals, compared to the irradiated animals without the quercetin application.

Ying Zheng. / Thesis submitted in: October 2001. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 84-90). / Abstracts in English and Chinese. / ABSTRACT --- p.ii / 中文摘要 --- p.iv / ACKNOWLEDGEMENTS --- p.vi / TABLE OF CONTENTS --- p.vii / LIST OF FIGURES --- p.x / LIST OF TABLES --- p.xii / ABBREVIATIONS --- p.xiii / Chapter CHAPTER 1. --- Introduction --- p.1 / Chapter 1.1. --- Rationale of the Study --- p.2 / Chapter 1.2. --- Flavonoids --- p.3 / Chapter 1.2.1. --- Introduction --- p.3 / Chapter 1.2.2. --- Potential Health Effects --- p.5 / Chapter 1.2.3. --- Absorption Studies --- p.6 / Chapter 1.3. --- Drug Absorption --- p.9 / Chapter 1.3.1. --- Pathways and Mechanisms of Intestinal Absorption --- p.9 / Chapter 1.3.2. --- Transporters Potentially Involved in the Absorption of Flavonoids --- p.11 / Chapter 1.3.2.1. --- Glucose Transporters --- p.11 / Chapter 1.3.2.2. --- Multidrug Resistance Systems --- p.13 / Chapter 1.3.2.2.1. --- P-glycoprotein --- p.13 / Chapter 1.3.2.2.2. --- Non-P-glycoprotein Efflux Mechanisms --- p.15 / Chapter 1.4. --- In vitro Models to Study Absorption --- p.15 / Chapter 1.4.1. --- Ussing Chamber --- p.16 / Chapter 1.4.2. --- Cultured Cells --- p.17 / Chapter 1.4.2.1. --- Choice of Cells --- p.17 / Chapter 1.4.2.2. --- Caco-2 Cell Monolayers as in vitro Model --- p.18 / Chapter 1.4.2.3. --- Correlation Between in vivo Absorption and in vitro Permeability Coefficients --- p.19 / Chapter 1.4.3. --- Everted Gut Sacs --- p.20 / Chapter 1.4.4. --- Brush Border Membrane Vesicles (BBMVs) --- p.20 / Chapter 1.4.5. --- In situ Experiments --- p.21 / Chapter 1.5. --- Aims and Scope of the Present Study --- p.23 / Chapter CHAPTER 2. --- Materials & Methods --- p.25 / Chapter 2.1. --- Materials --- p.26 / Chapter 2.1.1. --- Chemicals --- p.26 / Chapter 2.1.2. --- Materials for Cell Culture --- p.27 / Chapter 2.1.3. --- Instruments --- p.28 / Chapter 2.1.4. --- Animals --- p.28 / Chapter 2.2. --- Methods --- p.29 / Chapter 2.2.1. --- Preformulation Studies on Selected Flavonoids --- p.29 / Chapter 2.2.1.1. --- Determination of Stability --- p.29 / Chapter 2.2.1.2. --- Thermal Analysis --- p.29 / Chapter 2.2.1.3. --- Determination of Solubility --- p.29 / Chapter 2.2.1.4. --- Determination of Partition Coefficient --- p.30 / Chapter 2.2.2. --- Validation of in vitro Models --- p.30 / Chapter 2.2.2.1. --- Ussing Chamber --- p.30 / Chapter 2.2.2.1.1. --- Tissue Preparation --- p.30 / Chapter 2.2.2.1.2. --- Electrical Measurements --- p.31 / Chapter 2.2.2.1.3. --- Experimental Protocols --- p.31 / Chapter 2.2.2.1.4. --- Calculations of Permeability --- p.32 / Chapter 2.2.2.2. --- Caco-2 Cell Monolayers --- p.32 / Chapter 2.2.2.2.1. --- Preparation of Caco-2 Cell Monolayers --- p.32 / Chapter 2.2.2.2.2. --- Validation of Caco-2 Cell Monolayers --- p.32 / Chapter 2.2.2.2.3. --- Calculation of Permeability --- p.34 / Chapter 2.2.3. --- Transport Studies of Selected Flavonoids --- p.34 / Chapter 2.2.4. --- Brush Border Membrane Vesicles (BBMVs) --- p.35 / Chapter 2.2.4.1. --- Preparation of BBMVs --- p.35 / Chapter 2.2.4.2. --- Uptake of D-glucose by BBMVs --- p.38 / Chapter 2.2.4.3. --- Counting of 3H-D-glucose in BBMVs --- p.39 / Chapter 2.2.4.4. --- Calculation of Glucose Uptake --- p.39 / Chapter 2.2.4.5. --- Total Protein Assay --- p.40 / Chapter 2.2.5. --- Analytical Methods --- p.41 / Chapter 2.2.5.1. --- HPLC Analysis --- p.41 / Chapter 2.2.5.1.1. --- HPLC Analysis of Quercetin and Related Glycosides --- p.41 / Chapter 2.2.5.1.2. --- HPLC-MS Analysis of Degradation Products --- p.41 / Chapter 2.2.5.1.3. --- HPLC Analysis of Propranolol --- p.42 / Chapter 2.2.5.2. --- UV Analysis --- p.42 / Chapter 2.2.5.3. --- Fluorescence Analysis --- p.42 / Chapter 2.2.5.4. --- Analysis of Radiolabeled Markers --- p.42 / Chapter 2.2.6. --- Statistical Analysis --- p.42 / Chapter CHAPTER 3. --- Results & Discussions --- p.44 / Chapter 3.1. --- Preformulation Studies on Selected Flavonoids --- p.45 / Chapter 3.1.1. --- Stability --- p.45 / Chapter 3.1.2. --- Thermal Analysis --- p.52 / Chapter 3.1.3. --- Aqueous Solubility --- p.58 / Chapter 3.1.4. --- Partition Coefficient --- p.61 / Chapter 3.2. --- Validation of in vitro Models --- p.62 / Chapter 3.2.1. --- Selection of Marker Compounds --- p.62 / Chapter 3.2.2. --- Validation of Ussing Chamber --- p.63 / Chapter 3.2.3. --- Validation of Caco-2 Cell Monolayers --- p.64 / Chapter 3.2.3.1. --- Integrity of Caco-2 Cell Monolayers --- p.64 / Chapter 3.2.3.2. --- Permeabilities of Marker Compounds --- p.65 / Chapter 3.2.3.3. --- Selection of in vitro Models --- p.66 / Chapter 3.2.3.3. --- Validation of Sodium/Glucose Cotransporter (SGLT1) --- p.66 / Chapter 3.3. --- Transport Studies of Quercetin and Related Flavonoids --- p.67 / Chapter 3.3.1. --- Direction of Transport --- p.67 / Chapter 3.3.2. --- Concentration Dependence --- p.69 / Chapter 3.3.3. --- Inhibition of P-gp by Verapamil --- p.71 / Chapter 3.3.4. --- Metabolism of Quercetin in Caco-2 Cells --- p.72 / Chapter 3.3.5. --- Studies of Quercetin-3-glucoside with Sugar Transporters --- p.73 / Chapter 3.4. --- Uptake of D-glucose by Brush Border Membrane Vesicles (BBMVs) --- p.75 / Chapter CHAPTER 4. --- Conclusions --- p.80 / References --- p.83

Submitted by Francine Silva (francine.silva@unipampa.edu.br) on 2019-03-26T18:42:20Z No. of bitstreams: 1 Caracterização da atividade entomotóxica induzida pelo extrato metanólico de araucaria angustifolia em baratas da espécie phoetalia pallida.pdf: 1288498 bytes, checksum: 743a39a2337c5be31393482af81a2fb6 (MD5) / Made available in DSpace on 2019-03-26T18:42:21Z (GMT). No. of bitstreams: 1 Caracterização da atividade entomotóxica induzida pelo extrato metanólico de araucaria angustifolia em baratas da espécie phoetalia pallida.pdf: 1288498 bytes, checksum: 743a39a2337c5be31393482af81a2fb6 (MD5) Previous issue date: 2012-01-05 / Neste trabalho foi demostrado, pela primeira vez, a atividade inseticida do extrato metanólico de Arauacaria angustifolia (Bert.) O. Kuntze 1898 (AAME) e seu metabólito secundário, a quercetina, em baratas da espécie Phoetalia pallida. A investigação fitoquímica preliminar, realizada através da Cromatografia em Camada Delgada (CCD), demonstrou a presença do flavonóide quercetina no AAME. A confirmação da presença da quercetina no extrato foi obtida por Cromatografia Líquida de Alta Eficiência (HPLC), com tempo de retenção em 10.6min. A determinação de fenólicos totais indicou uma alta concentração destes compostos (1,03%) no AAME. Os ensaios para a determinação da dose letal mínima (DLM) em baratas da espécie P. pallida, confirmaram a atividade inseticida do extrato em doses a partir de (800g/g de animal). A mesma atividade foi demonstrada pela quercetina (80μg/g), porém, com maior potência comparada ao AAME. Ambos, AAME (200μg/g) e quercetina (40μg/g) foram eficazes em bloquear significativamente a atividade da enzima acetilcolinesterase no inseto. Os ensaios de atividade biológica demonstram uma atividade neurotóxica do AAME e da quercetina, tanto em nível central quanto periférico do inseto. Dessa forma, o AAME (200μg/g) e a quercetina (40μg/g) induziram um aumento no tempo total de grooming realizado pelo inseto, (138.11±5s /30min; p<0.05 e 2305s/30min; p<0.05), respectivamente. A administração de Atropina (40μg/g), previamente à adição de quercetina (40μg/g) induziu um aumento significativo na atividade de grooming quando comparado à quercetina isoladamente (3503s/30min; p<0.05). Quando o animal foi pré-tratado com Metoctramina (40μg/g), um inibidor seletivo de receptores colinérgicos M2-M3, observou-se o maior aumento no tempo de grooming induzido pela quercetina (40μg/g) (6008s/30min; p<0.01 teste t). Por outro lado, o pré-tratamento com o SCH23390 (40μg/g), um inibidor seletivo de receptores DA-D1, reduziu significativamente o grooming induzido pela quercetina (40μg/g) (906s/30min; p<0.05). A administração de Tiramina (40μg/g) e hidroxilamina (40μg/g), um inibidor da guanilato ciclase, aumentaram significativamente o tempo de grooming induzido pela quercetina (20415s/30min; p<0.05) e (32515s/30min; p<0.01), respectivamente. Quando ensaiados em preparação músculo coxal-adutor metatorácico de P. pallida, tanto o AAME (200μg/g de animal) quando a quercetina (40μg/g) induziram bloqueio neuromuscular irreversível em 120 min de registros (50±9%; p<0.05 e 100±7%; p<0.05), respectivamente. Este último resultado indica uma ação direta do extrato de A. angustifolia sobre o Sistema Nervoso Periférico da barata. Os resultados mostrados neste trabalho validam a atividade inseticida do AAME em P. pallida. Compostos fenólicos presentes no extrato provavelmente estão envolvidos na atividade inseticida, como demonstrado pela quercetina. O mecanismo de ação inseticida é complexo, e envolve tanto a neurotoxicidade sobre o Sistema Nervoso Central quanto sobre o Periférico. A ativação de uma cascata de eventos que se inicia com a ativação de autoreceptores muscarínicos no soma dopaminérgico e/ou em interneurônios colinérgicos, induziria um aumento da concentração do IP3 citosólico bem como do Ca2+ favorecendo a liberação da dopamina no sistema nervoso central do inseto. Quanto à atividade bloqueadora neuromuscular, estudos mais detalhados usando-se moduladores farmacológicos de receptores de glutamato e do ácido-gama-aminobutírico (GABA) poderão elucidar esse efeito. / We have demonstrated, for the first time, the insecticidal activity of Araucaria angustifolia methanolic extract (AAME) and one of its chemical secondary metabolites, quercetin against Phoetalia pallida. Preliminary investigation of AAME phytochemical compounds by thin layer chromatography showed the presence of quercetin. The total phenolic contents measured by spectrophotometry showed high content of phenolic acids (1,03%). High Performance Liquid Cromatography (HPLC) proved the presence of quercetin that was eluted at 10.6min. In doses ranging from 800-1200g/g (animal weight) AAME was effective to kill all cockroaches injected after 24 hours. Quercetin was more effective than AAME whole extract being lethal at 80g/g (animal weight). Both AAME (200μg/g of animal weight) and quercetin (40μg/g of animal weight) were able to induce a significative blockage at insect acetylcholinesterase activity. these compounds also induced increase in the time of grooming activity (138.11±5s /30min; p<0.05) and (2305s/30min; p<0.05), respectively. The injection of atropine (40μg/g) combined with quercetin (40μg/g of animal weight) significantly increased the grooming levels to over the control values of quercetin (3503s/30min; p<0.05). When methoctramine (40μg/g), a selective inhibitor of M2-M3 cholinergic receptor was combined with quercetin (40μg/g of animal weight) there was the highest increase on the grooming pattern (6008s/30min; p<0.01). When the SCH 23390 (40μg/g), a selective DA-D1 receptor blocker was administrated 15min earlier the treatment with quercetin (40μg/g) there was a significative inhibition of the grooming levels (906s/30min; p<0.05). Treatments with Tyramine (40μg/g) and Hydroxylamine (40μg/g), a Guanylate Cyclase (GC) induced a significative increase in the quercetin-induced grooming activity (20415s/30min; p<0.05) and (32515s/30min; p<0.01), respectively. Both AAME and quercetin were able to complete inhibit cockroach neuromuscular transmission in 120 min recordings (50±9% n=6; p<0.05) and (100±7% n=10; p<0.05), respectively . The later result, point out to a direct action of the extract on insect peripheral nervous system. The results presented here validate the insecticide activity of A. angustifolia methanolic extract in P. pallida. Phenolic compounds presents in this extract era likely to be involved in the insecticide activity of AAME. The mechanism of insecticide activity is complex and involve both Central and Peripheral Nervous System. The activation of events that initiate with the activation of Muscarinic Auto-receptors and/or cholinergic interneurons, could lead to an increase of cytosolic IP3 and Ca2+ concentration which could induce a dopamine release in the insect Nervous System. Concerning to the neuromuscular blockage, a further pharmacological investigation would be necessary to clarify this effect. However, one cannot disregard a direct action of quercetin on insect NMDA receptors.

O aumento da incidência de câncer tem sido expressivo nas ultimas décadas na população mundial, sendo confirmada segundo previsões de entidades nacionais e internacionais da área da saúde. O surgimento do câncer é influenciado predominantemente por fatores genéticos e ambientais, sendo manifestado com mais intensidade na população adulta. As principais modalidades para tratamento do câncer (radioterapia, quimioterapia e cirurgia) podem ser usadas individualmente ou em combinação, dependendo do tipo de câncer. Entre as modalidades citadas, a radioterapia é aquela com maior abrangência no tratamento de pacientes, tendo associado um efeito colateral denominado radiodermite que possui graus de severidade que variam de um simples eritema até radionecrose. As manifestações da radiodermite poderão ocorrer durante o tratamento ou após as seções de radioterapia, ambas as situações terão grande relevância na qualidade de vida do paciente e no custo social. Uma das terapias alternativas estudadas para atenuar a radionecrose é a aplicação cutânea de quercetina. Para avaliar a efetividade desta atenuação foi elaborado um modelo animal de radionecrose a ser utilizado em ratos Wistar. Após estudos in vitro, foi possível determinar as concentrações e momento de aplicação da quercetina, redundo o número de animais a serem utilizados nos experimentos in vivo. Com a aplicação tópica de 250 mol/L de quercetina, uma hora antes da irradiação gama com dose de 85 Gy, foi possível minimizar os efeitos secundários da radiação, evitando a formação de radionecrose e uma tendência de atenuar a área da ferida nos animais estudados, em comparação aos animais irradiados sem a aplicação da mesma. / The increased incidence of cancer has been significant in recent decades in the world population, as confirmed by national and international institutions in the health area. The emergence of cancer is influenced, predominantly by genetic and environmental factors, being manifested more in the adult population. The main modalities for cancer treatment (radiotherapy, chemotherapy and surgery) may be used separately or in combination, depending on the type of cancer. Among the methods mentioned, radiation therapy is the one more broadly used for the treatment of patients, having an associated side effect called radiodermatitis, which has degrees of severity ranging from simple erythema to radionecrosis. The manifestation of radiodermatitis may occur during the treatment or after the radiotherapy sessions: both situations have great relevance in the patient\'s quality of life and social costs. One of the studied alternative therapies for attenuating the radionecrosis is the quercetin cutaneous application. One of the alternative therapies, studied to mitigate or eliminate the radionecrosis, is based on the topical application of quercetin. To evaluate the effectiveness of this mitigation, an animal model of radionecrosis was developed, to be used in Wistar rats. After in vitro studies, the quercetin concentrations and time of application were determined, reducing the number of animals, when in vivo experiments are carried out. With the topical application of 250 mol/L of quercetin, one hour prior to gamma irradiation, at a dose of 85 Gy, the side effects of radiation were minimized, avoiding the formation of radionecrosis. There was, also, a tendency to attenuate the wound area in the studied animals, compared to the irradiated animals without the quercetin application.

Quercetin (Q), a water-soluble flavonoid that is ubiquitous to foods of plant origin is postulated to protect against colon cancer due to its antioxidant activity. In contrast, we have shown that a dietary combination of fish oil (FO; n-3 fatty acids) and pectin may protect against colon cancer by decreasing endogenous antioxidant enzyme activities leading to increased reactive oxygen species (ROS), an inducer of apoptosis. We hypothesized that adding an antioxidant to a FO diet may negate the beneficial effects of FO by counteracting FO effects on colonocyte redox status. To test this, we provided 40 rats with FO or CO (fiber = pectin) diets with Q being 0 or 0.45% of the diet for 10 wk. All rats were injected with azoxymethane (AOM) on d 21 and 28. Measurements included: aberrant crypt (AC) enumeration (colon cancer marker); apoptosis (TUNEL assay); catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities; reduced and oxidized glutathione concentrations (GSH/GSSG); and oxidative DNA damage (8-OHdG adducts). AC numbers were lower in FO vs CO rats (p<0.0001), but tended to increase for FO diets containing Q (P<0.098). The apoptotic index was higher (p<0.0001) when Q was added to the FO and CO diets. Total SOD (lipid main effect, p=0.0136) and GPX activity (p=0.0025) was elevated in CO rats. CAT activity was higher (p=0.0204) in FO rats, however Q diminished this effect. GSH was not affected by diet; yet, GSSG accumulated (p=0.0554) in CO rats with Q as compared to CO rats without Q. The GSH/GSSG ratio was lower (p=0.0314) in CO rats than in FO rats. There was no difference in 8-OHdG adduct levels in FO vs CO rats, however, Q decreased 8-OHdG adducts in CO rats (p=0.0428). Despite increasing apoptosis, Q did not significantly lower AC formation. These data suggest that the distinct effects of the CO/Q and FO/Q combinations are functioning through different mechanisms to induce apoptosis. The long-term consequences of adding antioxidants such as Q to a diet thought to exert its anticancer effect through a pro-oxidant mechanism are unknown and deserve further study.

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Agradecemos a compreensão. on 2016-05-13T16:24:02Z (GMT) / Submitted by BRUNO RAFAEL PEREIRA LOPES null (brunorpl@hotmail.com) on 2016-05-16T19:16:16Z No. of bitstreams: 1 Dissertação numerado FINAL Capa Dura versão folha de aprovação.pdf: 7936969 bytes, checksum: b93b6e0c25c357b92f65cec6ffb9e789 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-05-18T13:48:58Z (GMT) No. of bitstreams: 1 lopes_brp_me_assis.pdf: 7936969 bytes, checksum: b93b6e0c25c357b92f65cec6ffb9e789 (MD5) / Made available in DSpace on 2016-05-18T13:48:58Z (GMT). No. of bitstreams: 1 lopes_brp_me_assis.pdf: 7936969 bytes, checksum: b93b6e0c25c357b92f65cec6ffb9e789 (MD5) Previous issue date: 2016-03-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No mundo, estima-se que exista cerca de 12 milhões de casos graves e 3 milhões de casos muito graves de infecção do trato respiratório inferior em crianças anualmente. Dentre os agentes etiológicos destas infecções, o vírus sincicial respiratório humano (hRSV) é a principal causa de internações infantis em países desenvolvidos, agravando os casos de bronquiolite, pneumonia e infecções pulmonares obstrutivas crônicas em pessoas de todas as idades, principalmente crianças e idosos. Estudos preliminares demonstraram que a Quercetina possui ação virucida sobre hRSV, além de inibir sua replicação. Entretanto, não se tem conhecimento do quão promissora é a atividade antiviral de Quercetina sobre o vírus hRSV ou mesmo se esta atividade poderia ser melhorada através de mudanças químicas em sua estrutura molecular. Assim, o objetivo deste trabalho foi estabelecer o índice de seletividade (IS) para Quercetina e seus derivados acetilados durante a infeção por hRSV através de ensaios in vitro. A análise de viabilidade celular através da adição do sal de MTT determinou os valores de CC50 para Quercetina na presença/ausência do vermelho de fenol (85 e 11,4 µM, respectivamente). Dentre as condições testadas, Quercetina apresentou atividade virucida (16-30% de proteção celular) sem apresentar efeitos no pré ou pós-tratamentos. Os valores de CC50 dos compostos derivados Q1 e Q2 foram 37,1 µM e 53,15 µM, respectivamente. O composto Q1 apresentou atividade anti-hRSV nos protocolos virucida e pós-tratamento (60-90%; 4-8 µM). O composto Q2 não apresentou atividade anti-hRSV relevante em nenhuma das condições testadas. A proteção celular apresentada pela Quercetina não possibilitou o cálculo de IS (CC50/CE50) o que nos sugere que este composto não seja um promissor agente anti-hRSV. Os índices de Seletividade calculados para o composto Q1 nos protocolos virucida e pós-tratamento foi de 9,27. O conjunto de resultados obtidos neste trabalho apresenta menor citotoxicidade e melhor performance anti-hRSV do composto Q1 em relação à Quercetina comercial. Estes dados nos estimulam a dar continuidade aos estudos do composto Q1 com o intuito de melhorarmos sua atividade antiviral e assim propormos um novo composto que seja efetivos na prevenção e/ou tratamento das infecções por hRSV. / Worldwide, is estimated that there are about 12 million serious cases and 3 million severe cases of lower respiratory tract infection in children every year. Among the etiological agents of these infections, respiratory syncytial virus (hRSV) is the leading cause of children's hospitalizations in developed countries, aggravating cases of bronchiolitis, pneumonia and chronic obstructive pulmonary infections in people of all ages, especially children and the elderly. Preliminary studies demonstrated that Quercetin has virucidal action on hRSV, and inhibits replication. However, we do not know how promising is the antiviral activity of Quercetin on the hRSV. The objectives of this work is to understand the action of Quercetin and some of its derivatives acetylated on the steps of the replicative cycle of hRSV, determining the selectivity index for each compound. The development of this project will assist in the search for effective compounds in the prevention and/or treatment of hRSV infections. In the cytotoxicity assays, Quercetin showed CC50 values variable depending on the presence/absence of phenol red (11.4 and 85 μM respectively). Among the concentrations tested Quercetin only showed a slight virucidal activity (16-30% concentration 5-10 μM). The CC50 values were derived compounds 37.1 μM for Q1 and Q2 to 53.15 μM. Compound Q1 showed anti-hRSV activity in virucidal and post-treatment protocol (60-90% at 4-8 μM). The Q2 compound showed no anti-hRSV relevant activity. The presence or absence of phenol red had great influence in determining the CC50 values of Quercetin (11.4 μM and 85 μM with phenol red). In addition, Quercetin showed little (virucidal protocol without phenol) or no anti-hRSV activity. Thus it has not been possible to establish the EC50 of Quercetin and determine its selectivity index (SI). The Q1 compound showed a greater CC50 value (37.1 μM) and relevant anti-hRSV activity in post-treatment and virucidal protocols (SI 9.27). Among the compounds tested, Q2 showed the highest value of CC50 (53.15 μM without phenol) however, had little or no anti-hRSV activity, making it impossible to determine their SI.