Folate blood levels in North America have dramatically increased over the past decade owing to folic acid (FA) fortification and widespread supplement use. Furthermore, over 50% of newly diagnosed colorectal cancer (CRC) patients use vitamin supplements containing FA while receiving chemotherapy whose mechanisms of action are based on interruption of folate metabolism. This study therefore investigated whether FA supplementation can affect chemosensitivity of human colon cancer cells to 5FU, the cornerstone of CRC treatment, using a xenograft model. FA supplementation was associated with a non-dose dependent decrease in chemosensitivity, where mice receiving 8 mg FA did not respond to 5FU and had greater tumor growth with treatment, compared to 2 (control) or 25 mg FA. Results of this study pose concern given the drastically increased intake of FA, particularly among recently diagnosed CRC patients, and from mandatory fortification. Further studies are warranted to confirm our findings and to elucidate underlying mechanisms.

Folate blood levels in North America have dramatically increased over the past decade owing to folic acid (FA) fortification and widespread supplement use. Furthermore, over 50% of newly diagnosed colorectal cancer (CRC) patients use vitamin supplements containing FA while receiving chemotherapy whose mechanisms of action are based on interruption of folate metabolism. This study therefore investigated whether FA supplementation can affect chemosensitivity of human colon cancer cells to 5FU, the cornerstone of CRC treatment, using a xenograft model. FA supplementation was associated with a non-dose dependent decrease in chemosensitivity, where mice receiving 8 mg FA did not respond to 5FU and had greater tumor growth with treatment, compared to 2 (control) or 25 mg FA. Results of this study pose concern given the drastically increased intake of FA, particularly among recently diagnosed CRC patients, and from mandatory fortification. Further studies are warranted to confirm our findings and to elucidate underlying mechanisms.

No description available.

No description available.

A molécula 5-fluorouracil (5FU) é muito utilizada em tratamentos de câncer. Seu espectro de absorção é caracterizado por duas bandas de diferentes intensidades, as transições n-p* e p-p*, e seu estudo em diferentes solventes é de considerável importância para compreender a fotofísica do estado excitado. Este é o primeiro passo essencial para obter a caracterização da dinâmica de emissão. Neste trabalho, nós estudamos teoricamente o espectro de absorção da 5FU em dois solventes, água e acetonitrila, usando o método Sequential Quantum Mechanics/ Molecular Mechanics (SQM/MM). Uma etapa importante para uma simulação realista é a polarização do soluto pelo solvente. Neste estudo, esta polarização foi obtida usando dois modelos: Polarizable Continuum Model (PCM), que é uma alternativa simples e um método iterativo usando Average Solvent Electrostatic Configuration (ASEC). Após isso, simulações usando Monte Carlo Metrópolis no ensemble NVT em condições normais de temperatura e pressão foram realizadas e configurações estatisticamente descorrelacionadas separadas para subsequentes cálculos de Mecânica Quântica usando diversos métodos: Configuration Interaction (CI), Time Dependent Density Functional Theory (TD-DFT) e um método semi-empírico (INDO/CIS). Os espectros calculados em ambos os solventes foram obtidos em mais de uma aproximação: contínua, discreta e explícita. Os resultados estão em boa concordância com os valores experimentais e enfatizam a importância da inclusão de moléculas de solvente explícitas nos cálculos. Nós especialmente notamos que em solventes, a transição n-p* é deslocada para o azul enquanto a transição p-p* é deslocada para o vermelho, indicando uma tendência para reversão dessas duas bandas se comparadas à fase gasosa. Isto aponta para diferenças na fotofísica, dependendo da polaridade do solvente. Os resultados também permitem uma avaliação dos diferentes procedimentos teóricos utilizados. / The 5-fluorouracil molecule is very used in cancer treatment. Its absorption spectrum is characterized by two broad bands of different intensities, the n-p* and p-p* transitions, and its study in different solvents is of considerable importance for the understanding of the photophysics of the excited state. It is the first essential step for obtaining the characterization of the emission dynamics. In this work we have theoretically studied the absorption spectrum of 5FU in two solvents, water and acetonitrile, using the Sequential Quantum Mechanics/Molecular Mechanics method (SQM/MM). An important step for a realistic simulation is the polarization of the solute by the solvent. In this study, this polarization was obtained by using two models: Polarizable Continuum Model (PCM), which is a simple alternative, and an iterative method using the Average Solvent Electrostatic Configuration (ASEC). After this, Monte Carlo Metropolis simulations in the NVT ensemble in normal conditions of temperature and pressure were made and statistically uncorrelated configurations sampled for the subsequent Quantum Mechanics calculations using several methods: Configuration Interaction (CI), Time Dependent Density Functional Theory (TD-DFT) and a semiempirical method (INDO/CIS). The calculated spectra in both solvents were obtained using more than one approach: continuum, discrete and explicit. The results are in good agreement with experimental values and emphasize the importance of explicitly including solvent molecules. We specially note that in solvents, the n-p* is blue-shifted and the p-p* transition is red-shifted leading to a tendency for reversal of these two bands compared to gas phase. This points to differences in the photophysics, depending on the solvent polarity. The results also allow an evaluation of the different theoretical procedures used.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / Este trabalho teve como objetivo elucidar o efeito do 5-fluorouracil (5-FU) em glÃndulas salivares maiores, fluxo e composiÃÃo salivar, utilizando um modelo prà estabelecido de mucosite oral (MO) induzida em hamsters. A MO foi induzida por administraÃÃes intraperitoneais de 5-FU, nos 1 e 2 dias do modelo experimental (60mg/kg e 40mg/kg, respectivamente). No 4 dia, os animais foram submetidos ao trauma mecÃnico em mucosa jugal. Previamente a coleta das glÃndulas salivares, foi administrado pilocarpina (10mg/kg) para a medida do fluxo salivar e posterior coleta da saliva. As glÃndulas salivares maiores foram coletadas para anÃlise histopatolÃgica, contagem das cÃlulas inflamatÃrias, avaliaÃÃo do estresse oxidativo (SOD, CAT, nitrito/nitrato, NPSH e MDA), quantificaÃÃo de citocinas prÃ-inflamatÃrias (TNF-α e IL-1β) e investigaÃÃo de morte e proliferaÃÃo celular celular, nÃveis de CAT, SOD, lisozima e IgA foram avaliados em amostras de saliva. Os resultados mostraram que o 5-FU reduziu significativamente o fluxo salivar estimulado pela pilocarpina no 4 dia do modelo experimental, associado ao aumento dos nÃveis de SOD na saliva. No 10 dia, foi observada recuperaÃÃo do fluxo salivar, concomitante a reduÃÃo dos nÃveis de lisozima de saliva. AlÃm disso, o 5-FU promoveu vacuolizaÃÃo na glÃndula parÃtida e edema periductal na glÃndula submandibular no 4 dia, associada ao aumento do influxo de cÃlulas inflamatÃrias, principalmente no 4 dia na glÃndula submandibular e nos 4 e 10 dias na glÃndula parÃtida. O 5-FU estimulou a produÃÃo de citocinas prÃ-inflamatÃrias (IL-1β e TNF-α) no dia 10 nas glÃndulas submandibular e sublingual concomitante ao estresse oxidativo. Contudo, apesar do aumento do estresse oxidativo no 10 dia, o 5-FU produziu efeito inibitÃrio das mesmas citocinas prÃ-inflamatÃrias na glÃndula parÃtida. De acordo com os resultados acima descritos, podemos concluir que o 5-FU induz resposta inflamatÃria nas glÃndulas salivares maiores, mais frequentemente observado 10 dias apÃs a primeira administraÃÃo do 5-FU, o que pode contribuir para a hipofunÃÃo das glÃndulas salivares, levando a alteraÃÃes no fluxo e composiÃÃo salivar. / The aim of this study was to elucidate the effect of 5-Fluorouracil (5-FU) on major salivary glands, salivary flow and saliva composition using an established oral mucositis (OM) model, in hamsters. OM was induced by two intraperitoneal administrations of 5-FU on 1st and 2nd days of the experimental model (60mg/kg and 40mg/kg, respectively), followed by cheek pouch mucosa scratch. Pilocarpine stimulated salivary flow were measured, saliva was collected, salivary glands were harvested for histopathologycal analysis, measurement of inflammatory cells, evaluation of oxidative stress (SOD, CAT, nitrite, NP-SH and MDA), quantification of pro-inflammatory cytokines (TNF-α and IL-1β) and investigation of cell death and proliferation. CAT and lysozyme activities and IgA and SOD levels were evaluated in saliva samples. This study demonstrated that 5-FU significantly reduced the pilocarpine stimulated salivary flow rate on the 4th experimental day, associated with an increase in SOD levels in saliva. Recovery of salivary flow was observed on day 10, when a decrease in the saliva lysozyme levels was detected. In addition, 5-FU promoted vacuolization in parotid gland and periductal edema in submandibular gland, combined with an increase in the inflammatory cells influx, mostly observed on the 4th day in submandibular gland and on 4th and 10th days in parotid gland. 5-FU stimulated pro-inflammatory cytokines (TNF-α and IL-1β) production on 10th day in submandibular and sublingual glands associated with oxidative stress. Although the stimulation of oxidative stress on 10th day, 5-FU promoted inhibitory effect on both pro-inflammatory cytokines in parotid gland. According to the above mentioned results, 5-FU induced an inflammatory response in major salivary glands, most observed 10 days after its first injection, which may contribute to glands hypofunction, leading to alterations in the salivary flow rate and composition.

Selon une étude précédente, une limitation à l'efficacité anticancéreuse du 5-Fluorouracile (5-FU) repose sur la sécrétion d'IL-1β par des cellules myéloïdes immunosuppressives (MDSC). La libération d'IL-1β mature provient de l'activation de NLRP3 induite par le 5- FU et de l’augmentation de l’activité de la caspase-1 dans les MDSC, qui favorise la reprise de la croissance tumorale chez des souris traitées avec 5-FU. L'acide docosahexaénoïque (DHA) appartient à la famille des acides gras oméga-3 et possède des propriétés anticancéreuses et anti-inflammatoires qui pourraient améliorer la chimiothérapie à base de 5-FU. Dans ces travaux, nous démontrons que le DHA inhibe la sécrétion d'IL 1β induite par le 5 FU dans une lignée cellulaire de MDSC (MSC-2). Chez des souris porteuses de tumeurs traitées par 5 FU, nous avons montré qu'un régime alimentaire enrichi en DHA réduit la concentration d'IL 1β circulante et la récidive tumorale après une injection de 5 FU. Le traitement par 5 FU conduit à l'activation de JNK dans les MDSC et l'inhibiteur de JNK SP600125 diminue la sécrétion d’IL-1β. De plus, le DHA est capable de contrecarrer l'activation de JNK induite par 5-FU dans les MDSC, entraînant la chute de la libération de l’IL 1β. De plus, nous avons montré que la supplémentation en DHA dans les MDSC exposées au 5 FU diminuait l’activité de la caspase-1 ainsi que la modification des interactions entre NLRP3 et la caspase-1, ASC ou β-arrestine-2. De manière inattendue, la régulation de l'activité de la caspase-1 par le DHA était indépendante de JNK, ce qui suggère que le DHA pourrait contrôler la sécrétion de l’IL 1β par le biais de l'inflammasome NLRP3 et de la voie JNK. Enfin, nous avons trouvé une corrélation négative entre la teneur en DHA dans le plasma et l'induction du niveau d'IL 1β ou de la caspase-1 dans le sang de patients traités par chimiothérapie à base de 5-FU.L’ensemble de ces données fournissent de nouvelles informations sur la régulation de la sécrétion de l’IL-1β par le DHA et son bénéfice potentiel dans la chimiothérapie à base de 5-FU. / A limitation to 5-Fluorouracil (5-FU) anti-cancer efficacy relies on the secretion of IL-1β by myeloid-derived suppressor cells (MDSC) according to a previous pre-clinical report. The release of mature IL-1β originates from 5 FU mediated NLRP3 activation with increased caspase-1 activity in MDSC and sustains tumor growth recovery in 5 FU treated mice. Docosahexaenoic acid (DHA) belongs to omega-3 fatty acid family and harbors both anti cancer and anti inflammatory properties which might could improve 5 FU chemotherapy. Here, we demonstrate that DHA inhibits 5 FU induced IL 1β secretion produced by a MDSC cell line (MSC-2). In tumor-bearing mice treated with 5 FU, we showed that a DHA enriched diet reduces circulating IL 1β concentration and tumor recurrence after 5 FU injection. 5 FU treatment led to JNK activation in MDSC and JNK inhibitor SP600125 decreased IL 1β secretion. Moreover, DHA was able to counteract 5 FU mediated JNK activation in MDSC leading to the drop of IL 1β release. In addition, we showed that DHA supplementation in 5 FU exposed MDSC decreases caspase-1 activity along with a modification of the interactions between NLRP3 and caspase-1, ASC or β arrestin-2. Unexpectedly, the regulation of caspase-1 activity by DHA was independent of JNK which suggests that DHA could control IL 1β secretion through both NLRP3 inflammasome and JNK pathway. Interestingly, we found a negative correlation between DHA content in plasma and the induction of circulating IL 1β level or caspase-1 activity in patients treated with 5 FU based chemotherapy.Together, these data provide new insights on the regulation of IL 1β secretion by DHA and its potential benefit in 5-FU based chemotherapy.

No description available.

A molécula 5-fluorouracil (5FU) é muito utilizada em tratamentos de câncer. Seu espectro de absorção é caracterizado por duas bandas de diferentes intensidades, as transições n-p* e p-p*, e seu estudo em diferentes solventes é de considerável importância para compreender a fotofísica do estado excitado. Este é o primeiro passo essencial para obter a caracterização da dinâmica de emissão. Neste trabalho, nós estudamos teoricamente o espectro de absorção da 5FU em dois solventes, água e acetonitrila, usando o método Sequential Quantum Mechanics/ Molecular Mechanics (SQM/MM). Uma etapa importante para uma simulação realista é a polarização do soluto pelo solvente. Neste estudo, esta polarização foi obtida usando dois modelos: Polarizable Continuum Model (PCM), que é uma alternativa simples e um método iterativo usando Average Solvent Electrostatic Configuration (ASEC). Após isso, simulações usando Monte Carlo Metrópolis no ensemble NVT em condições normais de temperatura e pressão foram realizadas e configurações estatisticamente descorrelacionadas separadas para subsequentes cálculos de Mecânica Quântica usando diversos métodos: Configuration Interaction (CI), Time Dependent Density Functional Theory (TD-DFT) e um método semi-empírico (INDO/CIS). Os espectros calculados em ambos os solventes foram obtidos em mais de uma aproximação: contínua, discreta e explícita. Os resultados estão em boa concordância com os valores experimentais e enfatizam a importância da inclusão de moléculas de solvente explícitas nos cálculos. Nós especialmente notamos que em solventes, a transição n-p* é deslocada para o azul enquanto a transição p-p* é deslocada para o vermelho, indicando uma tendência para reversão dessas duas bandas se comparadas à fase gasosa. Isto aponta para diferenças na fotofísica, dependendo da polaridade do solvente. Os resultados também permitem uma avaliação dos diferentes procedimentos teóricos utilizados. / The 5-fluorouracil molecule is very used in cancer treatment. Its absorption spectrum is characterized by two broad bands of different intensities, the n-p* and p-p* transitions, and its study in different solvents is of considerable importance for the understanding of the photophysics of the excited state. It is the first essential step for obtaining the characterization of the emission dynamics. In this work we have theoretically studied the absorption spectrum of 5FU in two solvents, water and acetonitrile, using the Sequential Quantum Mechanics/Molecular Mechanics method (SQM/MM). An important step for a realistic simulation is the polarization of the solute by the solvent. In this study, this polarization was obtained by using two models: Polarizable Continuum Model (PCM), which is a simple alternative, and an iterative method using the Average Solvent Electrostatic Configuration (ASEC). After this, Monte Carlo Metropolis simulations in the NVT ensemble in normal conditions of temperature and pressure were made and statistically uncorrelated configurations sampled for the subsequent Quantum Mechanics calculations using several methods: Configuration Interaction (CI), Time Dependent Density Functional Theory (TD-DFT) and a semiempirical method (INDO/CIS). The calculated spectra in both solvents were obtained using more than one approach: continuum, discrete and explicit. The results are in good agreement with experimental values and emphasize the importance of explicitly including solvent molecules. We specially note that in solvents, the n-p* is blue-shifted and the p-p* transition is red-shifted leading to a tendency for reversal of these two bands compared to gas phase. This points to differences in the photophysics, depending on the solvent polarity. The results also allow an evaluation of the different theoretical procedures used.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / INTRODUÃÃO: A mucosite oral (MO) à um efeito colateral frequente em pacientes sob tratamento oncolÃgico, em especial à quimioterapia (QT). Caracteriza-se por hiperemia, edema e Ãlceras em toda a cavidade oral e faringe. A importÃncia da MO à devido à dor, alteraÃÃes do paladar e infecÃÃes locais. Surge incapacidade de alimentar-se, ingerir lÃquidos, risco de infecÃÃes sistÃmicas, necessidade de interrupÃÃo da QT, necessidade de hospitalizaÃÃo, tornando o tratamento mÃrbido, dispendioso, doloroso e muitas vezes impossÃvel ou ineficaz. Ainda nÃo hà terapÃutica totalmente eficaz, com nÃvel de evidÃncia que torne a MO manejÃvel. OBJETIVOS: Avaliar os efeitos do tratamento tÃpico com duas plantas medicinais, a Myracrodruon urundeuva (aroeira) e a Aloe barbadensis (babosa) sobre o desfecho da MO experimental induzida por 5-Fluorouracil (5-FU) em hamsters, atravÃs de escores macro e microscÃpicos e avaliaÃÃo de perda ponderal. Investigar os possÃveis mecanismos envolvidos nesses efeitos, atravÃs de anÃlise da atividade de mieloperoxidase (MPO) e expressÃo tissular de TNF-alfa e iNOS. MATERIAIS E MÃTODOS: Hamsters Goldem siriam receberam injeÃÃes i. p. de 60 e 40 mg/Kg de 5-FU, nos dias 1 e 2, respectivamente. No dia 4 os animais eram anestesiados, tinham suas mucosas jugais submetidas a trauma mecÃnico (TM) com agulha de ponta romba. Em seguida, eram tratadas com gel inerte (controle), gel de aroeira a 5, 10 ou 20% (AR) ou gel de babosa (ALOE) a 25, 50 e 100% . Tais tratamentos eram realizados 2xdia atà o dia 9. Os animais eram pesados diariamente. No dia 10, ocorriam os sacrifÃcios para: 1. AnÃlise macroscÃpica das mucosas; 2. Retiradas de amostras para histopatologia, imunohistoquÃmica para e dosagem de MPO. RESULTADOS: Na anÃlise macroscÃpica, AR determinou inibiÃÃo significativa da MO (AR 5% - Md 2; AR 10% - Md 3; Controle â Md 4), ALOE tambÃm inibiu a MO (ALOE 25% - Md 1; ALOE 50% - Md 1,5; ALOE 100% - Md 1; Controle â Md 4). à histopatologia confirmou-se inibiÃÃo significativa da MO pela AR (p < 0,01) e pela ALOE a 50 e 100% ( p< 0,01). Houve tambÃm inibiÃÃo dos nÃveis de MPO pelos extratos das duas drogas e a expressÃo de TNF-alfa e iNOS tambÃm foi reduzida. Houve uma tendÃncia a uma menor perda ponderal nos grupos experimentais. CONCLUSÃES: Extratos de ALOE e AR foram capazes de inibir a MO experimental induzida por 5-FU atravÃs de aplicaÃÃes tÃpicas e tal efeito pode ser modulado por suas atividades anti-inflamatÃrias sobre a produÃÃo de citocinas envolvidas com o processo e de NO. / INTRODUCTION: Oral mucositis (OM) is a frequent dose-limiting and costly complication of antineoplastic chemotherapy. Itâs caractherized by ulcerative lesions and causes pain, restrict food and fluids oral intake and causes substancial risk for sepsis. In severe cases, hospitalization, parenteral nutrition and opiode analgesics are required. OBJECTIVES: Evaluate the effects of extracts of two herbal medicines, Aloe barbadensis Miller (Ab) and Myracrodruon urundeuva AllemÃo (Mu) on 5-fluorouracil-induced OM in hamsters. To evaluate the possible mechanisms by the extracts act, it was performed analysis of intensity of activity of myeloperoxidase (MPO) and analysis of immunohistochemistry for TNF-alpha and iNOS in mucosa specimens. METHODS: Golden siriam hamsters were submitted to intra-peritoneal 60 and 40 mg/Kg injections of 5-fluorouracil (5-FU) in day 1 and 2, respectively. On day 4, animals were submitted to anaesthesia, followed by mecanic trauma with needle to potenciate the effect of 5-FU. After that, the mucosas were treated with topical gel containing Mu extracts at 5, 10 or 20%, Ab extracts at 25, 50 or 100% (experimental groups) or carbapol gel (control group). The treatments above were mantained twice daily until day 9. On day 10 the animals were sacrified. Diferent parameters were evaluated: macroscopic and microscopic scores of OM, body mass variation and immunohistochemistry for TNF-alpha e iNOS. RESULTS: Mu significantly inhibited macroscopic oral mucositis at 5 and 10% concentrations (5% Mu â Md 2; 10% Mu â Md 3; control â Md 4, p < 0,01). Ab also inhibited OM (25% Ab â Md 1; 50% Ab â Md 1,5; 100% Ab â Md 1; control â Md 4, p < 0,001). These results were confirmed by histological analysis (5% Mu â Md 1,5; 10% Mu â Md 1; 25% Ab â Md 1; 50% Ab â Md 1,5; 100% Ab â Md 1; control â Md 2, p < 0,01). MPO activity was significantly decreased by Mu and Ab compared to control animals. Both Mu and Ab decreased expression of TNF-alpha and iNOS on tissue. It was observed a decrease on ponderal lost in experimental groups. CONCLUSIONS: Myracrodruon urundeuva and Aloe barbadensis cause important inhibitory effects in oral mucositis 5-FU induced probably by their antiinflamatory properties.