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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.
61

Ausência de atividade quimiopreventiva por parte da vitamina A quando administrada a ratas na etapa de pós-iniciação da carcinogênese mamária / Lack of chemopreventive activity of vitamin A when administered to rats during the stage of post-initiation of mammary carcinogenesis

Okamoto, Leticia 11 February 2010 (has links)
Avaliou-se a eventual atividade quimiopreventiva por parte da vitamina A (VA) quando administrada a ratas Sprague-Dawley durante a etapa de pós-iniciação da carcinogênese mamária induzida pelo 7-12 dimetilbenz(a)antraceno (DMBA). Com exceção de 10 animais que constituíram um grupo controle à parte de ratas consideradas normais [grupo normal (N)], e que não foram submetidas a qualquer procedimento experimental durante todo o estudo, 40 ratas com 50 dias de idade receberam o agente carcinogênico DMBA, por meio de entubação gástrica na dose de 60 mg/kg/peso corpóreo. Após 2 semanas, as ratas iniciadas receberam durante 12 semanas consecutivas, por entubação gástrica, 0,25 mL/100 g de peso corpóreo de óleo de milho (grupo OM; controle, n=20) e 2,5 mg/100 g de peso corpóreo de vitamina A (grupo VA, n=20), sendo, então, eutanasiadas. Não houve diferenças (p>0,05) entre os grupos OM e VA quanto à latência de aparecimento da primeira neoplasia mamária, incidência, multiplicidade e peso médio das neoplasias mamárias, todas classificadas como malignas. Em comparação ao grupo OM, o grupo VA apresentou maior concentração (p<0,05) de retinol no tecido mamário neoplásico e hepático, além de maiores concentrações hepáticas (p<0,05) de palmitato de retinila. Não se detectou palmitato de retinila em neoplasias mamárias de ambos os grupos. Não houve diferença (p>0,05) entre neoplasias mamárias do grupo OM e o tecido mamário do grupo N quanto à metilação global do DNA. Em comparação a neoplasias mamárias do grupo OM, neoplasias do grupo VA apresentaram menor (p<0,05) metilação global do DNA. Conclui-se que a VA não apresentou atividades quimiopreventivas e seu metabolismo encontra-se alterado em neoplasias mamárias. / The potential chemopreventive activity of vitamin A (VA) was evaluated when administered to Sprague-Dawley rats during the stage of post-initiation of mammary carcinogenesis induced by 7-12 dimethylbenz(a)anthracene (DMBA). Except for 10 animals that constituted a separate control group of normal rats [normal group (N)], that were not subjected to any experimental procedure throughout the study, 40 rats with 50 days of age received the carcinogen DMBA by gavage at the dose of 60 mg/kg/body weight. After 2 weeks, the rats received for 12 consecutive weeks, by gavage, 0.25 mL/100 g body weight of corn oil (OM group, control, n = 20) or 2.5 mg/100 g body weight of vitamin A (VA group, n = 20), being then euthanized. There were no differences (p> 0.05) between the OM and VA groups regarding the latency of onset of first breast neoplasm, incidence, multiplicity and average weight of breast tumors, all classified as malignant. Compared to the OM group, the VA group had a higher concentration (p <0.05) of retinol in neoplastic breast tissue and liver as well as higher concentrations (p <0.05) of retinyl palmitate in the liver. Retinyl palmitate was not detected in breast tumors of both groups. There was no difference (p> 0.05) between breast tumours of OM group and mammary tissue of N group regarding global DNA methylation. Compared to breast tumors of OM group, breast tumors of VA group had lower (p <0.05) global DNA methylation. VA did not show chemopreventive activity when administered to rats during the stage of post-initiation of mammary carcinogenesis. Furthermore, the metabolism of VA is altered in breast tumors.
62

Avaliação do potencial quimiopreventivo do óleo de Pequi (Caryocar brasiliense Camb.) na hepatocarcinogênese quimicamente induzida em camundongos / Evaluation of potential chemopreventive oil pequi (Caryocar brasieliense Camb) in chemically induced Hepatocarcinogenesis in mice

Palmeira, Simone Morais 12 November 2014 (has links)
A flora brasileira possui várias plantas com grande potencial quimiopreventivo contra processos neoplásicos, sendo uma delas o fruto do Pequi (Caryocar brasiliense Camb). Essa fruta da região central do Brasil contêm na sua polpa e principalmente no extrato do óleo da sua polpa, várias substâncias antioxidantes. Relatos científicos recentes indicam que as substâncias no Pequi estão relacionadas com a intensificação do sistema imunológico e a redução do risco de doenças degenerativas como o câncer. Portanto, o presente trabalho avaliou o potencial quimiopreventivo do óleo de Caryocar brasiliense contra lesões hepáticas pré-neoplásicas induzidas quimicamente pela dietilnitrosamina (DEN) em camundongos. O iniciador dietilnitrosamina (DEN) na concentração de 10ug/g foi injetado intraperitonialmente em camundongos de 14 dias de idade. Foram formados cinco grupos experimentais: C (controle sem nenhum tratamento); DEN (Dietilnitrosamina 10ug); OP400 (óleo de Pequi 400mg/kg); DEN+OP100 (DEN+100mg/kg de óleo de Pequi); e DEN+OP400 (DEN+400 mg/kg de óleo de Pequi). Estes três últimos grupos receberam o óleo a partir do 30º dia até o 189° dia de vida. Os parâmetros estereológicos densidade de volume (Vv) e volume total (VTot) das lesões pré-neoplásicas (LPN) foram avaliados juntamente com a expressão das citoqueratinas CK8/18. O óleo de C. brasiliense reduziu o volume total das lesões pré-neoplásicas em 51% no fígado dos camundongos e em 20% no número total de animais acometidos com estas lesões na dose de 400 mg/kg. Redução no número de perfis de focos de hepatócitos alterados (FHA) CK8/18 - positivos foram observados no grupo DEN+OP400. Estes efeitos foram atribuídos às substâncias antioxidantes como os carotenóides (com ou sem atividade pró-vitamina A) e vitamina C que possivelmente atuaram na fase de promoção inibindo a proliferação celular e também pela indução da remodelação dos FHA. Portanto, concluímos que o óleo de C. brasiliense possui efeito hepatoprotetor no desenvolvimento de lesões pré-neoplásicas em fígado de camundongos induzidos por DEN e com potencial para uso na prevenção do câncer hepático / The brazilian flora has several plants with large chemopreventive potential against neoplastic processes, being one of them the Pequi fruit (Caryocar brasiliense Camb). This fruit of the central region of Brazil contains at its pulp and especially in the oil extract of its pulp, various antioxidant substances. Recent scientific reports indicate that the substances in Pequi are related to the intensification of the immune system and the reduction of risk of degenerative diseases, such as cancer. Therefore, this study evaluated the chemopreventive potential of the Caryocar brasiliense oil against pre-neoplastic liver lesions chemically induced by diethylnitrosamine (DEN) in mice. The initiator diethylnitrosamine (DEN) at a concentration of 10ug/g was intraperitoneally injected into14 days of age mice. Five experimental groups were formed: C (control without any treatment); DEN (diethylnitrosamine 10ug); OP400 (oil Pequi 400 mg/kg); DEN+OP100 (DEN + 100 mg/kg of Pequi oil); and DEN+OP400 (DEN + 400 mg/kg of Pequi oil). These last three groups received oil from the 30th day to the 189th day of life. The stereological parameters volume density (Vv) and total volume (VTot) of pre-neoplastic lesions (PNL) were evaluated together with the expression of cytokeratins CK8/18. The oil of C. brasiliense reduced the total volume of pre-neoplastic lesions in the liver in 51% of mice and 20% in the total number of affected animals with these lesions at a dose of 400 mg / kg. Reduction in the number of foci of altered hepatocytes (FAH) CK8/18 profiles-positive were observed in DEN+OP400 group. These effects have been attributed to antioxidants substances such as carotenoids (with or without provitamin A activity) and Vitamin C which possibly acted on the promotion stage inhibitting cell proliferation and also by inducing remodeling of FHA. Therefore, we conclude that the oil of C. brasiliense has hepatoprotective effect on the development of pre-neoplastic lesions in the mice liver induced by DEN and with potential for use in the prevention of liver cancer
63

Growth inhibitory effects of chlorophyllin on human breast carcinoma MCF-7 cells.

January 2005 (has links)
Kong Ka-lai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 126-149). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Abstract (Chinese Version) --- p.vi / Table of Contents --- p.ix / List of Figures/Table --- p.xiii / List of Abbreviations --- p.xvi / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- An Overview on Cancer --- p.1 / Chapter 1.2 --- Biological Effects of Chlorophyllin --- p.7 / Chapter 1.2.1 --- CHL as Photosensitizer --- p.7 / Chapter 1.2.2 --- CHL as Antioxidant --- p.8 / Chapter 1.2.3 --- CHL as Anticarcinogenic Agent --- p.9 / Chapter 1.3 --- Regulation of Cell Cycle --- p.13 / Chapter 1.3.1 --- Cell-Cycle Checkpoints --- p.13 / Chapter 1.3.2 --- Cell-Cycle Regulatory Proteins --- p.15 / Chapter 1.4 --- Regulation of Mitogen-Activated Protein Kinase (MAPK) Signaling Cascade --- p.21 / Chapter 1.5 --- Programmed Cell Death (or Apoptosis) --- p.27 / Chapter 1.5.1 --- Regulation of Caspase-Dependent Apoptosis --- p.28 / Chapter 1.5.2 --- Regulation of Caspase-Independent Cell Death --- p.32 / Chapter 1.5.3 --- Bcl-2 Family Proteins in Modulation of Cell Death --- p.32 / Chapter 1.6 --- In Vivo Antitumor Screening System --- p.37 / Chapter 1.7 --- Aims of the Present Study --- p.38 / Chapter Chapter 2 --- In Vitro Studies of the Anticancer Effect of Chlorophyllin / Chapter 2.1 --- Introduction --- p.39 / Chapter 2.1.1 --- DNA-Flow Cytometric Analysis --- p.51 / Chapter 2.1.2 --- Western Blot Analysis --- p.54 / Chapter 2.2 --- Materials and Methods --- p.56 / Chapter 2.2.1 --- Maintenance of Cell Lines --- p.56 / Chapter 2.2.2 --- Cytotoxic and Cytostatic Effects on the Cancer Cells --- p.56 / Chapter 2.2.3 --- DNA-Flow Cytometric Analysis --- p.60 / Chapter 2.2.4 --- Western Blot Analysis --- p.61 / Chapter 2.2.5 --- JC-1 Mitochondrial Potential Sensor --- p.64 / Chapter 2.2.6 --- Caspase Inhibitors --- p.65 / Chapter 2.2.7 --- Statistical Analysis --- p.66 / Chapter 2.2.8 --- Densitometric Analysis --- p.66 / Chapter 2.3 --- Results --- p.67 / Chapter 2.3.1 --- Effects of CHL on the Growth of Human Cancer Cells by MTT Assay --- p.67 / Chapter 2.3.2 --- Effect of CHL on the Proliferation of MCF-7 Cells by Chemi-BrdU Incorporation --- p.69 / Chapter 2.3.3 --- Effect of CHL on Cell Cycle of MCF-7 Cells --- p.71 / Chapter 2.3.4 --- Effect of CHL on the Cyclin D1 Expression in MCF-7 Cells --- p.74 / Chapter 2.3.5 --- Effects of CHL on JNK and c-Jun Expressions and Their Phosphorylations in MCF-7 Cells --- p.76 / Chapter 2.3.6 --- Effect of CHL on DNA fragmentation in MCF-7 Cells --- p.78 / Chapter 2.3.7 --- Effect of CHL on Mitochondrial Membrane Potential of MCF-7 Cells --- p.80 / Chapter 2.3.8 --- Effects of CHL on the PARP Expression and Cleavage in MCF-7 Cells --- p.83 / Chapter 2.3.9 --- "Effects of CHL on Bcl-2, Bcl-xL and Bad Expressions in MCF-7 Cells" --- p.85 / Chapter 2.3.10 --- Effects of CHL on Caspase Activations in MCF-7 Cells --- p.88 / Chapter 2.3.11 --- Effects of Caspase Inhibitors on the CHL-Induced Apoptosis in MCF-7 Cells --- p.90 / Chapter 2.4 --- Discussion --- p.93 / Chapter Chapter 3 --- In Vivo Studies of the Anticancer Effect of Chlorophyllin / Chapter 3.1 --- Introduction --- p.104 / Chapter 3.2 --- Materials and Methods --- p.106 / Chapter 3.2.1 --- Transplantation of MCF-7 Cells into the Nude Mice and Treatment --- p.106 / Chapter 3.2.2 --- Western Blot Analysis --- p.107 / Chapter 3.2.3 --- Statistical Analysis --- p.107 / Chapter 3.3 --- Results --- p.108 / Chapter 3.3.1 --- In Vivo Antitumor Activity of CHL --- p.108 / Chapter 3.3.2 --- In Vivo Effects of CHL on Cyclin D1 and Bcl-2 Expressions in MCF-7 Solid Tumor --- p.111 / Chapter 3.4 --- Discussion --- p.113 / Chapter Chapter 4 --- General Discussion --- p.115 / References --- p.126
64

Tratamento de tuberculose latente: um desafio para o controle da doença

Vasconcelos, Ludmila Moreira 17 April 2017 (has links)
Submitted by Suzana Dias (suzana.dias@famerp.br) on 2018-10-31T18:37:25Z No. of bitstreams: 1 LudmilaMoreiraVasconcelos_dissert.pdf: 1613747 bytes, checksum: af77415c21324e1dbbeddf59d74195ea (MD5) / Made available in DSpace on 2018-10-31T18:37:25Z (GMT). No. of bitstreams: 1 LudmilaMoreiraVasconcelos_dissert.pdf: 1613747 bytes, checksum: af77415c21324e1dbbeddf59d74195ea (MD5) Previous issue date: 2017-04-17 / early detection of latent tuberculosis infection is one of the TB control strategy recommended by the World Health Organization. Objective: to analyze the association of latent tuberculosis infection with sociodemographic, clinical and risk factors for active TB cases chemoprophylaxis. Material and Methods: A retrospective cross-sectional epidemiological study, based on secondary data chemoprophylaxis notification form of tuberculosis of the state information system (TBWEB) of Epidemiological Surveillance Group XXIX (GVE 29) of São José do Rio Preto. They considered all reported cases from 2009 to 2013. The selected variables were sociodemographic and clinical. For the analysis, all statistical tests were applied with a 0.05 significance level. The software used for analysis were Minitab® 17 (Minitab Inc.) and Statistica 10 (StatSoft Inc.). Results: predominance of females, mean age 37.51 years and median of 40.00 years. Smear the day with negative sputum was associated significantly with cough (P = 0.001) and occupation (P <0.001). Few HIV / AIDS and health care professionals made the smear and sputum culture. Conclusion: The study found it hard both in screening latent tuberculosis, as in diagnosis and treatment, which may contribute to the spread of TB and multidrug resistance, increasing the morbidity and mortality rates from the disease, particularly among co-infected with HIV. / a detecção precoce da tuberculose infecção latente é uma das estratégias de controle da tuberculose recomendada pela Organização Mundial de Saúde. Objetivo: analisar a associação da tuberculose de infecção latente com variáveis sociodemográficas, clínicas e fatores de risco para tuberculose ativa de casos de quimioprofilaxia. Material e Método: estudo epidemiológico transversal retrospectivo, a partir de dados secundários da ficha de notificação de quimioprofilaxia da tuberculose do sistema de informação estadual (TBWEB) do Grupo de Vigilância Epidemiológica XXIX (GVE 29) de São José do Rio Preto. Foram considerados todos os casos notificados de 2009 a 2013. As variáveis selecionadas foram as sociodemográficas e clínicas. Para a análise, todos os testes estatísticos foram aplicados com nível de significância de 0,05. Os softwares utilizados para análise foram o Minitab® 17 (Minitab Inc.) e Statistica 10 (StatSoft Inc.). Resultados: predomínio do sexo feminino, idade média 37,51 anos e mediana de 40,00 anos. Realização da baciloscopia com resultado negativo do escarro se associou de forma significativa com a tosse (P=0,001) e ocupação (P<0,001). Poucos portadores de HIV/Aids e profissionais de saúde realizaram a baciloscopia e cultura do escarro. Conclusão: O estudo mostrou dificuldades tanto no rastreio de tuberculose infecção latente, como no diagnóstico e tratamento, o que pode contribuir para a multirresistência e disseminação da TB, aumentando as taxas de morbimortalidade pela doença, principalmente entre os coinfectados pelo HIV.
65

Efeito quimiopreventivo da &#946;-ionona nas fases de iniciação e seleção/promoção da hepatocarcinogênese associada ao desenvolvimento de esteatose hepática não alcoólica em ratos Wistar / Chemopreventive effect of &#946;-ionone in the phases of initiation and selection/promotion of hepatocarcinogenesis associated with the development of non-alcoholic steatosis in Wistar rats

Aline Henriques Guariento 07 November 2017 (has links)
O câncer é um dos principais problemas de saúde pública no mundo. Dentre as neoplasias primárias que acometem o fígado, o carcinoma hepatocelular (HCC) é a mais frequente. Diversos fatores de risco predispõem ao HCC, entre eles a doença hepática gordurosa não-alcoólica (NAFLD). Segundo estudos prévios do grupo, a &#946;-ionona (BI), presente em uvas e aromatizantes de vinho, apresenta potencial quimiopreventivo da hepatocarcinogênese. Além disso, a &#946;I parece atuar na redução da colesterolemia podendo, assim, influenciar a NAFLD. Desta forma pretendeu-se, neste projeto, avaliar o desenvolvimento da NAFLD e sua influência nas etapas de iniciação e seleção/promoção da hepatocarcinogênese em ratos Wistar submetidos ao modelo do hepatócito resistente (RH), além da atividade quimiopreventiva da &#946;I, nessas condições experimentais em ratos. Para isso, os animais foram alocados em 6 grupos experimentais: RH iniciação (n=11), NAFLD iniciação (n=15), BI iniciação (n=15), RH seleção/promoção (n=11), NAFLD seleção promoção (n=15) e BI seleção/promoção (n=15). Na fase de iniciação os animais do grupo NAFLD receberam, diariamente, emulsão hipercalórica até a sexta semana do experimento um dia antes da administração de DEN. Já na fase de seleção/promoção os animais do grupo NAFLD receberam a emulsão hipercalórica, a partir de um dia após a DEN. Os animais dos grupos RH da iniciação e da seleção/promoção servem como controles e receberam, diariamente, 1mL/100g peso corpóreo de água até a sexta semana do experimento e um dia após a DEN, respectivamente. Na fase de iniciação, após 13 semanas os animais do grupo NAFLD não demonstraram sinais de esteatose, apresentaram maiores níveis séricos de triacilglicerol, colesterol total e LDL comparados ao grupo RH (P<0,05). O grupo NAFLD apresentou maior porcentagem de nódulos macroscópicos, bem como maior número e porcentagem de área hepática de lesões pré neoplásicas persistentes (pLPN) comparado ao grupo RH (P<0,05). Já o grupo BI apresentou menor número de pLPN e maior número de lesões em remodelação e uma maior porcentagem de área hepática de rLPN (p<0,05). Em relação a proliferação celular, o grupo NAFLD apresentou maior número de células em sourrounding, pLPN e rLPN comparada ao grupo RH e o grupo BI menor número em pLPN comparada a NAFLD. Já na fase de seleção/promoção foi possível observar o grupo NAFLD tem maiores valores de focos de inflamação, hepatócitos balonizados e grau de esteatose hepática em relação ao grupo BI, assim como maiores níveis séricos de triacilgliceróis, colesterol total e LDL (p<0,05). O grupo NAFLD apresentou maior porcentagem de nódulos macroscópicos <1, maior número, menor tamanho médio de pLPN comparados ao grupo RH (p<0,05). O grupo BI apresentou menor número e menor porcentagem de área em pLPN e maior porcentagem de área em rLPN (p<0,05). Em relação a proliferação celular, o grupo NAFLD apresentou maior número de células em sourrounding, pLPN e rLPN comparada ao grupo RH (p<0,05). Na expressão gênica, o grupo BI apresentou maior expressão de HMGCR em relação grupo NAFLD (p<0,05), O grupo NAFLD apresentou maior expressão de INSIG1 em relação ao grupo RH (p<0,05) e tendência na expressão de INSIG 2. / Cancer is a major public health problems in the world. Among the primary neoplasm affecting the liver, hepatocellular carcinoma (HCC) is the most frequent. Several risk factors predispose to HCC, including the non-alcoholic fatty liver disease (NAFLD). According to previous studies of the group, &#946;-ionone (BI), present in grapes and flavors of wine, it presents potential chemopreventive of hepatocarcinogenesis. Furthermore, &#946;I appears to act in reducing blood cholesterol and may thus influence NAFLD. In this way it was intended in this project, evaluate the development of NAFLD and its influence on the steps of initiation and selection/promotion of hepatocarcinogenesis in Wistar rats resistant hepatocyte model (HR), and the chemopreventive activity of &#946;I, these experimental conditions in rats. For this, the animals were divided into 6 groups: RH initiation (n = 11), NAFLD initiation (n = 15), BI initiation (n = 15), HR selection / promotion (n = 11), NAFLD selection promotion ( n = 15) and BI selection / promotion (n = 15). In the inception phase of the NAFLD group animals received daily calorie emulsion until the sixth week of the experiment one day prior to DEN administration. In the selection / promotion stage NAFLD group of animals received hypercaloric emulsion, from one day after the DEN. The animals of groups HR and selection of initiation / promotion serve as controls and received daily 1mL / 100g body weight of water until the sixth week of the experiment, and one day after DEN respectively. In the initiation phase, after 13 weeks the animals of group NAFLD showed no signs steatosis, had higher serum levels of triglyceride, total cholesterol and LDL compared to the HR group (P <0.05). The NAFLD showed higher prevalence of macroscopic nodules as well as higher number and percentage of liver area of persistent pre-neoplastic lesions (pLPN) compared to the HR group (P <0.05). But the BI group had fewer pLPN and higher number of lesions in remodeling and a higher percentage of liver area rLPN (p <0.05). In relation to cell proliferation, the NAFLD group had a higher number of cells in sourrounding, pLPN and rLPN compared to the RH group and the lowest number in pLPN BI group compared to NAFLD. In the selection / promotion layer was observed NAFLD group has the highest values of inflammation foci, balonizados hepatocytes and hepatic steatosis grade in relation to BI group as well as higher serum levels of triglyceride, total cholesterol and LDL (p <0 , 05). The NAFLD showed higher prevalence of macroscopic nodules <1, more, smaller average size pLPN compared to the HR group (p <0.05). The BI group had fewer and smaller percentage area in pLPN and higher percentage of area rLPN (p <0.05). In relation to cell proliferation, the NAFLD group had a higher number of cells in sourrounding, pLPN and rLPN compared to the HR group (p <0.05). In gene expression, the BI group showed higher expression of HMGCR regarding NAFLD group (p <0.05), the NAFLD group had higher expression of INSIG1 against the RH group (p <0.05) and a tendency in the expression of INSIG 2.
66

Avaliação do efeito quimiopreventivo do óleo de pequi (Caryocar brasiliense Camb.) em cólon de camundongo Balb/C / Evaluation of chemopreventive effect of pequi (Caryocar brasiliense Camb.) em cólon de camundongos BALB/c

Pampaloni, Amanda Carolina Montevechi 14 January 2016 (has links)
A flora brasileira possui plantas com grande potencial de investigação na carcinogênese humana, sendo uma delas o Pequi (Caryocar brasiliense Camb.). Esta fruta da região central do Brasil contém na sua polpa e principalmente no extrato do óleo da sua polpa, várias substâncias antioxidantes, as quais estão relacionadas com a redução do risco de doenças degenerativas. Neste estudo propomos avaliar o potencial quimiopreventivo do C. brasiliense contra mecanismos pré-neoplásicos no cólon induzidas quimicamente pelo azoximetano (AMO) em camundongos. O iniciador AMO na concentração 10mg/kg foi injetado por injeção subcutânea em camundongos de 40 dias de idade. Foram formados quatro grupos experimentais: C (controle sem tratamento); AMO (azoximetano 10mg/kg), PQ400 (óleo de pequi 400mg/kg) e OMAPQ400 (OMA+ 400mg/kg de óleo de pequi). Estes dois últimos grupos receberam o óleo de pequi a partir do 40º dia até o 110° dia de vida. A altura das criptas intestinais analisadas, não revelou diferença em nenhum dos grupos. O óleo de C. brasiliense reduziu em 18,7% a proliferação celular no grupo OMAPQ400 quando comparado com os grupos C e AMO. Houve aumento da produção de muco neutro no grupo AMO quando comparado com o C e diminuição no grupo AMOPQ400. Houve hipermetilação do DNA no grupo AMO, e hipometilação no grupo AMOPQ400, sendo estes iguais ao grupo controle (C). A expressão do gene oncogênico (c-Myc) diminuiu no grupo tratado com óleo de pequi em comparação com o grupo tratado com o iniciador AMO. Todos esses efeitos podem ser devidos à presença de antioxidantes na polpa do óleo. Por isso, concluímos que o óleo de C. brasiliense possui efeito protetor contra alguns mecanismos precursores de lesões pré-neoplásicas do cólon / The Brazilian native flora has several plants which have thigh research potential, among those the Pequi (Caryocar brasiliense Camb.). This fruit from the central region of Brazil contains several antioxidant substances in its pulp and mainly in its pulp oil extract, which are related with the reduction of the risk of degenerative diseases. In this study we propose to evaluate the chemopreventive potential of C. brasiliense against neoplastic mechanisms in the colon induced chemically by azoximetano (AMO) in mice. AMO 10mgkg concentration initiator was subcutaneous injection in mice of 40 days of age. Four experimental groups were formed: C (untreated control); AMO (azoximetano 10mg/kg), PQ400 (pequi oil 400mgkg) and AMOPQ400 (AMO 400mgkg pequi oil). These last two groups received the pequi. The height of the intestinal crypts analyzed revealed no difference among groups. The oil of C. brasiliense reduced the cell proliferation by 18.7% in AMOPQ400 group when compared with the groups C and AMO. There was increased production of neutral mucus in the group AMO when compared with the C group and decrease in the AMOPQ400 group. The pequi oil induced DNA hipomethylation in the AMOPQ400 group and hipermethylation in AMO group. The expression of the oncogenic gene c-Myc decreased in the group treated with pequi oil compared to the group treated with the initiator AMO alone. All these effects can be due to the presence of antioxidants in pulp oil. Therefore, we conclude that the oil of C. brasiliense has protective effect against some mechanisms that precede of neoplastic lesions of the colon
67

Chlorophyllin chemoprevention against Dibenzo[a,l]pyrene-initiated multi-organ carcinogenesis in the rainbow trout model

Pratt, Mary Margaret 22 January 2003 (has links)
Chlorophyllin (CHL), a water-soluble derivative of the green plant pigment, chlorophyll, is an effective antimutagen and anticarcinogen in various model systems when used as a modulator against a class of carcinogens that, in general, have a structure consisting of at least three fused rings. Dibenzo[a,l]pyrene (DBP), an extremely potent environmental carcinogen, has been isolated from urban air samples, tobacco smoke, and coal smoke condensate. A study was conducted to evaluate the complex interrelationships among dietary DBP doses with co-exposure to a range of CHL doses. In order to achieve adequate statistical power in the generation of multiple dose-response curves, this dose-dose matrix experiment utilized over 12,000 rainbow trout. The resulting DNA adducts were assessed and evaluated as biomarkers of exposure to discern their relationship with the final tumor outcome. CHL was highly effective in reducing DBP-initiated DNA adduct formation in the liver and stomach and strongly inhibited tumor formation in the liver (56-79% inhibition), stomach (30-68%), and swim bladder (over 80% at the highest DBP dose). Molecular dosimetry revealed adduct formation to be predictive of final tumor response in both organs regardless of CHL dose. Other parameters evaluated were consistent with CHL-mediated protection. A clinical CHL preparation, evaluated in a human population subsequent to the seminal demonstration of CHL chemopreventive properties against AFB��� in trout (1), revealed CHL to be just as effective in reducing biomarkers of alfatoxin exposure to humans (2). Dietary administration of this clinical preparation along with DBP in the rainbow trout demonstrated CHL protective capacity against DBP-initiated multi-organ DNA adduct formation and final tumor incidence. Sucrose was evaluated, deemed unlikely to be sequestered in a complex with CHL, and was used as a control in a pharmacokinetic study evaluating the biodistribution of DBP with and without CHL. The results provide evidence against a non-specific masking mechanism for CHL-mediated blocking of DBP (or aflatoxin)-initiated tumorigenesis. CHL at multiple doses provided significant protection against multi-dose DBP-initiated DNA adduction and tumor formation in multiple organs. CHL-mediated protection, primarily by reduced carcinogen biouptake and consistent with a complexation mechanism, is supported by these results. / Graduation date: 2003
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Dietary Chemoprevention Agent Sulforaphane Inhibits Growth, Survival and Tumorigenic Activity in Human Neuroblastoma

Bayat Mokhtari, Reza 14 December 2010 (has links)
Objective: To evaluate the anti-tumor and histone deacetylase (HDAC) inhibitory activity of the dietary isothiocyanate, sulforaphane (SFN) in the paediatric cancer,neuroblastoma (NB). Materials and Methods: NB cell line (NUB-7), fibroblasts (FLF; negative control) and MCF-7 (positive control), were treated with SFN for up to 7 days and effects on growth, cytotoxicity, differentiation and tumorigenicity assessed. HDAC inhibition was determined by histone (H3/ H4) acetylation. Results: 10 μM SFN significantly decreased in vitro growth and survival of NUB-7 to 10.22 ± 0.71% (p < 0.001) with no significant effect on FLF. SFN induced G1, G2 and S phase cell cycle arrests and stimulated H3/H4 histone acetylation. SFN markedly decreased NUB-7 clonogenicity and tumorigenicity in vivo. Conclusion: Results suggest that low dose SFN reduces proliferation, survival and tumorigenicity of NB NUB-7. As a dietary factor of negligible intrinsic toxicity SFN is a promising therapeutic agent for the treatment of NB.
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Dietary Chemoprevention Agent Sulforaphane Inhibits Growth, Survival and Tumorigenic Activity in Human Neuroblastoma

Bayat Mokhtari, Reza 14 December 2010 (has links)
Objective: To evaluate the anti-tumor and histone deacetylase (HDAC) inhibitory activity of the dietary isothiocyanate, sulforaphane (SFN) in the paediatric cancer,neuroblastoma (NB). Materials and Methods: NB cell line (NUB-7), fibroblasts (FLF; negative control) and MCF-7 (positive control), were treated with SFN for up to 7 days and effects on growth, cytotoxicity, differentiation and tumorigenicity assessed. HDAC inhibition was determined by histone (H3/ H4) acetylation. Results: 10 μM SFN significantly decreased in vitro growth and survival of NUB-7 to 10.22 ± 0.71% (p < 0.001) with no significant effect on FLF. SFN induced G1, G2 and S phase cell cycle arrests and stimulated H3/H4 histone acetylation. SFN markedly decreased NUB-7 clonogenicity and tumorigenicity in vivo. Conclusion: Results suggest that low dose SFN reduces proliferation, survival and tumorigenicity of NB NUB-7. As a dietary factor of negligible intrinsic toxicity SFN is a promising therapeutic agent for the treatment of NB.
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Investigation Of Chemopreventive And Apoptotic Characteristics Of Turkish Medicinal Plant Rheum Ribes

Uyar, Pembegul 01 March 2011 (has links) (PDF)
Rheum species are medicinally important plants due to the presence of anthracene derivatives and in this study antioxidative, cytotoxic, apoptotic and chemopreventive characteristics of R. ribes extracts were evaluated. R. ribes shoot and root dry powder samples were prepared and extracted with ethyl acetate, ethanol and water. The extracts were revealed to be a potential scavenger of DPPH radicals and the chemical composition of the extracts was quantified by colorimetric determination of total phenol (GAE) and flavonoid (CAE) contents. HL&ndash / 60 cells were cultured in the presence of various concentrations of extracts up to 72 hr. R. ribes inhibited the surviv al of HL-60 cells in a concentration- and time-dependent manner, shown by trypan blue and XTT. R. ribes caused HL-60 cells apoptosis via formation of phosphatidylserine externalization, as evidenced by flow cytometry. Exposure of HL-60 cells to higher concentrations of extracts for 72 h resulted in a shift of 87% of the cell population from normal to the early/late apoptotic stage. The R. ribes induced apoptosis may be partially attributed to the activation of caspase-3 and up-regulation of caspase-3 expression was detected in western blot. The significant release of cytochrome c from the mitochondria into the cytosol was observed. The mRNA expression ratio of Bax/Bcl-2 was increased. The apoptosis was also demonstrated by DNA ladder and TUNEL. Chemopreventive effects of R.ribes were investigated at the gene level of CYP1B1 and CYP1A1, and GST enzyme activity against cDNB and concluded that R.ribes modulated activities of these enzymes generally at a time dependent level. T h ese findings suggest that Rheum ribes exhibits potential antioxidant and anticancer properties by inducing caspase-dependent cell death in HL-60 cells.

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