Os herbicidas são destinados ao controle das ervas daninhas e seu uso torna o fornecimento de alimentos abundante e livre de pragas, porém a exposição ocupacional e ambiental a esses compostos pode trazer riscos à saúde. O Brasil é o maior consumidor de praguicidas desde 2008, e os herbicidas correspondem por 45% do volume dessas substâncias. O tebutiurom e a trifluralina são herbicidas muito utilizados em culturas de cana-de-açúcar, e apesar de serem descritos como seletivos em seu mecanismo de ação, seus efeitos em organismos não alvo, como células humanas, são pouco conhecidos. O objetivo do trabalho foi avaliar os efeitos dos herbicidas tebutiuron e trifluralina em organismos não alvo. Para isso, utilizou-se a linhagem celular HepG2, e as concentrações testadas dos herbicidas foram de 1 a 100 ?mol/L e o tempo de exposição variou de 4 h à 14 dias de acordo com o ensaio. Utilizou-se também as linhagens TA98 TA100, TA97a e TA1535 da bactéria S typhimurium. Neste caso, as concentrações testadas dos herbicidas variaram de 0,1 à 5000 ?g/placa e o tempo de exposição foi de 66 h. As análises indicaram que o tebutiurom não apresenta potencial citotóxico, genotóxico, ou mutagênico nas condições testadas, evidenciando sua seletividade. Testes com a trifluralina, no entanto, mostraram que HepG2 apresentaram uma diminuição da capacidade em formar clones quando expostas à 100 ?mol/L por 14 dias, e uma redução na densidade celular quando expostas à 50 e 100 ?mol/L por 24, 48 e 72h. Tais efeitos ocorreram devido a uma diminuição da viabilidade celular, observada em 50 e 100 ?mol/L pelo ensaio MTT, e devido a um bloqueio no ciclo celular na fase S, evidenciado em 100 ?mol/L, ambos nos tempos de 24, 48 e 72h. O tipo de morte celular inicialmente observada foi a apoptose, através da marcação por anexina V em 100 ?mol/L após 48 e 72 h de exposição, e através da condensação e fragmentação nuclear em 100 ?mol/L após 24 e 48 h de exposição. Em 72 h, observou-se também necrose em 100 ?mol/L, por meio dos testes anexina V/PI e liberação de LDH. A morte celular pode estar relacionada à diminuição do potencial de membrana mitocondrial, observada em 50 e 100 ?mol/L após 24, 48 e 72h, e a um aumento na produção de espécies reativas, efeito observado em células expostas à 100 ?mol/L de trifluralina por 24 e 48 h. No entanto, observou-se que a via de resposta ao estresse oxidativo Keap1/Nrf2-ARE não foi ativada no tempo analisado de 24 h. Além disso, os testes de cometa e micronúcleo não indicaram potencial da trifluralina em provocar danos no material genético de HepG2. Complementarmente, o teste de Ames em linhagens de S typhimurium também não evidenciaram potencial mutagênico do herbicida. As análises com a trifluralina mostraram que o herbicida, apesar de não induzir genotoxicidade e mutagenicidade, possui potencial citotóxico em HepG2, indicando que pode afetar organismos não alvo, como células humanas / Herbicides are used to control weeds in agriculture. The use of these chemicals makes possible an abundant and pest free supply of food. However, occupational and environmental exposure to these compounds can lead to health risks. Brazil is the largest consumer of pesticides since 2008, and herbicides match for 45% of the volume of these substances. The tebutiurom and trifluralin herbicides are widely used in sugarcane crops, and although they are described as selective in its mechanism of action, effects on non-target organisms, such as human cells, are are poorly known. The aim of this work was to evaluate the effects of tebuthiuron and trifluralin herbicides on non-target organisms. To this end, we used the cell line HepG2, and herbicides were tested at concentrations of 1 to 100 ?M and the exposure time ranged from 4 h to 14 days in accordance with the assay. We also used the strains TA100 TA98, TA97a and TA1535 of the bacterium S. typhimurium. In this case, the herbicide concentrations tested ranged from 0.1 to 5000 ?g / plate and the exposure time was 66 h. Analyzes indicated that the tebutiurom has no cytotoxic, genotoxic or mutagenic potential at tested conditions, highlighting its selectivity. Tests with the Trifluralin, however, showed that HepG2 had a decreased ability in forming clones when exposed to 100 ?M for 14 days, and a reduction in cell density when exposed to 50 and 100 ?M of the herbicide for 24, 48 and 72h. These effects occurred due a decrease in cell viability observed at 50 and 100 ?M by MTT assay, and due to a block in the cell cycle into S phase, as evidenced in 100 ?M, both at 24, 48 and 72h. The type of cell death detected first was apoptosis. It was observed by staining with annexin V in cells exposed to 100 ?M of trifluralin during 48 and 72 h, and through the nuclear condensation and fragmentation in exposure with 100 ?M during 24 and 48 h of exposure. At 72 h, necrosis was also observed in 100 ?M through the annexin V / PI and LDH assays. Cell death occurrence may be associated with decreased mitochondrial membrane potential observed in 50 and 100 ?M after 24, 48 and 72h of exposure, and also may be associated with incresed production of reactive species, observed in cells exposed to 100 ?M of trifluralin for 24 and 48 h. However, it was observed that the oxidative stress response pathway Keap1 / Nrf2-ARE was not activated within 24 hours. Furthermore, comet assay and micronucleus test indicated no potential of trifluralin in causing DNA damage of HepG2. In addition, the Ames test using S. typhimurium strains also showed no mutagenic potential of the herbicide. The analyzes showed that the trifluralin, despite not induce genotoxicity and mutagenicity, have cytotoxic potential in HepG2, indicating that can affect non-target organisms, such as human cells.

A raiz pulverizada de Pfaffia paniculata e seu extrato butanólico apresentam propriedades antineoplásicas, quimiopreventivas e antiangiogênicas, onde muitos indícios conferem às saponinas triterpenóides presentes nestas raízes as propriedades antitumorais observadas. Sabe-se que saponinas de diversos tipos de plantas possuem capacidade de interferir diretamente no ciclo celular de células tumorais. Assim, considerando os efeitos inibitórios das raízes e extratos de P. paniculata sobre a proliferação celular, o objetivo deste trabalho foi compreender os mecanismos envolvidos na ação quimiopreventiva desta raiz, tanto na fase de iniciação da carcinogênese hepática, quanto sobre células tumorais já estabelecidas. Inicialmente, foram avaliados os efeitos de diferentes concentrações da raiz em pó de P. paniculata adicionada à ração em camundongos submetidos ao modelo de hepatocarcinogênese, pela análise da proliferação celular, indução da apoptose e a comunicação intercelular hepática. Seqüencialmente, foram avaliados os efeitos das frações purificadas do extrato butanólico destas raízes sobre linhagem de células de carcinoma hepatocelular humano. Neste experimento foram analisadas a influência do tratamento sobre a viabilidade celular, fases e proteínas do ciclo celular, proliferação e presença de morte celular. No modelo de hepatocarcinogênese o tratamento com a raiz reduziu a proliferação celular, aumentou a apoptose e desencadeou processo inflamatório crônico em intensidades dependentes da concentração testada e não afetou a comunicação intercelular. Estes resultados indicam que os efeitos quimiopreventivos da P. Paniculata são decorrentes do controle da proliferação celular e apoptose, e são diretamente influenciados pela concentração da raiz. No experimento in vitro o tratamento reduziu a concentração das células vivas sem aumentar a concentração de células mortas, diminuiu a porcentagem de células na fase G2 do ciclo celular, reduziu a expressão dos genes das proteínas ciclinas D1, E e CDK6 e aumentou a expressão de p27, e não induziu apoptose. Estes resultados mostraram que a redução na concentração de células observadas após o tratamento com a fração do extrato butanólico de P. paniculata não foi decorrente de indução de apoptose. O tratamento parou o ciclo celular das células tumorais HepG2 em G1, inibindo proteínas importantes para a progressão do ciclo e estimulando a expressão de p27 um conhecido gene inibidor de CDKs. Os efeitos antiproliferativos observados no experimento in vivo em camundongos, reproduziram-se in vitro em células tumorais humanas, o que pode indicar que as propriedades antineoplásicas anteriormente observadas não são espécie específica. Em linhas gerais, as raízes e/ou as frações do extrato butanólico obtido a partir das raízes de P. paniculata apresentam propriedades antineoplásicas por inibir a proliferação celular e induzir apoptose in vivo e por parar o ciclo celular in vitro. Estes resultados consagram as propriedades antineoplásicas de Pfaffia paniculata e motivam o desenvolvimento de mais estudos sobre as suas potencialidades. / The powdered roots of Pfaffia paniculata and their butanolic extract present antineoplastic, chemopreventive and antiangiogenic properties, and many evidences suggest that the triterpenoid saponins are the responsible for these properties. It is well known that saponins from several types of plants have the capacity to directly interfere on the tumor cell cycle. Therefore, considering the inhibitory effects of the roots and extracts of P. paniculata on cell proliferation, the aim of this study was to search for the mechanisms involved in the chemopreventive effects of this root, both in the initiation phase of the hepatocarcinogenesis and on tumor cell lineage. Initially, the effects of different concentrations of the powdered root of P. paniculata added to the mouse food were evaluated in mice submitted to hepatocarcinogenesis model. Cell proliferation, induction of apoptosis, and hepatic intercellular communication were evaluated. The effects of the purified fractions of the butanolic extract of these roots were then evaluated in human hepatocarcinoma cells. In this experiment, the influence of the treatment on cell viability, phases and proteins of cell cycle, cell proliferation and cell death were evaluated. In the hepatocarcinogenesis model, the treatment with the root decreased cell proliferation, increased apoptosis and induced a chronic inflammatory process dependent on the concentration tested, and did not affect cell communication. These results indicate that the chemopreventive effects of P. Paniculata are apparently dependent on the control of cell proliferation and apoptosis and are directly influenced by the concentration of the root. In the in vitro treatment, it has been observed a reduction in the concentration of live cells without increasing the concentration of dead cells, decreased the level of G2 phase cells, reduced the expression of proteins cyclins D1, E and CDK6, increased the expression of p27, and did not induce apoptosis. These results showed that the reduction in the concentration of cells after the treatment with the butanolic extract of P. paniculata was not due to induction of apoptosis. The treatment inhibited the progression of the cell cycle of HepG2 cells in phase G1, by the inhibition of the expression of proteins that are important to the progression of the cycle, and stimulating the expression of p27, a known inhibitor of CDKs. The antiproliferative effects observed in the in vivo experiments were repeated in the in vitro study with human tumor cells. This may indicate that the antineoplastic properties previously observed are not species-specific. In conclusion, the roots and/or butanolic extract obtained from P. paniculata present antineoplastic properties due to inhibition of cell proliferation and induction of apoptosis in vivo, and due to the cell cycle arrest in vitro. These results reinforce the antineoplastic properties of Pfaffia paniculata and motivate the development of more studies focusing on its antineoplastic potentials.

A raiz pulverizada de Pfaffia paniculata e seu extrato butanólico apresentam propriedades antineoplásicas, quimiopreventivas e antiangiogênicas, onde muitos indícios conferem às saponinas triterpenóides presentes nestas raízes as propriedades antitumorais observadas. Sabe-se que saponinas de diversos tipos de plantas possuem capacidade de interferir diretamente no ciclo celular de células tumorais. Assim, considerando os efeitos inibitórios das raízes e extratos de P. paniculata sobre a proliferação celular, o objetivo deste trabalho foi compreender os mecanismos envolvidos na ação quimiopreventiva desta raiz, tanto na fase de iniciação da carcinogênese hepática, quanto sobre células tumorais já estabelecidas. Inicialmente, foram avaliados os efeitos de diferentes concentrações da raiz em pó de P. paniculata adicionada à ração em camundongos submetidos ao modelo de hepatocarcinogênese, pela análise da proliferação celular, indução da apoptose e a comunicação intercelular hepática. Seqüencialmente, foram avaliados os efeitos das frações purificadas do extrato butanólico destas raízes sobre linhagem de células de carcinoma hepatocelular humano. Neste experimento foram analisadas a influência do tratamento sobre a viabilidade celular, fases e proteínas do ciclo celular, proliferação e presença de morte celular. No modelo de hepatocarcinogênese o tratamento com a raiz reduziu a proliferação celular, aumentou a apoptose e desencadeou processo inflamatório crônico em intensidades dependentes da concentração testada e não afetou a comunicação intercelular. Estes resultados indicam que os efeitos quimiopreventivos da P. Paniculata são decorrentes do controle da proliferação celular e apoptose, e são diretamente influenciados pela concentração da raiz. No experimento in vitro o tratamento reduziu a concentração das células vivas sem aumentar a concentração de células mortas, diminuiu a porcentagem de células na fase G2 do ciclo celular, reduziu a expressão dos genes das proteínas ciclinas D1, E e CDK6 e aumentou a expressão de p27, e não induziu apoptose. Estes resultados mostraram que a redução na concentração de células observadas após o tratamento com a fração do extrato butanólico de P. paniculata não foi decorrente de indução de apoptose. O tratamento parou o ciclo celular das células tumorais HepG2 em G1, inibindo proteínas importantes para a progressão do ciclo e estimulando a expressão de p27 um conhecido gene inibidor de CDKs. Os efeitos antiproliferativos observados no experimento in vivo em camundongos, reproduziram-se in vitro em células tumorais humanas, o que pode indicar que as propriedades antineoplásicas anteriormente observadas não são espécie específica. Em linhas gerais, as raízes e/ou as frações do extrato butanólico obtido a partir das raízes de P. paniculata apresentam propriedades antineoplásicas por inibir a proliferação celular e induzir apoptose in vivo e por parar o ciclo celular in vitro. Estes resultados consagram as propriedades antineoplásicas de Pfaffia paniculata e motivam o desenvolvimento de mais estudos sobre as suas potencialidades. / The powdered roots of Pfaffia paniculata and their butanolic extract present antineoplastic, chemopreventive and antiangiogenic properties, and many evidences suggest that the triterpenoid saponins are the responsible for these properties. It is well known that saponins from several types of plants have the capacity to directly interfere on the tumor cell cycle. Therefore, considering the inhibitory effects of the roots and extracts of P. paniculata on cell proliferation, the aim of this study was to search for the mechanisms involved in the chemopreventive effects of this root, both in the initiation phase of the hepatocarcinogenesis and on tumor cell lineage. Initially, the effects of different concentrations of the powdered root of P. paniculata added to the mouse food were evaluated in mice submitted to hepatocarcinogenesis model. Cell proliferation, induction of apoptosis, and hepatic intercellular communication were evaluated. The effects of the purified fractions of the butanolic extract of these roots were then evaluated in human hepatocarcinoma cells. In this experiment, the influence of the treatment on cell viability, phases and proteins of cell cycle, cell proliferation and cell death were evaluated. In the hepatocarcinogenesis model, the treatment with the root decreased cell proliferation, increased apoptosis and induced a chronic inflammatory process dependent on the concentration tested, and did not affect cell communication. These results indicate that the chemopreventive effects of P. Paniculata are apparently dependent on the control of cell proliferation and apoptosis and are directly influenced by the concentration of the root. In the in vitro treatment, it has been observed a reduction in the concentration of live cells without increasing the concentration of dead cells, decreased the level of G2 phase cells, reduced the expression of proteins cyclins D1, E and CDK6, increased the expression of p27, and did not induce apoptosis. These results showed that the reduction in the concentration of cells after the treatment with the butanolic extract of P. paniculata was not due to induction of apoptosis. The treatment inhibited the progression of the cell cycle of HepG2 cells in phase G1, by the inhibition of the expression of proteins that are important to the progression of the cycle, and stimulating the expression of p27, a known inhibitor of CDKs. The antiproliferative effects observed in the in vivo experiments were repeated in the in vitro study with human tumor cells. This may indicate that the antineoplastic properties previously observed are not species-specific. In conclusion, the roots and/or butanolic extract obtained from P. paniculata present antineoplastic properties due to inhibition of cell proliferation and induction of apoptosis in vivo, and due to the cell cycle arrest in vitro. These results reinforce the antineoplastic properties of Pfaffia paniculata and motivate the development of more studies focusing on its antineoplastic potentials.

Tetraidrofurano (THF) é um solvente muito utilizado industrialmente, com demonstrada ação carcinogênica em animais experimentais, mas pouco se sabe sobre sua toxicidade celular, danos a biomoléculas e genotoxicidade. Em trabalho anterior realizado no laboratório, foi verificado que adutos de DNA são formados a partir da reação de THF oxidado com 2\'-desoxiguanosina (dGuo), 2\'-desoxiadenosina (dAdo) e 2\'-desoxicitidina (dCyd) in vitro. A ocorrência dessas lesões em sistemas biológicos expostos a THF nunca foi demonstrada e pode indicar uma via de ação genotóxica desse solvente, até o momento não considerada nos estudos de carcinogênese e toxicidade. Neste trabalho foi investigada a indução de lesões em DNA e RNA de sistemas biológicos expostos ao THF, assim como alterações epigenéticas. Como sistemas biológicos foram utilizados homogenato de fígado de camundongos, cultura de células HepG2 e fígado e rim de camundongos que foram, em trabalho anterior, expostos a vapores do solvente. Métodos de HPLC-ESI-MS/MS foram validados para quantificação de todas as lesões em DNA. Foi verificado que THF é um solvente de baixa citoxicidade para células HepG2, sendo necessárias concentrações acima de 50 mM por período de incubação superior a 24 h para ser observada perda de viabilidade. Houve indução de dano oxidativo em DNA de células HepG2 e de fígado de camundongos expostos. Uma vez que o solvente esteja oxidado, a espécie reativa THF-OH presente no meio de cultura é capaz de reagir com RNA e DNA das células e DNA de homogenato de fígado de camundongos, gerando adutos com dAdo, dGuo e Ado. A espécie reativa possui maior afinidade por dGuo que por dAdo no DNA. Entretanto, as células HepG2 não biotransformaram THF para o intermediário reativo. Além disso, THF induziu hipermetilação no DNA das células HepG2 expostas a 50 e 100 mM do solvente e em DNA de fígado de camundongos fêmeas C57BL/6J expostos a vapores de THF (vapor de 1 mL/h, 6h/dia, 5 dias). Este estudo mostra pela primeira vez a reatividade do solvente THF oxidado (contendo THF-OH) com DNA e RNA em sistemas biológicos, assim como alteração epigenética induzida pelo solvente, e servirá para uma melhor compreensão dos mecanismos envolvidos na indução de câncer por THF. / Tetrahydrofuran (THF) is a widely used industrial solvent with demonstrated carcinogenic action in experimental animals, but little is known about its cellular toxicity and genotoxic damage to biomolecules. Previous work of this group showed that DNA adducts are formed from the reaction of oxidized THF with 2\'-deoxyguanosine (dGuo), 2\'-deoxyadenosine (dAdo), and 2\'-deoxycytidine (dCyd) in vitro. The occurrence of these lesions in biological systems exposed to THF has never been demonstrated and may indicate a genotoxic pathway of this solvent, so far not considered in carcinogenesis and toxicity studies. It was investigated here the induction of DNA and RNA lesions in biological systems exposed to THF, as well as epigenetic changes. The biological systems used were mice liver homogenate, HepG2 cell culture, and liver and kidney of mice that were exposed to solvent vapors in a previous work. HPLC-ESI-MS/MS methods were validated for quantitation of all lesions in DNA. It was found that THF is of low cytotoxicity to HepG2 cells, requiring concentrations above 50 mM for incubation period over 24 h to induce loss of viability. DNA oxidative damage was induced in HepG2 cells and liver of exposed mice. Once the solvent is oxidized, the reactive species THF-OH present in the culture medium is able to react with DNA and RNA of HepG2 cells and DNA from mice liver homogenate, generating adducts with dAdo, dGuo and Ado. The reactive species has higher affinity for dGuo than for dAdo in DNA. However, HepG2 cells were not able to activate THF to the reactive intermediate. In addition, THF induced DNA hypermethylation in HepG2 cells exposed to 50 and 100 mM of the solvent and in liver of C57BL/6J female mice exposed to THF vapors (1 mL vapor / h 6h/dia, 5 days). This study shows for the first time the reactivity of oxidized THF (containing THF-OH) with DNA and RNA in biological systems, as well as epigenetic change induced by the solvent, and may contribute for a better understanding of the mechanisms involved in the induction of cancer by THF.

Dietary antioxidants are believed to play an important role in the prevention and treatment of a variety of diseases associated with oxidative stress. Although there is a wide range of dietary antioxidants, the bulk of the research to date has been focused on the nutrient antioxidants vitamin C, E, and carotenoids. Certain relatively uncommon antioxidants such as lipoic acid (LA), and phenolic compounds such as (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG), have not been extensively investigated although they may exert greater antioxidant potency than that of carotenoids and vitamins. Extracts from selected plants and plant byproducts may represent rich sources for one or more of such antioxidants and therefore exhibit higher effects than a single antioxidant due to the synergistic effects produced between such antioxidants. However, in the last decade a number of epidemiological, animal and in vitro studies have suggested a protective and therapeutic potency of these antioxidants in a broad range of diseases such as cancer, diabetes, atherosclerosis, cataract and acute and chronic neurological disorders. Inflammation, the response of the host toward any infection or injury, plays a central role in the development of many chronic diseases. Several evidences demonstrated the rise of different types of cancer from sites of inflammation. This suggests that active oxygen species and some cytokines generated in the inflamed tissues can cause injury to DNA and ultimately lead to carcinogenesis. Diethylnitrosamine (DEN) is one of the most important environmental carcinogens, present in a variety of foods, alcoholic beverages, tobacco smoke and it can be synthesized endogenously. In addition to the liver it can induce carcinogenesis in other organs like kidney, trachea, lung, esophagus, fore stomach, and nasal cavity. Several epidemiological and laboratory studies indicate that nitroso compounds including DEN may induce hyperplasia and chronic inflammation which is closely associated with the development of hepatocellular carcinoma. Despite increasing evidence on the potential of antioxidants in modulating the etiology of chronic diseases, little is known about their role in inflammation and acute phase response (APR). Therefore the aim of the present work was to study the protective effect of water and solvent extracts of eight plant and plant byproducts including green tea, artichoke, spinach, broccoli, onion and eggplant, orange and potato peels as well as eight antioxidants agents including EC, EGC, ECG, EGCG, ascorbic acid (AA), acetylcysteine (NAC), α-LA, and alpha-tocopherol (α-TOC) toward acute inflammation induced by interleukin-6 (IL-6) and hepatotoxicity induced by DEN in vitro. The negative acute phase proteins (APP), transthyretin (TTR) and retinol-binding protein (RBP) were used as inflammatory biomarkers analyzed by ELISA, whereas neutral red assay was used for evaluating the cytotoxicity. All experiments were performed in vitro using human hepatocarcinoma cell line (HepG2). Additionally the antioxidant activity was measured by TEAC and FRAP assays, phenolic content was measured by Folin–Ciocalteu and characterized by HPLC. Moreover, the microheterogeneity of TTR was detected using immunoprecipitation assay combined with SELDI-TOF MS. Results of present study showed that HepG2 cells provide a simple, sensitive in vitro system for studying the regulation of the negative APP, TTR and RBP under free and inflammatory condition. IL-6, a potent proinflammatory cytokine, in a concentration of 25 ng/ml was able to reduce TTR and RBP secretion by approximately 50-60% after 24h of incubation. With exception of broccoli and water extract of onion which showed pro-inflammatory effects in this study, all other plant extracts, at specific concentrations, were able to elevate TTR secretion in normal condition and even under treatment of IL-6 where the effect was quite lower. Green tea followed by artichoke and potato peel exhibited the highest elevation in TTR concentration which reached 1.1 and 2.5 folds of control in presence and absences of IL-6 respectively. In general Plant extracts were ordered according their anti-inflammatory potency as following: in water extracts; green tea > artichoke > potato peel > orange peel > spinach > eggplant peel, where in solvent extracts; green tea > artichoke > potato peel > spinach > eggplant peel > onion > orange peel. The antiinflammatory effect of water extracts of green tea, artichoke and orange peel were significantly higher than their corresponding solvent extracts whereas water extracts of eggplant-, potato peels and spinach showed lower effect than their solvent extracts. On the other hand α-LA followed by EGCG and ECG exhibited the highest elevation in TTR concentration compared to other antioxidants. The relation between the anti-inflammatory potential and antioxidants activity and phenolic content for the investigated substances was generally weak. This may suggest the involvement of other mechanisms than antioxidants properties for the observed effect. TTR secreted by HepG2 cells has a molecular structure quite similar to the purified standard and serum TTR in which all the three main variants are contained including native, S-cystinylated and Sglutathionylated TTR. Interestingly, a variant with molecular mass of 13453.8 + 8.3 Da has been detected only in TTR secreted by HepG2. Among all investigated antioxidants and plant extracts, six substances were able to elevate the native preferable TTR variant. The potency of these substances can be ordered as following α-LA > NAC > onion > AA > EGCG > green tea. A weak correlation between elevation on TTR and shifting to the native form was observed. Similar weak correlation has also been observed between antioxidants activity and elevation in native TTR. Although DEN was able to induce cell death in a concentration dependent manner, it requires considerably higher concentrations for its effects especially after 24h. This may be attributed to a lack in cytochrome P450 enzymes produced by HepG2. At selected concentrations some antioxidants and plant extracts significantly attenuate DEN cytotoxicity as following: spinach > α-LA > artichoke > orange peel > eggplant peel > α-TOC > onion > AA. Contrary all other substances especially green tea, broccoli, potato peel, and ECG stimulate DEN toxicity. In conclusion, this study demonstrated that selected antioxidants and plant extracts may attenuate the inflammatory process, not only by their antioxidants potency but also by other mechanisms which remain unclear. They may also play a vital role on stabilizing the tetramic structure of TTR and thereby prevent amyloidosis diseases. Lipoic acid represents in this study unique function against inflammation and hepatotoxicity. Despite the protective effect demonstrated by investigated substances, attention should also be given to the pro-oxidant and potential cytotoxic effects produced at higher concentrations. / Substanzen und Lebensmittelinhaltstoffe mit antioxidativer Wirkung spielen eine entscheidende Rolle in Prävention und Behandlung zahlreicher Erkrankungen, die mit oxidativen Stress assoziiert sind. Dabei stehen v. a. die Lebensmittelinhaltsstoffen Vitamin C (Ascorbinsäure, AA), Vitamin E und die Carotinoide im Zentrum der Forschung. Da einige bislang relativ ungebräuchliche Antioxidantien wie Liponsäure (LA) und phenolische Substanzen wie (-)-Epicatechin (EC), (-)-Epigallocatechin(EGC), (-)-Epicatechingallat (ECG), und (-)-Epigallocatechingallat (EGCG) ein größeres antioxidatives Potential als Carotinoide und die Vitamine C und E aufweisen, geraten diese in zunehmendem Maße in den Fokus der Forschung und wecken auch immer mehr das Interesse gesundheitsbewusster Verbraucher. Einige ausgewählte Pflanzenextrakte und Extrake pflanzlicher Nebenprodukte stellen ergiebige Quellen der oben erwähnten Substanzen dar und zeichnen sich daher durch eine höhere Wirksamkeit aus, die teilweise auch auf synergetische Effekte zwischen diesen Antioxidantien zurückzuführen ist. Eine Vielzahl epidemiologischer Studien sowie zahlreiche Tier- und in-vitro-Experimente deuten daher darauf hin, daß die oben erwähnten Antioxidantien bei einer Vielzahl von Erkrankugen, wie Krebs, Diabetes, Arteriosklerose, Katarakt, akute bzw. chronische neurologische Störungen, ein schützendes und therapeutisches Potential entfalten. Entzündungen, als Antwort eines Individuums auf Infektion oder Verletzungen, spielen eine zentrale Rolle bei der Entwicklung vieler chronischer Erkrankungen. So konnten mehrere Studien den Zusammenhang zwischen der Entstehung verschiedener Krebsarten und zugrundeliegender Infektionen belegen. Dies deutet darauf hin, dass reaktive Sauerstoffspezies und einige Zytokinen, die im entzündeten Geweben generiert werden und DNA-Schäden verursachen können, letztendlich auch eine Karzinogenese auslösen können. Diethylnitrosamin (DEN) ist eines der bekanntesten Umweltkarzinogene, daß neben Hepatokarzinomen auch Krebs in Nieren, Trachea, Lunge, Speiseröhre, Magen und Nasenhöhle hervorrufen kann und in vielen Lebensmitteln, alkoholischen Getränke sowie Tabakrauch enthalten ist und darüber hinaus endogen synthetisiert wird. Dabei geht man auf Grundlage mehrere epidemiologischer und Forschungsstudien davon aus, dass durch Nitroso-Verbindungen, u.a. auch DEN, induzierte Hyperplasien und chronische Entzündungen die Entwicklung hepatozellulärer Karzinome begünstigt. Trotz zunehmender Beweise bezüglich des Potentials von Antioxidantien die Ätiologie chronischer Erkrankungen zu modulieren, ist bislang nur sehr wenig über ihre Rolle im Entzündungsprozess und der Akutphasereaktion (APR) bekannt. Deshalb war das Ziel der vorliegenden Arbeit die schützende Wirkung von Extrakten verschiedener Pflanzen und Pflanzennebenprodukten sowie isolierten Antikoxidantien bei akuten Entzündungssituationen zu testen. Dazu wurden wässrige und Lösungsmittelextratke aus acht Pflanzen bzw. deren Nebenprodukten (Grüntee, Artischocke, Spinat, Brokkoli, Zwiebel, Aubergine-, Orangen- und Kartoffelschalen) hergestellt und ihre Wirkung sowie die acht weiterer reiner Antioxidantien (EC, EGC, ECG, EGCG, Ascorbinsäure (AA), Acetylcystein (NAC), LA, und -Tocopherol (TOC) in in-vitro-Modellen der akuten Entzündung, induziert durch interleukin-6 (IL-6), bzw. der Hepatoxizität, induziert durch DEN, getestet.. Transthyretin (TTR) und Retinol-Bindungsprotein (RBP), zwei negative Akutphasenproteine (APP) wurden als Entzündungsbiomarker (Analyse per ELISA) und Neutral-Red-Assay als ein Maß für die Cytotoxizität herangezogen. Alle Experimente wurden in-vitro in einer immortalisierten humanen Hepatokarzinom-Zelllinie (HepG2) durchgeführt. Die antioxidativen Kapazität wurde mittels TEAC und FRAP-Methoden evaluiert und der Gesamtphenolgehalt durch die Folin–Ciocalteu-Methode erfasst, wobei die qualitative Charakterisierung über die HPLC erfolgte. Die Mikroheterogenität des TTR wurde durch Immunopräzipitation in Kombination mit SELDI-TOF-MS Technik analysiert. Die Ergebnisse dieser Studie zeigen, dass HepG2-Zellen ein einfaches und empfindliches in-vitro System zur Regulierung von negativen Akutphasenproteinen, TTR und RBP, unter physiologischen und infllammatorischen Bedingungen darstellen. IL-6, ein potentes Pro-Entzündungszytokine, war bei einer 24stündigen Inkubation mit einer Konzentration von 25 ng/ ml in der Lage die Sekretion von TTR und RBP um ca. 50-60% zu reduzieren. Mit Ausnahme von Broccoli und Wasser Extrakt der Zwiebel, die zeigten, proinflammatorischen Effekt Wirkungen in dieser Studie, die alle anderen Pflanzenextrakten, in bestimmten Konzentrationen, waren in der Lage zu erheben TTR Sekretion im normalen, aber auch bei der Behandlung von IL-6 bei denen die Wirkung war niedriger. Grüntee, gefolgt von Artischocken und Kartoffelschälen zeigte die höchste Erhebung in der TTRKonzentration, die erreicht, 1,1 und 2,5 Falten der Kontrolle in Behandlung und ohne Behandlung von IL-6 bzw. Die wässrigen Pflanzenextrakte lassen sich in der folgenden Reihenfolge des anti-Entzündungspotentials einordnen: Grüntee > Artischocke > Kartoffelschalen > Orangenschalen > Spinat > Aubergineschalen, wogegen bei Lösungsmittelextrakte folgende Reihenfolge ermittelt wurde: Grüntee > Artischocke > Kartoffelnschalen > Spinat > Aubergineschalen > Zwiebel > Orangenschalen. Die schützende Wirkung der wässrigen Extrakte von Grüntee, Artischocke und Orangenschalen war signifikant höher als die der entsprechenden Lösungsmittelextrakte. Wohingegen wässrige Extrakte aus Aubergineschalen, Kartoffelschalen, Spinat und Zwiebel weniger effektiv waren. Auf der anderen Seite, LA gefolgt von EGCG und ECG zeigte die höchste Erhebung in der TTRKonzentration im Vergleich zu anderen Antioxidantien. Somit konnte ein schwacher aber Zusammenhang zwischen antinflammatorischem Potential, antioxidativer Aktivität und Phenolgehalt nachgewiesen werden. Daher ist anzunehmen, dass den beobachteten Effekten anderen Mechanismen zu Grunde liegen. Das durch HepG2-Zellen sezernierte TTR erwies eine molekulare Struktur ähnlich der des verwendeten Standards bzw. des TTR aus humanem Serum auf. Es enthielt alle drei Hauptvarianten, einschließlich der nativen, S-cystinylierten und S-glutathionylierten TTR-Formen. Darüber hinaus wurde nur im in-vitro sezerniertem TTR (TTR aus HepG2-Zellen) eine Variante mit einer molekularen Masse von 13453.8 + 8.3 Da nachgewiesen. Von den untersuchten Substanzen wiesen nur sechs Verbindungen die Fähigkeit auf den Anteil der günstigen nativen TTR-Form zu erhöhen aus. Dabei konnte folgende Wirksamkeitsreihenfolge zugeordnet werden : LA > NAC > Zwiebel > AA > EGCG > Grüntee. Eine schwache Korrelation zwischen der Erhöhung der TTRKonzentration und der Verschiebung zu der nativen Form hin wurde festgestellt. Ein ähnlicher Zusammenhang zwischen der antioxidativen Aktivität und dieser Erhöhung wurde auch beobachtet. Obwohl DEN in der Lage war konzentrationsabhängig den Zelltod zu induzieren, war eine wesentlich höhere Konzentration notwendig, um die volle Wirksamkeit während 24stündiger Inkubation zu gewährleisten. Dies mag auf die mangelnde Ausstattung mit Cytochrom-P450-Enzymen, die in den HepG2 Zellen produziert werden, zurück zu führen sein. Ausgewählte Konzentrationen einiger eingesetzter Substanzen führten zu einer signifikanten Schwächung der DEN-induzierten Zytotoxizität mit folgender Wirksamkeit: Spinat > LA > Artischocke > Orangen- > Aubergineschalen > TOC > Zwiebel > AA. Im Gegensatz dazu, stimulierten alle anderen Substanzen, insbesondere Grüntee, Brokkoli, Kartoffelschalen und ECG, die DEN –induzierten Toxizität. Diese Arbeit zeigt somit, dass ausgewählte Antioxidantien und Pflanzenextrakten in der Lage sind, den antinflammatorischen Prozess sowohl durch ihre antioxidative Wirkung als auch durch bislang nicht aufgeklärten Mechanismen grundlegend zu beeinflussen. Sie könnten daher eine entscheidende Rolle bei der Stabilisierung von Proteinstrukturen übernehmen (gezeigt am Beispiel vom TTR) und in diesem Zusammenhang möglicherweise auch zur Prävention von Krankheiten wie Amyloidosen beitragen. Liponsäure überzeugte in dieser Arbeit durch seine einzigartigen Funktion gegenüber Entzündungssituationen und Hepatoxizität. Wie oft beobachtet und durch diese Studie bestätigt, weisen die verwendeten Subsatzen neben der schützenden anti- auch pro-oxidativen Wirkungen auf, wodurch die Notwendigkeit weiterer Untersuchungen zur Erfassung der Zytotoxizität beim Einsatz höherer Konzentration verdeutlicht wird.

Os herbicidas são destinados ao controle das ervas daninhas e seu uso torna o fornecimento de alimentos abundante e livre de pragas, porém a exposição ocupacional e ambiental a esses compostos pode trazer riscos à saúde. O Brasil é o maior consumidor de praguicidas desde 2008, e os herbicidas correspondem por 45% do volume dessas substâncias. O tebutiurom e a trifluralina são herbicidas muito utilizados em culturas de cana-de-açúcar, e apesar de serem descritos como seletivos em seu mecanismo de ação, seus efeitos em organismos não alvo, como células humanas, são pouco conhecidos. O objetivo do trabalho foi avaliar os efeitos dos herbicidas tebutiuron e trifluralina em organismos não alvo. Para isso, utilizou-se a linhagem celular HepG2, e as concentrações testadas dos herbicidas foram de 1 a 100 ?mol/L e o tempo de exposição variou de 4 h à 14 dias de acordo com o ensaio. Utilizou-se também as linhagens TA98 TA100, TA97a e TA1535 da bactéria S typhimurium. Neste caso, as concentrações testadas dos herbicidas variaram de 0,1 à 5000 ?g/placa e o tempo de exposição foi de 66 h. As análises indicaram que o tebutiurom não apresenta potencial citotóxico, genotóxico, ou mutagênico nas condições testadas, evidenciando sua seletividade. Testes com a trifluralina, no entanto, mostraram que HepG2 apresentaram uma diminuição da capacidade em formar clones quando expostas à 100 ?mol/L por 14 dias, e uma redução na densidade celular quando expostas à 50 e 100 ?mol/L por 24, 48 e 72h. Tais efeitos ocorreram devido a uma diminuição da viabilidade celular, observada em 50 e 100 ?mol/L pelo ensaio MTT, e devido a um bloqueio no ciclo celular na fase S, evidenciado em 100 ?mol/L, ambos nos tempos de 24, 48 e 72h. O tipo de morte celular inicialmente observada foi a apoptose, através da marcação por anexina V em 100 ?mol/L após 48 e 72 h de exposição, e através da condensação e fragmentação nuclear em 100 ?mol/L após 24 e 48 h de exposição. Em 72 h, observou-se também necrose em 100 ?mol/L, por meio dos testes anexina V/PI e liberação de LDH. A morte celular pode estar relacionada à diminuição do potencial de membrana mitocondrial, observada em 50 e 100 ?mol/L após 24, 48 e 72h, e a um aumento na produção de espécies reativas, efeito observado em células expostas à 100 ?mol/L de trifluralina por 24 e 48 h. No entanto, observou-se que a via de resposta ao estresse oxidativo Keap1/Nrf2-ARE não foi ativada no tempo analisado de 24 h. Além disso, os testes de cometa e micronúcleo não indicaram potencial da trifluralina em provocar danos no material genético de HepG2. Complementarmente, o teste de Ames em linhagens de S typhimurium também não evidenciaram potencial mutagênico do herbicida. As análises com a trifluralina mostraram que o herbicida, apesar de não induzir genotoxicidade e mutagenicidade, possui potencial citotóxico em HepG2, indicando que pode afetar organismos não alvo, como células humanas / Herbicides are used to control weeds in agriculture. The use of these chemicals makes possible an abundant and pest free supply of food. However, occupational and environmental exposure to these compounds can lead to health risks. Brazil is the largest consumer of pesticides since 2008, and herbicides match for 45% of the volume of these substances. The tebutiurom and trifluralin herbicides are widely used in sugarcane crops, and although they are described as selective in its mechanism of action, effects on non-target organisms, such as human cells, are are poorly known. The aim of this work was to evaluate the effects of tebuthiuron and trifluralin herbicides on non-target organisms. To this end, we used the cell line HepG2, and herbicides were tested at concentrations of 1 to 100 ?M and the exposure time ranged from 4 h to 14 days in accordance with the assay. We also used the strains TA100 TA98, TA97a and TA1535 of the bacterium S. typhimurium. In this case, the herbicide concentrations tested ranged from 0.1 to 5000 ?g / plate and the exposure time was 66 h. Analyzes indicated that the tebutiurom has no cytotoxic, genotoxic or mutagenic potential at tested conditions, highlighting its selectivity. Tests with the Trifluralin, however, showed that HepG2 had a decreased ability in forming clones when exposed to 100 ?M for 14 days, and a reduction in cell density when exposed to 50 and 100 ?M of the herbicide for 24, 48 and 72h. These effects occurred due a decrease in cell viability observed at 50 and 100 ?M by MTT assay, and due to a block in the cell cycle into S phase, as evidenced in 100 ?M, both at 24, 48 and 72h. The type of cell death detected first was apoptosis. It was observed by staining with annexin V in cells exposed to 100 ?M of trifluralin during 48 and 72 h, and through the nuclear condensation and fragmentation in exposure with 100 ?M during 24 and 48 h of exposure. At 72 h, necrosis was also observed in 100 ?M through the annexin V / PI and LDH assays. Cell death occurrence may be associated with decreased mitochondrial membrane potential observed in 50 and 100 ?M after 24, 48 and 72h of exposure, and also may be associated with incresed production of reactive species, observed in cells exposed to 100 ?M of trifluralin for 24 and 48 h. However, it was observed that the oxidative stress response pathway Keap1 / Nrf2-ARE was not activated within 24 hours. Furthermore, comet assay and micronucleus test indicated no potential of trifluralin in causing DNA damage of HepG2. In addition, the Ames test using S. typhimurium strains also showed no mutagenic potential of the herbicide. The analyzes showed that the trifluralin, despite not induce genotoxicity and mutagenicity, have cytotoxic potential in HepG2, indicating that can affect non-target organisms, such as human cells.

O fator alimentar pode ser considerado um promotor tumorigênico responsável pela etiologia do câncer gástrico no estado do Pará. A mandioca (Manihot esculenta Crantz) é uma das muitas espécies da Amazônia consumida de modo indiscriminado pelos habitantes da região norte. O cianeto, seu principal componente tóxico, pode ser liberado durante o processamento da mandioca por meio da hidrólise do glicosídeo cianogênico linamarina. No organismo, o cianeto bloqueia a cadeia de transporte de elétrons inibindo a respiração celular e, provocando, entre outras coisas, a produção de radicais livres que podem agir no DNA, através da formação de adutos exocíclicos. O objetivo deste trabalho foi a avaliação da atividade citotóxica, genotóxica e mutagênica de folhas e tucupi, crus e cozidos, de mandioca mansa e brava, usando os ensaios do MTT, cometa e citoma em células HepG2. Os resultados obtidos demonstraram que a viabilidade celular decai à medida que a concentração aumenta na maioria dos grupos de tratamento. No ensaio do cometa, a análise visual demonstrou que o cianeto de potássio, usado como padrão, foi genotóxico em todas as concentrações testadas (5,0; 15,0 e 25,0 ?g/mL). As amostras de folhas de mandioca brava foram genotóxicas somente nas concentrações 15,0 e 25,0 ?g/mL (cruas) e 5,0; 15,0 e 25,0 ?g/mL (cozidas). As amostras de mandioca mansa foram genotóxicas apenas quando cozidas (5,0 e 25,0 ?g/mL). Já as amostras de tucupi, tanto cruas quanto cozidas, demonstraram dano ao DNA de células HepG2 em todas as concentrações testadas (20,0; 40,0 e 60.0 ?g/mL). Utilizando análise de fragmentação de DNA observamos que o cianeto de potássio foi genotóxico apenas na avaliação da porcentagem de DNA na cauda. Já amostras de mandioca brava e mansa, de maneira geral, demonstraram valores de porcentagem de DNA na cauda, tail moment e olive moment maiores em relação ao grupo controle negativo, mas, somente as folhas de mandioca, em algumas concentrações, demonstraram valores estatisticamente significativos. Observando o ensaio do citoma, as concentrações de folhas e tucupi, crus e cozidos, tanto de mandioca brava quanto de mandioca mansa mostraram um discreto aumento no número de micronúcleos em células HepG2 binucleadas, estatisticamente não significativo, em relação ao grupo controle negativo. Já o número de pontes nucleoplasmáticas e brotos nucleares foi menor que no grupo controle. Os danos aqui observados pelo ensaio do cometa podem estar transitoriamente presentes ii como intermediários formados durante o reparo de lesões no DNA. A ausência de brotos nucleares, pontes nucleoplasmáticas e resultados estatísticos significativos em relação ao grupo controle negativo, não nos permitem afirmar presença de mutagenicidade em células HepG2 tratadas com mandioca tanto brava quanto mansa. De maneira geral, o cozimento das amostras não foi um fator determinante na diminuição do dano observado em células HepG2. Nossos resultados confirmam apenas citotoxicidade e genotoxicidade das variedades da mandioca nas concentrações e sistema celular utilizados. Os mecanismos moleculares que envolvem a genotoxicidade da mandioca requerem estudos futuros. Para o consumo da mandioca devem ser levados em consideração tipo de processamento realizado para extração de compostos cianogênicos, níveis de glicosídeos cianogênicos nos produtos consumidos, quantidade de mandioca consumida e estado nutricional do consumidor / The food factor can be considered a tumor causing agent reponsasible for the etiology of gastric cancer in the state of Pará Cassava ( Manihot esculenta Crants is one of the many food species of the Amazon indiscriminately consumed by the inhabitants of the northern region Cyanide, its main toxic component, can be released during cassava processing through the hydrolysis of the cyanogenic glycoside linamarin. In the body, cyanide blocks the electron transport chain by inhibiting cell respiration which brings about, among other things, the production of free radicals which can act upon DNA through the formation of exocyclical adducts. The main goal of this study was the assessment of the citotoxic, genotoxic and mutagenic role of the leaves and tucupi juice of wild and sweet cassava, both raw and cooked, using the MTT, comet and cytome assays in HepG2 cells. The results gathered have shown that cell viability decreases as the concentration increases in most treatment groups. In the comet assay, a visual analysis has shown that potassium cyanide, used as a standard, was genotoxic in all concentrations tested (5.0, 15.0 and 25.0 ?g/mL). Samples of wild cassava leaves were genotoxic only in concentrations of 15.0 and 25.0 ?g/mL for raw leaves, and 5.0, 15.0 and 25.0 ?g/mL for cooked leaves. Samples of sweet cassava leaves were genotoxic only when cooked (5.0 and 25.0 ?g/mL). Yet, samples of tucupi juice, both raw and cooked, have shown damage to DNA in HepG2 cells at all concentrations tested (20.0, 40.0 and 60.0 ?g/mL). In performing DNA fragmentation analysis, it was observed that potassium cyanide was genotoxic only in the assessment of percentage DNA in tail. Whereas the wild and sweet cassava samples, in a general fashion, have shown greater values of percentage DNA in tail, tail moment and olive moment than the negative control group, but only the cassava leaves revealed statistically significant values, in some concentrations. For the cytome assay, concentrations of leaves and of tucupi juice, raw and cooked, of both wild and sweet cassava, have shown a slight increase in the number of micronuclei in binucleated HepG2 cells, not statistically significant as compared to the negative control group. On the other hand, the number of nucleoplasmic bridges and nuclear buds in binucleated cells was lower than the value found in the negative control group. The damages verified herein by the comet assay may be transiently present as intermediates formed during repair of DNA lesions. The absence of iv nucleoplasmic bridges, nuclear buds and of statistically significant results vis-à-vis the negative control group do not warrant the assertion for the presence of mutagenicity in HepG2 cells treated with either wild or sweet cassava. In general, the cooking of the samples was not determining factor of the decrease in damage observed in HepG2 cells. Our results only confirm cytotoxicity and genotoxicity of wild and sweet cassava species in the concentrations and cell system used. The molecular mechanisms involving genotoxicity of cassava require further studies. For the consumption of cassava, the way of processing performed for extracting cyanogen contents, the levels of cyanogenic glycosides in the products consumed, amount of cassava consumed as well as the nutritional condition of the consumer must be taken into account.

Les liposomes d’ATP incluant des ligands hépatiques pourraient contribuer à améliorer le statut énergétique du greffon hépatique. Une première phase de développement a mis en évidence la nécessité de stabiliser la forme (i) et de valider un modèle cellulaire à statut énergétique altéré (ii) afin de pouvoir tester différentes formulations liposomales d’intérêt. Afin de résoudre la première problématique, différentes stratégies ont été mises en place lors de la lyophilisation de liposomes blancs ou chargés en ATP. Le saccharose et le tréhalose ont conduit à une stabilisation de la forme avant et après lyophilisation. Néanmoins, quel que soit le procédé, la lyophilisation s’est accompagnée d’une fuite en ATP. L’ajout d’un agent inhibant la cartinine palmitoyl transferase, l’Etomoxir, s’est révélé un modèle intéressant pour moduler le niveau énergétique des HepG2 en fonction de la température et de la concentration utilisée. En conclusion, ce travail contribue à mieux comprendre les facteurs critiques liés à la lyophilisation des liposomes (i) et décrit des modèles cellulaires hépatiques à statut énergétique altéré qui pourraient être mis à profit pour tester différents principes actifs ou formes galéniques innovantes. / ATP liposome incorporating hepatic ligands may contribute to improve the energetic status of the liver graft. In a first phase of development, it has been emphasized the great need of stabilizing the liposome (i) and of validating a cellular model with an altered energetic status in order to test the formulations of interest. To provide a stable liposomal preparation, different strategies have been carried out to freeze-dry liposome with or without ATP. Sucrose and trehalose better stabilize the liposome preparation during the freeze-drying process. Nevertheless, in all conditions, a significant ATP leakage has been observed. An inhibitor of the cartinine palmitoyl transferase (i.e. Etomoxir) has shown great interest to modulate the energetic level in HepG2 cells by varying Etomoxir concentration and culture temperature. In conclusion, this study contributes to a better understanding of the critical factors related to liposome freeze-drying and describes hepatic cell models with altered energetic status that may have great interest to test specific agent or innovating formulations.

Submitted by FERNANDA DA SILVA VON PORSTER (fdsvporster@univates.br) on 2016-09-22T19:02:03Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 2016JulianoLeipelt.pdf: 2508061 bytes, checksum: 100e43c73eddacc8441a11de473e260c (MD5) / Approved for entry into archive by Ana Paula Lisboa Monteiro (monteiro@univates.br) on 2016-09-29T19:20:07Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 2016JulianoLeipelt.pdf: 2508061 bytes, checksum: 100e43c73eddacc8441a11de473e260c (MD5) / Made available in DSpace on 2016-09-29T19:20:08Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 2016JulianoLeipelt.pdf: 2508061 bytes, checksum: 100e43c73eddacc8441a11de473e260c (MD5) Previous issue date: 2016-09 / O câncer é apontado como a segunda maior causa de morte em todo o mundo, com previsão de em breve ser tornar a primeira. O câncer de próstata está entre os 5 tipos de câncer mais diagnosticados em homens, sendo que o câncer hepático está em segundo lugar em taxa de mortalidade entre homens e mulheres. Indícios apontam para uma ativação das vias da inflamação associados a uma inibição das vias de morte celular no processo de carcinogênese. A regulação destas vias torna-se alvo importante e complementar no controle do câncer, sendo estimulada a busca de biomoléculas com este potencial. As plantas são importante fonte de descoberta de novas biomoléculas com ampla utilização para o tratamento de diversas patologias. A família Myrtaceae possui diversas espécies que são apontadas como fortes candidatos em potencial nesta busca, incluindo as do gênero Myrciaria. A espécie Myrciaria plinioides não possui estudos referentes suas propriedades terapêuticas ou a atuação em vias de sinalização envolvidas na inflamação ou na carcinogênese. Neste contexto, este estudo teve por objetivo avaliar a atividade do extrato etanólico de M. plinioides em células de carcinoma hepatocelular (HepG2) e próstata (LNCaP) , através da análise de expressão dos marcadores p38-α, pp38-α, NF-κB e caspase-3, envolvidos na carcinogênese, e o efeito sobre a viabilidade celular através do método de MTT. A viabilidade das células foi alterada significativamente, em ambas as linhagens celulares quando tratadas com o extrato etanólico. A análise da expressão proteica demonstra significativa inibição da expressão de p38-α e caspase-3 nas células LNCaP, quando tratadas com extrato etanólico de M. plinioides seguido de LPS. Em células HepG2, somente houve alteração na expressão da caspase-3 na concentração de 200 μg/mL, com ou sem adição de LPS após tratamento com extrato. Os resultados deste estudo demonstraram redução da viabilidade celular nas duas linhagens tumorais, expressão diferenciada de proteínas envolvidas em apoptose, o que leva a indícios da ativação de mecanismos distintos pelo extrato em cada tipo celular. Estudos futuros para averiguar o mecanismo celular e a indução de morte em células tumorais de câncer de próstata e de fígado podem contribuir para a identificação e elucidação de novas biomoléculas com potencial antitumoral. / Cancer is touted as the second leading cause of death worldwide, forecast to soon be making the first. Prostate cancer is among the five most cancers diagnosed in men, and liver cancer is second in mortality between men and women. Evidence points to the activation of pathways of inflammation associated with an inhibition of cell death pathways in carcinogenesis. The regulation of these pathways becomes important and complementary target in cancer control, and stimulated the search for biomolecules with this potential. The plants are important source of discovery of new biomolecules with wide use for the treatment of various diseases. The Myrtaceae family has many species that are identified as potential candidates strong in this search, including the Myrciaria genre. The species Myrciaria plinioides not have studies on its therapeutic properties or performance in signaling pathways involved in inflammation or carcinogenesis. In this context, this study aimed to evaluate the activity of the ethanol extract of M. plinioides in hepatocellular carcinoma cells (HepG2) and prostate (LNCaP) by expression analysis of p38-α markers, PP38-α, NF-kB and caspase-3, involved in carcinogenesis, and the effect on cell viability by the MTT method. The viability of cells was significantly altered in both cell lines when treated with ethanolic extract. Protein expression analysis demonstrates significant inhibition of p38-α expression and caspase-3 in LNCaP cells, when treated with ethanolic extract of M. plinioides followed by LPS. In HepG2 cells there was only a change in the expression of caspase-3 at a concentration of 200 / ml, with or without addition of LPS after treatment with extract. The results showed reduction of cell viability in both tumor lines, differential expression of proteins involved in apoptosis, leading to evidence of activation by distinct mechanisms in each extract cell type. Further studies to investigate the cellular mechanism, and induction of death in tumor cells of prostate and liver cancer may contribute to the identification and elucidation of new biomolecules with antitumor potential.

The cytotoxic effects of exposure to low concentrations of the herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D) that are typically found in groundwater were investigated, in vitro. Most 2,4-D toxicology studies use high concentrations of the herbicide that are above those typically found in groundwater and measure overt biological endpoints. In contrast, this thesis examines the effects of low concentrations of 2,4-D and measures more subtle and sensitive endpoints such as gene expression and the generation of reactive oxygen species. This work derives from recent cDNA microarray analysis conducted in our laboratory that revealed significant alterations in the expression of 238 genes in cells exposed to nanomolar (nM) concentrations of a commercial formulation of 2,4-D. These findings are extended in this thesis to include the in vitro cytotoxic effects of low concentrations of both technical and commercial 2,4-D on two cell lines. Cells derived from liver (HepG2) and kidney (HEK293) respectively, were chosen, since liver and kidney are known to metabolize 2,4-D in vivo. Cell viability was measured using the Resazurin assay, reactive oxygen species (ROS) were measured with 2,7-dichlorofluorescin diacetate (2,7-DCFH-DA), and real timepolymerase chain reaction (RT-PCR) was used to assess changes in mRNA expression while protein expression was examined by Western blot.<p>Cell viability studies revealed that low environmental concentrations (0.1 to 100 nM) of 2,4-D induced small, but statistically significant decreases in cell viability. No concentration or time-dependent decreases in cell viability were observed in cells exposed to either forms of low environmental 2,4-D concentrations. HEK293 cells were more susceptible than HepG2 cells to the toxic effects of both forms of 2,4-D, having statistically significant lower viability at all exposure concentrations and durations. Both forms of 2,4-D reduced cell viability in both cell lines, suggesting that cytotoxicity was induced directly by 2,4-D, and not by the inert ingredients in the commercial formulation.<p>The ROS assays illustrated that 2,4-D induced statistically significant ROS production in HepG2 and HEK293 cell cultures at concentrations greater than 10 µM and 100 nM respectively. This was both a concentration and time-dependent effect in both cell lines. Although HEK293 cells were more susceptible to 2,4-D, they had 50 to 70% less ROS production than HepG2 cells, at all exposure concentrations and times.<p>The RT-PCR and Western blot analyses showed that exposure of HepG2 and HEK293 cells to low 2,4-D concentrations induced (< 2 fold) alterations in mRNA and protein levels of FTL, FTH1 and PCNA however these changes did not consistently vary with concentration.<p>Taken together, cell viability, ROS and gene expression studies show that low environmental 2,4-D concentrations induced subtle in vitro cytotoxic effects. However we have no evidence that these subtle changes pose a serious health threat to exposed humans.