Made available in DSpace on 2014-06-11T19:31:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2005Bitstream added on 2014-06-13T19:20:19Z : No. of bitstreams: 1 fonteque_jh_dr_botfmvz.pdf: 314172 bytes, checksum: a0386e439bd656f3236dc3ec523e7bea (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A produção de espécies reativas de oxigênio (ERO) é um evento presente em todas as células do organismo e pode estar aumentada em condições como hipóxia induzida pela anemia causando lesões em moléculas como DNA, lipídeos e proteínas. Com o objetivo de avaliar o estresse oxidativo na anemia induzida por perda aguda de sangue, foram utilizados 10 ovinos, mestiços da raça Texel, machos e fêmeas, com idade entre seis e oito meses, clinicamente sadios, mantidos em regime de confinamento. Os animais foram submetidos a duas flebotomias para a retirada de 30% e 20% do volume sangüíneo com intervalo de 12 horas. Amostras de sangue foram colhidas imediatamente antes da flebotomia, 6h e 12h após a primeira flebotomia, 6h, 12h, 24h, 48h, 72 horas, 4d, 5d, 6d, 10d, 14d, 21d e 28 dias após a segunda flebotomia. Foram avaliados o óxido nítrico, substâncias reativas ao ácido tiobarbitúrico, malondialdeído, cortisol e lactato séricos, hemograma e bioquímica sérica. A análise estatística dos dados foi realizada por meio do Teste de Análise de Variância de Medidas Repetidas (ANOVA) ao nível de 5% de significância. Os resultados demonstraram que o protocolo de indução de anemia foi capaz de induzir anemia 12 horas após a segunda flebotomia, estresse oxidativo e lipoperoxidação caracterizado pelo aumento das substâncias reativas ao ácido tiobarbitúrico. O cortisol elevou-se e alterou o leucograma aumentando o número de leucócitos, neutrófilos e a relação neutrófilo:linfócito. Todos os animais recuperaram-se dentro do período de 28 dias após a flebotomia. Conclui-se que a retirada de 30% e 20% do volume de sangue com intervalo de 12 horas provoca estresse oxidativo e lipoperoxidação em ovinos. / Reactive oxygen species (ROS) are produced in all cells and an increase can be associated with hypoxia induced by anemia. This results in DNA, lipid and protein damage. The aim of this work was to evaluate the oxidative stress induced by experimental acute blood loss. Ten healthy cross Texel sheep underwent two phlebotomies with 12 hours interval. Blood samples were collected before the first phlebotomy (30% of blood volume) and 6 and 12 hours after. A second phlebotomy was performed 12 hours after the first one (20% of blood volume) and blood samples were collected, 6h, 12h, 24h, 48h, 72h, 4 days, 5 days, 6 days, 10 days, 14 days, 21 days and 28 days after. Thiobarbituric acid-reactive substances, malondialdehyde, nitric oxide, lipid peroxidation, serum cortisol, serum lactate, CBC and serum biochemistry were evaluated. Statistical analysis was reformed using repeated measures ANOVA. The experimental protocol used was able to induce anemia 12 hours after the second phlebotomy resulting in oxidative stress and lipoperoxiation characterized by the thiobarbituric acid-reactive substances increase. There was also a cortisol increase causing white blood cell changes: increased number of leukocytes, neutrophils and neutrophil and lymphocyte rate. All animals were normal 28 days after the phlebotomy. In conclusion, the protocol used showed that phlebotomy causing 30 and 20% at blood loss can induce oxidative stress and, lipid peroxidation in sheep.

Orientador: Aguemi Kohayagawa. / Resumo: A produção de espécies reativas de oxigênio (ERO) é um evento presente em todas as células do organismo e pode estar aumentada em condições como hipóxia induzida pela anemia causando lesões em moléculas como DNA, lipídeos e proteínas. Com o objetivo de avaliar o estresse oxidativo na anemia induzida por perda aguda de sangue, foram utilizados 10 ovinos, mestiços da raça Texel, machos e fêmeas, com idade entre seis e oito meses, clinicamente sadios, mantidos em regime de confinamento. Os animais foram submetidos a duas flebotomias para a retirada de 30% e 20% do volume sangüíneo com intervalo de 12 horas. Amostras de sangue foram colhidas imediatamente antes da flebotomia, 6h e 12h após a primeira flebotomia, 6h, 12h, 24h, 48h, 72 horas, 4d, 5d, 6d, 10d, 14d, 21d e 28 dias após a segunda flebotomia. Foram avaliados o óxido nítrico, substâncias reativas ao ácido tiobarbitúrico, malondialdeído, cortisol e lactato séricos, hemograma e bioquímica sérica. A análise estatística dos dados foi realizada por meio do Teste de Análise de Variância de Medidas Repetidas (ANOVA) ao nível de 5% de significância. Os resultados demonstraram que o protocolo de indução de anemia foi capaz de induzir anemia 12 horas após a segunda flebotomia, estresse oxidativo e lipoperoxidação caracterizado pelo aumento das substâncias reativas ao ácido tiobarbitúrico. O cortisol elevou-se e alterou o leucograma aumentando o número de leucócitos, neutrófilos e a relação neutrófilo:linfócito. Todos os animais recuperaram-se dentro do período de 28 dias após a flebotomia. Conclui-se que a retirada de 30% e 20% do volume de sangue com intervalo de 12 horas provoca estresse oxidativo e lipoperoxidação em ovinos. / Abstract: Reactive oxygen species (ROS) are produced in all cells and an increase can be associated with hypoxia induced by anemia. This results in DNA, lipid and protein damage. The aim of this work was to evaluate the oxidative stress induced by experimental acute blood loss. Ten healthy cross Texel sheep underwent two phlebotomies with 12 hours interval. Blood samples were collected before the first phlebotomy (30% of blood volume) and 6 and 12 hours after. A second phlebotomy was performed 12 hours after the first one (20% of blood volume) and blood samples were collected, 6h, 12h, 24h, 48h, 72h, 4 days, 5 days, 6 days, 10 days, 14 days, 21 days and 28 days after. Thiobarbituric acid-reactive substances, malondialdehyde, nitric oxide, lipid peroxidation, serum cortisol, serum lactate, CBC and serum biochemistry were evaluated. Statistical analysis was reformed using repeated measures ANOVA. The experimental protocol used was able to induce anemia 12 hours after the second phlebotomy resulting in oxidative stress and lipoperoxiation characterized by the thiobarbituric acid-reactive substances increase. There was also a cortisol increase causing white blood cell changes: increased number of leukocytes, neutrophils and neutrophil and lymphocyte rate. All animals were normal 28 days after the phlebotomy. In conclusion, the protocol used showed that phlebotomy causing 30 and 20% at blood loss can induce oxidative stress and, lipid peroxidation in sheep. / Doutor

Diabetes mellitus (DM) refers to a group of common metabolic disorders that share the phenotype of hyperglycemia, is a chronic condition that arises when the pancreas does not produce enough insulin or when the body can not effectively use the insulin produced.The condition of chronic hyperglycemia promotes an imbalance between the production of free radicals and endogenous antioxidant defense, causing oxidative stress and finally lipid peroxidation, structures and cell membranes rich in lipids. Quercetin (QUE) is a flavonoid that has antioxidant and anti-inflammatory properties and is therefore investigated as a possible adjuvant in the treatment of diabetes. In this study we analyzed the actions of excess free radicals, promoted by type 1 diabetes mellitus (DM T1) at both systemic and mainly in the cholinergic system. Moreover, the possible effects of antioxidant protection and anti-inflammatory of QUE were analysed. We used 130 male Wistar rats, weighing 160 to 250 g and divided into 2 groups: non-diabetic and diabetic, which are divided into 5 treatments: 0.9% saline, 25% ethanol and QUE (5, 25 and 50 mg/kg).The induction of DM T1 occurred with a single intraperitoneal injection of 70 mg/kg streptozotocin (STZ). Fifteen days later, the treatment with QUE for 40 days started. At the end of the experiment behavioral tests and collection of biological material (blood and tissues) were performed. The untreated diabetic group compared to non-diabetic control showed: reduction of the islets and beta-cell population, weight loss, chronic hyperglycemia, leukopenia associated with neutropenia, decreased insulin and albumin, increase in fructosamine, triglycerides, urea, alkaline phosphatase (ALP), alanine aminotransferase (ALT), in addition to protein fractions of beta and gamma globulin.The increase of thiobarbituric acid reactive substances (TBARS) levels was accompanied by a reduction in the concentration of hepatic superoxide dismutase. Failed aversive memory formation and anxious behavior were observed in these animals, as well as increase in the activity of acetylcholinesterase (AChE) in brain structures and sites (cortex, hippocampus, striatum and synaptosomes) and TBARS (cortex, hippocampus and striatum). Diabetic rats treated with QUE in relation to diabetic control had increased albumin (50 mg/kg), reduction in betaglobulins (25 and 50 mg/kg) and gamma globulins (50 mg/kg), decreased triglycerides (5, 25 and 50 mg/kg). Quercetin reverted the aversive memory failure and showed anxiolytic properties. AChE activity were decreased in the cortex (50 mg/kg), hippocampus (5 and 50 mg/kg) and synaptosomes (50 mg/kg). Levels of TBARS were reduced in the cortex, hippocampus and striatum (5, 25 and 50 mg/kg). Quercetin increased the concentration of insulin in non-diabetic and diabetic groups (5, 25 and 50 mg/kg). When administered in non-diabetic animals, QUE increased the uneasiness of the animals (50 mg/kg) increased AChE activity in the hippocampus (5, 25 and 50 mg/kg), striatum (5 mg/kg) and synaptosomes (25 mg/kg), lowering in the cortex (5 mg/kg), furthermore, increased the level of TBARS in the cortex (25 mg/kg).From these results we conclude that QUE have antioxidant and anti-inflammatory properties which may be used in conjunction with treatment of diabetes. However, it also had undesirable properties, such as pro-oxidant effect and induces insulin resistance. / Diabetes melito (DM) refere-se a um grupo de distúrbios metabólicos comuns que compartilham o fenótipo da hiperglicemia, sendo uma condição crônica que surge quando o pâncreas não produz insulina em quantidade suficiente ou quando o organismo não consegue utilizar de modo eficaz a insulina produzida. A condição de hiperglicemia crônica favorece o desequilíbrio entre a produção de radicais livres e a defesa antioxidante endógena, gerando o estresse oxidativo e por fim a peroxidação lipídica de estruturas e membranas celulares, ricas em lipídios. A quercetina (QUE) é um flavonoide que apresenta propriedades antioxidantes e anti-inflamatórias, sendo por isso, investigada como possível adjuvante no tratamento do DM. No presente trabalho foram analisadas as ações do excesso de radicais livres, promovido pelo diabetes melito tipo 1 (DM T1) tanto em nível sistêmico como, principalmente, no sistema colinérgico. Além disso, os possíveis efeitos de proteção antioxidante e anti-inflamatória da QUE. Foram utilizados 130 ratos Wistar, machos, pesando entre 160 a 250 g, distribuidos em 2 grupos: não diabéticos e diabéticos, sendo cada um deles divididos em 5 tratamentos: salina 0,9%, etanol 25% e QUE (5, 25 e 50 mg/Kg). A indução do DM T1 se deu com uma única injeção intraperitoneal de 70 mg/Kg de estreptozotocina (STZ). Quinze dias depois, teve início o tratamento com QUE por 40 dias. Ao término do experimento, foram realizados os testes comportamentais e a coleta de material biológico (sangue e tecidos corporais). O grupo diabético sem tratamento em relação ao controle não diabético apresentou: redução das ilhotas de Langerhans e da população de células beta, perda de peso, hiperglicemia crônica, leucopenia associada à neutropenia, redução na insulina e albumina, elevação na frutosamina, triglicerídeos, ureia, fosfatase alcalina (FA), alanina aminotransferase (ALT), além das frações proteicas de beta e gamaglobulinas. Houve aumento das substâncias reativas ao ácido tiobarbitúrico (TBARS) sérico e redução na atividade de superóxido dismutase hepática. Falha na formação de memória aversiva e comportamento ansioso foram observados nesses animais, bem como, elevação na atividade da acetilcolinesterase (AChE) nas estruturas e sítios cerebrais (córtex, hipocampo, estriado e sinaptossomas) e TBARS (córtex, hipocampo e estriado). Os ratos diabéticos tratados com QUE em relação ao grupo controle diabético: apresentaram elevação na albumina (50 mg/Kg), redução nas betaglobulinas (25 e 50 mg/Kg) e gamaglobulinas (50 mg/Kg), diminuição dos triglicerídeos (5, 25 e 50 mg/Kg). A quercetina nas concentrações utilizadas reverteu a falha de memória aversiva e apresentou propriedades ansiolíticas. A atividade da AChE foi reduzida: no córtex (50 mg/Kg), no hipocampo (5 e 50 mg/Kg) e sinaptossomas (50 mg/Kg). Houve diminuição nos níveis séricos das TBARS no córtex, hipocampo e estriado (5, 25 e 50 mg/Kg). A quercetina elevou a concentração da insulina, nos grupos não diabéticos e diabéticos (5, 25 e 50 mg/Kg). Quando administrada em animais não diabéticos a QUE aumentou a inquietação dos animais (50 mg/Kg); aumentou a atividade da AChE no hipocampo (5, 25 e 50 mg/Kg), estriado (5 mg/Kg) e sinaptossomas (25 mg/Kg), diminuindo no córtex (5 mg/Kg). Além disso, aumentou o nível de TBARS no córtex (25 mg/Kg). A partir desses resultados conclui-se que a QUE possui propriedades antioxidantes e anti-inflamatórias que podem ser utilizadas no tratamento auxiliar do DM. Contudo, também apresentou propriedades não desejáveis, como efeito pró-oxidante, o que sugere a resistência à insulina.

Consumer demand for fresher and minimally processed foods has brought about a movement to find effective, non-thermal processing technologies for the treatment of milk. The influence of temperature on bacterial reduction in UV irradiated milk was tested. Commercially processed skim, reduced fat (2%), and whole milk samples were inoculated with a naladixic acid resistant E. coli O157:H7 surrogate (ATCC 25922), maintained at or brought to 4oC and 20oC, respectively, and then exposed to a UV light dose between 5.3-6.3 mJ/cm2 for approximately 1.5 sec using the CiderSure 3500 apparatus (FPE Inc., Macedon, NY). Bacterial concentrations before and after UV exposure were enumerated and the results indicated that processing temperature was not significantly related to bacterial reduction (p > 0.05). The results did indicate that skim milk samples had a greater bacterial reduction, regardless of processing temperature compared to reduced fat milk and whole milk samples (p < 0.05). Solids such as milk fat, protein, lactose and minerals, in the milk have a greater effect over bacterial reductions than processing temperatures. Traditional goat cheeses are produced using unpasteurized milk, which increases the food safety concerns for these types of products. Fresh goat's milk was inoculated to 107 cfu/ml with Listeria monocytogenes (L-2289) and exposed to UV light using the CiderSure 3500 apparatus. Inoculated milk was exposed to an ultraviolet dose range between 0 and 20 mJ/cm2 to determine the optimal UV dose. A greater than 5-log reduction was achieved (p < 0.0001) when the milk was processed 12 times for a cumulative exposure time of roughly 18 sec and a cumulative UV dose of 15.8 +/- 1.6 mJ/cm2. The results of this study indicate that UV irradiation could be used for the reduction of L. monocytogenes in goat's milk. Organoleptic consequences of goat's milk treated with UV technology were assessed. Olfactory studies were conducted and a highly significant difference was determined between the odor of fresh goat's milk and UV processed milk (p < 0.05). The extent of lipid oxidation and hydrolytic rancidity was measured by thiobarbituric acid reactive substances (TBARS) and acid degree values (ADVs). Results indicated that as the UV dose increased, there was a significant increase in TBARS values and ADVs of the milk samples (p < 0.05). Milk samples were processed using the UV processor under the same conditions as previously described without exposure to the UV source to determine if the agitation from pumping was causing off-flavors by way of hydrolytic rancidity. The ADVs from these samples increased at the same rate as the UV irradiated samples; however, sensory studies indicated that the increase of free fatty acids (FFA) was not enough to cause detectable off-odors in the milk. Solid phase microextraction and gas chromatography (SPME-GC) was utilized to quantify the production of volatile compounds that were formed due to UV processing. The formation of pentanal, hexanal and heptanal was identified after as little as 1.3 mJ/cm2 UV dose. Peak areas were measured and analyzed after 7.8 mJ/cm2 and 15.6 mJ/cm2 and were determined to increase significantly as UV dose increased (p < 0.05). The chemical analyses supported the findings from the olfactory studies. The outcome of this research showed that UV irradiation at the wavelength 254 nm, was detrimental to certain chemical properties of fluid milk. The properties that were perceived as negative in fluid milk may be considered an attribute in certain types of cheese and future studies in the cheese production sector should be considered. Other applications for this technology could be for use in developing countries where milk is not typically processed because of the high costs of thermal pasteurization. On-farm applications for the treatment of replacement milk should also be considered. / Ph. D.

A morbimortalidade dos pacientes em hemodiálise permanece alta apesar da evolução tecnológica do procedimento, sendo que os eventos cardiovasculares são a sua principal causa. Estes desencadeados pela alta prevalência de fatores de risco tradicionais, fatores relacionados ao procedimento dialítico e estresse oxidativo. Considerando o procedimento dialítico e o estresse oxidativo, foi avaliado o quanto a habitual prática de reuso de dialisadores/RD (difundida nas Américas e amparada principalmente por questões econômicas) e uso único de dialisadores, influenciam nos marcadores inflamatórios e de estresse oxidativo. Para isto, foram utilizados como marcadores laboratoriais as medidas de PCR ultrassensível (u PCR), interleucina 6 (IL6), a determinação de substâncias reativas ao ácido tiobarbitúrico (TBARS), superóxido dismutase (SOD), glutationa (GSH) e albumina, em 29 pacientes em tratamento de hemodiálise. Estes pacientes encontravam-se em tratamento com dialisadores de alto fluxo do tipo polieterssulfona e reuso manual, e ao iniciar este estudo foram programados 3 ciclos sequenciais com duração de 6 semanas com as seguintes características: primeiro ciclo (uso único de dialisadores;); segundo ciclo (reuso de dialisadores); terceiro ciclo (reuso de dialisadores e administração de N-acetilcisteína/NAC, na dose de 1200 mg/dia). Foram coletadas amostras de sangue de cada paciente no início e final da última sessão de hemodiálise anteriormente ao início dos ciclos (denominado Período 1) e no início e final da última sessão de hemodiálise de cada ciclo (denominados Períodos 2, 3 e 4 respectivamente). O TBARS aumentou no período de uso único. Todas as demais variáveis não apresentaram diferença significativa. Os resultados indicaram que o RD pode proporcionar uma melhora no estresse oxidativo. O uso único foi associado com maior estresse oxidativo. Não foi encontrado nenhum benefício adicional com NAC / The morbidity and mortality of patients undergoing hemodialysis remains high despite the technological development of this procedure, and cardiovascular events are the main causes of morbidity and mortality. These cardiovascular events are triggered by the high prevalence of traditional risk factors, factors associated with dialysis procedures, and oxidative stress. Considering the factors associated with dialysis procedures and oxidative stress, we assessed how dialyzer reuse (DR; widespread in the Americas, especially because of economic issues) and use of single-use dialyzers influence oxidative stress and inflammatory markers. We used ultrasensitive PCR (u-PCR) to measure levels of the laboratory markers interleukin-6 (IL6), thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), glutathione (GSH), and albumin in 29 patients undergoing hemodialysis treatment. These patients were receiving treatment with polyethersulfone high-flux dialyzers and manual reuse. In the initial phase of this study, the 3 following sequential cycles, each lasting 6 weeks, were scheduled: first cycle (single-use dialyzers); second cycle (DR); and third cycle (DR and administration of N-acetylcysteine [NAC] at a dose of 1200 mg/day). Blood samples were collected from each patient at the beginning and end of the last hemodialysis session that preceded the start of the cycles (termed Period 1), and at the beginning and end of the last hemodialysis session of each cycle (termed Periods 2, 3, and 4, respectively). The levels of TBARS increased during the single-use period. The remaining variables did not show significant differences. The results indicated that DR may ameliorate oxidative stress. Single-use dialyzers were associated with higher oxidative stress. No additional benefit was found with use of NAC

This work was aimed at optimizing a formulation of silver catfish fishburgers (Rhamdia quelen) using filleting wastes and extract from fruit seeds. The utilization of filleting wastes from silver catfish in the formulation of fishburgers was evaluated by replacing grounded fish fillets with increasing levels (0-control, 20, 50, and 80%) of pulp obtained from filleting wastes (PFW). Fat content of burgers increased with increasing levels of PFW (p<0.05). Burgers with 50-80% PFW had lower n-6/n-3 ratio than control (p<0.05). Fat and moisture retention after cooking were not affected by PFW, while cooking yield increased in burgers with 50% PFW when compared to all other formulations (p<0.05). Texture and juiciness were not affected by PFW. However, burgers containing 80% PFW had lower overall acceptance than controls (p<0.05). Mango (Mangifera indica L.), peach (Prunus persica), and passion fruit (Passiflora sp.) seeds were examined for their total phenolic content, radical scavenging capacity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals, ferric-reducing antioxidant power (FRAP), and antioxidant activity against lipid oxidation in a fish model system (0.05, 0.1, 0.15, and 0.3 mg phenolic compounds/4.4ml of silver catfish homogenate). Mango seed extract (MSE) showed the highest phenolic content and total antioxidant activity by DPPH and FRAP assays. Lipid oxidation in fish model system (at 37oC during 90 min) was retarded by the three seed extracts at all concentrations tested. MSE that had the highest antioxidant activity in vitro, was also evaluated against lipid oxidation in fishburgers produced from silver catfish filleting wastes. Burger formulations with 50% pulp from filleting wastes were prepared containing MSE (0, 30, and 90 ppm phenolic compounds) and conjugated dienes, peroxide value, tiobarbituric acid reactive substances, and free fatty acids were the oxidation products measured during frozen storage at -10 and -20oC. All lipid damage measurements were affected by the storage time and temperature. However, after 120 days at both temperatures, TBARS levels of fishburgers did not reach threshold limit for human consumption. MSE had no antioxidant effect against lipid oxidation in silver catfish burgers. Filleting wastes could substitute up to 50% of fish fillets with no changes in sensory acceptance, an improvement of nutritional value, and cooking characteristics, with good lipid stability during at least 120 days of freezing storage. / Este trabalho avaliou o aproveitamento de resíduos resultantes da filetagem e de extratos vegetais de sementes de frutas na otimização de formulações de fishburgers de jundiá (Rhamdia quelen). Os resíduos da filetagem do jundiá foram processados e obteve-se uma polpa de resíduos da filetagem (PRF) utilizada em diferentes níveis (0-controle, 20, 50, e 80%) para substituir os filés de peixe na formulação de fishburger. O teor de gordura aumentou com a utilização de PSF nas formulações (p<0,05). Os fishburgers produzidos com 50-80% PRF apresentaram menores valores para as razões de ácidos graxos n-6/n-3 do que os valores obtidos para o controle (p<0,05). A capacidades de retenção de umidade e de retenção de gordura pós-cocção não foram afetadas pela utilização de PRF, no entanto as formulações com 50% de PRF tiveram os maiores rendimentos pós-cocção (p<0,05). A análise sensorial revelou que a textura e suculência das formulações não foram alteradas pela utilização de PRF, porém a incorporação de 80% de PRF reduziu a aceitação do produto em relação ao controle (p<0,05). Foram determinados, para extratos de sementes de manga (Mangifera indica L.), pêssego (Prunus persica), e maracujá (Passiflora sp.), o conteúdo fenólico, a atividade antioxidante pelos métodos do DPPH (1,1-difenil-2-picrilhidrazil), FRAP (poder antioxidante de redução do ferro) e a capacidade de impedir a oxidação lipídica em um sistema modelo contendo peixe (0,05, 0,1, 0,15 e 0,3 mg de compostos fenólicos/4,4ml de homogeneizado de carne de jundiá). As sementes de manga apresentaram o maior teor de compostos fenólicos totais e atividade antioxidante em DPPH e pelo método de FRAP. A oxidação lipídica no homogeneizado de carne de peixe submetido ao aquecimento (37ºC) por 90 minutos foi impedida pelo extrato das três sementes de frutas em todas as concentrações testadas. O extrato de semente de manga, que apresentou a maior atividade antioxidante in vitro, foi escolhido para a avaliação de sua capacidade em impedir a oxidação da uma formulação de fishburger produzida com resíduos da filetagem. Foram preparadas formulações de fishburger contendo 50% de resíduos de filetagem e diferentes níveis de extrato de semente de manga (0, 30 e 90 ppm de compostos fenólicos) que foram armazenadas a -10 ou -20 oC. A oxidação lipídica durante o congelamento foi acompanhada determinando-se os teores de dienos conjugados, valor de peróxidos, substâncias reativas ao ácido tiobarbitúrico e ácidos graxos livres. Todas as medidas de oxidação lipídica foram afetadas pela temperatura e tempo de estocagem. No entanto, ao final de 120 dias, os níveis de TBARS não alcançaram o valor limite para consumo humano. O extrato de semente de manga não apresentou efeito antioxidante contra a peroxidação lipídica nas formulações de fishburgers de jundiá. A substituição de filé de jundiá por polpa de resíduos da filetagem pode ser realizada até o nível de 50% na formulação de fishburger de jundiá significativas na qualidade sensorial, resultando em produtos com melhor valor nutricional e características pós-cocção, estáveis durante pelo menos 120 dias de congelamento.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Mercury is a heavy metal toxic for any living tissue, being kidneys the first target for the inorganic form. Oxidative stress has been pointed as an important molecular mechanism for kidney injury in inorganic mercury poisoning and the interaction of the metal with endogenous thiol-containing molecules, such as δ-aminolevulinate desidratase (δ-ALA-D), seems to contribute to this process. Lycopene and astaxanthin are plentiful carotenoids in tomatoes and algaes and seafoods, respectively. They have been widely studied because of their large antioxidant properties. This work evaluated the ability of lycopene and astaxanthin to prevent HgCl2 toxicity, assessing parameters like δ-ALA-D and glutathione S-transferase (GST) activities, non-protein sulfhydrylic groups content (NPSH), production of thiobarbituric acid reactive substances (TBARS) and activities of antioxidant enzymes like superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT), besides creatinine and uric acid plasma levels and histopathological analyses. Adult Wistar rats received lycopene or astaxanthin, by gavage, on doses of 0, 10, 25, or 50 mg/kg, six hours prior to the administration of 0 or 5 mg/kg HgCl2, yielding 8 experimental groups. After twelve hours of exposure to HgCl2 animals were killed. HgCl2 inhibited renal δ-ALA-D activity and increased TBARS levels in kidney and creatinine levels in plasma along with renal tubular necrosis. Lycopene prevented HgCl2-induced inhibition of δ-ALA-D activity and increase of lipid peroxidation in kidney, but not the increase in plasma creatinine levels or renal tubular necrosis caused by HgCl2. Although astaxanthin have not prevented HgCl2-induced inhibition of δ-ALA-D and increase in plasma creatinine levels, this carotenoid prevented lipid peroxidation and attenuated renal tubular necrosis caused by HgCl2. GPx and CAT activities were enhanced, while SOD activity was depressed, in mercury-treated rats when compared to control and these effects were prevented by some lycopene doses and by all astaxanthin doses evaluated. Some doses of lycopene negativelly affected antioxidant enzymes activities per se and the mechanism involved in this response has not been elucidated yet. Neither HgCl2 nor carotenoids treatment changed the content of NPSH groups or GST activity in kidney or uric acid levels in plasma. Our results indicate that although lycopene and astaxanthin did not prevent HgCl2-induced creatinine increase in plasma, changes in the activity of antioxidant enzymes might be limited by the use of these car / O mercúrio é um metal pesado com toxicidade comprovada, capaz de causar danos em qualquer tecido com o qual tenha contato, sendo o rim o principal alvo para sua forma inorgânica. O estresse oxidativo tem sido apontado como um importante mecanismo molecular para a injúria renal induzida por mercúrio inorgânico e a interação desse metal com moléculas contendo grupos sulfidrílicos, tais como a enzima δ-aminolevulinato desidratase (δ-ALA-D), parece contribuir para esse processo. Licopeno e astaxantina são carotenóides abundantes em tomates e em algas e frutos do mar, respectivamente. Ambos têm sido amplamente estudados por suas propriedades antioxidantes. No presente estudo foi avaliado o efeito do licopeno e da astaxantina sobre a toxicidade do HgCl2 em rins de ratos, utilizando-se como parâmetros a atividade das enzimas δ-ALA-D e glutationa Stransferase (GST), quantidade de grupos sulfidrílicos não protéicos (NPSH), produção de substâncias reativas ao ácido tiobarbitúrico (TBARS), atividade das enzimas antioxidantes superóxido dismutase (SOD), glutationa peroxidase (GSH-Px) e catalase (CAT), além dos níveis plasmáticos de creatinina e ácido úrico e análise histopatológica. Ratos Wistar adultos receberam, por gavage, licopeno ou astaxantina nas doses de 0, 10, 25 ou 50 mg/kg, seis horas antes de receberem uma injeção subcutânea de HgCl2 (0 ou 5 mg/kg), resultando assim, em 8 grupos experimentais. Após doze horas da exposição ao HgCl2, os animais foram sacrificados. O HgCl2 inibiu a δ-ALA-D renal, aumentou a produção de TBARS e níveis plasmáticos de creatinina, além de causar necrose tubular. O licopeno preveniu a inibição da δ-ALA-D e a peroxidação lipídica, mas não preveniu o aumento de creatinina no plasma nem a ocorrência de necrose tubular induzidos pelo HgCl2. Embora a astaxantina não tenha prevenido a inibição da δ-ALA-D e o aumento nos níveis plasmáticos de creatinina, este carotenóide preveniu a ocorrência da peroxidação lipídica e atenuou a necrose tubular causada pelo HgCl2. As atividades das enzimas GSH-Px e CAT aumentaram, enquanto a atividade da SOD diminuiu nos animais tratados com HgCl2 e esses efeitos foram prevenidos por algumas doses de licopeno e por todas as doses de astaxantina avaliadas. Algumas doses de licopeno tiveram efeito negativo sobre as enzimas antioxidantes per se e o mecanismo envolvido nessa resposta ainda não foi elucidado. O tratamento com HgCl2 ou carotenóides não alterou o conteúdo de NPSH ou a atividade da GST no tecido renal, nem os níveis plasmáticos de ácido úrico. Os resultados indicam que embora licopeno e astaxantina não tenham prevenido o aumento nos níveis plasmáticos de creatinina induzido por HgCl2, as alterações nas enzimas antioxidantes podem ser limitadas pelo uso destes carotenóides.

A morbimortalidade dos pacientes em hemodiálise permanece alta apesar da evolução tecnológica do procedimento, sendo que os eventos cardiovasculares são a sua principal causa. Estes desencadeados pela alta prevalência de fatores de risco tradicionais, fatores relacionados ao procedimento dialítico e estresse oxidativo. Considerando o procedimento dialítico e o estresse oxidativo, foi avaliado o quanto a habitual prática de reuso de dialisadores/RD (difundida nas Américas e amparada principalmente por questões econômicas) e uso único de dialisadores, influenciam nos marcadores inflamatórios e de estresse oxidativo. Para isto, foram utilizados como marcadores laboratoriais as medidas de PCR ultrassensível (u PCR), interleucina 6 (IL6), a determinação de substâncias reativas ao ácido tiobarbitúrico (TBARS), superóxido dismutase (SOD), glutationa (GSH) e albumina, em 29 pacientes em tratamento de hemodiálise. Estes pacientes encontravam-se em tratamento com dialisadores de alto fluxo do tipo polieterssulfona e reuso manual, e ao iniciar este estudo foram programados 3 ciclos sequenciais com duração de 6 semanas com as seguintes características: primeiro ciclo (uso único de dialisadores;); segundo ciclo (reuso de dialisadores); terceiro ciclo (reuso de dialisadores e administração de N-acetilcisteína/NAC, na dose de 1200 mg/dia). Foram coletadas amostras de sangue de cada paciente no início e final da última sessão de hemodiálise anteriormente ao início dos ciclos (denominado Período 1) e no início e final da última sessão de hemodiálise de cada ciclo (denominados Períodos 2, 3 e 4 respectivamente). O TBARS aumentou no período de uso único. Todas as demais variáveis não apresentaram diferença significativa. Os resultados indicaram que o RD pode proporcionar uma melhora no estresse oxidativo. O uso único foi associado com maior estresse oxidativo. Não foi encontrado nenhum benefício adicional com NAC / The morbidity and mortality of patients undergoing hemodialysis remains high despite the technological development of this procedure, and cardiovascular events are the main causes of morbidity and mortality. These cardiovascular events are triggered by the high prevalence of traditional risk factors, factors associated with dialysis procedures, and oxidative stress. Considering the factors associated with dialysis procedures and oxidative stress, we assessed how dialyzer reuse (DR; widespread in the Americas, especially because of economic issues) and use of single-use dialyzers influence oxidative stress and inflammatory markers. We used ultrasensitive PCR (u-PCR) to measure levels of the laboratory markers interleukin-6 (IL6), thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), glutathione (GSH), and albumin in 29 patients undergoing hemodialysis treatment. These patients were receiving treatment with polyethersulfone high-flux dialyzers and manual reuse. In the initial phase of this study, the 3 following sequential cycles, each lasting 6 weeks, were scheduled: first cycle (single-use dialyzers); second cycle (DR); and third cycle (DR and administration of N-acetylcysteine [NAC] at a dose of 1200 mg/day). Blood samples were collected from each patient at the beginning and end of the last hemodialysis session that preceded the start of the cycles (termed Period 1), and at the beginning and end of the last hemodialysis session of each cycle (termed Periods 2, 3, and 4, respectively). The levels of TBARS increased during the single-use period. The remaining variables did not show significant differences. The results indicated that DR may ameliorate oxidative stress. Single-use dialyzers were associated with higher oxidative stress. No additional benefit was found with use of NAC

The evolution of aerobic metabolic processes unavoidably led to the production of reactive oxygen species (ROS). ROS have the ability to cause harmful oxidative damage to biomolecules. Increased ROS generation and subsequent oxidative stress have been associated with aging and neurodegenerative disorders such as Parkinson’s and Alzheimer’s diseases as a result of the extreme sensitivity of the central nervous system to damage from ROS. Antioxidant defence systems have co–evolved with aerobic metabolic processes to counteract oxidative damage inflicted by ROS. The impact of neurodegenerative disorders on society is increasing rapidly as the life expectancy of the global population increases. In this day and age, a much younger group of the population is also experiencing neurodegenerative symptoms as a result of the harmful effect of the human immunodeficiency virus (HIV) on the central nervous system. Plants are an invaluable source of medicinal compounds. The use of plants for their healing properties is rooted in ancient times. The aim of this study was to select from twenty one plants, the plant with the most promising antioxidant activity and to determine whether extracts of this plant could act as free radical scavengers, comparing the results to Trolox, a known free radical scavenger. The next step was to isolate and characterize a compound from an extract exhibiting promising antioxidant activity. Bioassay–guided fractionation was followed to achieve this. During screening trials, twenty one plants, namely Berula erecta, Heteromorpha arborescens, Tarchonanthus camphoratus, Vernonia oligocephala, Gymnosporia buxifolia, Acacia karroo, Elephantorrhiza elephantina, Erythrina zeyheri, Leonotis leonurus, Plectranthus ecklonii, P. rehmanii, P. venteri, Salvia auretia, S. runcinata, Solenostemon latifolius, S. rotundifolius, Plumbago auriculata, Clematis brachiata, Vangueria infausta, Physalis peruviana and Lippia javanica were selected from literature, based on reported antioxidant activity within the plant families, for screening of their antioxidant activity. One hundred and ten extracts were prepared from the leaves, using Soxhlet extraction and the solvents petroleum ether (PE), dichloromethane (DCM), ethyl acetate (EtOAc) and ethanol (EtOH), consecutively. The focus during initial screening trials was on chemistry–based assays. The oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assays were employed for the primary screening of the one hundred and ten leaf extracts. The ORAC assay was used to determine whether the plant extracts were able to scavenge peroxyl radicals and the FRAP assay was used to determine the reducing abilities of the extracts. Quantification of the peroxyl radical scavenging activity by the ORAC assay revealed that activity was observed for most of the extracts, with the ethyl acetate and ethanol extracts of L. javanica exhibiting the most promising activity. This pattern of activity was also found with the reducing capacity evaluated by the FRAP assay in which the EtOAc and EtOH extracts of L. javanica also exhibited the most promising activity. L. javanica was selected for further study by screening for biological activity, employing the nitro–blue tetrazolium (NBT) assay and thiobarbituric acid reactive substances (TBARS) assay. Using a cyanide model to induce neurotoxic effects in rat brain homogenate, the neuroprotective properties of the extracts of L. javanica leaves were examined using the NBT assay and compared to that of Trolox. The NBT assay determines the level of superoxide anions. All the extracts of L. javanica significantly reduced superoxide anion generation at all concentrations used. The petroleum ether and ethyl acetate extracts, at all concentrations, reduced superoxide anion generation to values lower than that of the control, suggesting that these extracts may be able to attenuate normal free radical processes in the brain. The petroleum ether extract exhibited the most promising activity at a concentration of 1.25 and 2.5 mg/ml and also exhibited similar results as the ethyl acetate extract at a lower concentration than the ethyl acetate extract (2.5 mg/ml compared to 5 mg/ml). A toxin–solution consisting of hydrogen peroxide (H2O2), iron(III)chloride (FeCl3) and ascorbic acid was used to induce lipid peroxidation and the ability of the extracts of the leaves of L. javanica to attenuate lipid peroxidation was investigated in rat brain homogenate and compared to that of Trolox. All of the extracts of L. javanica significantly attenuated toxininduced lipid peroxidation at all concentrations used. All of the extracts were also able to significantly attenuate toxin–induced lipid peroxidation to values lower than that of the control. These results suggest that all of the extracts of L. javanica possess the ability to attenuate not only toxin–induced lipid peroxidation, but also lipid peroxidation that occurs during normal processes in the brain. The petroleum ether extract was subjected to bioassay–guided fractionation using column and thin–layer chromatography and the NBT and TBARS assays. Fraction DD1 was investigated by means of nuclear magnetic resonance, infrared and mass spectrometry. The exact structure of fraction DD1 was not elucidated. Considering all the results, it is clear that L. javanica shows great potential as a medicinal plant with antioxidant activity and may therefore be beneficial in diminishing the destructive oxidative effects inflicted by free radicals. There are however still many compounds to be isolated from L. javanica. Key words: Verbenaceae, Lippia javanica, antioxidant, neurodegeneration, oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), nitro–blue tetrazolium assay (NBT), thiobarbituric acid reactive substances assay (TBARS). / Thesis (M.Sc. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2011.

The evolution of aerobic metabolic processes unavoidably led to the production of reactive oxygen species (ROS). ROS have the ability to cause harmful oxidative damage to biomolecules. Increased ROS generation and subsequent oxidative stress have been associated with aging and neurodegenerative disorders such as Parkinson’s and Alzheimer’s diseases as a result of the extreme sensitivity of the central nervous system to damage from ROS. Antioxidant defence systems have co–evolved with aerobic metabolic processes to counteract oxidative damage inflicted by ROS. The impact of neurodegenerative disorders on society is increasing rapidly as the life expectancy of the global population increases. In this day and age, a much younger group of the population is also experiencing neurodegenerative symptoms as a result of the harmful effect of the human immunodeficiency virus (HIV) on the central nervous system. Plants are an invaluable source of medicinal compounds. The use of plants for their healing properties is rooted in ancient times. The aim of this study was to select from twenty one plants, the plant with the most promising antioxidant activity and to determine whether extracts of this plant could act as free radical scavengers, comparing the results to Trolox, a known free radical scavenger. The next step was to isolate and characterize a compound from an extract exhibiting promising antioxidant activity. Bioassay–guided fractionation was followed to achieve this. During screening trials, twenty one plants, namely Berula erecta, Heteromorpha arborescens, Tarchonanthus camphoratus, Vernonia oligocephala, Gymnosporia buxifolia, Acacia karroo, Elephantorrhiza elephantina, Erythrina zeyheri, Leonotis leonurus, Plectranthus ecklonii, P. rehmanii, P. venteri, Salvia auretia, S. runcinata, Solenostemon latifolius, S. rotundifolius, Plumbago auriculata, Clematis brachiata, Vangueria infausta, Physalis peruviana and Lippia javanica were selected from literature, based on reported antioxidant activity within the plant families, for screening of their antioxidant activity. One hundred and ten extracts were prepared from the leaves, using Soxhlet extraction and the solvents petroleum ether (PE), dichloromethane (DCM), ethyl acetate (EtOAc) and ethanol (EtOH), consecutively. The focus during initial screening trials was on chemistry–based assays. The oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assays were employed for the primary screening of the one hundred and ten leaf extracts. The ORAC assay was used to determine whether the plant extracts were able to scavenge peroxyl radicals and the FRAP assay was used to determine the reducing abilities of the extracts. Quantification of the peroxyl radical scavenging activity by the ORAC assay revealed that activity was observed for most of the extracts, with the ethyl acetate and ethanol extracts of L. javanica exhibiting the most promising activity. This pattern of activity was also found with the reducing capacity evaluated by the FRAP assay in which the EtOAc and EtOH extracts of L. javanica also exhibited the most promising activity. L. javanica was selected for further study by screening for biological activity, employing the nitro–blue tetrazolium (NBT) assay and thiobarbituric acid reactive substances (TBARS) assay. Using a cyanide model to induce neurotoxic effects in rat brain homogenate, the neuroprotective properties of the extracts of L. javanica leaves were examined using the NBT assay and compared to that of Trolox. The NBT assay determines the level of superoxide anions. All the extracts of L. javanica significantly reduced superoxide anion generation at all concentrations used. The petroleum ether and ethyl acetate extracts, at all concentrations, reduced superoxide anion generation to values lower than that of the control, suggesting that these extracts may be able to attenuate normal free radical processes in the brain. The petroleum ether extract exhibited the most promising activity at a concentration of 1.25 and 2.5 mg/ml and also exhibited similar results as the ethyl acetate extract at a lower concentration than the ethyl acetate extract (2.5 mg/ml compared to 5 mg/ml). A toxin–solution consisting of hydrogen peroxide (H2O2), iron(III)chloride (FeCl3) and ascorbic acid was used to induce lipid peroxidation and the ability of the extracts of the leaves of L. javanica to attenuate lipid peroxidation was investigated in rat brain homogenate and compared to that of Trolox. All of the extracts of L. javanica significantly attenuated toxininduced lipid peroxidation at all concentrations used. All of the extracts were also able to significantly attenuate toxin–induced lipid peroxidation to values lower than that of the control. These results suggest that all of the extracts of L. javanica possess the ability to attenuate not only toxin–induced lipid peroxidation, but also lipid peroxidation that occurs during normal processes in the brain. The petroleum ether extract was subjected to bioassay–guided fractionation using column and thin–layer chromatography and the NBT and TBARS assays. Fraction DD1 was investigated by means of nuclear magnetic resonance, infrared and mass spectrometry. The exact structure of fraction DD1 was not elucidated. Considering all the results, it is clear that L. javanica shows great potential as a medicinal plant with antioxidant activity and may therefore be beneficial in diminishing the destructive oxidative effects inflicted by free radicals. There are however still many compounds to be isolated from L. javanica. Key words: Verbenaceae, Lippia javanica, antioxidant, neurodegeneration, oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), nitro–blue tetrazolium assay (NBT), thiobarbituric acid reactive substances assay (TBARS). / Thesis (M.Sc. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2011.