Thesis (MScMedSc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Introduction: A westernized diet rich in saturated fats and sugars, together with a sedentary lifestyle, has contributed to the dramatic increase in obesity during the last decade (Zimmett et al, 2001; Wild et al, 2004). Obesity is associated with dyslipidemia and insulin resistance which are major risk factors for the development of type 2 diabetes (T2D) (Zimmet et al, 2001, Kahn et al, 2006; Schröder et al, 2007). High-fat feeding in rodents induces symptoms similar to the human metabolic syndrome without progression to T2D (Woods et al, 2002; Weir and Bonner-Weir, 2007). The addition of fructose to a high-fat diet exacerbates the insulin resistance and leads to impaired pancreatic function of insulin secretion and glucose intolerance (Basciano et al, 2005; Stanhope et al, 2009). Aims: The aim of this study was to establish the effect of a high-fat and sucrose/fructose diet on glucose metabolism, the development of insulin resistance and β-cell dynamics. Methods: Weanling Wistar rats were randomized into two study groups; study one over an experimental period for three months and study two for twelve months. Each study consisted of a control group that received standard rat chow and water; and two experimental groups receiving either a high-fat diet and water (HFD) or a café diet consisting of HFD with the addition of 15% sucrose/fructose (CFD). Fasting glucose and insulin concentrations, intravenous glucose tolerance test (IVGTT), glucose stimulated insulin secretion rates and 2-deoxy-[3H]-D-glucose uptake in muscle, liver and fat were measured. The pancreata were harvested for immunohistochemical labeling of β-cells (insulin), α-cells (glucagon), GLUT2 (glucose transport) and MIB5 (proliferation). Samples of the pancreata were also collected for electron microscopy. Results and discussion: Feeding Wistar rats a CFD induced obesity, insulin resistance and glucose intolerance. By twelve months the rats had an impaired glucose response with increased IVGTT peak values, area under the curve (AUC) values and glucose clearance rates. Concomitantly, the glucose stimulated insulin secretion rate (GS-ISR) was attenuated. Stimulated glucose disposal as measured by 2-deoxy-[3H]-D-glucose uptake was reduced in muscle and adipose tissue at three months. By twelve months, due to the age of the rats, stimulated glucose uptake declined compared to three months with no difference between groups. After three months the diets had no observable effect on the islets using light microscopy. However, by twelve months morphological changes were observed in both the HFD and CFD groups. In the HFD group large hypertrophied irregular islets with fibrous changes were observed. In the CFD group these morphological changes were more prominent with fibrous segregation and disruption of the normal endocrine arrangement. In addition, the presence of inflammatory cells within the affected islets is consistent with T2D. Conclusion: High-fat diet fed to Wistar rats induced obesity, abdominal adiposity and insulin resistance. The addition of sucrose/fructose to a high-fat diet exacerbated the insulin resistance and resulted in glucose intolerance and mild hyperglycemia. Morphological changes in the large islets were observed which are consistent with the development of T2D. / AFRIKAANSE OPSOMMING: Inleiding: ‘n Verwesterde dieët, ryk aan versadigde vette en suikers tesame met 'n passiewe lewenstyl, het bygedra tot die dramatiese verhoging in vetsug gedurende die laaste dekade (Zimmett et al, 2001; Wild et al, 2004). Vetsug word met dislipidemie en insulienweerstandigheid geassosieer wat hoof risikofaktore is vir die ontwikkeling van tipe 2 diabetes (T2D) (Zimmet et al, 2001; Kahn et al, 2006; Schröder et al, 2007). Hoë-vet voeding in knaagdiere induseer simptome soortgelyk aan menslike metaboliese sindroom sonder die ontwikkeling van T2D (Woods et al, 2002; Weir and Bonner-Weir, 2007). Die byvoeging van fruktose tot 'n hoë-vet dieët vererger insulienweerstandigheid en lei tot verswakte pankreas funksie, insuliensekresie en glukoseintoleransie (Basciano et al, 2005; Stanhope et al, 2009). Doelwitte: Die doelwitte van die studie was om die effek van hoë-vet en sukrose/fruktose voeding op glukosemetabolisme, die ontwikkeling van insulienweerstandigheid en β-sel dinamika te bepaal. Metodes: Gespeende Wistar rotte was in twee groepe gerandomiseer; studie een oor ʼn tydperk van drie maande en studie twee oor ʼn tydperk van twaalf maande onderskeidelik. Elke studie het 'n kontrole groep met standaard rot kos en water (control); en twee experimentele diëte wat of ʼn hoë-vet dieët en water (HFD) of 'n kafeedieët groep wat die HFD met die byvoeging van 15% sukrose/fruktose in hul drink water (CFD) ontvang. Fastende glukose en insulien, binneaarse glukose toleransie toets (IVGTT), glukose gestimuleerde insulien sekresie tempo en 2-deoxi-[3H]-D-glukose opname in spier, lewer en vet is gebruik om die effek van die dieët op glukosemetabolisme te bepaal. Die pankreata is uitgehaal vir immunohistochemiese identifisering van β-selle (insulien), α-selle (glukagoon), GLUT2 (glukose transport) en MIB5 (proliferasie). Monsters van die pankreata was ook vir elektronmikroskopie versamel. Resultate en bespreking: Voeding van ʼn CFD aan Wistar rotte induseer vetsug, insulienweerstandigheid en glukose-intoleransie Teen twaalf maande toon die rotte 'n verswakte respons tot glukose met verhoogde IVGTT piekwaardes, AUC waardes en glukose opruimingswaardes. Terselfdetyd is die glukose gestimuleerde insuliensekresie tempo (GS-ISR) ook verswak. Gestimuleerde glukose opruiming, soos deur 2-deoxi-[3H]-D-glukose opname bepaal, was verlaag in spier en vetweefsel teen drie maande. Teen twaalf maande, weens die ouderdom van die rotte, is die gestimuleerde glukose opname verlaag in vergelyking met drie maande sonder 'n verskil tussen groepe. Na drie maande kon geen sigbare morfologiese verskille met ligmikroskopie tussen die diëte waargeneem word nie. Teen twaalf maande is morfologiese verskille waargeneem in beide die HFD en die CFD groepe. In die HFD groep is groot hipertrofiese onreëlmatige eilande met fibrotiese verandering waargeneem. In die CFD groep was die morfologiese verandering meer gevorder met fibrotiese onderverdeling en ontwrigting van die normale endokriene rangskikking. Die teenwoordigheid van inflammatoriese selle in die geaffekteerde eilande is verenigbaar met T2D. Afleiding: Die voer van 'n hoë-vet dieët aan Wistar rotte veroorsaak vetsug, abdominale adipositeit en insulienweerstandigheid. Die byvoeging van sukrose/ fruktose tot die hoë-vet dieët vererger die insulienweerstandigheid en veroorsaak glukoseintoleransie en matige hiperglukemie. Morfologiese veranderings in die groter eilande was verenigbaar met T2D.

The large capacity of brown adipose tissue (BAT) to expend energy as heat makes it an interesting potential player in weight regulation and other metabolic conditions. This is of particular interest as it has been recognized that adult humans possess BAT. The protein responsible for the heat production is uncoupling protein 1 (UCP1), which, as the name implies, uncouples the respiratory chain from ATP production; instead heat is produced. Cold is the strongest recruiter and activator of BAT. However, also obesogenic food has a low but nonetheless significant effect on the recruitment and activation of UCP1, although the significance of this has been discussed. In the present thesis, I have studied the effect of diet on BAT and the possibilities for it to be obesity-protective. This can be done by comparing responses in wild-type mice and in UCP1-ablated mice. Since the effect of diet on BAT is low, it is of importance to control the temperature and maintain thermoneutrality. Other confounding factors to keep in mind are differences in actual energy and composition of food and also cohort differences. When controlling all the parameters mentioned and giving the mice the same obesogenic diet, the mice possessing UCP1 compared to UCP1-ablated mice had higher energy expenditure, and lower weight gain, despite eating more. This confirms the presence of a UCP1-dependent diet-induced thermogenesis. Thus, the conclusion must be that possessing UCP1 does result in obesity protection at thermoneutrality. However, the relevance for human energy balance is still not established. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: Manuscript. Paper 3: Manuscript.</p>

Kidney failure is frequently associated with the risk factors linked to metabolic syndrome. Lipopolysaccharide (LPS) is a potent inflammatory molecule, which has increased absorption from the gut into blood circulation following a high fat and high-energy diet. We hypothesized that LPS from a high fat diet can amplify inflammation, thereby exacerbating chronic kidney disease and associated disorders. We have found that adding a high fat diet to renal insufficient mice significantly progressed their kidney disease as well as associated disorders, compared to both a high fat diet and renal insufficiency alone. Additionally, we were able to demonstrate in vitro that the combination of LPS and palmitic acid, a marker of high fat diet, induced inflammatory pathways significantly more than either LPS or palmitic acid alone. These results provide insight into connection between a high fat diet and the progression of chronic kidney disease as well as associated disorders.

Infertility is defined as an inability to conceive a child within one year of regular sexual intercourse. It affects up to 15 % of couples worldwide (WHO, 2010). The male factor contributes to the total infertility with more than 50 %. Fertility of a man is influenced by several factors such as genetic background, environment and various diseases such as diabetes mellitus (DM). Diabetes mellitus is a serious health problem that affects 451 million people worldwide (18-99 years) and the number of people with this disease still increases (Cho a spol., 2018). In addition, parenthood is postponed to middle age when the fertility decreases and metabolic diseases such as type 2 diabetes mellitus (DM2) appear. The aim of this thesis was to investigate the effect of type 2 diabetes on reproductive parameters of mouse inbred line C57BL/6J compared to the control group and the possible effect of paternal diabetes on the first filial generation. In the evaluation of the effect of DM2 on reproductive parameters, we used innovative methods to study internal state of sperm and testes. Results of our work showed that DM2 influenced the weight of body, prostate and liver. The weight of testes, epididymis and liver was reduced in the offspring. Furthermore, sperm morphology and intraacrosomal protein status were...

Breast cancer is a persistent public health problem. Interesting hypothesis suggests that its risk can be modulated in early life periods, a phenomenon known as fetal programming. In this context, most fetal programming studies focus on maternal influence, due to the greater interaction between mother and fetus in both fetal and lactation periods. However, recent studies show that paternal preconception diet has also a major role in the offspring\'s susceptibility to metabolic chronic non-communicable diseases. Therefore, this direct doctoral project aimed to assess whether the paternal consumption of different high fat diets during the development period of the reproductive system of male rats increased the susceptibility of female offspring to mammary carcinogenesis. In addition we sought to evaluate which mechanisms could be involved in this process. We used male rats of the Sprague-Dawley strain (n = 20/group) that consumed high fat diet with 60% of calories from lipids from lard (LB group) or corn oil (CB group), or AIN-93G control diet (CO group) for nine weeks, during development and sexual maturation periods. These rats were mated with females who consumed only commercial diet in 1:1 ratio. Their 50 days old offspring were subjected to mammary carcinogenesis model using 7,12-dimethylbenz[a]anthracene (50mg/kg). Paternal consumption of high fat diet of animal or plant source had opposite effects, with the paternal consumption of diet with high content of saturated fatty acids (LB) increasing and consumption of diet with high content of n-6 polyunsaturated fatty acids (CB) reducing the risk of breast cancer development in female offspring. These effects were due to changes in the expression of 89 miRNAs in the father\'s sperm and 23 miRNAs in the offspring\'s mammary gland, with overlapping of three miRNAs (miR-1897-5p, miR- 219-1-3p and miR-376a #) that were altered in both tissues. Additionally, female offspring of males fed diets with high content of saturated fatty acids showed less differentiation of the mammary gland, higher levels of cell proliferation, lower levels of apoptosis and altered expression of keys proteins that regulate important cellular functions, such as epithelial to mesenchymal transition. Finally, these females had also altered lipid profile of the fat pad similar to their male parent as well as epigenetic changes that may be related to the etiology of breast cancer. Thus, we conclude that the high-fat preconception paternal diet programmed the susceptibility of female offspring to mammary carcinogenesis, but this effect was dependent on the type of fatty acid consumed and the observed effects possibly results from changes in miRNA expression profile. / O câncer de mama é um persistente problema de saúde pública. Hipótese intrigante sugere que a suscetibilidade à doença pode ser modulada em períodos precoces da vida, fenômeno conhecido como programação fetal. Nesse sentido, a maior parte dos estudos de programação fetal refere-se à influência materna, dada a intensa interação existente entre mãe e feto tanto no período fetal, quanto na lactação. Entretanto, estudos recentes mostram que a dieta paterna pré-concepcional também tem um papel de grande importância na suscetibilidade da prole à uma série de doenças crônicas não-transmissíveis de origem metabólica. Portanto, o presente projeto de doutorado direto teve como objetivo avaliar se o consumo paterno de diferentes dietas hiperlipídicas, durante o período de desenvolvimento do sistema reprodutivo de ratos machos, aumentaria a suscetibilidade da prole feminina à carcinogênese mamária. Adicionalmente buscou-se avaliar quais mecanismos poderiam estar envolvidos nesse processo. Utilizaram-se ratos machos da linhagem Sprague-Dawley (n=20/grupo) que consumiram dieta hiperlipídica com 60% de calorias provenientes de lipídeos de banha (grupo LB) ou óleo de milho (grupo CB), ou dieta controle AIN-93G (grupo CO), por nove semanas, durante os períodos de desenvolvimento e maturação sexual. Esses ratos foram acasalados com fêmeas, que consumiram apenas dieta comercial, na proporção 1:1. Sua prole de 50 dias foi submetida ao modelo de carcinogênese mamária com o uso de 7,12-dimetil-benza[a]antraceno (50mg/kg). O consumo paterno de dietas hiperlipídicas de origem animal ou vegetal conferiram efeitos opostos, com o consumo de dieta com alto teor de ácidos graxos saturados (LB) aumentando e o consumo de dieta com alto teor de ácidos graxos poli-insaturados n-6 (CB) diminuindo o risco de desenvolvimento de câncer de mama na prole feminina. Esses efeitos foram associados à alteração da expressão de 89 miRNAS no espermatozoide dos pais e 23 miRNAs na glândula mamária da prole, com sobreposição de 3 miRNAs (miR-1897-5p, miR-219-1-3p e miR-376a#) que estavam alterados em ambos tecidos. Adicionalmente, a prole feminina de machos que consumiram dieta com alto teor de ácidos graxos saturados apresentou menor diferenciação da glândula mamária, maior nível de proliferação celular, menor nível de apoptose e alteração da expressão de proteínas chaves da regulação celular, como na transição epitélio-mesenquimal. Finalmente, essas fêmeas também apresentaram perfil lipídico alterado semelhante à do seu progenitor masculino, bem como modificações epigenéticas que podem estar relacionadas à etiologia do câncer de mama. Assim, concluímos que a dieta paterna hiperlipídica pré-concepcional programou a suscetibilidade da prole feminina à carcinogênese mamária, porém esse efeito é dependente do tipo de ácido graxo consumido e os efeitos observados possivelmente decorrem de alterações no perfil de expressão de miRNAs.

O presente trabalho investigou se a exposição em períodos precoces da vida à ração com alto teor de gordura animal altera o risco de câncer de mama na vida adulta em ratas. Ratas mães foram expostas à ração com alto teor de gordura (ATG) à base de banha de porco (60 % de energia proveniente de gordura) ou uma dieta controle AIN93G (16 % de energia proveniente de gordura) durante a gestação ou gestação e lactação. A prole feminina com 7 semanas de idade foi induzida a carcinogênese mamária com o carcinógeno 7,12-dimeti-benz[a]antraceno. Comparado à prole do grupo controle, observou-se menor suscetibilidade à carcinogênese mamária na prole do grupo de ratas prenhas submetidas à ração ATG durante a gestação (menor incidência de neoplasias, multiplicidade e peso das neoplasias) ou gestação e lactação (menor multiplicidade). Prole feminina de ratas exposta à ração ATG durante a gestação apresentou menor crescimento da árvore epitelial mamária, proliferação celular (Ki67) e expressão de NFkB p65 e maior expressão de p21 e níveis globais de H3K9me3 na glândula mamária. Além disso, esta apresentou uma tendência na redução da razão Rank/Rankl (p=0,09) e níveis de progesterona sérica (p=0,07). Glândula mamária da prole feminina do grupo exposto à ração ATG durante a gestação e lactação apresentou menor número de TEBs, crescimento da árvore epitelial e razão BCL-2/BAX e maiores níveis de leptina em comparação à prole do grupo controle. Análise de lipidômica das glândulas mamárias revelou que exposição à ração ATG especificamente durante a gestação apresentou pequenos efeitos no perfil de ácidos graxos na prole feminina, enquanto que a exposição à essa ração durante a gestação e lactação promoveu menor concentração de ácidos graxos saturados (exceto ácido esteárico) e maior concentração de ácidos graxos polinsaturados da série n-6, monoinsaturados e ácido linoleico conjugado (CLA). De acordo com análise de dependência de redes diferencial (DDN) dos genes diferentemente expressos pela análise de \"microarray\" exposição à ração ATG em períodos precoces da vida altera a rede transcricional da glândula mamária na vida adulta. Especificamente, ratas expostas à ração ATG somente durante o período fetal apresentou aumento da expressão de Hrh1 e Repin1 em comparação ao controle. A prole exposta à ração durante o período fetal e lactacional apresentou maior e menor expressão de Stra6 e Tlr1 em comparação ao contole, respectivamente e menor expressão de Crkrs em comparação à prole exposta à ração somente durante o período fetal. Nossos dados confirmam que o risco de câncer de mama da prole pode ser programado pela alimentação materna. No entanto, ao contrário do que se esperava, exposição a altos níveis de gordura animal no início da vida diminuiu a suscetibilidade ao câncer de mama na vida adulta. Dentre os possíveis mecanismos envolvidos nessa proteção encontram-se a modulação da morfologia e perfil lipídico da glândula mamária, redução da proliferação celular e aumento dos níveis proteicos de reguladores do ciclo celular, modulação de marcas epigenéticas como H3K9me3, modulação da expressão gênica global com alteração de redes de sinalização, bem como regulação de vias de sinalização específicas como RANK/RANKL/NF&#954;B. Porém esses mecanismos são dependentes do tempo e período de exposição. / The present study investigated whether early life exposure to high levels of animal fat changes breast cancer risk in adulthood in rats. Dams consumed a lard-based high-fat (HF) diet (60% fat-derived energy) or an AIN93G control diet (16% fat-derived energy) during gestation or gestation and lactation. Their 7-week-old female offspring were exposed to 7,12-dimethylbenz[a]anthracene to induce mammary tumors. Compared to the control offspring, significantly lower susceptibility to mammary cancer development was observed in the offspring of dams fed on HF diet during gestation (lower tumor incidence, multiplicity and weight), or gestation and lactation (lower tumor multiplicity only). Mammary epithelial elongation, cell proliferation (Ki67), and expression of NFkB p65 were significantly lower, and p21 expression and global H3K9me3 levels were higher in the mammary glands of rats exposed to HF lard diet in utero. They also tended to have lower Rank/Rankl ratios (p=0.09) and serum progesterone levels (p=0.07) than control offspring. In the mammary glands of offspring of dams consuming the HF diet during both gestation and lactation, the number of terminal end buds, epithelial elongation and the BCL-2/BAX ratio were significantly lower, and serum leptin levels were higher than in the controls. Lipidomic analysis on mammary glands showed that exposure to a lard-based HF diet only during gestation had little effects on fatty acids profile on offspring, whereas this exposure during gestation and lactation promoted significant changes on the offspring\'s mammary glands. In general, it decreased SFA (except for stearic acid) and increased n-6 PUFA, MUFA and CLA concentrations in mammary gland. According to Differential dependency network (DDN), analysis of genes differently expressed by microarray, exposure to HF diet during early life changes the transcriptional network of the mammary gland in adulthood. Specifically, rats exposed to HF diet only during the fetal period showed increased expression of Hrh1 e Repin1 compared to the control. The offspring exposed to the HF diet in utero and nursing had higher and lower expression of Stra6 and Tlr1, respectively, compared to the control and lower expression of Crkrs compared to the offspring exposed only in utero. Our data confirm that the breast cancer risk of offspring can be programmed by maternal dietary intake. However, contrary to our expectation, exposure to high levels of lard during early life decreased later susceptibility to breast cancer. The mechanisms involve modulation of mammary gland\'s morphology and lipid profile, decrease of cell proliferation and increase of cell cycle regulators, modulation of epigenetics marks as H3K9me3, modulation of global gene expression with alteration of transcriptional network and RANK/RANKL/NF&#954;B pathway. However, these mechanisms are dependent on the duration and period of exposure.

O consumo de dieta hiperlipídica e consequente acúmulo de lipídios nos adipócitos é uma condição associada ao estresse oxidativo e à perpetuação de um quadro inflamatório de leve intensidade que leva ao desenvolvimento de doenças crônicas não transmissíveis. Uma vez que alguns componentes da dieta são reconhecidos como fortalecedores do sistema antioxidante exógeno dos organismos vivos, o objetivo deste trabalho foi investigar o efeito metabólico do extrato de sementes do gênero Passiflora sobre parâmetros bioquímicos, oxidativos e inflamatórios de camundongos submetidos a uma dieta hiperlipídica. Para tanto, inicialmente realizou-se um estudo de composição química (centesimal, teores de minerais e ácidos graxos) e de otimização da extração de sementes de P. edulis Flavicarpa para obtenção de maiores teores de compostos polifenólicos com expressiva capacidade antioxidante in vitro, segundo os parâmetros de processo tempo, temperatura e concentração de etanol. Determinada a condição ideal de extração, esta foi empregada para as demais espécies em estudo P. alata BRS Mel do Cerrado e BRS Doce Mel, P. tenuifila BRS Vita e P. edulis BRS Sol do Cerrado e BRS Gigante Amarelo e P. setacea BRS Pérola do Cerrado e foi realizada o estudo de composição química. Os extratos etanólicos obtidos possuíram interessante atividade antioxidante, com destaque para a espécie P. setacea. O composto piceatanol foi o polifenol majoritário (0,41-10,28 g/ 100 g de semente em base seca) nas sementes de Passifloras analisadas, com exceção para a amostra P. setácea BRS Vita, cujo composto de íon molecular m/z 747,2 não foi identificado. As sementes ainda apresentaram alto teor de óleo, com o ácido linoleico em sua composição, e proteína. Os extratos das sementes de P. setacea BRS Pérola do Cerrado e Passiflora edulis Flavicarpa, nas concentrações de 500 e 1000 mg/Kg de ração foram utilizados para a realização do ensaio biológico. O consumo dos extratos, dependendo da dose, apresentou efeitos biológicos importantes, tais como a diminuição das concentrações séricas de colesterol, glicose, insulina e leptina a níveis aproximados ao determinado para os animais em consumo de dieta normolipídica. Adicionalmente, verificou-se a atenuação do estresse oxidativo hepático, por elevação da atividade enzimática das enzimas catalase e glutationa peroxidase e diminuição da lipoperoxidação, e do processo inflamatório, por redução da concentração tecidual das citocinas IL-6 e MCP-1. Os resultados obtidos neste estudo contribuem para o conhecimento a respeito das passifloras brasileiras e na potencial utilização das sementes, consideradas subprodutos, na contribuição da manutenção da saúde. / The consumption of a high fat diet and consequent excessive lipid accumulation in adipocytes is a condition associated with oxidative stress and perpetuation of a mild inflammatory condition that leads to the development of chronic diseases. Since some dietary components are recognized as empowering exogenous antioxidant system defenses of living organisms, the aim of this study is to investigate the metabolic effects of passion fruit seeds that possess a high content of bioactive compounds and high antioxidant capacity in vitro on oxidative stress and inflammatory conditions in mice subjected to a high fat diet. For this purpose, initially were performed a chemical composition study (proximate, minerals and fatty acids content) and extraction optimization of P. edulis Flavicarpa seed for obtaining higher levels of polyphenolic compounds with expressive antioxidant capacity in vitro through process parameters such as time temperature and ethanol concentration. Once the optimum condition of extraction was determined, it was applied to others studied species P. alata BRS Mel do Cerrado e BRS Doce Mel, P. tenuifila BRS Vita e P. edulis BRS Sol do Cerrado e BRS Gigante Amarelo e P. setacea BRS Pérola do Cerrado and the chemical composition study was carried out. The obtained ethanolic extracts had high antioxidant activity, particularly the species P. setacea. The piceatannol compound was the major polyphenol (0.41 to 10.28 g / 100 g seed in dry basis) in the analyzed Passiflora, except for the sample P. setacea BRS Vita, which molecular íon m/z 747.2 was not identified. The seeds also showed high content of oil, with linoleic acid in its composition, and protein. P. setacea BRS Pérola do Cerrado and Passiflora edulis Flavicarpa seed extracts at concentrations of 500 and 1000 mg / kg of feed were used to carry out the biological assay. The consumption of the extracts, depending on the concentration, exhibited significant biological effects, such as the reduction of serum cholesterol, glucose, insulin and leptin levels to those one observed in animals with normolipidic diet consumption. Additionally, hepatic oxidative stress was attenuated by elevating enzymatic activity of catalase and glutathione peroxidase and decrease in the lipid peroxidation and inflammation by reducing the tissue concentrations of IL-6 and MCP-1 cytokines. The results obtained in this study contributes to the knowledge of the Brazilian passiflora and potential use of the seeds, considered a by-products, in health maintenance.

Dietas hiperlipídicas e a esteatose hepática são condições extremamente prevalentes. Trabalhos anteriores mostraram que a esteatose está associada a um aumento na geração de espécies reativas de oxigênio (ERO), e que isso pode mediar danos no fígado. Neste trabalho nós investigamos os possíveis mecanismos que desencadeiam os aumentos nas taxas de geração de ERO por meio da administração de dietas hiperlipídicas. Nós descobrimos que mitocôndrias de animais sujeitos a dietas hiperlipídicas não apresentaram diferenças significativas quanto a capacidade respiratória máxima e acoplamento, mas eram capazes de gerar mais ERO especificamente quando usados substratos do metabolismo de ácidos graxos. Além disso, foi observado que muitas isoformas de acil-CoA desidrogenases estavam mais expressas nos fígados de animais alimentados pela dieta hiperlipídica. No entanto, quando realizados ensaios de atividade enzimática apenas a acil CoA desidrogenase de cadeia longa (VLCAD) foi mais ativa. Estudos conduzidos com mitocôndrias permeabilizadas e expostas a grupos acil-CoA de diferentes tamanhos sugerem que a VLCAD pode ser uma fonte da produção aumentada de ERO em animais submetidos a dietas hiperlipídicas. Esta produção foi estimulada pela ausência de NAD+. Concluindo, nossos estudos descobriram uma nova fonte importante na geração de ERO estimulada por dietas hiperlipídicas, a VLCAD / High fat diets and accompanying hepatic steatosis are highly prevalent conditions. Previous work has shown that steatosis occurs concomitantly with enhanced reactive oxygen species (ROS) generation, which may mediate further liver damage. Here we investigated mechanisms leading to enhanced ROS generation following high fat diets (HFD). We found that mitochondria from HFD livers present no differences in maximal respiratory rates and coupling, but generate more ROS specifically when fatty acids are used as substrates. Indeed, many acyl-CoA dehydrogenase isoforms were found to be more highly expressed in HFD livers, although only the very long chain acyl-CoA dehydrogenase (VLCAD) was more functionally active. Studies conducted with permeabilized mitochondria and different chain length acyl-CoA derivatives suggest that VLCAD is a source of enhanced ROS production in mitochondria from HFD animals. This production is stimulated by the lack of NAD+. Overall, our studies uncover VLCAD as a novel, diet-sensitive, source of mitochondrial ROS

A redução no desenvolvimento muscular de filhotes cujas mães foram submetidas ao consumo de dietas baseadas no padrão ocidental pode ser, ao menos em parte, explicada pela resistência periférica à insulina, condição na qual a atividade de proteínas relacionadas à via de sinalização intracelular sensível a esse hormônio encontra-se reduzida. A regulação positiva dessa via resulta no aumento da atividade do Alvo da Rapamicina em Mamíferos (mTOR) que atua como efetor positivo da taxa de tradução de RNAm e, consequentemente, da síntese proteica. Estudos que avaliam a atividade dessa proteína frente ao consumo crônico de dietas hiperlipídicas são escassos e controversos e, até o momento, não são conhecidos trabalhos que avaliaram esses marcadores em animais neonatos ou desmamados, provenientes de mães alimentadas com dieta hiperlipídica gestacional e pós-gestacional. O presente estudo objetiva avaliar o efeito do consumo de uma dieta hiperlipídica por ratas adultas sobre a morfologia e sobre a expressão e a fosforilação das proteínas que compõem a via de sinalização intracelular do mTOR no músculo esquelético da prole em dois momentos: nascimento e desmame. Para isso, inicialmente, 39 ratas foram distribuídas em dois grupos, de acordo com a dieta oferecida: controle (n=19) e hiperlipídica (n=20). Após o nascimento, cerca de seis filhotes por mãe foram eutanasiados para coleta de amostras e análise dos marcadores investigados. Os filhotes selecionados para dar continuidade ao experimento foram dispostos junto às mães que, por sua vez, foram distribuídas em outros quatro grupos, segundo a dieta gestacional e pós-gestacional: CON/CON (n=8); CON/HL (n=9); HL/HL (n=8); HL/CON (n=7). Ao final da lactação, os filhotes foram eutanasiados e amostras foram coletadas para análise. Os resultados obtidos indicam que, em relação aos animais neonatos, há redução das concentrações séricas de leptina e de IGF-I e aumento da fosforilação da Akt e do mTOR musculares, em resposta ao consumo materno da dieta hiperlipídica. Por sua vez, nos animais lactentes, observamos influência da dieta hiperlipídica materna pós-gestacional sobre a promoção de fenótipo obesogênico, com concomitante redução do desenvolvimento muscular e da fosforilação de proteínas alvo do mTOR em estado pós-prandial. Com base nos resultados obtidos, concluímos que a dieta hiperlipídica materna afeta a atividade do mTOR, sendo, esse efeito, dependente da idade e da condição fisiológica dos animais. / The decrease in muscle development of offspring whose mothers consume a typical Western diet can be partly explained by the progression of peripheral insulin resistance, a condition in which the activity of proteins related to the intracellular signaling pathway sensitive to this hormone is reduced. The positive regulation of this pathway results in increased activity of the Mammalian Target of Rapamycin (mTOR) that acts as a positive regulator of the rate of mRNA translation and protein synthesis. Studies that assess the activity of this protein in response to chronic consumption of high fat diets are scarce and controversial and, to date, studies that evaluated these markers in the offspring of mothers fed a high fat diet during gestational and lactation are not known. This study aims to evaluate the effect of consuming a high fat diet for female adult rats in morphology and expression and phosphorylation of proteins that comprise the intracellular signaling pathway of mTOR in skeletal muscle of offspring in two stages: birth and weaning. Therefore, initially, 39 rats were divided into two groups, according to the available diet: control (n = 19) and diet (n = 20). After birth, around six pups per mother were killed for sample collection and analysis of the markers investigated. The pups selected to continue the experiment were placed with the mothers who, in turn, were divided into four groups according to gestational and post-gestational diets: CON/CON (n = 8), CON/HL (n = 9), HL/HL (n = 8), HL/CON (n = 7). At the end of lactation, the pups were euthanized and samples were collected for analysis. The results indicate that, for the newborn animals, there is a reduction of serum leptin and IGF-I concentrations and increased phosphorylation of Akt and mTOR in muscle in response to maternal consumption of high fat diet. In turn, we found that maternal high-fat diet during lactation promoted an obese phenotype in weaned animals, with concomitant reduction of muscle development and mTOR target proteins phosphorylation in the postprandial state. Based on these results, we conclude that maternal high-fat diet affects the activity of mTOR, depending on age and physiological condition of the animals.

Dietas hiperlipídicas e a esteatose hepática são condições extremamente prevalentes. Trabalhos anteriores mostraram que a esteatose está associada a um aumento na geração de espécies reativas de oxigênio (ERO), e que isso pode mediar danos no fígado. Neste trabalho nós investigamos os possíveis mecanismos que desencadeiam os aumentos nas taxas de geração de ERO por meio da administração de dietas hiperlipídicas. Nós descobrimos que mitocôndrias de animais sujeitos a dietas hiperlipídicas não apresentaram diferenças significativas quanto a capacidade respiratória máxima e acoplamento, mas eram capazes de gerar mais ERO especificamente quando usados substratos do metabolismo de ácidos graxos. Além disso, foi observado que muitas isoformas de acil-CoA desidrogenases estavam mais expressas nos fígados de animais alimentados pela dieta hiperlipídica. No entanto, quando realizados ensaios de atividade enzimática apenas a acil CoA desidrogenase de cadeia longa (VLCAD) foi mais ativa. Estudos conduzidos com mitocôndrias permeabilizadas e expostas a grupos acil-CoA de diferentes tamanhos sugerem que a VLCAD pode ser uma fonte da produção aumentada de ERO em animais submetidos a dietas hiperlipídicas. Esta produção foi estimulada pela ausência de NAD+. Concluindo, nossos estudos descobriram uma nova fonte importante na geração de ERO estimulada por dietas hiperlipídicas, a VLCAD / High fat diets and accompanying hepatic steatosis are highly prevalent conditions. Previous work has shown that steatosis occurs concomitantly with enhanced reactive oxygen species (ROS) generation, which may mediate further liver damage. Here we investigated mechanisms leading to enhanced ROS generation following high fat diets (HFD). We found that mitochondria from HFD livers present no differences in maximal respiratory rates and coupling, but generate more ROS specifically when fatty acids are used as substrates. Indeed, many acyl-CoA dehydrogenase isoforms were found to be more highly expressed in HFD livers, although only the very long chain acyl-CoA dehydrogenase (VLCAD) was more functionally active. Studies conducted with permeabilized mitochondria and different chain length acyl-CoA derivatives suggest that VLCAD is a source of enhanced ROS production in mitochondria from HFD animals. This production is stimulated by the lack of NAD+. Overall, our studies uncover VLCAD as a novel, diet-sensitive, source of mitochondrial ROS