Дисертації з теми "Oxidation des lipides"
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Garcia, Darras Carolina. "Conception et développement d'un microcalorimètre pour l'étude de l'oxydation d'une huile végétale." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14517/document.
Lipid oxidation results of many reactions generating numerous oxidation products that are worth characterizing in fats and oils. Among the analysis methods available, differential scanning calorimetry, based on the differential measurement of heat flux dissipated during the oxidation reactions, is convenient because it avoids the use of organic solvents. In this context, we have conceived and developed a microcalorimeter that allows the analysis of up to 5 samples simultaneously, in containers of variable sizes (allowing to vary the surface/volume ratio). For the conception of the microcalorimeter, the thermopiles are used in adiabatic configuration. The system is very stable and allowed flux measurement with a high sensitivity. The validation of the method is performed by Joule effect and by comparison of melting points of paraffins with classical differential scanning calorimetry. The modelization of the oxidation reaction is performed to point out the influence of oxygen on the kinetics. For a polyunsaturated oil (cameline oil), the enthalpy values obtained, at the beginning of the oxidation process, under isothermal condition (100°C) are correlated with the diene conjugated hydroperoxide amount. On the whole, the developed device provided an adaptable, sensitive, solvent-free and low cost method for the measurement of lipid oxidation, particularly suitable for the fast screening of a large set of samples
Al-Sayed, Mahmoud Kassem. "Extraction, fractionnement et caractérisation des lipides polyinsaturés d'oeufs de la truite arc-en-ciel (Oncorhynchus mykiss)." Thesis, Vandoeuvre-les-Nancy, INPL, 2007. http://www.theses.fr/2007INPL087N/document.
Fish eggs, especially those of the rainbow trout (Oncorhynchus mykiss) in the present study, are an interesting nutritional aquatic source. They contain proteins of high value, as well as an oil rich in polyunsaturated fatty acids (PUFA) with a large percentage of phospholipids. However, they exhibit a high auto-protection capacity against environmental constraints and thus, the degree of hydrolysis of rainbow trout eggs by Alcalase®, Neutrase® and Protamex® proteases varied solely within 3-7 %. This value was low compared with the 20 % obtained in most animal proteins. The phospholipid content was high (53 % of total lipids) and PUFA accounted for 42 % of total fatty acids. Among PUFA, DHA was found preferably at the sn-2 position of the glycerol backbone, which is of special interest about nutritional properties. The oil release by enzymatic hydrolysis was found limited compared with chemical methods, probably because of the strong interactions engaged with the incomplete destructured protein network. The oxidative stability of the oil was studied through several methods in which the infrared Fourier transform appeared as the best tool for structural analysis along the oxidation process. As a conclusion, lipids from fish eggs, especially from rainbow trout, could be a nutritional breakthrough, as far the enzymatic hydrolysis of the vitellus and of the chorion proteins is achieved
Pernin, Aurélia. "Action antioxydante et antimicrobienne de composés phénoliques dans des milieux modèles et des émulsions riches en lipides insaturés." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLA033/document.
Phenolic compounds appear to be good candidates for ensuring the quality and safety of several perishable products like ready-to-eat food. Widely found in plants and byproducts from agro-industries, they offer a potential solution to limit the oxidation of omega-3 polyunsaturated fatty acids (e.g. DHA and EPA) and the growth of foodborne pathogens such as Listeria monocytogenes.The aim of this PhD is to evaluate dual antioxidant and antimicrobial activity in complex food media and to better understand the associated mechanisms of action.First experiments carried out with a series of phenolic compounds in simple model media confirmed this dual efficiency.Interesting structure/activity relationships were highlighted and some mechanisms of action were decrypted, involving parameters like number and chemical environment of phenolic groups, logP, dissociated/undissociated forms of phenolic acids. The performances of three selected phenolic compounds, i.e. eugenol, ferulic acid and α-tocopherol (added alone or as a mixture), were evaluated in more realistic complex food media: o/w emulsions composed of fish oil, aqueous phase and whey proteins or Tween 80 as emulsifiers. Ferulic acid shows no antioxidant activity but can inhibit the development of L. monocytogenes. In contrast, eugenol and α-tocopherol are good antioxidants but not antimicrobials in emulsions formulated with whey proteins. Mechanisms of action are proposed to explain these behaviors
Socrier, Larissa. "Influence de la localisation d’antioxydants sur la peroxydation des lipides membranaires : étude du mode d’action de dérivés PBN et de composés phénoliques." Thesis, Compiègne, 2017. http://www.theses.fr/2017COMP2382/document.
Reactive oxygen species (ROS) are essential in living cells as they intervene in several physiological processes like the immune system and signaling pathways. However, an excess of the production of ROS can alter the equilibrium with antioxidants. This imbalance is called oxidative stress. As oxidative stress has been reported to be implicated in more than 200 diseases, the action of antioxidants to limit the deleterious effects of ROS is crucial. The antioxidants used by the cells can be chemical. Among them, α-phenyl-N-tert-butyl nitrone (PBN) is widely used in biological systems to neutralize ROS. Because this molecule possesses a poor ability to target membranes, our collaborators synthesized amphiphilic nitrones bearing a PBN moiety. The first chapter describes the interactions of cholesterol derived PBN derivatives with the membrane. Results underlined the influence of the polar moiety on the nature of their interactions with membrane lipids. In addition, the evaluation of the antioxidant properties revealed the importance of the membrane localization of the nitrone moiety on the protective activity of the derivatives. The second chapter deals with a second set of amphiphilic nitrones that have the particularity of bearing a perfluorinated chain that constitutes the hydrophobic moiety. We noticed the membrane localization is important for the antioxidant efficiency; however the nature of the antioxidant moiety remains the most important parameter in this case. Finally, the strategy of grafting two different antioxidants on the same carrier seems to be promising to enhance the protective effect and create a synergistic antioxidant effect. However, cells also use natural antioxidants to defend themselves. These antioxidants come from food, especially from vegetables and fruits. Among them, phenolic compounds are known for their beneficial effects on health. Flavonoïds, phenolic acids, stilbenes and lignans constitute the 4 main classes of phenolic compounds. Lignans are particularly present in flaxseed (Linum usitatissimum). Flaxseed is the plant that possesses the highest quantity of secoisolariciresinol diglucoside. In order to understand their mechanisms of action and their interactions with membranes, lignans as well as hydroxycinnamic acids were purified from flaxseed. The third chapter describes the results obtained on model membranes. Generally speaking, both classes of compounds are efficient against lipid oxidation. Studying their interactions with membrane lipids allowed us to show that the mechanism of lignans, that penetrate membranes, is more efficient than the mechanism of hydroxycinnamic acids
Roman, Olesea. "Mesure et prédiction de la réactivité des lipides au cours du chauffage d'huiles végétales à haute température." Phd thesis, AgroParisTech, 2012. http://pastel.archives-ouvertes.fr/pastel-00806186.
Du, Zhen-Yu. "Consequences of fat feeding on growth and body lipids in a herbivorous fish (Grass carp, Ctenopharyngodon idella) : mechanisms related to fatty acid oxidation." Dijon, 2005. http://www.theses.fr/2005DIJOS019.
Ayoub, Pierre. "Molecular dynamics study of pyrene excimer formation and oxidation in lipid bilayer models." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAE038/document.
We propose a novel approach to extract the lateral diffusion coefficient in lipid bilayers using excimer formation. In contrast to previous statistical models that modeled the system as points undergoing jumps from site to site on a lattice, we use coarse-grained molecular dynamics to study lipid bilayers simulated using the Martini force field. We derive time dependent reaction rates from survival probabilities obtained a posteriori from numerically generated trajectories of symmetric DOPC (1,2-Dioleoyl-sn-glycero-3-phosphocholine) and POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) bilayers at 283K and 293K respectively. Collision dynamics are determined by virtually relabeling the simulated molecules. The fluorescent probes are assumed to behave like ordinary membrane lipids and therefore the dynamics remain unaffected. We derive a generalized expression for the survival probability combining independent pairs and size scaling assumptions, but no assumption is made regarding the kinetic rate of the excimer formation process. By fitting the numerically determined normalized fluorescence emission intensities to experimental titration curves, we obtain two sets of results for the lateral diffusion coefficients depending whether interleaflet excimer association is allowed or not. We use a capture radius of 0.5 nm, the distance at which the probes react to form excimers. By relating Martini dynamics to real fluorescence experiments, we estimate the numerical Martini acceleration factor. We also study mixtures of oxidized-non oxidized DOPC and POPC bilayers using a hydroperoxidized model of these lipids for different concentrations of the oxidized component (3.1%, 25% and 50%). Using pair correlation functions, we extract structural information on the systems and determine whether the two components are prone to mixing or not. Finally, we calculate the thermodynamic mixing parameters within the framework of the virial expansion
Garcia, Mendoza Maria del Pilar. "Enrichissement d’huiles végétales par des antioxydants de type phenolique en vue d’applications alimentaires." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0196.
Vegetable oils like camelina and sunflower oils are sources of healthy polyunsaturated fatty acids that are however highly susceptible to oxidative degradation. This work aimed at enhancing the oxidative stability of edible oils, mostly camelina oil by incorporating phenolics antioxidants, either as a pure component, quercetin, or as a more complex mixture extracted from a walnut by-product. The low solubility of quercetin in oils was successfully circumvented by developing a solvent-free route of enrichment in presence of phospholipids, so that quercetin-phospholipids formulation allowed to significantly increase both quercetin solubility and the oxidative stability of the oils. The enhanced oxidative stability, monitored under accelerated conditions of heating, was found to vary according to quercetin-phospholipid concentrations and ratios, and it was assumed that colloidal associations played a key role in the enhancement. Data of quercetin solubility in various solvents of industrial interest were also provided. For phenolic extract recovered from a walnut press-cake in addition to oxidative stability enhancement, modelling of batch and semi-continuous extractions was performed and influent parameters were identified. The protective effect against lipid oxidation of a walnut extract exhibiting high antiradical activity was dose-dependent and significantly extended the shelf life of enriched oils
Masoud, Rawand. "Modulating the activity of NADPH oxidase by oxidative stress participants ; lipids and nanoparticles A cell-free system study." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS028/document.
NADPH oxidase from phagocytes is a multi-subunit enzyme complex involved in the innate defense of organisms against pathogens. It is composed of the membrane-bound flavocytochrome b558 (Cyt b558), comprising two subunits (gp91phox, and p22phox) and four cytosolic components, p47phox, p67phox, p40phox, and Rac. Its function is to produce in the vicinity of the pathogen, superoxide ions that are transformed subsequently into other reactive oxygen species (ROS) and will damage lipids, proteins and DNA. Upon phagocyte activation, the cytosolic subunits undergo posttranslational modifications and migrate to the membrane bound Cyt b558 to constitute the activated NADPH oxidase complex. The damaging role of ROS in cardiovascular diseases has been known for some decades. The aim of my thesis was to study the influence on NADPH oxidase activity, of molecules coming from food and industrial products and known to be involved in increase of oxidative stress.In this work, we studied the NADPH oxidase functioning in an in vitro system in which the components of the enzyme are mixed and activated by the introduction of an amphiphile the arachidonic acid (AA). During my PhD, I have studied the influence of two types of oxidative stress participants: lipids and nanoparticles (NPs). For simplicity, we have replaced the cytosolic subunits by a single protein called trimera, which is a fused construction of three cytosolic proteins p47phox, p67phox and Rac. We have shown that trimera is functionally comparable with the separated cytosolic subunits. The rates of production of O2•−, the dependences of the activity in function of AA concentration and temperature, the presence of two states in the activation process and the sensitivity of NADPH oxidase to free radicals were comparable when either trimera or separated subunits were used.I investigated the consequences of the addition of cholesterol on NADPH oxidase, on the production of ROS. Our results clearly show that cholesterol and oxysterols are not efficient activators of NADPH oxidase. Concentrations of cholesterol similar to what found in neutrophiles trigger a low superoxide production. Addition of cholesterol during the assembly process (in presence of AA) at similar or higher concentrations, has an inhibitory effect on the production of O2•−. Added cholesterol acts on both cytosolic and membrane components, leading to imperfect assembly and decreasing the affinity of cytosolic subunits to the membrane ones. In conclusion, we showed that the cholesterol already present in the phagocyte membrane is optimal for the function NADPH oxidase.It was of interest to check the influence of titanium dioxide (TiO2) and platinum (Pt) NPs on NADPH oxidase especially that cellular internalization of NPs was shown to activate neutrophils and contribute to O2•− overproduction via NADPH oxidase. In the absence of activators and presence of TiO2 or Pt NPs, no production of O2•− could be detected in in vitro system as well as in neutrophils indicating that TiO2 and Pt NPs were unable to activate by themselves the complex. However once the NADPH oxidase was activated by AA, TiO2 NPs increased the rate of O2•− production by up to 40%, this effect being dependent on their concentration. Differently, Pt NPs had no effect both on in vitro system as well as on neutrophils. In conclusion, the hyper-activation of NADPH oxidase and the subsequent increase in ROS production by TiO2 NPs could participate to oxidative stress development while the absence of Pt-NPs effect suggest that they do not induce inflammation status via this complex
Kaleem, Muhammad. "Effets des produits d'oxydation de l'acide linoléique sur sa biohydrogénation ruminale." Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0042/document.
Ruminal biohydrogenation (BH) of polyunsaturated fatty acids (PUFA) produces some trans FA which can be found in ruminant products. Among them, t11 isomers would be beneficial for human health while t10 isomers are potentially deleterious. In farms, addition of oilseeds to the diet of dairy cows increases these fatty acids in milk. Oilseeds are often heated before incorporation to cow’s diets, to enhance their nutritional value. Experiments investigating effects on t11 isomers content in rumen and milk of cows receiving heated oilseeds provided variable results, but they usually increased t11 isomers and protected PUFA from BH. On the contrary, highly oxidized oil decrease t11 isomers and sometimes increase t10 isomers. Lipid oxidation products generated during heating of oilseeds and oils could be incriminated. The objectives of the present study were to investigate the effects of c9,c12-C18:2 oxidation products on its BH. Protection of PUFA in heated soybeans was linked to aldehydes, mainly hexanal. An increase of t11 isomers was observed with a long and unsaturated aldehyde, the t2,t4-decadienal, due to an inhibition of the last BH step. This effect was concomitant with a modification of bacterial community by t2,t4-decadienal. Hydroperoxides formed during c9,c12-C18:2 heating are 13HPOD and 9HPOD. The increase of t10 isomers in all of our experimentations was systematically linked with 13HPOD. No definitive explanation about the mechanism of action could be proposed, but 13HPOD would most probably act on microbiote since it had no effect on Δ9-isomerase. Our experiments did not explain the decrease of t11 isomers observed with heated oils, which could, at least in part, be due to 13HPOD and 9HPOD, which were able to inhibit Δ12-isomerase Some modifications of ruminal fermentation without measurable alteration of bacterial community abundance, diversity or structure also suggest an action of heated PUFA on bacterial activity
MEBARKI, SLIMANE. "Contribution a l'etude de l'utilisation metabolique de divers acides gras par l'adipocyte de rat : effets de l'age et des lipides alimentaires." Paris 7, 1987. http://www.theses.fr/1987PA077225.
Guzun-Cojocaru, Tatiana. "Peroxydation des lipides émulsionnés et transfert d'ions fer à l'interface huile / eau stabilisée par des protéines de lait : influence des résidus phosphates et de la stabilité du chélate de fer." Thesis, Dijon, 2010. http://www.theses.fr/2010DIJOS012/document.
Iron incorporated into food systems induces oxidation and precipitation. The consequences are a reduced bioavailability and a modification of other food flavor. The iron chelates such as Fe-bisglycinate and Fe-EDTA represent a possibility to avoid side effects, since the iron is protected. The inertety of Fe bisglycinate and NaFe EDTA for lipid peroxidation has been verified in oil-in-water emulsion models stabilized by sodium caseinate or by β lactoglobulin through the following studies: i/ increase of primary and secondary products of oxidation, ii/ change of the properties of the oil/water interface (tension and interfacial rheology), iii/ the stability of the chelate iron (Fe-bisglycinate) in the aqueous phase with β lactoglobulin at different pH (pH 2, 3.5 and 6.5). The oil/water interface stabilized by proteins with phosphate groups has induced peroxidation, which was not observed with proteins containing no phosphate residue. These results demonstrate also that the type of iron salts plays a crucial role in the oxidative stability of emulsions. The ability of the complex to retain iron ion and to avoid “free” ferrous ion is the first important factor to be controlled. The affinity of milk proteins to bind these free iron ions is the second factor that controls the transfer to oil/water interface. To sum up, the competition for iron ions between functional groups of protein and salt counter ions (glycinate, sulfate or EDTA) governs the oxidation state of the system in neutral conditions. In acidic medium, the oxidation is mainly governed by the stability of the complex and the possibility to free iron in bulk
Musigamart, Natedao. "Study of the role of lipids from maturated coagula from Hevea brasiliensis latex on natural rubber behavior in oxidative conditions." Thesis, Montpellier, SupAgro, 2015. http://www.theses.fr/2015NSAM0004/document.
Natural rubber (NR), a derived product from H. brasiliensis latex, is known for its high mechanical properties that are, for some, superior to those of its synthetic counterparts. However, the high degree of unsaturation of poly(cis-1,4-isoprene) makes it susceptible to thermo-oxidation. Fortunately, NR is endowed with non-isoprene components of which some have antioxidant properties. Especially, lipids, the main non-isoprene component retained in NR, have been reported to contain antioxidant substances, especially tocotrienols. It is well known that during the maturation of latex coagula, both NR physical properties and chemical composition are altered, but the complex mechanisms of this alteration are still to be elucidated. In the present work, the evolution of some native antioxidant molecules during maturation was followed in relation with some physical properties. Two experimental conditions of maturation were chosen. The first experiment involved uncontrolled conditions based on traditional unsmoked (USS) or ribbed smoked sheet (RSS) processing, while the second was performed in a dedicated maturation device with full control of environmental factors (relative humidity, temperature and oxygen content) followed by a processing based on that of Technically Specified Rubber (TSR). The evolution of samples during maturation was studied at different scales: bulk properties (P0, P30 and PRI), mesostructure (% gel content, Mw and Mn) and biochemical composition (lipids components). In parallel, in vitro antioxidant activity of NR lipid extracts was also investigated using an optimized DPPH method. Lipid quantity and quality evolved during maturation, especially under aerobic conditions. The total amount of lipid extract decreased, with a release of free fatty acids at early stage of maturation followed by a later decrease, unsaturated fatty acids being the first to disappear. The amount of extractable free γ-tocotrienol did not change much during maturation, while its esterified form was enriched in saturated fatty acids. The antioxidant activity measured in vitro correlated well with free γ-tocotrienol concentration but not with the resistance of rubber to thermo-oxidation assessed by P30 or PRI. Indeed, the in vitro conditions of measurement were far from those occurring inside rubber material. The localization of antioxidants in rubber and especially their physical possibility to interact with the double bonds of poly(cis-1,4-isoprene) or with oxidant species should be further investigated to understand what drives the drop of P30 along maturation time. Non extractable lipids or more polar non-isoprene molecular species (proteins, polyphenols, etc…) could also influence the resistance to thermo-oxidation
Škrabalová, Lada. "Hemoglobin-mediated oxidation of marine liposomes." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2012. http://www.nusl.cz/ntk/nusl-216833.
Janani, Tahereh. "Herbs as antioxidants in oxidation of marine lipids." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for biologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-23597.
Sparks, Darrell Lynn. "Oxidation of lipids in a supercritical-fluid medium." Diss., Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-03252008-162949.
Reid, Vanessa Claire. "Macrophage toxicity of lipid oxidation." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308384.
Nogueira, Marina Sayuri. "Avaliação do consumo de lipídios oxidados na indução do estresse oxidativo associado à aterosclerose em modelo animal." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/9/9132/tde-22122015-091244/.
Studies involving cell culture, animals and humans have been extensively applied in the monitoring of atherosclerosis, aiming its control or even this reversal. Among the animal models, it has been observed an appropriate response to the induction of dyslipidemia and inflammation, but a high resistance to oxidative stress induction. An alternative to overcome this limitation would be by the intake of diets containing oxidized fatty acids. However, studies that investigated the effect of consumption of peroxides and secondary products of lipid oxidation in the progression of atherosclerosis have shown controversial results. Therefore, the aim of this study was to alter an animal model for the development of atherosclerosis, aiming to raise the variation in biomarkers of oxidative stress through chronic consumption of polyunsaturated fatty acids partially oxidized under concentrations naturally present in the human diet. LDL receptor \"knockout\" mice (C57BL / 6) were divided into 4 experimental groups. All groups received a modified fat diet containing 30% fat for 90 days. Three levels of oxidation were induced in flaxseed oil, representing low, moderate and high levels, characterized by a hydroperoxide concentration of 2.47 ± 0.02 (LOW), 3.87 ± 0.04 (MED) and 4.69 ± 0.04 LOOHs meq / kg (HIGH), respectively. The fourth group received the LOW diet, beyond diabetes mellitus type 1 through induction by streptozotocin at baseline (CONT +). The pre-oxidized flaxseed oil used to prepare the diets was maintained at 4 °C. The pelletization changed the concentration of primary and secondary products, but proportionally, maintaining the difference between the three levels. CONT + group showed less weight gain than the others. No differences were observed between groups in relation to the lipoprotein profile. The CONT + and HIGH groups showed lower concentration of fatty acids in the liver, especially polyunsaturated fatty acids. In addition both CONT+ and HIGH groups showed higher concentrations MDA in the liver than MED and LOW groups, suggesting increased oxidative stress resulting from the intake of polyunsaturated fatty acids partially oxidized. The HIGH group also showed an increase in the thickness of the vascular wall and the size of the aorta lumen. This profile suggests that the chronic ingestion of partially oxidized polyunsaturated fatty acids contributes to increase oxidative stress in mice LDLr (-/-) , similar to that obtained with models using more aggressive forms of induction. Considering the trend of increased consumption of polyunsaturated fatty acids Omega 3, the results of this study conducted with flaxseed oil highlight to the need of controlling the oxidative stability of these oils during processing and storage, since moderate oxidation levels already present atherogenic potential.
Ma, Yanshan. "Factors Influencing the Oxidation of Lipoproteins and Plasma Lipids." Digital Commons @ East Tennessee State University, 1994. https://dc.etsu.edu/etd/2724.
Anderson, Richard Anthony. "Lipids, oxidative stress and endothelial function." Thesis, King's College London (University of London), 2004. https://kclpure.kcl.ac.uk/portal/en/theses/lipids-oxidative-stress-and-endothelial-function(ca261d48-d716-4156-9a38-dbb72775b36a).html.
Fogaça, Fabíola Helena dos Santos [UNESP]. "Efeito do tocoferol no desempenho e na estabilidade lipidica da tilápia nilotica (Oreochromis niloticus)." Universidade Estadual Paulista (UNESP), 2006. http://hdl.handle.net/11449/86711.
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
A vitamina E é usada nas dietas com a finalidade de melhorar o crescimento, a resistência ao estresse e a doenças, assim como a sobrevivência de peixes. Também pode ser eficiente na conservação do pescado durante o processamento e estocagem, inibindo a degradação dos lipídios pela oxidação. O presente trabalho avaliou os efeitos antioxidantes da vitamina E in vivo e in vitro na qualidade final dos hambúrgueres produzidos com filés de tilápias congelados durante 0, 30, 60 e 90 dias. Foi utilizado um delineamento inteiramente casualizado, com seis tratamentos, em esquema fatorial 3x2, caracterizado pela suplementação de dois níveis de vitamina E nas dietas (100 e 200 mg / kg de ração) e o grupo controle (zero mg/kg de ração) e adição ou não de 100 ppm de vitamina E aos hambúrgueres, com quatro repetições. Os peixes, com peso médio inicial de 184,23 + 1,68g foram alimentados com as dietas experimentais durante 63 dias. Após esse período, foram abatidos e os filés processados em hambúrgueres. Foram avaliados os parâmetros de desempenho, composição centesimal e a oxidação lipídica, determinada pelas substâncias reativas ao ácido tiobarbitúrico (SRATB). Os resultados mostraram que não houve diferença significativa para as variáveis de ganho de peso, conversão alimentar e crescimento específico entre os tratamentos. A composição química variou dentro dos valores encontrados para pescados. O aumento do nível de vitamina E promoveu redução nos valores de SRATB das amostras em todos os intervalos de tempo, e que a adição in vivo da vitamina E protegeu os hambúrgueres da oxidação lipídica de forma mais eficiente do que a adição in vitro, sendo que a interação entre ambas resultou em maior redução nas taxas de oxidação.
Vitamin E is used in diets with the aim of enhancing growth, resistance to stress and pathology, and also fish survival. It can be efficient in fish conservation during processing and frozen storage, inhibiting lipid degradation from oxidation. The present work evaluated the antioxidant effects of vitamin E utilization in vivo and in vitro in the final quality of hamburgers made from tilapia filets during frozen storage over 3 months. A randomized design, in a 3x2 factorial scheme was utilized, which correspond to the two levels of diet vitamin E (100 and 200 mg / kg diet) and the control group (zero mg/kg diet) and addition or not of 100 ppm of vitamin E to the hamburgers, with four repetitions. The fishes, with initial weight 184.23 + 1.68 g, were fed the experimental diets for 63 days, after which they were killed and processed into hamburgers. The performance parameters analyzed were centesimal composition and lipid oxidation, determined by the thiobarbituric acid reactive substances (TBARS). The results showed no significant difference between treatments for weight gain, food conversion or specific growth. The chemical composition varied within the values found for fish. Increased vitamin E levels promoted reduction of TBARS values over all time intervals. This means values suggested that the addition in vivo of tocopherol protected the hamburgers from lipid oxidation more efficiently when compared to in vitro addition, but the interaction between both resulted in higher reduction in rate of oxidation.
Ng, Su Chuen. "Effects of accelerated aging on lipid oxidation in quinoa (Chenopodium quinoa)." Online version, 2003. http://www.uwstout.edu/lib/thesis/2003/2003ngs.pdf.
Telles, Scott Gerard. "Change in zinc permeability of lipid bilayers as a function of fluidity and oxidation." Virtual Press, 1997. http://liblink.bsu.edu/uhtbin/catkey/1061869.
Department of Chemistry
Chido, Chakanya. "Fatty acid composition, colour stability and lipid oxidation of mince produced from fresh and frozen/thawed fallow deer meat." Thesis, University of Fort Hare, 2016. http://hdl.handle.net/10353/2479.
Mahachi, Leo Nyikadzino. "Physiochemical, fatty acids, lipid oxidation, sensory characteristics and consumer acceptance of warthog cabanossi produced with pork backfat and fat-tailed sheep backfat." Thesis, University of Fort Hare, 2017. http://hdl.handle.net/10353/6259.
Prado-Barragan, Lilia Arely. "Lipid oxidation in a meat fibre system." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294811.
Walters, Louise. "Lipid oxidation in salt-dried pelagic fish." Thesis, University of Lincoln, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262195.
McMoneagle, Andrew. "Antioxidant behaviour in photo-oxidation studies of model lipid compounds." Thesis, University of the West of Scotland, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311777.
Pradhan, Arati S. "Diffusion of zinc through oxidized lipid bilayers." Virtual Press, 2000. http://liblink.bsu.edu/uhtbin/catkey/1166400.
Department of Chemistry
Noble, Ronald. "Sensory methods used in meat lipid oxidation studies." Kansas State University, 2018. http://hdl.handle.net/2097/38563.
Food Science Institute
Kadri Koppel
Oxidation of meat decreases consumer acceptance and reduces market value making it an important problem for the meat industry. Odor and flavor of meat are significantly affected by lipid oxidation and researchers continue to explore new ways to control meat oxidation. Natural antioxidants, irradiation and oxygen treatments are major areas of research in meat lipid oxidation. In recent studies researchers have been exploring ways to extend shelf life of meat and in many case rely on sensory results. This report deals with sensory methods used to measure changes associated with treatments and outlines how researchers are using these methods.
Hoyland, David Vernon. "Chemical methods for assessing lipid oxidation in food." Thesis, University of Nottingham, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254588.
Smith, G. "Lipid oxidation in S.E. Asian salted-dried fish." Thesis, University of Lincoln, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380661.
Jenkins, Benjamin John. "The role of alpha oxidation in lipid metabolism." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/278025.
Vereb, Heather A. "Biomarkers of Lipid Oxidation in the Oral Cavity." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/76887.
Master of Science
Saeed, Suhur. "Lipid oxidation mechanisms and lipid-protein interactions in frozen mackerel (Scomber scombrus)." Thesis, University of Surrey, 1998. http://epubs.surrey.ac.uk/843251/.
de, Miguel Pastor Cristina. "Lípidos de la dieta y cáncer de mama experimental: efectos sobre el estrés oxidativo." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/399983.
Breast cancer is the most common malignancy among women all over the world. Besides the genetic, epigenetic and hormonal factors, there are epidemiologic and experimental evidences that nutritional and environment factors have a role in the etiology and the development of this cancer. The dietary lipids are directly related with cancer, mainly breast cancer. Previous results have demonstrated that high corn oil, rich in polyunsaturated fatty acids (PUFA) n-6, and the high extra virgin olive oil diets, rich in monounsaturated fatty acids (MUFA) n-9 and several bioactive compounds, in the experimental breast cancer, resulting in a stimulating and a potentially protective effect, respectively. These diets mostly acted on the carcinogenesis promotion stage, but there are evidences of their action on the initiation stage. The aim of this study was to investigate whether these lipids could exert their modulatory effects through changes on the oxidative stress state in the organism at different levels: in the healthy animal, in the carcinogenesis initiation stage and in the tumor-bearing adult animal. Results proceed from and experimental series, developed in the breast cancer model induced in the Sprague-Dawley rat with the polycyclic aromatic hydrocarbon 7,12-dimethylbenz(a)anthracene (DMBA). The antioxidant enzymatic defense was studied through CAT, SOD1, SOD2, GPX1, GPX4 and GR expression on the liver and mammary gland, and the non-enzymatic defense through total GSH, GSH, GSSG, GSH/GSHtotal and GSH/GSSG glutathione parameters in plasma. Furthermore, plasmatic oxidative damage in lipids and proteins, and DNA damage in the mammary gland though 8-OHdG levels and reparation OGG and PARP reparation damage enzymes were determined. Results showed that, high fat diets increased oxidative levels comparing with the control diet. The high corn oil diet showed a higher effect, both in healthy and especially in the carcinogenesis initiation stage. This was in accordance with an earlier tumor appearance and higher tumor content due to the high corn oil diet. On the other hand, the high extra virgin olive oil diet showed a weak stimulatory c effect which was associated with intermediate oxidative stress levels in serum and liver between the high corn oil and control diets, both in healthy and initiated animals. In the initiated mammary gland, dietary lipids exerted their effects on the oxidative stress parameters through specific mechanisms. Finally, once cancer disease was established, dietary lipids exerted a much lower effect.
Ingram, Katherine Heimburger. "Skeletal Muscle Lipid Peroxidation and its Relationships with Intramyocellular Lipids and Insulin Sensitivity in Obese Subjects." Digital Archive @ GSU, 2009. http://digitalarchive.gsu.edu/kin_health_diss/6.
Bôas, Eloísa Aparecida Vilas. "Tratamento crônico com ácido palmítico aumenta o conteúdo de superóxido e a apoptose de células BRIN-BD11com participação da NADPH oxidase, sem envolvimento do GPR40." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/42/42137/tde-18062014-132020/.
Chronic exposure to saturated fatty acids can lead to pancreatic beta cell dysfunction, reduction of insulin secretion and apoptosis, condition known as lipotoxicity, that has been related to: endoplasmic reticulum stress, chronic stimulation of GPR40 and increased production of reactive oxygen species (ROS) from, among other sources, the enzime NADPH oxidase. We intended to explore as mechanisms of lipotoxicity: reticulum stress, chronic stimulation of GPR40 and NADPH oxidase generation of ROS, as well as relations between NADPH oxidase and reticulum stress. Our results show that chronically palmitic acid induced an increase in the superoxide, in part from NADPH oxidase. NADPH oxidase inhibition by VAS2870 reverted the apoptosis induced by chronic exposure to palmitic acid, and was related to a lower expression of a reticulum stress marker (PERK). GW9508, GPR40 agonist, did not produced the same effects observed after chronic treatment with palmitic acid, suggesting that activation of GPR40 pathway is not involved in these processes.
Oliveira, Patrícia Martinez. "Avaliação dos efeitos hipolipêmico e antioxidante in vivo dos extratos hidroalcoólicos da folha e raíz do yacon (smallanthus sonchifolius)." Universidade Federal do Pampa, 2015. http://dspace.unipampa.edu.br:8080/xmlui/handle/riu/261.
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As doenças cardiovasculares (DCV) lideram as causas de morte em todo o mundo, sendo a dislipidemia o principal fator de risco. A alimentação é reconhecida como a intervenção mais importante na prevenção de patologias e as plantas são consideradas a melhor fonte de antioxidantes naturais. Entre elas, um alimento funcional que tem se destacado é o Yacon, uma raiz tuberosa, originária da região Andina que possui frutooligossacarídeos (FOS) como principal carboidrato de reserva, diferenciando-se da maioria das espécies tuberosas que estocam energia na forma de amido. Além desses compostos, o Yacon apresenta polifenóis em quantidade significativa tanto nas raízes como nas folhas. Estudos demonstram que o Yacon possui atividade hipoglicêmica, entretanto pouco se sabe sobre outras propriedades. Assim, o objetivo deste estudo foi investigar os efeitos hipolipêmico e antioxidante in vivo dos extratos hidroalcoólicos da folha e raiz do Yacon (Smallanthus sonchifolius). Foram utilizados ratos Wistar, machos, divididos em: G1 (controle dieta normal), G2 (controle dieta hipercalórica) (NaCl 0,9%), G3: suspensão oral de sinvastatina 10 mg/Kg (SIM), G4: extrato folha Yacon 20 mg/kg (EFY20), G5: extrato folha Yacon 40 mg/kg (EFY40), G6: extrato folha Yacon 20 mg/kg + sinvastatina (EFY20+SIM), G7: extrato folha Yacon 40 mg/kg + sinvastatina (EFY40+SIM), G8: extrato raiz Yacon 20 mg/kg (ERY20), G9: extrato raiz Yacon 40 mg/kg (ERY40), G10: extrato raiz Yacon 20 mg/kg + sinvastatina (ERY20+SIM) e G11: extrato raiz Yacon 40 mg/kg + sinvastatina (ERY40+SIM). As formulações foram administradas uma vez ao dia por gavage durante 14 dias consecutivos. Os parâmetros hematológicos, bioquímicos e de estresse oxidativo foram determinados através de metodologias clássicas. Os grupos que receberam o extrato de Yacon apresentaram melhora do perfil glicêmico e lipídico. A dieta hipercolesterolêmica aumentou os níveis séricos da creatina-quinase, CK-MB, homocisteína e LDH porém a administração do extrato diminuiu significativamente os níveis destes marcadores quando comparado ao grupo não tratado. Além disso, o extrato, reduziu a peroxidação lipídica, a carbonilação proteica, e frequência de micronúcleos induzida por hipercolesterolemia e aumentou as defesas antioxidantes (CAT, SOD, GPx, GSH, vitamina C e polifenóis) no sangue. Verificou-se ainda que, a suplementação do Yacon não mostrou efeito hepatotóxico ou nefrotóxico. A dieta hipercolesterolêmica aumentou o processo inflamatório, avaliado através de seus marcadores, e a administração do extrato melhorou esse parâmetro. Além disso, a suplementação com a raiz do Yacon controlou o ganho de peso dos animais. Assim, os resultados sugerem que o extrato liofilizado do Yacon apresentou uma atividade hipoglicêmica, hipolipêmica e antioxidante, possivelmente devido ao seu alto conteúdo de compostos fenólicos.
Cardiovascular diseases (CVD) are the leading cause of death worldwide, and dyslipidemia a major risk factor. Feeding is recognized as the most important intervention in the prevention of diseases and plants are considered the best source of natural antioxidants. Among them, a functional food that has been highlighted is the Yacon, a tuberous root, originate in the Andean region with fructooligosaccharides (FOS) as the main reserve carbohydrate, differing from most tuberous species which store energy in the form of starch. In addition to these compounds, Yacon presents significant amount of polyphenols in both roots and leaves. Studies show that Yacon has hypoglycemic activity, however little is known about other properties. The objective of this study was to investigate the hypolipemic and antioxidant effects in vivo of hydroalcoholic extracts of leaf and root of Yacon (Smallanthus sonchifolius). Male Wistar rats were used, divided into: G1 (normal control diet), G2 (control calorie diet) (NaCl 0.9%), group 3: oral suspension of simvastatin 10 mg/kg (SIM), group 4: Yacon leaf extract 20 mg/kg (YLE20), group 5: Yacon leaf extract 40 mg/kg (YLE50), group 6: Yacon leaf extract 20 mg/kg and simvastatin 10 mg/kg (YLE20+SIM), group 7: Yacon leaf extract 40 mg/kg and simvastatin 10 mg/kg (YLE40+SIM), group 8: Yacon root extract 20 mg/kg (YRE20), G9: Yacon root extract 40 mg/kg (YRE40), G10: Yacon root extract 20 mg/kg and simvastatin 10 mg/kg (YRE20+SIM), G11: Yacon root extract 40 mg/kg and simvastatin 10 mg/kg (YRE40+SIM), The formulations were administered once daily by gavage for 14 consecutive days. Hematological, biochemical and oxidative stress parameters were determined by classical methods. The groups that received the Yacon extract showed improvement of glycemic and lipid profile. The hypercholesterolemic diet increased serum levels of creatine kinase, CK-MB, homocysteine and LDH, but the extract administration decreased the levels of these markers significantly when compared to the untreated group. Moreover, the extract, reduced lipid peroxidation, protein carbonylation and frequency of micronucleus induced by hypercholesterolemia and increase antioxidant defenses (CAT, SOD, GPx, GSH, vitamin C, polyphenols) in the blood. Moreover, supplementation of Yacon showed no hepatotoxic or nephrotoxic effect. The hypercholesterolemic diet increased the inflammatory process, evaluated through your markers, and extract administration has improved this parameter. Furthermore, supplementation with the root of Yacon controlled weight gain of animals. Thus, the results suggest that the lyophilized Yacon extract showed a hypoglycemic, hypolipemic and antioxidant activity, possibly due to its high content of phenolic compounds.
Kristinova, Vera. "Oxidation of marine lipids in liposomes and emulsions mediated by iron and methemoglobin." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for bioteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-25022.
Filho, Adriano de Britto Chaves. "Eventos redox na biologia dos lipídios: modificação de tióis e alterações do lipidoma em ALS." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-20072018-085559/.
Lipids encompass a wide range of hydrophobic molecules present in cells. The molecular characteristics of lipids determine their cellular localization and biological function. In general, lipids are regarded as essential components of membranes, as energy reservoir and modulators of signaling pathways linked to cellular metabolism and survival, among others. In mammals, a large part of the lipids are esterified to polyunsaturated fatty acids (PUFAs), especially docosahexaenoic (DHA) and arachidonic (ARA) acids, essential for several physiological processes, including normal brain development. However, PUFAs are very susceptible to oxidation by reactive oxygen species (ROS) generated endogenously. Once oxidized, lipids are able to modify thiol groups of peptides and proteins leading to modulation of signaling pathways and cellular redox balance. In the chapter 1, we investigated the mechanisms involved in modification of thiol groups of peptides and protein by autoxidation products derived from PUFAs. Here, we identified several glutathione (GSH) adducts covalently modified by hydroxy-endoperoxides derived from both DHA and ARA. Detailed inspection of MS/MS spectra of GSH-adducts revealed that GSH and hydroxy-endoperoxides are likely bonded through a sulfur-oxygen chemical bond in a reaction which involves a nucleophilic attack by the thiolate anion. Also, we suggest that the efficiency of modification of thiol by hydroxy-endoperoxides are also dependent of the thiol reactivity, as demonstrated by covalent modification of the most reactive cysteine residue (Cys111) of the antioxidant enzyme Cu,Zn-superoxide dismutase (SOD1). Chemical modifications of thiol groups by hydroxy-endoperoxides may modulate protein aggregation and cellular redox status, yieldingGSH adducts capable to modulate inflammation, as reported for the enzymatically generated counterparts. In the chapter 2, we investigated the role of lipids in amyotrophic lateral sclerosis (ALS), since inflammation and oxidative stress in motor neurons are hallmarks of this neurodegenerative disease. Using an untargeted lipidomics approach based on mass spectrometry coupled to liquid chromatography (UHPLC-MS/MS), we investigated the lipid metabolism in motor cortex and spinal cord tissues of a rodent model of ALS. Analysis of the motor cortex showed that the main lipid alterations were age-dependent and linked to metabolism of sphingolipids. In contrast, the major lipid alterations in the spinal cord were found in ALS symptomatic group, being the metabolism of ceramides, cholesteryl esters and cardiolipin the most affected. According to our findings and data reported in the literature, we proposed a mechanism based on neuroprotection that involves accumulation of cholesteryl esters esterified to PUFAs in astrocytes. Collectively, our findings suggest that lipids play a crucial role in modulation of cellular process linked to thiol metabolism and neurodegeneration.
Bothma, Karien. "The involvement of lipid and protein oxidation in hypertension : the SABPA study / Karien Bothma." Thesis, North-West University, 2012. http://hdl.handle.net/10394/8652.
Thesis (MSc (Biochemistry))--North-West University, Potchefstroom Campus, 2013
Turner, Rufus. "Lipid oxidation by denatured haemproteins in heat-processed vegetables." Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365990.
Arnold, Andrew Richard. "Lipid oxidation in a model system and in meat." Thesis, University of St Andrews, 1989. http://hdl.handle.net/10023/14168.
Sickler, Marsha Lynn. "Inhibition of Lipid Oxidation with Phosphates in Muscle Foods." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/9866.
Master of Science
Romain, Cindy. "Effets et recherche de mécanismes d'action d'un extrait de sarments de vigne et de vins rouges riches en resvératrol et ses oligomères : Quel rôle dans la prévention des maladies cardio-vasculaires ?" Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20199/document.
Cardiovascular diseases (CVD) are increasing globally and are now an expensive public health problem. Overnutrition and lack of physical activity are key factors in the disease development. In recent years, studies on the pathogenesis of CVD showed many factors contributing to the development of these complex diseases including overweight, centralobesity, oxidative stress, vascular and systemic inflammation, insulin ressitance or endothelial dysfunction. Prevention of these disorders is the focus of pharmaceutical and dietarystrategies and polyphenols have already demonstrated beneficial and preventive effects. Among the 8000 phenolic compounds described to date, resveratrol has emerged as a strong candidate for the prevention of nutrition-related diseases.The objective of this work was to study the potential action of vine shoot extract (Vineatrol®) and red wines rich in resveratrol and its oligomers, in an animal model of nutritionallyinduced atherosclerosis.The first part of this study was to develop a diet triggering the best early atherosclerosis in theSyrian golden hamster. From this model, a preventive effect of Vineatrol® was highlighted: Vineatrol® induces adecrease in aortic lipid deposition but also improves the oxidative and inflammatory status of the animals. In the third part , Vineatrol®-enriched red wines showed preventive effects on risk factors foratherosclerotic disease and disorders related to the consumption of a high-fat diet. Possible mechanisms of action, explaining the beneficial effects of these wines have been consideredand sough. These mechanisms could involve modulation of the NF-κB and/or SIRT1pathways. The degree of importance of these different pathways will have to be confirmed
Zopyrus, Nadia. "On the Origin of Secosterols Upon Oxidation of Cholesterol." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/35885.
Irankunda, Rachel. "Nickel Chelating Peptides & Chromatography : From Peptides Separation Simulation up to their Antioxidant Activities - related Applications." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0213.
Metal-Chelating Peptides (MCPs), from protein hydrolysates, present various applications in nutrition, pharmacy, cosmetic etc. Yet, the empirical approach generally used to discover bioactive peptides from hydrolysates is time consuming and expensive due to many steps of fractionation, separation and biological activities evaluation. Thus, this PhD aimed to develop a novel approach for MCPs separation prediction using chromatography modelling and simulation based on the analogy between Immobilized Metal ion Affinity Chromatography (IMAC) and Surface Plasmon Resonance (SPR). For the first time, the SPR-IMAC analogy was experimentally investigated on 22 peptides and 70% of them validated this analogy, since peptides well retained in IMAC were also endowed with a good affinity for Ni2+ in SPR. In the second time, peptides with high affinity for Ni2+ (i.e low dissociation constant KD in SPR and a high retention time in IMAC) were used to study the modelling and simulation of peptide concentration profiles at the column outlet in IMAC. Since knowledge of adsorption isotherms was required to perform simulation, it was necessary to develop a methodology for predicting Langmuir isotherm parameters in IMAC from SPR data. The validity of simulation was evaluated by comparing experimental and simulated retention times that should be close for reliable prediction. Therefore, several approaches were evaluated to determine Langmuir sorption parameters, the most interesting one introduces a correction factor on the maximum adsorption capacity qmax alone, assuming that the affinity of peptides for immobilized Ni2+ did not change depending on the technology used (SPR vs. IMAC), thus affinity constant KA was not modified. Meanwhile, industrial application of MCPs and hydrolysates were studied. First, pea protein hydrolysates were produced by either Alcalase® followed by Flavourzyme® (Alc+Flav≤1kDa) or Protamex® followed by Flavourzyme® (Prot+Flav≤1kDa). SwitchSENSE® technology evidences the presence of Ni2+ chelating peptides and antioxidants tests showed that Prot+Flav≤1kDa has higher radical scavenging and reducing power, related to its higher degree of hydrolysis and small-size peptides quantity. Secondly, pea hydrolysates and MCPs were investigated for their ability to inhibit the lipid oxidation in emulsions. They slowed down lipid oxidation through chelation of prooxidant (metals such as Fe2+) reducing primary and secondary oxidation products responsible of deterioration of lipid containing products. Thus, pea hydrolysates and MCPs could be used as antioxidants in food and cosmetic products, as alternative to chemicals such as EDTA, BHT and TBHQ
Shehadeh, Sandra C. "The Effects of Soy Protein and Isoflavones on Lipid Oxidation and Blood Lipid Profile on Humans Participating in Moderate Physical Activity." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/36112.
Master of Science
Afonso, Milessa da Silva. "Avaliação do efeito do extrato aquoso e da fração fenólica livre do Alecrim (Rosmarinus officinalis L.) sobre o estado antioxidante e o perfil lipídico em ratos com hipercolesterolemia induzida pela dieta." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/9/9132/tde-17012011-163651/.
Hypercholesterolemia is considered an important risk factor for cardiovascular diseases, since hyperlipidemia associated to oxidative stress is one of the risk factors for these diseases. In this context, antioxidants derived from foods such as vitamins, phenolic compounds and others have been receiving increased attention due to their chemopreventive function against oxidative damages. Rosemary (Rosmarinus officinalis L.) belongs to the Labiatae family, whose antioxidant properties have been attributed to a variety of phenolic compounds capable of reacting with free radicals and quenching reactive oxygen species. The aim of this work was to evaluate the in vitro antioxidant capacity of extracts and phenolic acids fractions obtained from rosemary leaves and their effect on rats fed with 0.50% cholesterol and 0.25% cholic acid enriched diet. The results showed that extracts and fractions had high levels of total phenolic compounds and expressive antioxidant activity in vitro in both methods β-caroteno/ linoleic acid cooxidation and in the DPPH radical scavenge. Analysis in vivo showed a significant increase (p≤0.05) in total cholesterol and LDL cholesterol in hypercholesterolemic animals. Phenolic compounds present in rosemary aqueous extract and non-esterified fraction were capable to act on the activity of CAT, GPx and SOD, confirming the action of antioxidant compounds present in this spice on parameters of oxidative stress. Aqueous extract in concentration of 70 mg/Kg had reduced total cholesterol (39.8%) and LDL-c (45.6%) values and improved the animals\' antioxidant status, once it increased heart GPx activity (43.2%) and decreased SRATB production (32.3%) in the serum of this group. There was no dose response effect on serum lipids of these animals, suggesting a threshold of the aqueous extract activity. In a general context, the aqueous extract and non-esterified fraction of rosemary presented significant antioxidant capacity in vitro and in the conditions of the study, played an important role on the oxidative stress in experimental hypercholesterolemia, and the results obtained for the aqueous extract administered in the concentration of 70 mg/kg suggests an important role of phenolic compounds present in this extract on cholesterol metabolism.