Made available in DSpace on 2014-08-20T14:38:50Z (GMT). No. of bitstreams: 1 Dissertacao_Carolina_Boschini.pdf: 903597 bytes, checksum: 9c67bbb615d36cec975435c06e8ceb28 (MD5) Previous issue date: 2011-02-24 / This study aimed to investigate the effects of a product containing a combination of antioxidants (CA) and different levels of vitamin E on performance, carcass traits and meat quality of broilers. A total of 840 Cobb male broilers were fed experimental diets from 1 to 35 days. A completely randomized experimental design was used. Dietary treatments consisted of T1- 200ppm CA, T2- 200ppm CA + Vitamin E (20 ppm), T3- 200ppm CA + Vitamin E (40ppm), T4- 200ppm CA + vitamin E (60ppm), T5- 200ppm CA + vitamin E (80ppm), T6- vitamin E (80ppm). A basal corn-soybean meal diet was formulated according to requirements established by Cobb. Performance was not affected by dietary treatments. Carcass yield and cut-ups were not signifi-cantly influenced, but a numerical improvement of breast and thigh was observed in birds fed T3. Meat colorimetry was significantly affected, finding the best results to L* (T5), a* (T1 and T5) and b* (T6), but results did not differ from T2, T3, T4 and T5. A lowest TBARs index was observed in birds fed T5, indicating lower meat lipidic pe-roxidation. These results indicate that the CA with any level of vitamin E did not change the broiler performance and efficiency factor. The CA improved carcass yield and cut-ups, color and decreases meat lipid peroxidation. / Este estudo teve como objetivo investigar os efeitos de um produto com uma combinação de antioxidantes (CA) e diferentes níveis de vitamina E no desempenho, características de carcaça e qualidade da carne de frangos de corte. Um total de 840 frangos de corte Cobb machos foram alimentados com dietas experimentais de 1 a 35 dias. O delineamento experimental utilizado foi o completamente casualizado. As dietas experimentais consistiram de T1- CA-200ppm, T2-200ppm CA + Vitamina E (20 ppm), T3-200ppm CA + Vitamina E (40ppm), T4-200ppm CA + vitamina E (60ppm), T5-200ppm CA vitamina E + (80ppm) E e T6-vitamina E (80ppm). A dieta base de milho e soja foi formulada de acordo com os requisitos estabelecidos pela Cobb. O desempenho não foi afetado pelos tratamentos. O rendimento de carcaça e corte não foram significativamente influenciados, mas uma melhora numérica do peito e coxa foi observada nas aves alimentadas com T3. Colorimetria da carne foi afetada significativamente, encontrando melhores resultados de L * para o T5, a * (T1 e T5) e b * (T6) não diferindo de T2, T3, T4 e T5. Um menor índice de TBARS foi observado nas aves alimentadas T5, indicando menor peroxidação lipídica na carne. Estes resultados indicam que a CA com qualquer nível de vitamina E não alterou o desempenho de frangos de corte. A CA melhorou o rendimento de carcaça e corte, cor e diminuiu a peroxidação lipídica da carne.

Aluminium (Al) and silicon (Si) are contaminants found in substances used in the parenteral nutrition (PN). Because of its large volume, nutrition and infusion solutions are pharmaceutical products parenterally administered, which present higher risks of adverse effects when contaminated. Insoluble and biologically inert species of hydroxyaluminosilicates (HAS) may be formed in solutions containing Al and Si when pH > 4.5. This chemical interaction is considered of great interest in biology because of its possible role in detoxification or protection against metal toxicity. In this study the Al bioavailability was investigated in the presence of Si and some PN components in vivo. Al and Si body distribution in Wistar rats was analyzed after 60 administrations of Al 0.5 mg/kg/day and/or Si 2 mg/kg/day in the presence or absence of calcium gluconate or potassium dihydrogenphosphate in concentrations similar to those used in the PN solutions. δ -Aminolevulinic acid dehydratase enzyme activity and tiobarbituric acid reactive species (TBARS) content was also evaluated in animal tissues. Tissue digestion methods were optimized for the determination of both Al and Si in the same samples by Graphite Furnace Atomic Absorption Spectrometry (GFAAS). Better Al and Si recoveries in animal tissue samples occurred after dissolution with tetramethylammonium hydroxide (TMAH) using Si 15 mg/L as modifier for Al determination and Pd 2 g/L for Si. Before the measurements, graphite furnace was coated with Zr following a specific heating program. Al accumulated in all tissues, especially in the liver, kidneys, bones and blood. Si decreased Al accumulation, this effect was less pronounced in the presence of PN components though. Si tissue accumulation was also observed, mainly when administered together with phosphate. Although Al was deposited in the tissues, pronounced toxicity effects were not observed. Increase in lipidic peroxidation was observed in a few tissues. When δ-ALA-D activity was altered, it was increased in Al treated groups, mainly in Ca gluconate treatment. As a conclusion, Si did not decrease Al deposition and therefore the metal biodisponibility amidst the NP components. / O alumínio (Al) e o silício (Si) são contaminantes encontrados em substâncias usadas na nutrição parenteral (NP). Devido ao seu grande volume, soluções de nutrição e de infusão são os fármacos, administrados por via parenteral, que apresentam mais efeitos adversos se contiverem contaminantes. Hidroxialuminosilicatos (HAS) insolúveis e biologicamente inertes podem se formar em soluções contendo Al e Si quando o pH > 4,5. Esta interação química é considerada de grande interesse no campo biológico devido ao seu possível papel na desintoxicação ou proteção contra a toxicidade do metal. Neste trabalho, foi investigada a biodisponibilidade do Al na presença do Si e de alguns componentes da NP in vivo. Primeiramente otimizou-se os métodos de abertura de tecido biológico para análise de Al e Si coexistentes nas amostras por espectromentria de absorção atômica com forno de grafite. Foi analisada a distribuição do Al e Si no organismo de ratos Wistar após 60 administrações de 0,5 mg/kg/dia de Al e/ou 2 mg/kg/dia de Si na presença ou não de gluconato de cálcio ou dihidrogenofosfato de potássio em concentrações semelhantes as usadas nas soluções de NP. Foi também avaliada a atividade da enzima δ-aminolevulinato desidratase (δ-ALA-D) e espécies reativas ao ácido tiobarbitúrico (TBARS) nos tecidos dos animais. As melhores recuperações de Al e Si nas amostras de tecido animal ocorreram após dissolução com hidróxido de tetrametilamônio (HTMA) utilizando Si 15 mg/L como modificador para determinação de Al e Pd 2 g/L para Si. Foi necessário o recobrimento do forno com Zr para a medida das amostras dissolvidas com HTMA. O Al se acumulou em todos os tecidos, principalmente no fígado, rim, osso e sangue. O Si diminuiu o acúmulo do metal nos tecidos, mas esse efeito é menos pronunciado em meio aos componentes da NP. Foi observado o depósito de Si nos tecidos, principalmente no tratamento com fosfato. Apesar do Al ter se depositado nos tecidos, não foram observados efeitos pronunciados de toxicidade. Em poucos tecidos observou-se aumento na peroxidação lipídica nos tratamentos e a atividade da enzima δ-ALA-D, quando alterada, aparece aumentada nos grupos tratados com Al, principalmente no tratamento com gluconato de Ca. Como conclusão, o Si não diminui a deposição do Al e, portanto, a biodisponibilidade do metal em meio aos componentes da NP.

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

Oxidation limits the shelf life of many food products. Adding antioxidants to foods is the most common way to solve this problem. Reports on safety issues of synthetic food additives have raised consumer interest in "all natural" foods, without added antioxidants or with synthetic replaced with natural antioxidants. The natural antioxidants now in use are much more expensive and less potent than the synthetic antioxidants. Thus, effective and economical natural antioxidants are of great interest to researchers. Teng Cha is a type of herbal tea found in China that has reported high levels of antioxidants. Antioxidant activity of Teng Cha extract and its major component dihydromyricetin has been reported, but no studies have provided clear evidence for the antioxidant effectiveness of Tech Cha extracts. The goal of this study was to measure the antioxidant activity of Teng Cha extract and dihydromyricetin (DHM), a major component of Tech Cha extract. The DPPH assay was conducted and antioxidant activities of the crude extract and dihydromyricetin were evaluated in soybean oil based on the peroxide value, anisidine value, Totox value, headspace volatiles and headspace oxygen. Antioxidant effectiveness was also evaluated in a cooked beef model system. DHM was more potent than BHA in preventing soybean oil oxidation. The crude extract was not as effective as BHA and DHM, possibly because it contained transition metals. In cooked beef, DHM and the crude extract showed lower activity than BHA, possibly due to their low solubility. Overall, Teng Cha extract and DHM are potential natural food antioxidants for future applications. / Master of Science in Life Sciences

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

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

There is a growing number of evidences, associating the oxidative stress produced by the reactive species of oxygen, with the aging process at one hand, and with the beginning and development of the vascular complications of several chronic and degenerative diseases at another. The type of diet and the usage of specific medicines may be related among the responsible factors by the generation of free radicals. In Brazil, the consuming of higher amounts of fat on the diet has increased in the last years and haloperidol has been the most used neuroleptic in brazilian public health system due to its low cost when compared with other antipsychotic drugs. The objective of this study was to determine the lipid peroxidation through TBARS production in rats tissues, as an oxidative stress measure, promoted by the high fat diet associated with the chronic usage of haloperidol, the correlation between the abdominal fat content and the intracellular magnesium concentration as well as the correlation between the intracellular magnesium concentration and the hepatic production of TBARS. The high fat diet has promoted a significant increase on the TBARS levels in Wistar rat livers when compared to the control diet (one way ANOVA ), considering that the chronic usage of haloperidol has increased the hepatic production of TBARS promoted by high fat diet, raising twice the levels of TBARS when compared to control group ( two way ANOVA). The TBARS production promoted by the association of high fat diet with chronic usage of haloperidol seems to be related with the intra-erythrocyte concentration of magnesium, for there was a statistically positive correlation, between the content of intracellular magnesium and the TBARS production in rats livers . Supporting previous works that report a possible ionic base to the metabolic syndrome development, in this dissertation a negative correlation has occurred, statistically significant, between the intracellular magnesium concentration and the abdominal fat content among all the animals. The group fed by high fat diet as well as the group treated with haloperidol seems to be responsable, by diferent ways, for this result. / O tipo de dieta e o uso de certos medicamentos podem estar relacionados dentre os fatores responsáveis pela geração de radicais livres. No Brasil, o consumo de maior quantidade de gordura na dieta tem aumentado consideravelmente nos últimos anos e o haloperidol tem sido o neuroléptico mais usado pela saúde pública brasileira devido ao seu baixo custo quando comparado com outras drogas antipsicóticas. O objetivo deste estudo foi determinar a peroxidação lipídica através da produção de TBARS em tecidos de ratos, como medida de estresse oxidativo, promovido pela ingestão de dieta com alto teor de lipídio associada ao uso crônico de haloperidol, avaliar a correlação entre o conteúdo de gordura abdominal e concentração de magnésio intracelular e a correlação entre a concentração de magnésio intracelular e a produção hepática de TBARS. A dieta com alto teor lipídico promoveu aumento significativo nos níveis de TBARS em fígado de ratos Wistar quando comparado à dieta controle (ANOVA de uma via), sendo que o uso crônico de haloperidol potencializou a produção hepática de TBARS promovido pela dieta com alto teor lipídico, aumentando em duas vezes os níveis de TBARS quando comparado ao grupo controle (ANOVA de duas vias). A produção de TBARS, promovido pela associação da dieta com alto teor lipídico e o uso crônico de haloperidol, parece estar associada com a concentração intraeritrocitária de magnésio, pois houve uma correlação estatisticamente positiva entre o conteúdo de magnésio intracelular e a produção de TBARS em fígado de ratos . Apoiando trabalhos prévios que relatam uma possível base iônica para o desenvolvimento da síndrome metabólica, neste trabalho ocorreu uma correlação negativa, estatisticamente significativa, entre a concentração de magnésio intracelular e o conteúdo de gordura abdominal considerando todos os animais, sendo que o grupo consumindo dieta com alto teor de lipídio e o grupo sob uso crônico de haloperidol, contribuíram, de maneira distinta, para este resultado.

Monosialoganglioside (GM1) is a component of most cell membranes and is thought to play a role in development, recognition and cellular differentiation. Furthermore, GM1 is a neuroprotective agent that has been reported to scavenge free radicals generated during reperfusion and to protect receptors and enzymes from oxidative damage. In the present study we investigate the effect of GM1 on the catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, on the spontaneous chemiluminescence and total radical-trapping potential (TRAP) in cortex of rats ex vivo and in vitro. Systemic GM1 administration (50 mg/kg, i.p.; twice) reduced spontaneous chemiluminescence and increased CAT activity ex vivo. On the other hand, GM1 (103-104 nM) reduced CAT activity in vitro. The other parameters were not affected by GM1 administration. These findings agree with the view that the antioxidant action of GM1 is not due to an intrinsic antioxidant activity of this glycolipid, but due to a secondary decrease of reactive species generation and/or increase of antioxidant defenses. Moreover, we evaluated whether GM1 could have a neuroprotective action on the experimental model of glutaric acidemia, an inherited metabolic disorder characterized by glutaric acid (GA) accumulation and neurological dysfunction, as striatal degeneration and convulsion. The systemic GM1 administration (50 mg/kg, i.p. twice) protected against the convulsions, oxidative damage markers increase (total protein carbonylation and thiobarbituric acid-reactive substances - TBARS) production and Na+,K+-ATPase activity inhibition induced by GA (4 mol/ 2 l) in striatum of rats. Furthermore, convulsive episodes induced by GA strongly correlated with Na+,K+-ATPase activity inhibition in the injected striatum, but not with oxidative stress marker measures. In addition, GM1 (50-200 M) protected against Na+,K+-ATPase inhibition induced by GA (6 mM), but not against oxidative damage in vitro. Intrastriatal administration of muscimol (46 pmol/striatum), a GABAA receptor agonist, but not glutamatergic receptor antagonists MK-801 (3 nmol/striatum) and DNQX (8 nmol/striatum), prevented GA-induced convulsions and inhibition of Na+,K+-ATPase activity. The protection of GM1 and muscimol against GA-induced seizures strongly correlated with Na+,K+-ATPase activity maintenance in the injected striatum with GA. Since GM1 and muscimol prevented neurotoxic effects induced by GA, we investigated the GM1 action after intrastriatal administration of pentylenetetrazole (PTZ), a GABAA receptor antagonist. GM1 treatment prevented seizures, Na+,K+-ATPase inhibition, and increase of TBARS and protein carbonyl induced by PTZ (1.8 mol/striatum) in the rats striatum. Furthermore, these data suggest that Na+,K+-ATPase and GABAA receptor-mediated mechanisms may play important roles in GA-induced seizures and in their prevention by GM1. / O monossialogangliosídeo (GM1) é um componente natural de membrana plasmática que está envolvido no crescimento, reconhecimento e diferenciação celular, além de proteger o SNC da ação dos radicais livres. No presente estudo investigou-se o efeito do GM1 sobre a atividade das enzimas antioxidantes catalase (CAT), superóxido dismutase (SOD) e glutationa peroxidase (GPx), assim como na quimiluminescência e capacidade antioxidante total (TRAP) em córtex cerebral de ratos machos adultos ex vivo e in vitro. A administração sistêmica de GM1 (50 mg/kg, i.p.; duas doses: 24 horas e 30 minutos antes do sacrifício) reduziu a quimiluminescência e aumentou significativamente a atividade da CAT ex vivo. A adição de GM1 (103-104 nM) ao meio de incubação diminuiu a atividade da CAT in vitro. Estes resultados sugerem que o efeito neuroprotetor do GM1 não é devido à ação antioxidante intrínseca deste glicoesfingolipídeo, mas devido ao aumento secundário das defesas antioxidantes e/ou uma redução da geração de radicais livres. Além disso, avaliamos se o GM1 tinha efeito neuroprotetor em um modelo experimental da acidemia glutárica, um erro inato do metabolismo caracterizado pelo acúmulo tecidual de ácido glutárico (GA) e alterações neurológicas, como degeneração estriatal e convulsões. A administração de GM1 preveniu as convulsões, o aumento da produção dos marcadores do dano oxidativo (carbonilação protéica total e substâncias reativas do ácido tiobarbitúrico - TBARS) e a inibição da atividade da Na+,K+-ATPase induzidas pelo GA (4 mol/2 µl) em estriado de ratos. Além disso, os episódios convulsivos induzidos por GA apresentaram uma correlação significativa com a inibição da atividade da Na+,K+-ATPase no estriado injetado, mas não com os níveis dos marcadores do estresse oxidativo. A adição de GM1 (50 200  ao meio de incubação preveniu a inibição da Na+,K+-ATPase, mas não reduziu o dano oxidativo induzido por GA (6 mM) in vitro. A administração intraestriatal de muscimol (46 pmol/0,5 l), um agonista de receptor GABAA, mas não dos antagonistas de receptores glutamatérgicos, MK-801 (3 nmol/0,5 l) e DNQX (8 nmol/0,5 l), preveniu as convulsões e a inibição da atividade da Na+,K+-ATPase induzidas por GA. A proteção do GM1 e muscimol contra as convulsões induzidas por GA apresentou uma correlação significativa com a manutenção da atividade da Na+,K+-ATPase no estriado injetado com GA. Desde que o GM1 e o muscimol preveniram os efeitos neurotóxicos induzidos pelo GA, investigou-se a ação do GM1 após a administração intraestriatal de pentilenotetrazol (PTZ), um antagonista de receptores GABAA. O tratamento com GM1 preveniu as convulsões, o dano oxidativo e a inibição da atividade da Na+,K+-ATPase induzidas por PTZ (1,8 µmol/2 µl). Esses dados sugerem que a atividade da Na+,K+-ATPase e mecanismos mediados pela ativação de receptores GABAérgicos podem ser de grande importância para a atividade convulsiva induzida por GA, bem como nos mecanismos de neuroproteção induzidos pelo GM1.

Introdução: A fisiopatologia da doença de Parkinson está associada a lesões por estresse oxidativo/nitrosativo. O ferro encontra-se acumulado na substância negra (SN) de pacientes com DP e está relacionado com esse dano através das espécies reagentes de oxigênio (EROs) e de nitrogênio (ERNs) na reação de Fenton. EROs e ERNs são produzidas normalmente em processos celulares e inflamatórios, e controladas por sistemas antioxidantes. Objetivo: Avaliar níveis periféricos de ferro em pacientes com DP para determinar se acúmulo na SN está relacionado com níveis elevados no sangue. Determinar biomarcadores periféricos confiáveis de estresse oxidativo/nitrosativo Métodos: Selecionados 40 pacientes com DP e 46 indivíduos controles para comparar níveis séricos de ferro, ferritina e transferrina, e de biomarcadores de estresse oxidativo/nitrosativo: superóxido dismutase (SOD), catalase, óxido nítrico (NOx), substâncias reativas ao ácido tiobarbitúrico (TBARS), tióis não-proteicos, “advanced oxidation protein products” (AOPP), “ferric reducing ability of plasma” (FRAP), NTPDases, ecto-5’-nucleotidase, adenosina deaminase (ADA), mieloperoxidase, albumina modificada pela isquemia (IMA) e vitamina C. Resultados: Níveis de ferro estavam diminuídos em pacientes com DP, enquanto ferritina e transferrina não mostraram diferença. Os biomarcadores de estresse oxidativo como TBARS, AOPP, NTPDases, IMA, mieloperoxidase, FRAP, vitamina C e tiois não-proteicos encontraram-se significativamente aumentados na DP. SOD, catalase, ecto-5’-nucleotidase não foram diferentes entre os grupos e os marcadores NOx e ADA foram significativamente aumentados nos controles. Nenhuma correlação foi encontrada entre os biomarcadores e dados sociodemográficos e de características da doença. Conclusão: Níveis plasmáticos de ferro encontram-se diminuídos em pacientes com DP comparados com controles saudáveis. Os biomarcadores TBARS, AOPP, NTPDases, IMA e mieloperoxidase mostraram-se confiáveis para lesão oxidativa, enquanto tióis não-proteicos, FRAP e vitamina C demonstram diminuição da capacidade antioxidante na DP. / Background: Parkinson’s disease (PD) pathophysiology is associated with oxidative/nitrosative stress damage. Iron accumulates in the substantia nigra (SN) of PD patients and is related to this damage along with oxygen and nitrogen reactive species (ROS, RNS) through Fenton reaction. ROS and RNS are normally produced in cell and inflammatory processes, controlled by antioxidant systems. Objective: To determine peripheral levels of iron, ferritin and transferrin in PD patients to evaluate whether iron accumulation in the SN could be related to serum levels. To determine reliable peripheral biomarkers of oxidative/nitrative stress. Methods: Forty PD patients and 46 controls were selected to compared serum levels of iron, ferritin, transferrin and oxidative/nitrative stress biomarkers: superoxide dismutase (SOD), catalase, nitric oxide (NOx), thiobarbituric acid reactive substances (TBARS), non-protein thiols, advanced oxidation protein products (AOPP), ferric reducing ability of plasma (FRAP), NTPDases, ecto-5’-nucleotidase, adenosine deaminase (ADA), myeloperoxidase, ischemic-modified albumin (IMA) and vitamin C. Results: Iron levels were decreased in patients with PD, while ferritin and transferrin were not different. Oxidative stress biomarkers, TBARS, AOPP, NTPDases, IMA, myeloperoxidase, FRAP, vitamin C and non-proteic thiols were significantly higher in PD. SOD, catalase, ecto-5’-nucleotidase were not different between the groups and biomarkers NOx and ADA were significantly increased in the controls. No correlation was found between biomarkers and sociodemographic and disease data. Conclusion: Plasmatic levels of iron are decreased in patients with PD compared to healthy controls. Biomarkers TBARS, AOPP, NTPDases, IMA and myeloperoxidase presented as reliable to measure oxidative/nitrative damage, while non-proteic thiols, FRAP and vitamin C show a decrease in the antioxidant capacity in PD.

Pollution of the aquatic environment with xenobiotics has become a serious health concern in recent years. In the present study the effect of DQ, TBBPA, BPA and VIN on sperm quality parameters, DNA integrity and oxidative stress indices in sterlet (Acipenser ruthenus) sperm and sperm from brook trout (Salvenilus fontinalis) were investigated. To do this, an in vitro spermatozoa motility assay was used by a computer-aided Motion-Analysis system. The sperm of sterlet (Acipenser ruthenus) was diluted to obtain the spermatozoa density of 5×108 cells×ml?1 and then exposed for 2 h to final concentrations of xenobiotics: DQ - 25, 50, 100 and 150 ?M, TBBPA - 0.5, 1.75, 2.5, 5, 7.5 and 10 ?g/l, BPA - 0.5, 1.75, 2.5, 5 and 10 ?g/l and Vin - 0.5, 1.75, 2.5, 5 and 10 ?g/l. Spermatozoa velocity and percentage of motile sperm were significantly decreased at each time post-activation compare to control. The level of DNA damage expressed as a % DNA in Tail and Olive Tail moment significantly increased when spermatozoa were exposed to higher concentrations of xenobiotics. The level of oxidative stress indices lipid peroxidation (LPO) and carbonyl derivatives of proteins (CP) and antioxidant activity of superoxide dismutase (SOD) increased significantly with increasing concentration of xenobiotics. On the other hand the intracellular ATP content in sperm samples had a significantly decreasing effect. In short, xenobiotics can induce reactive oxygen species (ROS) stress in fish spermatozoa, which could impair the sperm DNA integrity, quality and antioxidant defense system. The present study confirms that environmental concentrations of xenobiotics are capable to induce oxidative stress, leading to impaired sperm quality, DNA fragmentation and intracellular ATP content Obtained results also suggested that the use of fish spermatozoa in vitro assays may provide a novel and efficiently means for monitoring residual pharmaceutical in aquatic environment.