Η ολοκληρωμένη εκτίμηση της θειολικής οξειδοαναγωγικής κατάστασης (ΘΟΚ) ενός οργανισμού ιστού ή κυττάρου είναι πολύ σημαντική καθώς οξειδοαναγωγικές αλλαγές των διαφόρων θειολικών μορίων συνδέονται με το οξειδωτικό στρες και με αρκετές ασθένειες. Η γενική ΘΟΚ (ΓΘΟΚ) χαρακτηρίζεται από τις συγκεντρώσεις ορισμένων συνόλων θειολικών μορίων στην αναγμένη και την οξειδωμένη μορφή τους (θειολικά οξειδοαναγωγικά ζεύγη). Αυτά τα ζεύγη μπορεί να είναι μη πρωτεϊνικά (non-protein ή NP) (όπως NPSH και NPSSNP με το NP να συμβολίζει οποιαδήποτε άλλη μη πρωτεϊνική θειόλη) ή πρωτεϊνικά (protein ή P) (όπως PSH, PSSP και PSSNP). Ειδικότερα, οι κυριότερες μη πρωτεϊνικές θειόλες γλουταθειόνη (GSH) και κυστεΐνη (CSH) μαζί με τα συμμετρικά, μεικτά δισουλφίδιά τους και τις οξειδωμένες τους μορφές (GSSG, PSSG, PSSC, NPGSHox, NPCSHox,) είναι τα οξειδοαναγωγικά ζεύγη τα οποία χαρακτηρίζουν την ειδική ΘΟΚ (ΕΘΟΚ), καθώς είναι εκείνα που απαντώνται σε υψηλότερη συγκέντρωση στους οργανισμούς. Στη διεθνή βιβλιογραφία δεν υπάρχει μεθοδολογία για την ταυτόχρονη ποσοτικοποίηση των θειολικών μορίων που χαρακτηρίζουν τη ΘΟΚ των οργανισμών. Συνεπώς, στόχος της παρούσας μελέτης είναι η ανάπτυξη μιας νέας μεθόδου ποσοτικοποίησης τόσο της ΓΘΟΚ όσο και της ΕΘΟΚ, που να είναι εφαρμόσιμη σε όλους τους οργανισμούς. Για το διαχωρισμό πρωτεϊνικών και μη πρωτεϊνικών μορίων χρησιμοποιήθηκε το τριχλωροακετικό οξύ που σε ορισμένη συγκέντρωση (>5%) καταβυθίζει αποτελεσματικά όλες τις πρωτεΐνες. Ο ποσοτικός προσδιορισμός των δισουλφιδικών μορίων και οξειδωμένων μορφών (NPSSNP, PSSP, PSSNP, GSSG, NPGSHox, NPCSHox, PSSG και PSSC) πραγματοποιήθηκε μετά από αναγωγή τους (με το αντιδραστήριο tributyl phosphine), ενώ ο ποσοτικός προσδιορισμός των ελεύθερων θειολών (PSH, NPSH, GSH και CSH) πραγματοποιήθηκε χωρίς την αναγωγή τους. Ειδικότερα, η ποσοτικοποίηση των αναγμένων διθειολικών ομάδων (δισουλφιδίων) και των ελεύθερων θειολών έγιναν με τα αντιδραστήρια 4,4-dithiodipyridine (για τις -SH ομάδες των αναγμένων δισουλφιδίων, καθώς και για τις ελεύθερες NPSH και PSH), o-phthalaldehyde (για την GSH, GSSG και NPGSHox) και νινυδρίνη (για την CSH και την NPCSHox), σε συνδυασμό με κατάλληλη μαθηματική επεξεργασία βασισμένη στη στοιχειομετρία των αντιδράσεων αναγωγής. Η υψηλή ευαισθησία της μεθόδου (στο επίπεδο του nmol) την καθιστά εφαρμόσιμη ακόμη και σε βιολογικά δείγματα χαμηλής περιεκτικότητας σε θειόλες (όπως πχ. το οφθαλμικό και το εγκεφαλονωτιαίο υγρό). / The thiol redox state (TRS) is an essential condition of prokaryotic and eukaryotic cells associated with all major biological processes. The general TRS (GTRS) part of it, is characterized by the levels of all thiol compounds of protein or non-protein origin in their reduced or oxidized form (thiol redox couples), while the specific TRS (STRS) by the levels of certain thiols, reduced and oxidized, free or membrane bound. The GTRS redox couples are composed of non-protein (NP) (such as NPSH and NPSSNP) or protein (P) (such as PSH, PSSP and PSSNP) thiols. On the other hand, the STRS redox couples are composed of the main non-protein thiol glutathione (GSH) and cysteine (CSH) together with their symmetric, mixed disulfides and oxidized forms (GSSG, PSSG, PSSC, NPGSHox, NPCSHox). In light of the fact that there is not available any appropriate method in literature for the simultaneous determination of the main thiol components that characterize TRS, a new method is developed for the purpose of this study for the quantification of GTRS and STRS, applicable to any organism. For the separation of protein from non protein thiols, trichloroacetic acid was chosen (at 5%) as the most effective protein precipitant. The determination of disulfides and oxidized forms (NPSSNP, PSSP, PSSNP, GSSG, PSSG, PSSC, NPGSHox and NPCSHox) was accomplished after their reduction with the tributyl phosphine (which, because of its hydrophobicity effectively reduces protein thiols as well), whereas the quantification of free thiols (PSH, NPSH, GSH and CSH) was accomplished without reduction. Reduced disulfides and free thiols were quantified by the more effective than DTNB 4,4-dithiodipyridine (for the determination of -SH groups of reduced disulfides as well as of free NPSH and PSH), o-phthalaldehyde (for the specific determination of GSH, GSSG and NPGSHox) and ninhydrin (for the specific determination of CSH and NPCSHox). The high sensitivity of the method (in the level of nmoles) makes it applicable even in biological samples of very low thiol concentration (such as ophthalmic or cerebrospinal fluid).

Magnetic resonance spectroscopy (MRS) allows the non-invasive measurement of selected biological compounds in vivo. Despite MRS proven potential it is not yet a routine clinical tool operated by clinicians. This is mainly due to the complex procedure of MRS acquisition, lack of standardisation in both acquisition and analysis protocols along with lack of a standard quality control. This thesis intended to address these issues with the focus on four metabolites glutathione, glutamate, glutamine and GABA using MEGA-PRESS pulse sequence. Recommendations on acquisition and spectra analysis is made for the MRS protocol MEGA-PRESS aiming to detect glutathione in vivo. This is based on an investigation of glutathione acquisition in vivo and in vitro and was aimed to answer the question: can glutathione be measured reliably using conventional pulse sequence PRESS or does it require editing? The results showed strong evidence of using editing in order to have a reliable glutathione concentration measurement. An analysis along with a quality control method is also presented to enable the extraction of glutamate and glutamine from a GABA-optimised MEGA-PRESS pulse sequence. This enables simultaneous measurements of GABA, glutamate and glutamine in a single acquisition. A criterion of NAA linewidth < 8 Hz and Glx CRLB < 16% were defined as optimum features in the GABA-edited spectrum for a reliable glutamate and glutamine quantification. Finally, due to the increasing interest in functional MRS of GABA using MEGAPRESS an investigation on the feasibility of measuring GABA in a functional-MRS setting was performed with recommendations on study designs and subject size. Power calculations suggest that detecting a 40% change in GABA using a 4'30" acquisition requires 9-93 subjects per group in a between-group study design and 13- 68 participants in a within-session design, depending on the region of interest. This thesis is set out in the Journal format thesis. Three introductory chapters, with each experimental study presented as a chapter and a final chapter that summarizes and discusses the work. Results in this thesis provide a basis for a standard and reliable MRS pipeline to reliably measure glutathione, glutamate, glutamine and GABA using MEGA-PRESS pulse sequence at 3 Tesla.

Ticks acquire nutrients only by a parasitic nature of feeding on animals, including humans. During this process, a wide array of pathogens is transmitted. Ticks of the Ixodidae family receive exactly one blood meal in each active developmental. Knowing the trophic dependence of tick metabolism on the host blood meal components may enable discovering processes essential for the tick physiology and development. Exploiting a membrane system of tick feeding and whole blood fractionation, we have revealed that adult ticks need to acquire host haemoglobin-derived haem so that they can produce viable larvae, and reproduce. Haem is not further catabolised in ticks, and iron is thus acquired via independent route with the host serum transferrin as a source molecule. Using RNA-seq, we compared transcriptome compositions between guts of blood- and serum-fed ticks. We identified fifteen gut transcripts that change their levels with respect to the presence/absence of dietary red blood cells. Glutathione S-transferase, one of the identified encoded molecules, shows a clear haeminresponsive expression at both transcript and protein levels. Its apparent haem-binding properties suggest that this protein is directly involved in haem homeostasis maintenance within the tick gut. The ultimate goal of such research is to identify and verify targets that, when blocked, would render the acquisition and/or distribution system of haem in ticks nonfunctional. This would represent a novel way of anti-tick interventions in veterinary and human medicine.

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Salvador, BA, Brasil / Doença de Parkinson (DP) é caracterizada por uma perda seletiva e profunda dos neurônios dopaminérgicos da substância nigra pars compacta (SNpc) do mesencéfalo, acompanhada pela espoliação de dopamina no corpo estriado. A maioria dos casos de DP apresenta etiologia multifatorial, com a presença de componentes genéticos e ambientais. Embora existam diferentes causas possíveis, a patogênese da desordem parece convergir para mecanismos relacionados à disfunção mitocondrial, estresse oxidativo e mau enovelamento proteico. Um modelo estabelecido na literatura para estudo desta doença, tanto in vitro quanto in vivo é a administração de rotenona, um pesticida derivado de plantas que inibe o complexo I mitocondrial e favorece a geração de espécies reativas de oxigênio (ERO), levando a uma espoliação de glutation reduzido (GSH) através do processo de detoxificação destes compostos eletrofílicos, catalisados por glutation S-transferases (GSTs). Sendo assim, a busca por novas substâncias com atividade neuroprotetora é atualmente o foco de estudos, e metabólitos isolados de plantas podem ser fontes destas moléculas. Dessa forma, o 8-metoxipsoraleno (8-MOP), uma furocumarina, foi testado como um possível agente protetor sobre a citotoxicidade causada pela rotenona em modelos in vitro de gliomas, considerando o papel do glutation neste processo. O estudo adotou uma abordagem que associa técnicas bioquímicas e de biologia celular. Ensaios de viabilidade celular foram realizados em células de glioma murino (C6) e glioblastoma multiforme humano (U251) através da redução do brometo de 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium (MTT), e visualização por microscopia de contraste de fase. O tipo de morte celular provocada pela rotenona nas células U251 foi realizado por marcação com anexina V e iodeto de propídeo (IP), seguido por quantificação por citometria de fluxo. A determinação do conteúdo de GSH intracelular após tratamento com rotenona e 8-MOP foi visualizado por marcação com monoclorobimano (MCB) nas linhagens C6 e U251. Os resultados demonstraram que a rotenona foi citotóxica em ambas as linhagens, reduzindo a viabilidade e alterando a morfologia celular, enquanto que o 8-MOP não apresentou atividade citotóxica. Contudo, o tratamento com o 8-MOP não foi capaz de proteger as células contra os efeitos deletérios da rotenona. No estudo do tipo de morte celular, a porcentagem de células marcadas com anexina V foi maior nos grupos tratados com rotenona, demonstrando que a morte celular ocorre principalmente por apoptose. A análise com MCB demonstrou que a rotenona espoliou GSH, porém o pré-tratamento com 8-MOP inibiu a espoliação. Embora o 8-MOP não tenha sido bem sucedido na proteção das células, a manutenção do conteúdo de GSH corrobora com estudos prévios que descrevem este composto como um potencial inibidor de GST, uma atividade farmacológica que deve ser testada para confirmar a sua eficácia como agente terapêutico. / Parkinson’s disease (PD) is characterized by a profound and selective loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) accompanied by midbrain dopamine depletion in the striatum. Most cases of PD present multifactorial etiologies, with the presence of genetic and environmental components. Although there are different possible causes, the pathogenesis of the disorder seems to converge to mechanisms related to mitochondrial dysfunction, oxidative stress and bad protein folding. An established model in the literature to study this disease, both in vitro and in vivo is rotenone administration, a pesticide derived from plants that inhibits the mitochondrial complex I and favors the generation of reactive oxygen species (ROS), leading to reduced glutathione (GSH) depletion through the detoxification process of this electrophilic compound catalyzed by glutathione S-transferases (GSTs). Thus, the search for new substances with neuroprotective activity is currently the focus of studies, and plant isolated metabolites can be sources of these molecules. Thus, 8-methoxypsoralen (8-MOP), a furocoumarin, was tested as a potential protective agent on the cytotoxicity caused by rotenone in glioma cells in vitro models, considering the role of glutathione in the process. The study adopted an approach that combines biochemical and cell biology techniques. Cell viability assays were performed in murine glioma cells (C6) and human glioblastoma (U251) cells through the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and visualization by phase contrast microscopy. The type of cell death caused by rotenone in U251 cells was performed by staining with annexin V and propidium iodide (PI) followed by flow cytometric quantitation. The determination of intracellular GSH content after treatment with rotenone and 8-MOP was visualized by staining with monochlorobimane (MCB) in the lineages U251 and C6. The results demonstrated that rotenone was cytotoxic to both cell lineages, reducing the viability and changing the cell morphology, whereas the 8-MOP did not show cytotoxic activity. However, the treatment with 8-MOP was not able to protect cells against the deleterious effects of rotenone. In the type of cell death studies, the percentage of cells stained with annexin V was higher in the groups treated with rotenone, demonstrating that cell death occurs primarily by apoptosis. The analysis with MCB has shown that rotenone depleted GSH, but pre-treatment with 8-MOP inhibited the depletion. Although the 8-MOP has not been successful in protecting cells, the maintenance of GSH content corroborates with previous studies that describe this compound as a potential inhibitor of GST, a pharmacological activity that should be tested to confirm its effectiveness as a therapeutic agent.

Master of Science / Biochemistry and Molecular Biophysics Interdepartmental Program / Gerald Reeck / Pea aphids (Acyrthosiphon pisum) are sap-sucking insects that feed on the phloem sap of some plants of the family Fabaceae (legumes). Aphids feed on host plants by inserting their stylets between plant cells to feed from phloem sap in sieve elements. Their feeding is of major agronomical importance, as aphids cause hundreds of millions of dollars in crop damage worldwide, annually. Salivary gland transcripts from plant-fed and diet-fed pea aphids were studied by RNASeq to analyze their expression. Most transcripts had higher expression in plant-fed pea aphids, likely due to the need for saliva protein in the aphid/plant interaction. Numerous salivary gland transcripts and saliva proteins have been identified in aphids, including a glutathione peroxidase. Glutathione peroxidases are a group of enzymes with the purpose of protecting organisms from oxidative damage. Here, I present a bioinformatic analysis of pea aphid expressed sequence tag libraries that identified four unique glutathione peroxidases in pea aphids. One glutathione peroxidase, ApGPx1 has high expression in the pea aphid salivary gland. Two glutathione peroxidase genes are present in the current annotation of the pea aphid genome. My work indicates that the two genes need to be revised.

Autism spectrum disorder (ASD) affects about 1 in 45 individuals in the United States, yet effective treatments are yet to be defined. There is growing evidence that ASD is associated with abnormalities in several metabolic pathways, including the inter-connected folate, methylation and glutathione pathways. Several treatments that can therapeutically target these pathways have been tested in preliminary clinical trials. The combination of methylcobalamin (mB12) with low-dose folinic acid (LDFA) and sapropterin, a synthetic form of tetrahydrobiopterin (BH4) have been studied in open label trials while high-dose folinic acid has been studied in a double-blind placebo controlled trial. All of these treatments have the potential to positively affect folate, methylation and glutathione pathways. Although the effect of mB12/LDFA and BH4 on methylation and glutathione metabolism have been examined in the open-label studies, these changes have not been compared to controls who received a placebo in order to account for the natural variation in the changes in these pathways. Furthermore, the recent study using high-dose folinic acid (HDFA) did not analyze the change in metabolism resulting from the treatment. Thus, we compared changes in methylation and glutathione metabolism and biomarkers of chronic oxidative stress as a result of these three treatments to individuals receiving placebo. In general, mB12/LDFA treatment had a significant effect on glutathione and cysteine metabolism with a medium effect size while BH4 had a significant effect on methylation and markers of chronic oxidative stress with a large effect size. HDFA treatment did not significantly influence biomarkers of methylation, glutathione or chronic oxidative stress. One caveat was that participants in the mB12/LDFA and BH4 studies had significantly worse markers of glutathione metabolism and chronic oxidative stress at baseline, respectively. Thus, the participants selected in these two clinical trials may have been those with the most severe metabolic abnormalities and most expected to respond to these treatments. Overall this study supports the notion that metabolic abnormalities in individuals with ASD may be amenable to targeted treatments and provide some insight into the mechanism of action of these treatments.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / As cordiaquinonas sÃo naftoquinonas meroterpenÃides isolados de plantas pertencentes ao gÃnero Cordia com vÃrias atividades biolÃgicas descritas, incluindo atividades antifÃngica, larvicida e citotÃxica. O objetivo deste trabalho foi avaliar o potencial anticÃncer de uma cordiaquinona isolada das raÃzes da planta Cordia leucocephala. O presente estudo avaliou o potencial citotÃxico da cordiaquinona J em vÃrias linhagens de cÃlulas tumorais e normais pelo teste do MTT e seu possÃvel mecanismo de aÃÃo. A cordiaquinona J mostrou valores de CI50 variando de 4,6 a 6,8 &#956;M em cÃlulas leucÃmicas e 33,6 a 37 &#956;M em cÃlulas normais, apÃs 24 horas de incubaÃÃo. Nas cÃlulas HL-60 foi observado induÃÃo de apoptose preferencialmente pela via extrÃnseca. A induÃÃo do dano ao DNA observado pelo tratamento com a cordiaquinona J atravÃs do ensaio do cometa foi associado com a ativaÃÃo de proteÃnas quinases da via ATM/ATR. O dano ao DNA, assim como a ativaÃÃo das proteÃnas quinases da via ATM/ATR foi visualizado em cÃlulas HL-60, mas nÃo em cÃlulas normais. Estes efeitos em HL-60 podem estar relacionados com a depleÃÃo da expressÃo proteica de glutationa e de c-myc observados. O potencial anticÃncer foi confirmado in vivo atravÃs da inibiÃÃo do tumor sarcoma-180 em 72,5% apÃs o tratamento com 50 mg/kg de cordiaquinona J. O prÃ-tratamento tanto das cÃlulas quanto dos animais com N-acetil-L-cisteina inibiu todos os efeitos observados in vitro e in vivo reforÃando o papel da geraÃÃo das espÃcies reativas de oxigÃnio na atividade antitumoral da cordiaquinona J. / Cordiaquinones are meroterpenoid naphtoquinones from plants belonging to the genus Cordia with several described biological activities, including antifungal, larvicidal and cytotoxic effects. The aim of this study was to evaluate the anticancer potential of a cordiaquinone isolated from the roots of Cordia leucocephala plant. The present study evaluated the cytotoxic potential of cordiaquinone J in several tumor and normal cell lines by MTT assay and its possible mechanism of action. The study of the mechanism of action of cordiaquinones L and M, in human leukemia cells (HL-60) showed induction of cell death by apoptosis, and these effects were related to the induction of oxidative stress. Then the study was continued only with the cordiaquinone J. The cordiaquinone J showed IC50 values ranging from 4.6 to 6.8&#956;M in leukemia cells and 33.6 to 37 &#956;M in normal cells, after 24 hours of incubation. In HL-60 cells was observed apoptosis induction preferentially by extrinsic pathway. The induction of DNA damage by cordiaquinone J observed by comet assay was associated with activation of protein kinases of ATM/ATR pathway. The DNA damage, as well as activation of protein kinases via the ATM / ATR was observed in HL-60 cells but not in normal cells. These effects in HL-60 cells may be related to the depletion of protein expression of glutathione and c-myc observed. The anticancer potential was confirmed in vivo through inhibition of sarcoma-180 tumor by 72.5% after the treatment with 50 mg/kg of cordiaquinone J. The pre-treatment of cells or animals with N-acetyl-L-cysteine abolished most of the in vitro and in vivo observed effects, reinforcing the role of reactive oxygen species generation in cordiaquinone J activity.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O (-)-a-bisabolol, um Ãlcool sesquiterpenico comumente obtido de Matricaria chamomilla e de espÃcies do gÃnero Vanillosmopsis, foi testado em modelos animais padronizado de nocicepÃÃo, inflamaÃÃo e Ãlcera gÃstrica em camundongos. Nestes ensaios, o (-)-a-bisabolol foi utilizado nas doses de 25 e 50 mg/Kg nos modelos de nocicepÃÃo e 100 e 200 mg/Kg nos modelos de inflamaÃÃo e Ãlceras gÃstricas, administrados por via oral. O (-)-a-bisabolol demonstrou possuir atividade antinociceptiva nos modelos de nocicepÃÃo visceral induzida por Ãcido acÃtico intraperitoneal e na segunda fase do teste de nocicepÃÃo induzida pela injeÃÃo intraplantar de formalina. O (-)-a-bisabolol nÃo demonstrou atividade no modelo de nocicepÃÃo tÃrmica da placa quente. Esses achados sugerem que a aÃÃo antinociceptiva do (-)- a-bisabolol nÃo està ligada a mecanismos centrais e deve estar relacionada com o processo inflamatÃrio. Nos modelos de edema de pata induzidos por carragenina e dextrano os animais tratados com (-)-a-bisabolol exibiram edemas menores em comparaÃÃo com os animais tratados apenas com veÃculo. (-)-a-bisabolol foi capaz de diminuir os edemas de pata induzidos por 5-HT, mas nÃo os edemas induzidos por histamina, assim, pode-se relacionar a atividade anti-inflamatÃria do (-)-a-bisabolol a sua interferÃncia na aÃÃo/liberaÃÃo ou na sÃntese/metabolismo da 5-HT. O (-)-a-bisabolol mostrou ter atividade gastroprotetoras frente Ãs lesÃes gÃstricas induzidas por etanol absoluto ou indometacina. O mecanismo dessa aÃÃo foi testado farmacologicamente, realizando prÃ-tratamentos com L-NAME, Glibenclamida e Indometacina. Estes experimentos demonstraram que a aÃÃo gastroprotetora do (-)-a- bisabolol parece nÃo envolver o Ãxido nÃtrico, os canais de potÃssio ATP-dependentes ou a sÃntese de prostaglandinas. Por outro lado, a quantificaÃÃo de GSH nos tecidos gÃstricos dos animais nÃo lesionados e lesionados por etanol ou indometacina mostraram que o tratamento com (-)-a-bisabolol atenua o decrÃscimo de GSH associado as lesÃes pelos agentes lesivos, mas nÃo aumenta a sua quantidade nos estÃmagos dos animais nÃo tratados com etanol ou indometacina. Dessa forma o (-)-a-bisabolol aumenta a disponibilidade de GSH no tecido gÃstrico, possuindo aÃÃo antioxidante in vivo, o que nos permite associar esse achado a sua aÃÃo gastroprotetora. / (-)-a-bisabolol, a sesquiterpenic Ãlcool, is commonly obtained from Matricaria chamomilla and from species of Vanillosmopsis, it was tested in animal standardized models of nociception, inflamation and gastric ulcer in mice. In this assays, (-)-a-bisabolol was used in the doses of 25 and 50 mg/Kg in the models of nociception and 100 and 200 mg/Kg in the models of inflamatiom and gastric ulcers, administered by via oral. (-)-a-bisabolol demonstrated to have an antinociceptive activity in the models of visceral nociception induced by intraperitoneal acetic acid and in the second phase of the test nociception was induced by intraplantar administration of formaline. (-)-a-bisabolol did not demonstrate activity in the thermal nociception model of hot plate. These findings suggests that the antinociceptive action of (-)-a-bisabolol is not linked to central mechanisms and may be related with pre inflamatory process. In the models of paw oedema induced by carragenine and dextran the animals treated with (-)-a-bisabolol showed smaller oedemas as compared to animals treated only with the vehicle. (-)-a-bisabolol was capable to reduce the paw oedemas induced by 5- HT, but not the oedema induced by histamine, so it could relate the antiinflamatory activity of (-)-a-bisabolol to the interference in the action/liberation or in the systesis/metabolism of 5- HT. (-)-a-bisabolol demostrated having gastroprotective activity in the absolute ethanol and indomethacin-induced gastric lesions. The mechanism of this action was pharmacologicaly tested, doing pre-treatments with L-NAME, Glibenclamide and Indomethacin. These experiments demonstrated that tha gastroprotective action of (-)-a-bisabolol seems not to be involved the nitric oxide, potassium channels ATP-dependents or the sysntesis of prostaglandines. By the way, the quantification of GSH in the gastric tissues of not lesioned animals e lesionated by ethanol or indomethacin showed that the treatment with (-)-a- bisabolol atenuate the decrease of GSH associated with the lesive agents, but it did not increase its levels in the animals that not recieve ethanol or indomethacin. This way (-)-a- bisabolol increase the disponibility of GSH in the gastric tissue, having in vivo antioxidant activity, that allows us to associate this finding to its gastroprotective action.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / No processo do envelhecimento humano ocorrem alteraÃÃes significativas no organismo,incluindo o aumento do estresse oxidativo, que tem sido responsabilizado pelo desencadeamento de muitas doenÃas degenerativas. A adoÃÃo de estratÃgia capaz de interferir no processo oxidativo seria fundamental para amenizar ou retardar o surgimento de afecÃÃes prevalentes na idade avanÃada. A utilizaÃÃo de substÃncias em doses nutracÃuticas, como precursoras de antioxidantes, tem sido muito estudada. A seguranÃa e os efeitos da suplementaÃÃo via oral de glutamina, em doses nutracÃuticas, sobre o estresse oxidativo e o metabolismo glicÃmico foram analisados em indivÃduos de meia-idade e idosos. Para tanto, foi realizado um ensaio clÃnico randomizado, controlado, cruzado, duplo-cego. Foram selecionados, pelos critÃrios do Protocolo SENIEUR com modificaÃÃes, 32 residentes em instituiÃÃo de longa permanÃncia, divididos em 2 grupos e submetidos à suplementaÃÃo com L-glutamina e caseinato de cÃlcio via oral, na dose de 0,5g/Kg/dia por perÃodo de 14 dias intercalados por pausa temporal (washout period) de 5 dias. Foram realizados exames para avaliaÃÃo de alteraÃÃes hematolÃgicas, hepÃticas, renais e calculada a estimativa do Ritmo de FiltraÃÃo Glomerular (eRFG), avaliada a capacidade antioxidante pela dosagem da Glutationa Total, cÃlculo da razÃo GSH/GSSG, do potencial redox pela EquaÃÃo de Nerst e avaliada a peroxidaÃÃo lipÃdica pela dosagem do TBARS (substÃncia reativa Ãcido tiobarbitÃrico) antes (T0) e apÃs (T1) suplementaÃÃo. Dos 32 participantes que iniciaram o estudo, um foi excluÃdo por uso de antiinflamatÃrio e out o e retirou por vontade prÃpria. Dos 30 indivÃduos restantes, 16 (53,3%) eram homens, mÃdia de idade 69  8,8 anos, peso mÃdio 61,8  14,2Kg,albumina sÃrica 4,0  0,3g/dL. NÃo houve efeito clÃnico adverso durante a utilizaÃÃo de Lglutamina,tampouco alteraÃÃo significativa dos parÃmetros laboratoriais, exceto aumento nos nÃveis de urÃia, tanto no grupo caseinato (T0 = 33,033  8,688; T1 = 43,066  11,732; p <0,0001) quanto no grupo glutamina (T0 = 34,100  9,117; T1 = 44,200  8,833; p<0,0001) e aumento estatisticamente significante de creatinina no grupo glutamina (T0 = 0,917  0,123;T1 = 1,050  0,138; p<0,0001) e reduÃÃo da eRFG: 13,3% na suplementaÃÃo de L-glutamina e de 2,9% na suplementaÃÃo de caseinato de cÃlcio, porÃm sem significado clÃnico. A concentraÃÃo sanguÃnea de Glutationa Total nÃo mostrou alteraÃÃo com a suplementaÃÃo de L-glutamina, tampouco houve alteraÃÃo na capacidade de antioxidaÃÃo do sistema glutationa avaliada pelo cÃlculo da razÃo GSH/GSSG, pela equaÃÃo de Nerst e na peroxidaÃÃo de lipÃdeos avaliada pela dosagem de TBARS. A suplementaÃÃo de L-glutamina nÃo teve impacto sobre a via glicolÃtica e secretagoga de insulina. Conclui-se que aumento nos nÃveis sÃricos de urÃia e creatinina e a reduÃÃo da estimativa de Ritmo de FiltraÃÃo Glomerular sÃo provavelmente devidos à dificuldade dos rins envelhecidos de metabolizar suplementos de fonte protÃica. Embora nÃo clinicamente significativas, estas alteraÃÃes impÃem um rigoroso controle na avaliaÃÃo dos parÃmetros da funÃÃo renal durante a suplementaÃÃo de L-glutamina na dose de 0,5g/kg/dia em indivÃduos de meia-idade e idosos. Na ausÃncia de estresse adicional, a suplementaÃÃo de L-glutamina nÃo altera o padrÃo das reaÃÃes orgÃnicas de estresse oxidativo, prÃprias do envelhecimento, nÃo justificando, portanto, seu uso nestas situaÃÃes. / Significant alterations in the organism occur in the human aging process, including the increase of oxidative stress which has been held responsible for unleashing many degenerative diseases. The adoption of a strategy able to interfere in the oxidative process would be essential to ease or retard the appearance of disorders prevailing in advanced age. The usage of substances in nutraceutic dosages as antioxidants precursors has been much studied. Safety and effects of the oral L-glutamine supplementation, in nutraceutic dosages,on oxidative stress and glucose metabolism were analyzed in middle-aged and elderly individuals. Thus, a randomized, controlled, cross-over, double-blind clinic trial was performed. Through the SENIEUR test protocol criteria with modifications, 32 people living in a nursing home were selected, divided in 2 groups and submitted to oral L-glutamine and calcium caseinate supplementation at the dosage of 0.5/kg/day for a 14-day period intercalated by a 5-day washout period. Tests were performed in order to evaluate hematological, hepatic, renal alterations and the estimated Glomerular Filtration Rate (eGFR) was calculated, the antioxidant capacity was evaluated through the total glutathione dosage,calculation of GSH/GSSG ratio of the redox (oxidation-reduction) potential through the Nerst equation and the lipid peroxidation was evaluated through dosage of TBARS (thiobarbituric acid reacting substances), before (T0) and after (T1) supplementation. From 32 participants that started the study, one was excluded due to anti-inflammatory usage and the other withdrew by own will. 16 (53.3%) out of 30 were men, average age 69 Â} 8.8 years, average weight 61.8 Â} 14.2 kg, serum albumine 4.0 Â} 0.3 g/dl. There was no clinical adverse effect during the L-glutamine usage, nor significant clinical alteration of laboratory parameters except for an increase in urea levels either at the caseinate group (T0= 34.100 Â} 9.117; T1 = 44.200 Â} 8.833; p<0.0001) as at the glutamine group (T0 = 34.100 Â} 9.117; T1 = 44.200 Â} 8.833; p<0.0001) and a statistically significant creatinine increase at the glutamine group (T0 = 0.917 Â} 0.123; T1 = 1.050 Â} 0.138; p<0.0001) and at the GFRe: 13.3% in Lglutamine supplementation and 2.9% in calcium caseinate supplementation, but without clinical significance. Blood levels of the Total Glutathione did not show alteration with Lglutamine supplementation, nor alteration in the anti-oxidation capacity of the glutathione system assessed through TBARS ratio calculation. L-glutamine supplementation had no impact on the glycolitic path and insulin secretagogue. It is concluded that the increase in urea and creatinine serum levels and the reduction of the estimated Glomerular Filtration Rate occur probably due to the difficulty of the aged kidneys to metabolize protein-sourced supplements. Although they are not clinically significant, these alterations impose a rigorous control in the evaluation of the kidney function parameters during the L-glutamine supplementation with doses of 0.5g/kg/day on middle-aged and elderly individuals. In absence of additional stress, the L-glutamine supplementation does not alter the organic reactions standard of oxidative stress, pertaining to aging, not justifying, therefore, its usage in these situations.

O gastrópode terrestre Helix aspersa (Müller) é um herbívoro generalista, que habita a região mediterrânea. Os gastrópodes terrestres em geral entram em estados dormentes durante o seu ciclo de vida. A dormência é uma forma de inatividade associada a uma redução na taxa metabólica, sem grandes alterações no estado hídrico do animal (Withers & Cooper, 2010). Os gastrópodes terrestres quando saem de um estado dormente podem apresentar um aumento na produção de espécies reativas de oxigênio (ROS) nas mitocôndrias (Turrens et al., 1982) levando a um quadro de possível estresse oxidativo (Hermes-Lima & Zenteno-Savin, 2002). Cerca de 0,1% a 2% da respiração normal celular in vitro resulta em formação de ânion superóxido (Fridovich, 2004; Murphy, 2009; Hamanaka & Chandel, 2010). Muitos estudos apontam para um aumento na produção de ROS (Duranteau et al., 1998; Chandel et al., 1998; Wood et al., 1999; Killilea et al., 2000) durante a hipóxia. O estresse oxidativo é definido como o desequilíbrio no balanço entre agentes pró-oxidantes e agentes antioxidantes, em favor dos pró-oxidantes, levando a uma perturbação na sinalização e no controle redox e/ou dano molecular (Sies & Jones, 2007). A GSH é o principal grupo sulfidrila não proteico encontrado em células de mamíferos. Esta normalmente em uma concentração de 1 a 10 mM, enquanto a GSSG é encontrada em uma concentração de 10 a 100 vezes menor (Rossi et al., 1995; Griffith, 1999). A GSH atua desativando radicais livres, preservando o status redox celular e defendendo o organismo contra xenobióticos (Meister, 1995a). A ativação do sistema de defesa antioxidante, incluindo aumento da atividade de enzimas antioxidantes, durante situações de depressão metabólica foi chamada de preparo para o estresse oxidativo (Hermes-Lima et al., 1998). Esta ativação protege o organismo durante o hipometabolismo e durante a reoxigenação/despertar de um possível estresse oxidativo. Os objetivos deste estudo foram: analisar as possíveis respostas durante um ciclo de anoxia e reoxigenação do sistema de defesa antioxidante de Helix aspersa com níveis reduzidos de glutationa total (eq-GSH); e examinar a liberação de ROS em mitocôndrias isoladas de Helix aspersa em estivação. O metabolismo de GSH mostrou-se em nosso estudo como importante fator na manutenção do equilíbrio redox de Helix aspersa durante a anoxia e reoxigenação, lidando com um provável aumento de produção de ROS durante a reoxigenação. E durante a estivação, foi demonstrado que as mitocôndrias de glândula digestiva de Helix aspersa liberam mais H2O2 in vitro. Este aumento na liberação de ROS na mitocôndria pode estar relacionado com a indução de respostas antioxidantes, que ocorrem durante a estivação em gastrópodes terrestres em diversos estudos (Hermes-Lima & Storey, 1995; Ramos-Vasconcelos & Hermes-Lima, 2003; Ramos-Vasconcelos et al., 2005) / The gastropod Helix aspersa (Müller) is a generalist herbivore that inhabits the Mediterranean region. The terrestrial gastropods generally go into dormant states during their life cycle. Dormancy is a form of inactivity associated with a reduction in metabolic rate, without major changes in the water status of the animal (Withers & Cooper, 2010). The terrestrial gastropods when they leave a dormant state may experience an increased production of reactive oxygen species (ROS) in mitochondria (Turrens et al., 1982) leading to a potential oxidative stress (Hermes-Lima & Zenteno-Savin, 2002). About 0.1% to 2% of the normal cellular respiration in vitro results in formation of superoxide anion (Fridovich, 2004; Murphy, 2009; Hamanaka & Chandel, 2010). Many studies point to an increased production of ROS (Duranteau et al. 1998; Chandel et al., 1998, Wood et al. 1999; Killilea et al., 2000) during hypoxia. Oxidative stress is defined as the imbalance between pro-oxidant agents and antioxidants in favor of pro-oxidants, leading to a disruption of redox signaling and redox control and/or molecular damages (Sies & Jones, 2007). GSH is the main non-protein sulfhydryl group found in mammalian cells. It´s usually in a concentration of 1 to 10 mM, whereas GSSG is found at a concentration of 10 to 100 times lower (Rossi et al. 1995; Griffith, 1999). GSH acts by disabling free radicals, maintaining the cellular redox status and defending the body against xenobiotics (Meister, 1995a). The activation of the antioxidant defense system, including increased activity of antioxidant enzymes, during situations of metabolic depression is called \"preparation for oxidative stress (Hermes-Lima et al., 1998). This activation protects the body during hypometabolism and during recovery of a possible situation of oxidative stress. The objectives of this study were: to analyze the possible response during a cycle of anoxia and reoxygenation of the antioxidant defense system of Helix aspersa with reduced levels of total glutathione (GSH-eq) and to examine the release of ROS in isolated mitochondria from Helix aspersa in aestivation. The metabolism of GSH presented itself in our study as an important factor in maintaining the redox balance of Helix aspersa during anoxia and reoxygenation, dealing with a probable increase in ROS production during reoxygenation. And during aestivation, it was demonstrated that the digestive gland mitochondria of Helix aspersa released more H2O2 in vitro. This increased release of ROS in mitochondria may be related to induction of antioxidant responses that occur during aestivation in terrestrial gastropods in several studies (Hermes-Lima & Storey, 1995; Ramos-Vasconcelos & Hermes-Lima, 2003, Ramos- Vasconcelos et al., 2005)