Lipid peroxidation is believed to play a key role in the onset and progression of degenerative disease. Interestingly, although cholesterol is the most abundant lipid in the human body, our understanding of its autoxidation and subsequent decomposition is relatively limited. In fact, until recently, cholesterol-7-hydroperoxide was accepted as the only primary product of cholesterol autoxidation in organic solution, however, our group exhibited that the 4-, 5-, and 6-hydroperoxides are also formed. Although this work facilitated thorough investigation of the complexities of both H-atom abstraction and addition in cholesterol autoxidation in organic solution, it did not account for the dynamic environment of a cell membrane. Herein, we report on the product distribution of these primary autoxidation products in lipid bilayers and how antioxidant supplementation, H-bonding interactions, and concentration of polyunsaturated fatty acid (PUFA) substrate influence both the product distribution and efficiency of autoxidation. Indeed, not only does H-bonding of the 3β-OH of cholesterol appear to shut-down C4 H-atom abstraction, the absence of kinetic chol-5α-OOH product is likely due to the poor potency of α- tocopherol (α-TOH), also as a result of H-bonding with phosphate head group of lipid membrane phospholipids. Therefore, within a lipid membrane the 7-hydroperoxide products predominate, consistent with literature precedent, however the factors involved are more complex than previously understood. Moreover, with the authentic cholesterol hydroperoxides in hand, we sought to determine if the different regioisomers exhibit different cytotoxicity. Glutathione peroxidases (GPXs) are cytoprotective enzymes that reduce harmful hydroperoxides to benign alcohols in vivo. Using RSL3, a small-molecule inhibitor for GPX4, we were able to sensitize mammalian cells to ferroptotic cell death via administration of our exogenously prepared chol-OOHs. Surprisingly, we found that the toxicities of each of 7α-OOH, 6β-OOH and 5α-OOH were only marginally augmented by RSL3 treatment, suggesting that they do not substantially sensitize cells to ferroptosis, perhaps because their decomposition to lipid peroxidation chain-initiating species (i.e. alkoxyl radicals) is not particularly efficient. Instead their cytotoxicities may derive from other mechanisms, such as the induction of apoptosis. This inspired our investigation of the fate of lipid hydroperoxides in vivo, namely the secondary products of the predominant 7-hydroperoxide species. Acid-catalyzed Hock fragmentation, known for the industrial synthesis of phenol and acetone from cumene or implication in the generation of 4-hydroxynonenal (4-HNE), of 5α- and 6β-OOH has been shown by our group to produce highly electrophilic secosterol species; we sought to investigate the same decomposition mechanism for 7α-OOH in light of our investigations in the lipid membrane. Interestingly, we found that Hock fragmentation of 7α-OOH does not exhibit products resulting from the anticipated O-vinyl oxocarbenium intermediate, rather, the mechanism appears to funnel through an α-epoxy carbenium to produce unprecedented A-ring cleavage and epoxide products. Herein, we describe our thorough analysis of this chol-7α-OOH Hock fragmentation and attempts to investigate the presence of these products in biological samples, similar to previous analyses of similar products in atherosclerotic plaque extracts. The products isolated and characterized through this work have provided new mechanistic insight with regards to the primary and secondary oxidation products of cholesterol in vivo; through further development of these findings, we hope to provide a better understanding of the implications of cholesterol oxidation in the pathogenesis of atherosclerosis.

by Hui Yee Han, Ellen. / Thesis (M.Sc.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 68-71). / acknowledgements --- p.i / abstract --- p.ii / table of contents --- p.iii-vi / list of figures --- p.vii / LIST OF TABLES --- p.viii / chapter / Chapter chapter i : --- introduction --- p.1 / Chapter chapter ii : --- background knowledge --- p.2 -33 / Chapter 2.1 --- Definition of Free Radical --- p.2 / Chapter 2.2 --- Oxygen Derived Radicals and Their Generation In Vivo --- p.2 -9 / Chapter 2.2.1 --- Production of Singlet Oxygen --- p.4 / Chapter 2.2.2 --- Production of Superoxide Radical (O2-) and Hydrogen Peroxide (H2O2) --- p.4 -8 / Chapter I. --- Endogenous Production --- p.4-7 / Chapter II. --- Exogenous Production --- p.7-8 / Chapter 2.2.3 --- Generation of Hydroxy Radical (OH) through H2O2 and O2- --- p.8 -9 / Chapter 2.3 --- Free Radical Damage and Lipid Peroxidation --- p.9 -13 / Chapter 2.4 --- Lipid Peroxidation and Atherosclerosis --- p.13 -14 / Chapter 2.5 --- Antioxidant --- p.15-21 / Chapter 2.5.1 --- Primary Preventive Antioxidants --- p.15-17 / Chapter 2.5.2 --- Secondary Radical Scavenging Antioxidants --- p.18-21 / Chapter I. --- Lipid Soluble Radical-Scavenging Antioxidants --- p.18-19 / Chapter II. --- Water Soluble Radical-Scavenging Antioxidants --- p.20 -21 / Chapter 2.6 --- Measurement of Oxygen-Derived Radical in Vivo --- p.21 -26 / Chapter 2.7 --- Principle of the TRAP assay --- p.27-33 / Chapter 2.7.1 --- Oxygen Consumption Method --- p.29 -30 / Chapter 2.7.2 --- Chemiluminescence Method --- p.31-33 / Chapter chapter III： --- materials and methods --- p.34 -43 / Chapter 3.1 --- Instrumentation and Materials --- p.34 / Chapter 3.2 --- Method --- p.34-43 / Chapter 3.2.1 --- Establishment of Chemiluminescence Method for Determination of TRAP --- p.34 -36 / Chapter I. --- Preparation of Luminometer --- p.35 / Chapter II. --- Preparation of Sample before Analysis --- p.3 5 / Chapter III. --- Manual Operation of the Chemiluminescence Method --- p.35-36 / Chapter IV. --- Calculation of TRAP --- p.36 / Chapter 3.2.2 --- Evaluation of the Chemiluminescence Method --- p.37 -42 / Chapter I. --- Linearity --- p.37 / Chapter II. --- Recovery --- p.37-38 / Chapter III. --- Precision --- p.39 / Chapter IV. --- Interference Experiment --- p.39 -41 / Chapter V. --- Effect of Storage on TRAP --- p.42 / Chapter 3.2.3 --- "Determination of Analytical, Intraindividual and Interindividual Biological Variation of TRAP in A Group of Healthy Chinese" --- p.42-43 / Chapter CHAPTER IV: --- ANALYTICAL RESULTS --- p.44-56 / Chapter 4.1 --- Method Evaluation --- p.44-51 / Chapter 4.1.1 --- Linearity --- p.44 / Chapter 4.1.2 --- Recovery --- p.45 / Chapter 4.1.3 --- Within-Day and Between-Day Precision --- p.46-47 / Chapter 4.1.4 --- Interference --- p.47-48 / Chapter 4.1.5 --- Effect of Storage on TRAP --- p.48-51 / Chapter 4.2 --- "Analytical, Intraindividual and Interindividual Variation of TRAP in A Group of Healthy Chinese Population" --- p.52 -56 / Chapter 4.2.1 --- Difference in TRAP value obtained from the 22 subjects over time --- p.52 -54 / Chapter 4.2.2 --- The Effect of Genders on Trap --- p.55 / Chapter 4.2.3 --- "Determination of Analytical, Intraindividual and Interindividual Variation of TRAP in A Group of Healthy Chinese" --- p.55-56 / Chapter CHAPTER V: --- DISCUSSION --- p.57-67 / Chapter 5.1 --- Validation of the Method Performance --- p.57 / Chapter 5.2 --- Effect of Storage on TRAP --- p.57 / Chapter 5.3 --- Interference of Hemolysis and Lipemia on TRAP assay --- p.58-60 / Chapter 5.3.1 --- Effect of Hemolysis on TRAP --- p.58-59 / Chapter 5.3.2 --- Effect of Lipemia on TRAP --- p.59-60 / Chapter 5.4 --- Possible Sources of Variation in TRAP Over Time --- p.60 -63 / Chapter 5.5 --- Usefulness of the Variation Data of TRAP obtained from a Group of Healthy Chinese --- p.64 -67 / reference --- p.68 -71

Freshwater zooplankton crustacean Daphnia frequently face strong temperature fluctuations in its natural environment, which necessitates adaptive plastic responses. This study focuses on changes in lipid peroxidation and total oxidative capacity in Daphnia tissues in response to long-term and short-term temperature changes. Long-term acclimation to 28ºC helped Daphnia survive longer at lethally high temperatures. This difference, however, was not accompanied by changes in lipid peroxidation, indicating that it isn’t a good measure of damage or predictor of temperature tolerance. On the other hand, total oxidation capacity was lower 28ºC- than in 18ºC-acclimated Daphnia, suggesting that acclimation resulted in higher amounts of antioxidants in Daphnia tissues. Exposure to hypoxia, known to up-regulate antioxidant pathways in Daphnia, further elevated heat tolerance in 28ºC- acclimated individuals. Yet, manipulations of glutathione, an important antioxidant, while predictably affecting oxidative capacity, didn’t influence heat tolerance in Daphnia, suggesting that other antioxidants may play a significant role in it.

Orientador: Antônio Fernando Monteiro Camargo / Banca: Rogério Falleiros Carvalho / Banca: Irineu Bianchini Junior / Resumo: O estresse oxidativo causado pela produção de espécies reativas de oxigênio (EROs) é uma das respostas que as plantas apresentam frente a um estresse ambiental. Nosso objetivo foi avaliar o estresse oxidativo das macrófitas aquáticas Crinum americanum e Spartina alterniflora em duas condições: salinidade e nutrientes que ocorrem no estuário do rio Itanhaém (SP). Raízes e folhas (5 plantas) de C. americanum foram coletadas em cada área (5 amostras/área). O material vegetal para análises de clorofila (a+b), carotenóides, peróxido de hidrogênio (H2O2), malonaldeído (MDA) e enzimas antioxidantes SOD e CAT foram acondicionado em N2 líquido no campo e posteriormente armazenado em freezer a -80 °C. Também foram coletados em cada réplica material vegetal para avaliar o teor de N e P totais da planta e do sedimento Os dados obtidos foram submetidos à Análise de Variância (ANOVA) e comparados pelo teste de Tukey (p < 0,05). Os resultados obtidos mostraram que: C. americanum e S. alterniflora sofreram maior estresse oxidativo em alto e médio estuário, respectivamente; Os indivíduos de S. alterniflora sofreram maior estresse na área de lançamento de esgoto. / Abstract: The oxidative stress caused by the production of reactive oxygen species (ROS) is one of the responses that plants exhibit facing environmental stress. Our objective was to evaluate the oxidative stress of the aquatic macrophytes Crinum americanum and Spartina alterniflora under two conditions: salinity and nutrients that occur in the estuary of the Itanhaém river (SP). Roots and leaves (5 plants) of C. americanum were collected in each area (5 samples / area). The plant material for analysis of chlorophyll (a + b), carotenoids, H2O2, MDA and antioxidant enzymes SOD and CAT with platform in N2 without field and liquid in freezer at -80 ° C. Vegetable material was also collected in each replicate to evaluate the total N and P content of the plant and of the sediment. The data were submitted to Analysis of Variance (ANOVA) and compared by the Tukey test (p <0.05). The results showed that: C. americanum and S. alterniflora suffered higher oxidative stress in upper and middle estuary, respectively; The State of São Paulo changes have suffered greater stress in the area of sewage / Mestre

Dairy products are important sources of calcium and other nutrients but are a poor source of dietary iron. Cheese comprises a substantial portion of dairy food consumption and has been determined an appropriate medium for iron-fortification. However, iron may promote the potentially harmful process in food and biological systems known as lipid peroxidation. Therefore, the safety of consuming iron-fortified cheese was examined. Commercial-scale batches of Cheddar cheese were iron-fortified to a level of two milligrams of iron per ounce with either ferric chloride, ferric-casein complex, or ferric-whey protein complex. Fifty-four premenopausal females were divided into three treatment groups and supplemented one and one-half ounces of iron-fortified Cheddar cheese into their normal diet on a daily basis for six consecutive weeks. Lipid peroxidation was measured as thiobarbituric acid-reactive substances in serum, urine, and feces. A significant increase in serum thiobarbituric acid-reactive substances occurred in all treatment groups sixteen days after initiation of iron-fortified cheese consumption. Thiobarbituric acid-reactive substances in serum returned to baseline levels after thirty days of iron-fortified cheese consumption. Thiobarbituric acid-reactive substances in serum, urine, and feces did not differ among iron-fortification methods. Average daily intake of iron during the six weeks of iron-fortified cheese consumption significantly increased above baseline intake levels without cheese by the approximate amount of iron fortified into the cheese. Increased dietary iron intakes were not correlated with increased lipid peroxidation as measured by thiobarbituric acid-reactive substances in serum, urine, or feces. These results indicated that the daily consumption of iron-fortified cheese increased dietary iron intake and produced a transient increase in lipid peroxidation as measured by thiobarbituric acid-reactive substances in human serum.

No description available.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 6 uppsatser.

Submitted by RACHEL SANTINI PAULINO null (rachel_santini@hotmail.com) on 2018-04-04T13:58:29Z No. of bitstreams: 1 Dissertação Mestrado 2.pdf: 1550212 bytes, checksum: 709a7ceb2f2c96479c741d61c71f0143 (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-04-04T14:13:00Z (GMT) No. of bitstreams: 1 paulino_rs_me_jabo.pdf: 1550212 bytes, checksum: 709a7ceb2f2c96479c741d61c71f0143 (MD5) / Made available in DSpace on 2018-04-04T14:13:00Z (GMT). No. of bitstreams: 1 paulino_rs_me_jabo.pdf: 1550212 bytes, checksum: 709a7ceb2f2c96479c741d61c71f0143 (MD5) Previous issue date: 2018-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O estresse oxidativo causado pela produção de espécies reativas de oxigênio (EROs) é uma das respostas que as plantas apresentam frente a um estresse ambiental. Nosso objetivo foi avaliar o estresse oxidativo das macrófitas aquáticas Crinum americanum e Spartina alterniflora em duas condições: salinidade e nutrientes que ocorrem no estuário do rio Itanhaém (SP). Raízes e folhas (5 plantas) de C. americanum foram coletadas em cada área (5 amostras/área). O material vegetal para análises de clorofila (a+b), carotenóides, peróxido de hidrogênio (H2O2), malonaldeído (MDA) e enzimas antioxidantes SOD e CAT foram acondicionado em N2 líquido no campo e posteriormente armazenado em freezer a -80 °C. Também foram coletados em cada réplica material vegetal para avaliar o teor de N e P totais da planta e do sedimento Os dados obtidos foram submetidos à Análise de Variância (ANOVA) e comparados pelo teste de Tukey (p < 0,05). Os resultados obtidos mostraram que: C. americanum e S. alterniflora sofreram maior estresse oxidativo em alto e médio estuário, respectivamente; Os indivíduos de S. alterniflora sofreram maior estresse na área de lançamento de esgoto. / The oxidative stress caused by the production of reactive oxygen species (ROS) is one of the responses that plants exhibit facing environmental stress. Our objective was to evaluate the oxidative stress of the aquatic macrophytes Crinum americanum and Spartina alterniflora under two conditions: salinity and nutrients that occur in the estuary of the Itanhaém river (SP). Roots and leaves (5 plants) of C. americanum were collected in each area (5 samples / area). The plant material for analysis of chlorophyll (a + b), carotenoids, H2O2, MDA and antioxidant enzymes SOD and CAT with platform in N2 without field and liquid in freezer at -80 ° C. Vegetable material was also collected in each replicate to evaluate the total N and P content of the plant and of the sediment. The data were submitted to Analysis of Variance (ANOVA) and compared by the Tukey test (p <0.05). The results showed that: C. americanum and S. alterniflora suffered higher oxidative stress in upper and middle estuary, respectively; The State of São Paulo changes have suffered greater stress in the area of sewage / 2018SLR05032

abstract: ABSTRACT Objective: The purpose of this randomized, placebo-controlled trial was to investigate the effect a daily coconut oil supplement (2 grams) would have on a common serum marker of systemic inflammation (C-reactive protein) and an indicator of oxidative stress (TBARS) when compared to the control group receiving a placebo capsule (white flour) in healthy, sedentary adults between the ages of 18-40 in Phoenix, Arizona. Design: This study was designed as secondary analyses of blood samples originally collected to study the effects of coconut oil supplementation on blood lipids and body composition. The original study consisted of 32 healthy, adult volunteers recruited from the Arizona State University campus in Phoenix, Arizona. Participants followed no food restrictions or special diets, exercised less than 150 minutes per week, had no diagnoses of chronic disease, were not taking statin medications, were non-smokers, and no female participants were pregnant. Participants were randomized into either the Coconut Oil group (CO) or the Placebo group (PL) at week 0, and baseline blood samples and anthropometric measurements were obtained. Each participant completed an 8-week protocol consisting of two supplement capsules daily (coconut oil or placebo). Final fasting blood samples and anthropometric measurements were taken at week 8. This study analyzed the blood samples for measurements of C-reactive protein (CRP) and thiobarbituric reactive substance (TBARS). Results: Eight weeks of 2 grams per day coconut oil supplementation, in comparison to placebo treatment, did not significantly reduce serum CRP ( -13% and +51% respectively, p=0.183) but did significantly increase TBARS ( +16% and -27% respectively, p=0.049). Conclusions: Coconut oil supplementation (2 g/day) may impact lipid peroxidation as indicated by an increase in plasma TBARS concentration. Future trials are necessary to corroborate these results using other indices of fatty peroxide formation. / Dissertation/Thesis / Masters Thesis Nutrition 2017

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.