Effect of Dietary Supplementation with Omega-3 Fatty Acid on the Generation of Regulatory T Lymphocytes and on Antioxidant Parameters and Markers of Oxidative Stress in the Liver Tissue of IL-10 Knockout Mice.

INTRODUCTION: chronic low-grade inflammation, or inflammaging, emerges as a crucial element in the aging process and is associated with cardiovascular and neurological diseases, sarcopenia, and malnutrition. Evidence suggests that omega-3 fatty acids present a potential therapeutic agent in the prevention and treatment of inflammatory diseases, mitigating oxidative stress, and improving muscle mass, attributes that are particularly relevant in the context of aging. The objective of the present study was to evaluate the effectiveness of supplementation with omega-3 fish oil in improving the immune response and oxidative stress in knockout mice for interleukin IL-10 (IL-10-/-). MATERIAL AND METHODS: female C57BL/6 wild-type (WT) and interleukin IL-10 knockout (IL-10-/-) mice were fed during 90 days with a standard diet (control groups), or they were fed/supplemented with 10% of the omega-3 polyunsaturated fatty acid diet (omega-3 groups). Muscle, liver, intestinal, and mesenteric lymph node tissue were collected for analysis. RESULTS: the IL-10-/-+O3 group showed greater weight gain compared to the WT+O3 (p = 0.001) group. The IL-10-/-+O3 group exhibited a higher frequency of regulatory T cells than the IL-10-/- group (p = 0.001). It was found that animals in the IL-10-/-+O3 group had lower levels of steatosis when compared to the IL-10-/- group (p = 0.017). There was even greater vitamin E activity in the WT group compared to the IL-10-/-+O3 group (p = 0.001) and WT+O3 compared to IL-10-/-+O3 (p = 0.002), and when analyzing the marker of oxidative stress, MDA, an increase in lipid peroxidation was found in the IL-10-/-+O3 group when compared to the IL-10-/- group (p = 0.03). Muscle tissue histology showed decreased muscle fibers in the IL-10-/-+O3, IL-10-/-, and WT+O3 groups. CONCLUSION: the findings show a decrease in inflammation, an increase in oxidative stress markers, and a decrease in antioxidant markers in the IL-10-/-+O3 group, suggesting that supplementation with omega-3 fish oil might be a potential intervention for inflammaging that characterizes the aging process and age-related diseases.

Coffee, but Neither Decaffeinated Coffee nor Caffeine, Elicits Chemoprotection Against a Direct Carcinogen in the Colon of Wistar Rats.

Colorectal cancer (CRC) is the third most frequent malignancy worldwide. Coffee is the second most consumed drink in the globe and suggested to decrease the CRC risk. Here, we explored whether coffee, decaffeinated coffee, or caffeine impact on the development of colorectal carcinogenesis induced by the direct carcinogen N-methyl-N-nitro-N-nitrosoguanidine (MNNG) in rats. To this end, sixty-four young male Wistar rats were divided into eight groups of eight animals each. We analyzed the frequency of dysplastic crypts and expression of metallothionein as a biomarker of the cancer risk, as well the expression of phosphorylated H2A histone family/member X (γH2AX) for DNA damage and cyclooxygenase-2 (COX-2) for inflammatory response. We also studied the oxidative stress profile in hepatic and colonic frozen samples (malondialdehyde [MDA], glutathione [GSH], and α-tocopherol). We found that coffee but neither decaffeinated coffee nor caffeine decreased the development of dysplastic crypts in MNNG-exposed rats. All treatments reduced DNA damage intensity in colonocytes. Only decaffeinated coffee increased the numbers of metallothionein positive crypts in comparison with coffee-treated rats. Coffee and caffeine inhibited COX-2 expression in the colon. Both decaffeinated coffee and caffeine decreased hepatic α-tocopherol levels. We suggest that coffee may have other compounds that elicit greater chemoprotective effects than caffeine reducing the CRC risk.

Omega-3 Fatty Acid Supplementation is Associated With Oxidative Stress and Dyslipidemia, but Does not Contribute to Better Lipid and Oxidative Status on Hemodialysis Patients.

OBJECTIVE: The aim of the study was to explore the effects of n-3 polyunsaturated fatty acids (PUFA) supplementation in physiological doses on oxidative stress (OS) and dyslipidemia in patients on hemodialysis (HD). DESIGN AND METHODS: Randomized, double-blind, controlled, experimental trial. A total of 88 HD patients ≥18 years old and on HD for at least 6 months. A total of 43 patients received 1.28 g/day of n-3 PUFA, and 45 other patients received soybean oil for 12 weeks. Both oil supplements were vitamin E standardized. Routine tests, lipid profile, advanced oxidation protein products, isoprostanes, vitamins C and E, total antioxidant capacity, serum fatty acids, and adverse effects were evaluated. RESULTS: Supplementation was not able to alter lipid or OS profiles. There was an increase in the serum n-3 PUFA levels (eicosapentaenoic acid: +116%; docosahexaenoic acid: +100%) and an improvement in the n-6/n-3 ratio (-49%) in the supplemented group. Associations between n-3 PUFA and improvement in isoprostane and advanced oxidation protein product and HDL were observed. Treatment was well tolerated. CONCLUSION: Although the n-3 PUFA supplementation was associated with lower concentrations of isoprostane and advanced oxidation protein product and higher HDL levels, it was not sufficient for the improvement of highly prevalent risk factors, such as OS and dyslipidemia in HD patients.

EFFECTS OF VITAMIN C SUPPLEMENTATION ON THE CHRONIC PHASE OF CHAGAS DISEASE.

INTRODUCTION: In order to examine the effectiveness of vitamin C (ascorbic acid) in combating the oxidative insult caused by Trypanosoma cruzi during the development of the chronic phase of Chagas disease, Swiss mice were infected intraperitoneally with 5.0 × 104 trypomastigotes of T. cruzi QM1strain. METHODS: Mice were given supplements of two different doses of vitamin C for 180 days. Levels of lipid oxidation (as indicated by thiobarbituric acid reactive substances-TBARS), total peroxide, vitamin C, and reduced glutathione were measured in the plasma, TBARS, total peroxide and vitamin C were measured in the myocardium and histopathologic analysis was undertaken in heart, colon and skeletal muscle. RESULTS: Animals that received a dose equivalent to 500 mg of vitamin C daily showed increased production of ROS in plasma and myocardium and a greater degree of inflammation and necrosis in skeletal muscles than those that received a lower dose or no vitamin C whatsoever. CONCLUSION: Although some research has shown the antioxidant effect of vitamin C, the results showed that animals subject to a 500 mg dose of vitamin C showed greater tissue damage in the chronic phase of Chagas disease, probably due to the paradoxical actions of the substance, which in this pathology, will have acted as a pro-oxidant or pro-inflammatory.

Effects of vitaiin c supplementation on the chronic phase of chagas iisease / Efeitos da suplementação de vitamina C na fase crônica da doença de Chagas

Introduction: In order to examine the effectiveness of vitamin C (ascorbic acid) in combating the oxidative insult caused by Trypanosoma cruzi during the development of the chronic phase of Chagas disease, Swiss mice were infected intraperitoneally with 5.0 × 104 trypomastigotes of T. cruzi QM1strain. Methods: Mice were given supplements of two different doses of vitamin C for 180 days. Levels of lipid oxidation (as indicated by thiobarbituric acid reactive substances-TBARS), total peroxide, vitamin C, and reduced glutathione were measured in the plasma, TBARS, total peroxide and vitamin C were measured in the myocardium and histopathologic analysis was undertaken in heart, colon and skeletal muscle. Results: Animals that received a dose equivalent to 500 mg of vitamin C daily showed increased production of ROS in plasma and myocardium and a greater degree of inflammation and necrosis in skeletal muscles than those that received a lower dose or no vitamin C whatsoever. Conclusion: Although some research has shown the antioxidant effect of vitamin C, the results showed that animals subject to a 500 mg dose of vitamin C showed greater tissue damage in the chronic phase of Chagas disease, probably due to the paradoxical actions of the substance, which in this pathology, will have acted as a pro-oxidant or pro-inflammatory. .

Introdução: Para verificar a eficácia da vitamina C em combater o insulto oxidativo causado pelo Trypanosoma cruzi durante a evolução da fase crônica da doença de Chagas, camundongos Swiss foram previamente infectados via intraperitoneal com 5.0 × 104 tripomastigotas da cepa QM1 de T. cruzi. Métodos: Camundongos foram suplementados com duas diferentes doses de vitamina C por 180 dias. Foram mensurados os níveis de peroxidação lipídica (indicado por substâncias reativas ao ácido tiobarbitúrico-TBARS), peróxido total, vitamina C, e glutationa reduzida no plasma e TBARS, peróxido total e vitamina C no miocárdio, e foi realizado o estudo histopatológico em coração, cólon e músculo esquelético. Resultados: Animais que receberam diariamente uma dosagem equivalente a 500 mg de vitamina C apresentaram aumento na produção de ROS e RNS no plasma e no miocárdio e maior grau de inflamação e necrose em músculo esquelético em comparação àqueles que receberam doses menores ou nenhuma vitamina C. Conclusão: Embora muitas pesquisas tenham mostrado o efeito antioxidante da vitamina C, nossos resultados mostraram que os animais que foram expostos a 500 mg de vitamina C apresentaram maior dano tecidual na fase crônica da doença de Chagas, provavelmente devido a ações paradoxais desta substância, onde nesta patologia, poderá agir como pró-oxidante ou pró-inflamatória. .

Phototherapy improves wound healing in rats subjected to high-fat diet.

This study aimed to compare the phototherapy effects on wound healing in rats submitted to normal and high-fat diets. Thirty-six rats received normal lipidic diet (NL) and 36 high lipidic (HL) diet for 45 days. The nutritional status was measured by body mass, blood glucose, total cholesterol, and triglycerides levels. Four experimental groups were performed according light (L) therapy applied "on" or "off" (660 nm, 100 mW, 70 J/cm(2), 2 J) on 1.5-mm-punched dorsum skin wounds as NLL+, NLL-, HLL+, and HLL-. The wound healing rate (WHR) and oxidative stress markers were analyzed on 2nd, 7th, and 14th days. Despite no difference among body mass, the HL rats presented higher blood glucose, total cholesterol, and triglycerides levels than NL rats. Respectively, on the 2nd and 14th days, the HLL+ group presented the highest WHRs (0.38 ± 0.16/0.97 ± 0.02) among all groups, while the HLL- (-0.002 ± 0.12/0.81 ± 12.1) the lowest WHRs. Hydroxyproline level was lower in HLL- (6.41 ± 1.09 µg/mg) than HLL+ (7.71 ± 0.61 µg/mg) and also NLL+ (9.33 ± 0.84 µg/mg). HLL+ presented oxidative stress markers similar to normal control group (NLL-) during follow up and highest antioxidant defense on 7th day. The results showed phototherapy accelerated the cutaneous wound healing by modulating oxidative stress in rats with metabolic disorders under a high-fat diet.

Effects of vitamin C supplementation on acute phase Chagas disease in experimentally infected mice with Trypanosoma cruzi QM1 strain / Efeitos da suplementação de vitamina C sobre a fase aguda da doença de Chagas em camundongos experimentalmente infectados pela cepa QM1 de Trypanosoma cruzi

The tissue changes that occur in Chagas disease are related to the degree of oxidative stress and antioxidant capacity of affected tissue. Studies with vitamin C supplementation did not develop oxidative damage caused by Chagas disease in the host, but other studies cite the use of peroxiredoxins ascorbate - dependent on T. cruzi to offer protection against immune reaction. Based on these propositions, thirty "Swiss" mice were infected with T. cruzi QM1 strain and treated with two different vitamin C doses in order to study the parasitemia evolution, histopathological changes and lipid peroxidation biomarkers during the acute phase of Chagas disease. The results showed that the parasite clearance was greater in animals fed with vitamin C overdose. There were no significant differences regarding the biomarkers of lipid peroxidation and inflammatory process or the increase of myocardium in animals treated with the recommended dosage. The largest amount of parasite growth towards the end of the acute phase suggests the benefit of high doses of vitamin C for trypomastigotes. The supplementation doesn't influence the production of free radicals or the number of amastigote nests in the acute phase of Chagas disease.

As alterações teciduais que ocorrem na doença de Chagas estão relacionadas ao grau de estresse oxidativo e à capacidade antioxidante do tecido afetado. Estudos realizados com suplementação de vitamina C revelaram redução no dano oxidativo causado no hospedeiro pela doença de Chagas, porém outros estudos citam o uso de peroxiredoxinas dependentes de ascorbato pelo T. cruzi para se proteger da ação imune. Com base nessas proposições, trinta camundongos "Swiss" foram infectados com a cepa QM1 de T. cruzi e tratados com duas diferentes doses de vitamina C para estudar a evolução da parasitemia, alterações histopatológicas e dosagem de biomarcadores de peroxidação lipídica durante a fase aguda da doença de Chagas. Os resultados mostraram que a parasitemia foi maior nos animais que receberam uma superdosagem de vitamina C. Não houve diferenças significativas quanto aos biomarcadores de peroxidação lipídica e houve maior processo inflamatório no miocárdio dos animais tratados com dosagem recomendada. O maior crescimento parasitário ao fim da fase aguda sugere benefício de altas doses de vitamina C aos tripomastigotas. A suplementação não exerceu influência sobre a produção de radicais livres e o número de ninhos de amastigotas na fase aguda da doença de Chagas.

Effects of vitamin C supplementation on acute phase Chagas disease in experimentally infected mice with Trypanosoma cruzi QM1 strain.

The tissue changes that occur in Chagas disease are related to the degree of oxidative stress and antioxidant capacity of affected tissue. Studies with vitamin C supplementation did not develop oxidative damage caused by Chagas disease in the host, but other studies cite the use of peroxiredoxins ascorbate - dependent on T. cruzi to offer protection against immune reaction. Based on these propositions, thirty "Swiss" mice were infected with T. cruzi QM1 strain and treated with two different vitamin C doses in order to study the parasitemia evolution, histopathological changes and lipid peroxidation biomarkers during the acute phase of Chagas disease. The results showed that the parasite clearance was greater in animals fed with vitamin C overdose. There were no significant differences regarding the biomarkers of lipid peroxidation and inflammatory process or the increase of myocardium in animals treated with the recommended dosage. The largest amount of parasite growth towards the end of the acute phase suggests the benefit of high doses of vitamin C for trypomastigotes. The supplementation doesn't influence the production of free radicals or the number of amastigote nests in the acute phase of Chagas disease.

Intestinal permeability and nutritional status in developmental disorders.

CONTEXT: Autism is a developmental disorder with a possible connection between dietary components and triggering or worsening of symptoms. An altered intestinal permeability might allow absorption of incompletely digested peptides (gluten and casein) that could produce opioid-like activity on the brain, causing significant changes in behavior. OBJECTIVE: To assess the intestinal permeability and nutritional status of participants with developmental disorders to determine if changes in the intestinal mucosal barrier and/or injury to the intercellular junctions have occurred that might justify application of further dietary modifications. DESIGN: To assess intestinal permeability, the research team analyzed participants urine under fasting conditions, using gas chromatography to determine chromatographic peaks. To assess nutritional status, the team determined participants heights and weights and performed a bioelectric bioimpedance examination at least 4 hours after their most recent meal. In addition, the team determined food intake using three diet diaries. They asked participants and caregivers to register each food consumed during 2 nonconsecutive weekdays and 1 weekend day. SETTING: The study occurred at the Ribeirao Preto School of Medicine, Sao Paulo University. PARTICIPANTS: Seven participants aged 9 to 23 years with developmental disorders (the developmental group, DG) completed the study. The research team recruited them through the Association of Friends of the Autistic Persons of Ribeirao Preto in Ribeirao Preto, Brazil. The control group (CG) consisted of nonsmoking healthy volunteers in the general population who were similar in age to the experimental group and did not suffer from diseases that potentially could influence nutritional status and intestinal function. INTERVENTION: To assess intestinal permeability, participants ingested 150 mL of an isosmolar solution of the sugars mannitol (2 g) and lactulose (7.5 g) under fasting conditions and the researchers collected all voided urine over a period of 5 hours. OUTCOME MEASURES: Using chromatographic peaks, the research team quantified the mannitol and lactulose in participants urine by calculating the percentage excreted in relation to the ingested amounts of sugar. This calculation gave them the lactulose-to-mannitol ratio (L/M). To evaluate nutritional status, they used data regarding bioimpedance resistance, heights, and weights to estimate lean mass and body water (in liters). They classified adults and adolescents using the body mass index (BMI). For children (2-10 y), they classified participants height-to-age and weight-to-height ratios. The research team used food intake to examine the macronutrient interval, the mean added sugar consumption, and the quantity of protein, in g/kg weight. RESULTS: Participants with developmental disorders (n = 7) were more likely to be overweight. Their usual diet revealed a high intake of lipids (%) and proteins (g/kg) (compared to reference values) and a high intake of calories (kcal) and carbohydrates (%) (compared to CG) as well as a high intake of food sources that are important contributors of casein and gluten. The DGs (n = 7) mean mannitol excretion was lower, and their L/M higher than the CGs (n = 7) (P < .05). Their increased L/M may indicate atrophy of the intestinal-mucosa surface and/or injury to the intercellular junctions or the effect of some other abnormality. The small number of participants, however, prevented more complex statistical analysis. CONCLUSIONS: Researchers need to complete additional studies to confirm the existence of abnormalities in autistic individuals intestines and to justify the use of dietary restrictions on gluten and casein to improve the symptoms of autism.

Folic acid supplementation during early hepatocarcinogenesis: cellular and molecular effects.

Folic acid (FA) supplementation during carcinogenesis is controversial. Considering the impact of liver cancer as a public health problem and mandatory FA fortification in several countries, the role of FA supplementation in hepatocarcinogenesis should be elucidated. We evaluated FA supplementation during early hepatocarcinogenesis. Rats received daily 0.08 mg (FA8 group) or 0.16 mg (FA16 group) of FA/100 g body weight or water (CO group, controls). After a 2-week treatment, animals were subjected to the "resistant hepatocyte" model of hepatocarcinogenesis (initiation with diethylnitrosamine, selection/promotion with 2-acetylaminofluorene and partial hepatectomy) and euthanized after 8 weeks of treatment. Compared to the CO group, the FA16 group presented: reduced (p < 0.05) number of persistent and increased (p < 0.05) number of remodeling glutathione S-transferase (GST-P) positive preneoplastic lesions (PNL); reduced (p < 0.05) cell proliferation in persistent GST-P positive PNL; decreased (p < 0.05) hepatic DNA damage; and a tendency (p < 0.10) for decreased c-myc expression in microdissected PNL. Regarding all these parameters, no differences (p > 0.05) were observed between CO and FA8 groups. FA-treated groups presented increased hepatic levels of S-adenosylmethionine but only FA16 group presented increased S-adenosylmethionine/S-adenosylhomocysteine ratio. No differences (p > 0.05) were observed between experimental groups regarding apoptosis in persistent and remodeling GST-P positive PNL, and global DNA methylation pattern in microdissected PNL. Altogether, the FA16 group, but not the FA8 group, presented chemopreventive activity. Reversion of PNL phenotype and inhibition of DNA damage and of c-myc expression represent relevant FA cellular and molecular effects.

Caracterização do consumo de suplementos nutricionais em praticantes de atividade física em academias / Caracterization of nutritional supplements use bypersons practicing physical exercise at gyms

A procura por suplementos nutricionais está tornando-se cada vez mais comum entre os freqüentadores de academias de ginástica, muitas vezes sem uma orientação adequada. Objetivo: O objetivo desse trabalho foi verificar o uso de suplementos nutricionais por praticantes de atividade física em academias de Ribeirão Preto-SP e seu impacto na composição corporal. Métodos: Para realização da pesquisa foram aplicados questionários em 102 indivíduos, do sexo masculino, com idades entre 20 e 40 anos, em 10 academias de ginástica de Ribeirão Preto-SP. Após o preenchimento do questionário, 30 indivíduos foram submetidos à avaliação da composição corporal e classificados em 3 grupos com 10 indivíduos: sem consumo de suplementos (GC), consumo exclusivo de suplementos protéicos (GP) e uso de suplementos protéico-energéticos (GPE)...

There is an increasingly common search for nutritional supplements among gym clients, often without appropriate orientation. Objective: The objective of the present investigation was to determine the use of nutritional supplements by persons practicing physical exercise at gyms in Ribeirão Preto-SP and the impact of this in the body composition. Methods: A questionnaire was applied to 102 males aged 20 to 40 years at 10 gyms in Ribeirão Preto-SP. After responding to the questionnaire, 30 individuals were submitted to evaluation of body composition and classified into 3 groups of 10 subjects each: no consumption of supplements(CG), exclusive consumption of protein supplements (PG), and use of protein-energy supplements(PEG)...

Lipid peroxidation and urinary excretion of vitamin E in rats submitted to an immunological inflammatory process.

Inflammation is a protective physiologic response, generally controlled by the organism at the injury site. Vitamin E is the most important antioxidant in the lipid phase present in nature and acts by interrupting the chain reaction produced by free radicals. The objective of this study was to evaluate the effect of inflammation on vitamin E levels and lipid peroxidation in rats. Forty Wistar rats (four groups of 10 rats each) were studied over a period of 15 days. Two substances inducing the inflammatory process were parenterally administered, anti-rat basement membrane serum (ABMG) and Freund's complete adjuvant (FAG). Lipid peroxidation levels in hepatic and renal tissue and in plasma and urine were analyzed and compared with the control (CG). Vitamin E was determined by HPLC and lipid peroxidation by quantification of thiobarbituric acid reactive substances (TBARS). ABMG produced more (p < 0.05) TBARS in renal and hepatic tissues (0.7 +/- 0.11 and 1.28 +/- 0.27 nmol/g protein, respectively) compared to CG (0.65 +/- 0.81 and 0.69 +/- 0.13 nmol/g protein). Analysis of TBARS in urine did not show statistically significant differences between the experimental groups and the control. Vitamin E levels in the hepatic tissue of ABMG and FAG (40.7 +/- 10.04 and 44.26 +/- 20.24 micrograms/g tissue) were higher than in CG (22.37 +/- 8.20 micrograms/g tissue) while in kidney tissue and plasma these values were lower (P < 0.05). Renal excretion was increased (P < 0.05) in the group that received anti-rat basement membrane serum (22.39 +/- 0.11 mmol/mL) compared to CG (0.56 +/- 0.056 mmol/mL). We conclude that the acute inflammatory process causes important alterations in the metabolism of vitamin E and lipid peroxidation leading to a significantly increased excretion of this vitamin in the urine.

Methionine supplementation of soya products: effects on nitrogen balance parameters

Soybean protein is one of the best quality foods available. Contribution of soy to human nutrition increases because of its overall positive nutritional profile, low cost, high protein and excellent functional properties. Addition of methionine to rat soybean diets improve biological value of soy protein. Few studies on methionine fortification of soya protein were carried in infants, but fortification of baby formulas with this amino acid is usually found. This study was carried out to demonstrate in malnourished children that the effect of methionine supplementation of soya milk and soy isolated protein, as well as to compare with their results to cows' milk. A total of 30 malnourished children, 1 to 3 years old, admitted to our metabolic unit and distributed in groups of 6 children were studied. They were fed experimental formulas with cows' milk, soya milk, soya milk plus methionine, soya isolated and soya isolated plus methionine. Nutrient compositions of formulas were calculated to be similar to mothers' milk. DL-methionine, 1.5 g per 100 g protein content was added to soya milk and soya isolated formulas. Two nitrogen balances, 3 days each, were carried out. Fecal and urinary nitrogen, serum proteins, creatinine and urea in serum and urine were followed during the study. Results showed differences of intake and retention of nitrogen between some of the groups, but there were no statistically significant differences on protein absorption in the groups. No differences were demonstrated in serum proteins, total nitrogen and other serum and urine parameters analyzed. Cows' milk fed children presented the highest nitrogen retention in both balance studies. The addition of methionine to the soya milk formula increased the nitrogen retention, not reaching the cows' milk levels and did not have the same effect when added to the isolate soy protein.

Teor de vitamina A em alimentos enriquecidos / Vitamin A concentration in enviched foods

A diversidade de produtos alimentícios adicionados de vitaminas, inclusive de vitamina A, vem aumentando no Brasil e o controle desses produtos é nescessário. Os objetivos desse estudo foram: 1) verificar o teor de vitamina A em alimentos enriquecidos avaliando a concentraçäo em relaçäo ao declarado no rótulo; 2) verificar a variabilidade dos níveis de enriquecimento desse nutriente em diferentes amostras de um mesmo produto; 3) avaliar a quantidade de vitamina A oferecida em uma porçäo individual de cada alimento em relaçäo à Dose Diária Recomendada (DDR) pelo National Research Council. Foram estudados 20 produtos enriquecidos. A concentraçäo de vitamina A foi determinada em 5 amostras provenientes de lotes diferentes de cada produto, totalizando 100 amostras. Dentre as amostras avaliadas, 45 apresentaram teor de vitamina A na faixa compreendida entre 20(por cento) abaixo e 20(por cento) acima do declarado no rótulo, 14 amostras apresentaram teor abaixo dessa faixa e 41 acima. A maioria dos produtos apresentou níveis de enriquecimento homogênio em cinco amostras diferentes. Os alimentos estudados supriam de 18 a 120(por cento) das DDR em uma porçäo única. Sugere-se que a legislaçäo brasileira estabeleça, para alimentos enriquecidos, níveis mínimo e máximo de vitamina A por porçäo diária habitualmente consumida; que se estenda o benefício dos alimentos enriquecidos com vitamina A às populaçöes de baixa renda através da adiçäo desse nutriente nos alimentos consumidos pela mesma; que se avalie melhor os alimentos que näo podem e aqueles que podem e devem ser enriquecidos

Efeito de uma dose aguda de etanol sobre a peroxidação lipídica em ratos: Ação da vitamina E / Acute dose of ethanol's effect on lipid peroxidation in rats: action of the vitamin E

A geração de radicais livres é um passo importante na patogênese da injúria hepática associada a ingestão de etanol. A ingestão do etanol induz a um aumento naperoxidação lipídica por dois mecanismos: uma maior produção de espécies reativas de oxigênio e/ou pela diminuição dos níveis dos antioxidantes endógenos. Este trabalho enfoca a geração de radicais livres em ratos, após a ingestão de uma dose aguda de etanol, e o papel de diferentes níveis de vitamina E na dieta oferecida aos animais. O objetivo do trabalho foi investigar o efeito de dietas com diferentes concentrações de vitamina E (Deficiente, Controle e Suplementada 20 vezes) sobre a peroxidação lipídica plasmática e hepática (medida por SRATB), vitamina E em plasma e fígado e glutationa hepática, em ratos alimentados com as dietas. Os animais receberam uma dose aguda de etanol (5 mg/Kg de peso) ao final do período experimental (4 semanas) e foram sacrificados em cinco períodos distintos: 0, 2, 4, 8 e 24 horas após o etanol...(AU)

Effect of different dietary levels of vitamin E on lipid peroxidation in rats / Efectos de diferentes niveles dietéticos de vitamina E en la peroxidación lipídica de ratas

The regulation of normal oxidative balance include the maintenance of adequate levels of dietary antioxidants such as vitamin E. The objetive of this investigation was to study the effect of three difeent dietary levels of vitamin E (normal, Supplemented 20 times higher and deficient) on plasma and liver peroxidation, assayed by determination of thiobarbituric acid reactive substances (TBARS) and vitamin E in plasma and liver and hepatic reduced glutathione. Administration of dietary vitamin E caused a dose-dependent increase in liver and plasma concentration of this vitamin to 42.11 µg/g liver and 29.52 µmol/l respectively, in the suplemented group, and a low concentration of TBARS, 0.67 nmol/mg protein, in liver. The group receiving the diet without vitamin E showed high values of hepatic TBARS, 2.95 nmol/mg protein, and low values of reduced glutathione and reduced concentration of hepatic and plasma vitamin E (1.75 µg/g liver and 3.67 µmol/l, respectively). In conclusion. the vitamin E deficiency alone induces the liver lipid peroxidation in rats, and maintenance of adequate or higher vitamin E levels acts as a protective factor against free radical generation