Oral glutamine dipeptide or oral glutamine free amino acid reduces burned injury progression in rats / O dipeptídeo de glutamina oral ou aminoácido livre de glutamina oral reduz a progressão da lesão por queimadura em ratos

Abstract This study was carried out to evaluate the effect of Glutamine, as a dipeptide or a free amino acid form, on the progression of burn injuries in rats. Thirty male Wistar rats were burned with a comb metal plate heated in boiling water (98 °C) for three minutes, creating four rectangular full-thickness burn areas separated by three unburned interspaces (zone of stasis) in both dorsum sides. The animals were randomized into three groups (n=10): saline solution (G1-Control) and treated groups that orally received Glutamine as dipeptide (G2-Dip) or free amino acid (G3-FreeAA). Two and seven days after burn injury, lesions were photographed for unburned interspaces necrosis evolution assessment. Seven days after injury, glutathione seric was measured and histopathological analysis was performed. By photographs, there was a significant reduction in necrosis progression in G3-Free-AA between days two and seven. Histopathological analysis at day 7 showed a significantly higher stasis zone without necrosis and a higher number of fibroblasts in G2-Dip and G3-FreeAA compared with G1-Control. Also, glutathione serum dosage was higher in G2-Dip. The plasmatic glutathione levels were higher in the G2-Dip than the G1-Control, and there was a trend to higher levels in G3-FreeAA. The reduction in histological lesions, greater production of fibroblasts, and greater amounts of glutathione may have benefited the evolution of burn necrosis, which showed greater preservation of interspaces.

Resumo Este estudo foi realizado para avaliar o efeito da Glutamina, como um dipeptídeo ou forma de aminoácido livre, na progressão de queimaduras em ratos. Trinta ratos Wistar machos foram queimados com um pente de metal aquecido em água fervente (98 °C) por três minutos, criando quatro áreas retangulares queimadas separadas por três interesespaços não queimados (zona de estase) em ambos os lados do dorso. Os animais foram randomizados em três grupos (n = 10): solução salina (G1-Controle) e grupos tratados que receberam glutamina via oral como dipeptídeo (G2-Dip) ou aminoácido livre (G3-FreeAA). Dois e sete dias após a queimadura, as lesões foram fotografadas para avaliação da evolução da necrose entre os espaços não queimados. Sete dias após a lesão, foi dosada a glutationa sérica e realizada análise histopatológica. Pelas fotografias, houve uma redução significativa na progressão da necrose no G3-Free-AA entre os dias dois e sete. A análise histopatológica no dia 7 mostrou uma zona de estase significativamente maior sem necrose e número mais elevado de fibroblastos em G2-Dip e G3-FreeAA em comparação com G1-Controle. Os níveis plasmáticos de glutationa foram maiores no G2-Dip em relação ao G1-Controle, e houve tendência a níveis mais elevados no G3-FreeAA. A redução das lesões histológicas, maior produção de fibroblastos, maior quantidade de glutationa podem ter beneficiado a evolução da necrose da queimadura, que mostrou maior preservação dos interespaços.

Oral glutamine dipeptide or oral glutamine free amino acid reduces burned injury progression in rats

Abstract This study was carried out to evaluate the effect of Glutamine, as a dipeptide or a free amino acid form, on the progression of burn injuries in rats. Thirty male Wistar rats were burned with a comb metal plate heated in boiling water (98 °C) for three minutes, creating four rectangular full-thickness burn areas separated by three unburned interspaces (zone of stasis) in both dorsum sides. The animals were randomized into three groups (n=10): saline solution (G1-Control) and treated groups that orally received Glutamine as dipeptide (G2-Dip) or free amino acid (G3-FreeAA). Two and seven days after burn injury, lesions were photographed for unburned interspaces necrosis evolution assessment. Seven days after injury, glutathione seric was measured and histopathological analysis was performed. By photographs, there was a significant reduction in necrosis progression in G3-Free-AA between days two and seven. Histopathological analysis at day 7 showed a significantly higher stasis zone without necrosis and a higher number of fibroblasts in G2-Dip and G3-FreeAA compared with G1-Control. Also, glutathione serum dosage was higher in G2-Dip. The plasmatic glutathione levels were higher in the G2-Dip than the G1-Control, and there was a trend to higher levels in G3-FreeAA. The reduction in histological lesions, greater production of fibroblasts, and greater amounts of glutathione may have benefited the evolution of burn necrosis, which showed greater preservation of interspaces.

Resumo Este estudo foi realizado para avaliar o efeito da Glutamina, como um dipeptídeo ou forma de aminoácido livre, na progressão de queimaduras em ratos. Trinta ratos Wistar machos foram queimados com um pente de metal aquecido em água fervente (98 °C) por três minutos, criando quatro áreas retangulares queimadas separadas por três interesespaços não queimados (zona de estase) em ambos os lados do dorso. Os animais foram randomizados em três grupos (n = 10): solução salina (G1-Controle) e grupos tratados que receberam glutamina via oral como dipeptídeo (G2-Dip) ou aminoácido livre (G3-FreeAA). Dois e sete dias após a queimadura, as lesões foram fotografadas para avaliação da evolução da necrose entre os espaços não queimados. Sete dias após a lesão, foi dosada a glutationa sérica e realizada análise histopatológica. Pelas fotografias, houve uma redução significativa na progressão da necrose no G3-Free-AA entre os dias dois e sete. A análise histopatológica no dia 7 mostrou uma zona de estase significativamente maior sem necrose e número mais elevado de fibroblastos em G2-Dip e G3-FreeAA em comparação com G1-Controle. Os níveis plasmáticos de glutationa foram maiores no G2-Dip em relação ao G1-Controle, e houve tendência a níveis mais elevados no G3-FreeAA. A redução das lesões histológicas, maior produção de fibroblastos, maior quantidade de glutationa podem ter beneficiado a evolução da necrose da queimadura, que mostrou maior preservação dos interespaços.

Oral glutamine dipeptide or oral glutamine free amino acid reduces burned injury progression in rats.

This study was carried out to evaluate the effect of Glutamine, as a dipeptide or a free amino acid form, on the progression of burn injuries in rats. Thirty male Wistar rats were burned with a comb metal plate heated in boiling water (98 °C) for three minutes, creating four rectangular full-thickness burn areas separated by three unburned interspaces (zone of stasis) in both dorsum sides. The animals were randomized into three groups (n=10): saline solution (G1-Control) and treated groups that orally received Glutamine as dipeptide (G2-Dip) or free amino acid (G3-FreeAA). Two and seven days after burn injury, lesions were photographed for unburned interspaces necrosis evolution assessment. Seven days after injury, glutathione seric was measured and histopathological analysis was performed. By photographs, there was a significant reduction in necrosis progression in G3-Free-AA between days two and seven. Histopathological analysis at day 7 showed a significantly higher stasis zone without necrosis and a higher number of fibroblasts in G2-Dip and G3-FreeAA compared with G1-Control. Also, glutathione serum dosage was higher in G2-Dip. The plasmatic glutathione levels were higher in the G2-Dip than the G1-Control, and there was a trend to higher levels in G3-FreeAA. The reduction in histological lesions, greater production of fibroblasts, and greater amounts of glutathione may have benefited the evolution of burn necrosis, which showed greater preservation of interspaces.

Influence of treadmill training on bone structure under osteometabolic alteration in rats subjected to high-fat diet.

Nutrition and physical training have important roles in the accumulation and maintenance of bone mass. The aim of this study was to evaluate, in ovariectomized rats (OVX), the effects of treadmill training (T) with high-fat diet (F) on weight gain and bone tissue properties with eight groups (n = 10) for 12 weeks: OVX SC (OVX, sedentary lifestyle, diet control); OVX SF; OVX TC; OVX TF; SH SC (SHAM, sedentary lifestyle, diet control); SH SF; SH TC; and SH TF. Weekly weight gain and final body composition were assessed. After euthanasia, tibiae were analyzed. The trained animals had higher body weight (P = 0.001), bone mineral density (P < 0.001), and trabecular bone (P < 0.001). The animals with a high-fat diet showed higher global fat (P < 0.001), percentage of global fat (P < 0.001) and deformation at impact (P = 0.031) and reduced tibial bone mineral content (P = 0.036). Physical training improves bone microarchitecture, without presenting an increase in impact resistance, and a high-fat diet increases body fat and impairs bone mineralization.

Assessment of indicators of vitamin A status in non-cirrhotic chronic hepatitis C patients.

Subjects with chronic liver disease are susceptible to hypovitaminosis A due to several factors. Therefore, identifying patients with vitamin deficiency and a requirement for vitamin supplementation is important. Most studies assessing vitamin A in the context of hepatic disorders are conducted using cirrhotic patients. A cross-sectional study was conducted in 43 non-cirrhotic patients with chronic hepatitis C to evaluate markers of vitamin A status represented by serum retinol, liver retinol, and serum retinol-binding protein levels. We also performed the relative dose-response test, which provides an indirect estimate of hepatic vitamin A reserves. These vitamin A indicators were assessed according to the stage of liver fibrosis using the METAVIR score and the body mass index. The sample study was predominantly composed of male subjects (63%) with mild liver fibrosis (F1). The relative dose-response test was <20% in all subjects, indicating vitamin A sufficiency. Overweight or obese patients had higher serum retinol levels than those with a normal body mass index (2.6 and 1.9 µmol/L, respectively; P<0.01). Subjects with moderate liver fibrosis (F2) showed lower levels of serum retinol (1.9 vs 2.5 µmol/L, P=0.01) and retinol-binding protein levels compared with those with mild fibrosis (F1) (46.3 vs 67.7 µg/mL, P<0.01). These results suggested an effect of being overweight on serum retinol levels. Furthermore, more advanced stages of liver fibrosis were related to a decrease in serum vitamin A levels.

Creatine Supplementation Increases Total Body Water in Soccer Players: a Deuterium Oxide Dilution Study.

This study aimed to evaluate changes in total body water (TBW) in soccer athletes using a deuterium oxide dilution method and bioelectrical impedance (BIA) formulas after 7 days of creatine supplementation. In a double-blind controlled manner, 13 healthy (under-20) soccer players were divided randomly in 2 supplementation groups: Placebo (Pla, n=6) and creatine supplementation (CR, n=7). Before and after the supplementation period (0.3 g/kg/d during 7 days), TBW was determined by deuterium oxide dilution and BIA methods. 7 days of creatine supplementation lead to a large increase in TBW (2.3±1.0 L) determined by deuterium oxide dilution, and a small but significant increase in total body weight (1.0±0.4 kg) in Cr group compared to Pla. The Pla group did not experience any significant changes in TBW or body weight. Although 5 of 6 BIA equations were sensitive to determine TBW changes induced by creatine supplementation, the Kushner et al. 16 method presented the best concordance levels when compared to deuterium dilution method. In conclusion, 7-days of creatine supplementation increased TBW determined by deuterium oxide dilution or BIA formulas. BIA can be useful to determine TBW changes promoted by creatine supplementation in soccer athletes, with special concern for formula choice.

Assessment of indicators of vitamin A status in non-cirrhotic chronic hepatitis C patients

Subjects with chronic liver disease are susceptible to hypovitaminosis A due to several factors. Therefore, identifying patients with vitamin deficiency and a requirement for vitamin supplementation is important. Most studies assessing vitamin A in the context of hepatic disorders are conducted using cirrhotic patients. A cross-sectional study was conducted in 43 non-cirrhotic patients with chronic hepatitis C to evaluate markers of vitamin A status represented by serum retinol, liver retinol, and serum retinol-binding protein levels. We also performed the relative dose-response test, which provides an indirect estimate of hepatic vitamin A reserves. These vitamin A indicators were assessed according to the stage of liver fibrosis using the METAVIR score and the body mass index. The sample study was predominantly composed of male subjects (63%) with mild liver fibrosis (F1). The relative dose-response test was <20% in all subjects, indicating vitamin A sufficiency. Overweight or obese patients had higher serum retinol levels than those with a normal body mass index (2.6 and 1.9 µmol/L, respectively; P<0.01). Subjects with moderate liver fibrosis (F2) showed lower levels of serum retinol (1.9 vs 2.5 µmol/L, P=0.01) and retinol-binding protein levels compared with those with mild fibrosis (F1) (46.3 vs 67.7 µg/mL, P<0.01). These results suggested an effect of being overweight on serum retinol levels. Furthermore, more advanced stages of liver fibrosis were related to a decrease in serum vitamin A levels.

Frequency and Duration Modulate Anticarcinogenic Effects of a Physical Training in the Colon.

Physical exercise has proven protective against colon carcinogenesis. We sought to clarify whether the frequency and duration of physical training were key factors for its anticarcinogenic effects on the colon. Either sedentary or physically trained male Wistar rats (n=82) were either exposed or not to the carcinogen dimethylhidrazine (DMH). The first protocol investigated whether swimming for 60 min in different frequencies modulates antipreneoplastic effects of physical training. Another protocol then explored whether the duration for training 5 times a week impacts on the development of colon preneoplastic lesions. After 8 weeks, serum and colon samples were collected and analyzed afterwards. Swimming once a week for 60 min did not promote those anticarcinogenic effects found in rats trained 5 times weekly. Such weekly sustained physical training not only decreased the development of colon preneoplastic, but also epithelial proliferation, and subepithelial cyclooxygenase 2 (COX-2) expression. Interestingly, a 5 time per week training for less than 60 min was not as protective against colon carcinogenesis as swimming for 90 min. This 90 min training indeed reduced serum cholesterol and triglycerides levels, as well as colonic lipid peroxidation in carcinogen-exposed rats. Our collective data suggest anticarcinogenic effects of physical exercises are potentially promoted when training 5 times a week for at least 60 min.

Evaluation of oxidative stress in the late postoperative stage of liver transplantation.

INTRODUCTION: Liver transplant recipients are at an increased oxidative stress risk due to pre-existing hepatic impairment, ischemia-reperfusion injury, immunosuppression, and functional graft rejection. This study compared the oxidative status of healthy control subjects, patients with liver cirrhosis on the list for transplantation, and subjects already transplanted for at least 12 months. PATIENTS AND METHODS: Sixty adult male patients, aged between 27 and 67 years, were subdivided into 3 groups: a control group (15 healthy volunteers), a cirrhosis group (15 volunteers), and a transplant group (30 volunteers). Oxidative stress was evaluated by activity of reduced glutathione, malondialdehyde, and vitamin E. RESULTS: There was a significant difference (P < .01) in the plasma concentration of reduced glutathione in the 3 groups, with the lowest values observed in the transplanted group. The malondialdehyde values differed significantly (P < .01) among the 3 groups, with the transplanted group again having the lowest concentrations. The lowest concentrations of vitamin E were observed in patients with cirrhosis compared with control subjects, and there was a significant correlation (P < .05) among the 3 groups. No correlations were found between reduced glutathione and vitamin E or between vitamin E and malondialdehyde. However, there were strong correlations between plasma malondialdehyde and reduced glutathione in the 3 groups: control group, r = 0.9972 and P < .0001; cirrhotic group, r = 0.9765 and P < .0001; and transplanted group, r = 0.8981 and P < .0001. CONCLUSIONS: In the late postoperative stage of liver transplantation, oxidative stress persists but in attenuated form.

Plasma malondialdehyde as biomarker of lipid peroxidation: effects of acute exercise.

The marker most frequently used to indicate the level of lipid peroxidation in the field of exercise and sports is malondialdehyde (MDA), which can be determined by many different techniques. However, there are few studies discussing differences and advantages of the methods for MDA assay in sports science field. The aim of the present study was to compare three techniques for quantification of MDA in plasma of humans subjected to acute exercise. MDA was determined by high performance liquid chromatography (MDA-HPLC), thiobarbituric acid reactive species (MDA-TBARS) and 1-methyl-2-phenylindole (MDA-MP) techniques in the plasma of 8 healthy male soccer athletes before and after acute exercise. Acute exercise significantly increased (P<0.05) plasma MDA concentration determined by MDA-HPLC (18%) and MDA-TBARS (56%) techniques. MDA-MP technique did not reveal significant differences, although it increased 25% after exercise. When correlated to the gold standard (MDA-HPLC), MDA-TBARS and MDA-MP techniques showed weak Lin concordance coefficients and non-significant correlation. Also, MDA-TBARS and MDA-MP techniques overestimated the MDA-HPLC technique by 100 and 122%, respectively. In conclusion, MDA-HPLC and MDA-TBARS are sensitive to detect change in MDA induced by acute exercise. MDA-HPLC is the most suitable technique for accurate detection of MDA in sports and exercise area due to its sensitivity and accuracy.

Assessment of oxidative status markers and NO bioavailability in hypertensive disorders of pregnancy.

The systemic oxidative status in hypertensives disorders of pregnancy (HDP) and its association with endothelial dysfunction is controversial. In the present study, we evaluated systemic plasma levels of oxidative stress markers (TBARS (thiobarbituric acid-reactive substances) and carbonyl) and total antioxidant status (FRAP (ferric reducing ability of plasma (ferric reducing/antioxidant power) and reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide))), as well as assessed the impact these markers have on nitric oxide (NO) status in healthy pregnant (HP, n=38), gestational hypertensive (GH, n=33) and preeclamptic pregnant women (PE, n=28). We found similar values of TBARS among all groups, and reduced carbonyl levels in HDP between the PE and GH. Conversely, significant increases in plasma activity of antioxidant status were observed in the GH and PE groups compared to the HP group (using both MTT or FRAP method). Importantly, HDP present significantly lower nitrite levels compared to HP women. In Conclusion, our findings show a compensatory antioxidant mechanism against reactive oxygen species (ROS) generation in HDP, which is not associated with nitrite levels restoration.

Validation of a FFQ for estimating ω-3, ω-6 and trans fatty acid intake during pregnancy using mature breast milk and food recalls.

BACKGROUND/OBJECTIVES: To assess the performance of a food frequency questionnaire (FFQ) for estimating ω-3, ω-6 and trans fatty acid intake during pregnancy. Moreover, we determined whether the fatty acid composition of mature breast milk represents a valuable biomarker for fatty acid intake during pregnancy. SUBJECTS/METHODS: A prospective study in 41 pregnant women, aged 18-35 years, was conducted. Food intake during pregnancy was evaluated by three 24-h recalls (24 hR), and 2 FFQ. The fatty acid composition of mature breast milk was determined by gas chromatography. The method of triads and joint classification between quartiles of intake were applied. RESULTS: The FFQ was accurate for estimating docosahexanoic (DHA), linoleic and total ω-6 fatty acids according to validity coefficients. Higher agreements (>70%) into the same or adjacent quartiles between the dietary methods were found for α-linolenic, total ω-3, linoleic and trans fatty acid intake. High validity coefficients for eicosapentanoic (EPA) and DHA acids of human milk were found (0.61 and 0.73, respectively), and the method was adequate for categorizing the intake of α-linolenic, total ω-3 and trans fatty acids compared with FFQ estimates, and for arachidonic acid and trans fatty acids compared with food recall estimates, during pregnancy. CONCLUSIONS: The FFQ was an accurate tool for categorizing α-linolenic, total ω-3 and trans fatty acid intake. According to the validity coefficients observed, the FFQ accurately estimated DHA, linoleic and total ω-6 fatty acids and the composition of mature breast milk was shown to be a suitable biomarker for EPA and DHA fatty acid intake during pregnancy.

Comparison of bioelectrical impedance with skinfold thickness and X-ray absorptiometry to measure body composition in HIV-infected with lipodistrophy.

INTRODUCTION: Human immunodeficiency vírus (HIV)-associated lipodystrophy syndrome (LS) includes body composition and metabolic alterations. Lack of validated criteria and tools make difficult to evaluate body composition in this group. OBJECTIVE: The aim of the study was to compare different methods to evaluate body composition between Brazilians HIV subjects with (HIV+LIPO+) or without LS (HIV+LIPO-) and healthy subjects (Control). METHODS: in a cross-sectional analyses, body composition was measured by bioelectrical impedance analysis (BIA), skinfold thickness (SF) and dual-energy x-ray absorptiometry (DXA) in 10 subjects from HIV+LIPO+ group; 22 subjects from HIV+LIPO- group and 12 from Control group. RESULTS: There were no differences in age and body mass index (BMI) between groups. The fat mass (FM) (%) estimated by SF did not correlate with DXA in HIV+LIPO+ group (r = 0,46/ p > 0,05) and had fair agreement in both HIV groups (HIV+LIPO+ =0,35/ HIV+ LIPO- = 0,40). BIA had significant correlation in all groups (p < 0,05) and strong agreement, meanly in HIV groups, for FM (HIV+LIPO+ = 0,79/ HIV+LIPO- = 0,85 / Control = 0,60) and for fat free mass (FFM) (HIV+LIPO+ = 0,93 / HIV+LIPO- = 0,92 / Control = 0,73). DISCUSSION: Total fat mass can be measured by BIA with good precision, but not by SF in HIV-infected patients with LS. Segmental BIA, triciptal SF, circumferences of arms, waist and legs maybe alternatives that need more studies.

The inflammatory stimulus of a natural latex biomembrane improves healing in mice.

The aim of the present study was to compare healing obtained with biomembranes with the natural healing process (sham) using biochemical and immunohistological assays. C57BL/6 mice were divided into 4 groups of 15 mice each and received different subcutaneous implants: natural latex biomembrane (NLB), denatured latex (DL), expanded polytetrafluorethylene (ePTFE), or sham. On the 2nd, 7th, and 14th days post-treatment, 5 mice per group were sacrificed and biopsied for the following measurements: oxidative stress based on malondialdehyde (MDA), myeloperoxidase (MPO) and hydrogen peroxide by the method of ferrous oxidation-xylenol orange (FOX), as well as glutathione and total proteins; histological evaluation to enumerate inflammatory cells, fibroblasts, blood vessels, and collagen, and immunohistochemical staining for inducible nitric oxide synthase, interleukin-1ß, vascular endothelial growth factor (VEGF), and transforming growth factor-ß1 (TGF-ß1). On day 2 post-treatment, NLB stimulated a dense inflammatory infiltrate mainly consisting of polymorphonuclear cells, as indicated by increased MPO (P < 0.05), but oxidative stress due to MDA was not observed until the 7th day (P < 0.05). The number of blood vessels was greater in NLB (P < 0.05) and DL (P < 0.05) mice compared to sham animals on day 14. NLB induced fibroplasia by day 14 (P < 0.05) with low expression of TGF-ß1 and collagenesis. Thus, NLB significantly induced the inflammatory phase of healing mediated by oxidative stress, which appeared to influence the subsequent phases such as angiogenesis (with low expression of VEGF) and fibroplasia (independent of TGF-ß1) without influencing collagenesis.

Metabolic effects of the ingestion of different fructose sources in rats.

INTRODUCTION: Fructose is a simple carbohydrate that should be ingested in a restricted manner. However, current data suggest increased daily consumption of fructose which may lead to an increased incidence of diseases such as obesity, diabetes and co-morbidities associated with excess weight. Thus, the objective of the present study was to assess the effect of the ingestion of different fructose sources on weight gain, glycemia and serum triglyceride levels in rats. METHODS: The study was conducted on male Wistar rats divided into 5 groups according to the source and concentration of fructuse (ingested AD LIBITUM in liquid form). RESULTS: Drink intake was increased and chow consumption was reduced in all groups compared to control ( P<0.05). The animals of the groups receiving 10 and 20% fructose solutions showed increased triglyceride levels and the 20% group also showed weight gain. The exaggerate consumption of fructose promotes a reduced consumption of chow, an increase in serum triglyceride levels, and weight gain in some animals.

Ausência de mutagenicidade e antimutagenicidade do extrato obtido das flores do ipê roxo [Tabebuia impetiginosa (Mart. ex DC.) Standl.] / Absence of mutagenicity and antimutagenicity of the extract obtained from the flowers of "ipê roxo" Tabebuia impetiginosa (Mart. ex DC.) Standl

A Tabebuia impetiginosa, conhecida popularmente como ipê-roxo, é uma planta nativa das florestas tropicais chuvosas da América do Sul e Central. Componentes químicos obtidos da casca têm mostrado efeito terapêutico, como antiinflamatório, antifúngico e antibacteriano. Porém, pela falta de dados na literatura, pouco se sabe sobre os efeitos do extrato das flores. Assim, o objetivo do presente trabalho foi avaliar o potencial mutagênico e antimutagênico do extrato obtido das flores da T. impetiginosa, em três diferentes concentrações (100, 300 e 500 mg kg-1 p.c.) pelo teste do micronúcleo. Para o teste de mutagenicidade, a doxorrubicina (DXR, 90 mg kg-1 p.c.) foi utilizada como indutor de danos no DNA e para o teste de antimutagenicidade, os tratamentos com o extrato foram realizados simultaneamente com este agente químico. O sangue periférico dos animais foi coletado 24 horas após os tratamentos. A comparação da frequência de eritrócitos policromáticos (PCEs) em 400 eritrócitos/animal entre os diferentes grupos não demonstrou qualquer citotoxicidade do extrato. Em relação às frequências de micronúcleos em PCEs (PCEMNs), não foram observadas diferenças significativas entre os grupos tratados com as diferentes concentrações de extrato e o controle negativo. Da mesma forma, todos os grupos de animais que receberam os tratamentos simultâneo do extrato (100, 300 ou 500 mg kg-1 p.c.) com a DXR, apresentaram valores de PCEMNs muito próximos quando comparados com os dados observados no grupo de animais que recebeu somente a DXR. Esses resultados apresentados indicam ausência de efeito mutagênico e antimutagênico do extrato obtido das flores da T. impetiginosa em sistema teste in vivo.

T. impetiginosa, known as "ipê-roxo", is a plant native to tropical rain forests of Central and South Americas. Chemical compounds obtained from its bark have shown anti-inflammatory, antifungal and antibacterial therapeutic effect. However, due to the lack of data in the literature, little is known about the effects of its flower extract. Thus, the aim of this study was to evaluate the mutagenic and antimutagenic potential of the extract obtained from T. impetiginosa flowers at three different concentrations (100, 300 and 500 mg kg-1 p.c.) by the micronucleus test. For the mutagenicity test, doxorubicin (DXR, 90 mg kg-1 p.c.) was used as DNA-damage inducer, while for the antimutagenicity test, treatments with the extract were performed simultaneously with this chemical agent. The peripheral blood of animals was collected 24 hours after the treatments. The frequency of polychromatic erythrocytes (PCEs) in 400 erythrocytes/animal was compared among the different groups and showed no extract cytotoxicity. As regards the frequency of micronuclei in PCEs (PCEMNs), there were no significant differences between the groups treated with different concentrations of extract and the negative control. Similarly, all groups of animals that received the simultaneous extract treatments (100, 300 or 500 mg kg-1 p.c.) with DXR showed very similar values of PCEMNs when compared with the data observed for the group of animals that received DXR alone. These results indicate no mutagenic and antimutagenic effect of the extract obtained from T. impetiginosa flowers in the testing system in vivo.

Oxidative stress biomarkers response to high intensity interval training and relation to performance in competitive swimmers.

AIM: Aim of the study is to investigate the modulations of oxidative stress biomarkers and some antioxidants induced by high intensity interval training bout and its relation to swimming performance. METHODS: Ten swimmers performed a set of 8 maximal swims along 100 m by style of their specialty, with 10 minute for a rest. The concentration of blood lactate ([Lac]) was determined after each swim. The lactate tolerance index (LTI) was determined by the ratio between [Lac] and the respective times of execution of the 8 swims. The time to complete first 100 m swim at maximum effort (P100) and the international point score (IPS) reached in a specific competition were considered performance parameters. Venous blood was collected before and after the anaerobic training effort. RESULTS: Mean blood lactate concentration in the eight swims was 10.9 ± 1.2 mM. Significant increases were observed for TBARS (pre: 4.1±0.7 ?mol/L; post: 4.9±1.1. ?mol/L), CK (pre: 206.4±170.7 U/L; post: 244.4±176.9. U/L), GSH (pre: 0.52±0.06; post: 0.62±0.05. mM), and ascorbic acid (pre: 0.06±0.02; post: 0.11±0.03. mg/dL) after the anaerobic training bout compared to the values obtained before it. In addition, significant correlations (P < 0.05) were detected between LTI and P100 (r = -0.87) and IPS (r = 0.64) and between variation of ascorbic acid and P100 (r = -0.60). CONCLUSION: Anaerobic training bout proposed induces oxidative stress and cell muscle damage markers as well as modulates some antioxidants of competitive swimmers. The modulation of ascorbic acid seems to play an important role in the performance of these athletes.

Impact of maternal vitamin A supplementation on the mother-infant pair in Brazil.

BACKGROUND/OBJECTIVES: Vitamin A deficiency (VAD) is a major public health problem. The supplementation of lactating women could be an effective strategy to combat it. The objective of this study was to assess the impact of maternal vitamin A supplementation on the mother-infant pair. SUBJECTS/METHODS: This was a double blind, placebo-controlled randomized clinical assay in which 33 women received 200 000 IU of vitamin A and 33 women received soy oil between 20th and 30th postpartum days. Maternal blood and milk samples were collected immediately before supplementation and 3 months after delivery, when blood was also collected from the babies. Retinol concentrations 0.70 µmol/l in serum and 1.05 µmol/l in milk were considered to indicate VAD. RESULTS: Increase in serum retinol level was observed in the supplemented group compared with the pre-supplementation levels (1.05 and 1.17 µmol/l, respectively; P=0.026) and to the post-supplementation levels of the control group (1.02 µmol/l; P=0.032). Reduction in breast milk retinol was observed in the control group compared with the pre-supplementation levels (1.93 and 1.34 µmol/l, respectively; P<0.0001) and to the post-supplementation levels of the supplemented group (1.56 µmol/l; P=0.0003). There was significant difference in the prevalence of VAD in breast milk after supplementation, 55.6% (15/27) in the control group and 16.1% (5/31) in the supplemented group (P=0.002). VAD was present in 66.1% (39/59) of infants, with mean serum retinol levels of 0.64±0.30 µmol/l in the control group and of 0.69±0.26 µmol/l in the supplemented group. CONCLUSIONS: Supplementation had a positive impact on maternal vitamin A status. No effect on infant status was detectable 2 months after supplementation with a single dose.

Blood and salivary oxidative stress biomarkers following an acute session of resistance exercise in humans.

The aim of the present study was to compare oxidative stress biomarkers determined in blood and saliva before and after acute resistance exercise. 1 week after 1 maximum repetition (1RM) test 11 healthy well-trained males completed a hypertrophy acute session of resistance training including 3 sets of 10 repetitions at 75% of the 1RM, with 90 s rest periods between sets. Venous blood and saliva samples were collected before (pre) and 10 min after (post) the resistance training session. A significant (p<0.05) rise in blood lactate accumulation (pre: 1.6+/-0.4 vs. post: 9.5+/-2.4) was found post-acute resistance training compared with baseline values. Significant increases (p<0.05) in TBARS (42%), AOPP (28%), uric acid (27%) and GSH (14%) were detected post-acute resistance training in relation to pre in blood samples. A significant increase (p<0.05) in uric acid (36%) was found in saliva post-acute resistance training as well as a significant correlation (p<0.05) between uric acid determined in blood and saliva. Statistical analysis did not reveal any other change in the salivary oxidative stress biomarkers. In conclusion, an acute session of resistance exercise induces oxidative stress in plasma of trained men after acute resistance training, which was not found in saliva samples except for uric acid.

Low-carbohydrate and high-fat diets on the promotion of hepatic steatosis in rats.

AIM: The present work looked for to evaluate in rats the impact of different diets (high-lipid and high-lipid+high-protein) on liver, verifying the occurrence of oxidative stress and steatosis. METHODS: The animals were treated with the respective diets (Group HLS: high-lipid diet with 50% of saturated fat; Group HPLS: high-lipid and high-protein diet with 50% of saturated fat and 40% of protein; Group Control: control diet AIN-93) for 28 days. After this period the animals were sacrificed for hepatic determinations of MDA, reduced GSH, vitamin E, steatosis and glycemia. RESULTS: The results showed higher glycemia in the group HPLS, high concentration of MDA and GSH in the group Control and decreased hepatic vitamin E concentration in the groups that received the high-lipid diets. The hepatic fat was higher in the groups HPLS and HLS in relation to the Group Control, however HPLS presenting high level of fat concentration, showing similar results as the steatosis. CONCLUSION: the fat increase in the diet promoted increase of the oxidative stress, evidenced by the decrease in the hepatic concentration of vitamin E, showing its antioxidant role against the probable generated free radicals, the ones which possibly exercised a role in the steatosis occurrence.