Juçara (Euterpe edulis Martius) improves time-to-exhaustion cycling performance and increased reduced glutathione: a randomized, placebo-controlled, crossover, and triple-blind study.

To examine the effects of 7-days juçara powder (JP) intake on oxidative stress biomarkers and endurance and sprint cycling performances. In a randomized, placebo-controlled, crossover, and triple-blind study, 20 male trained cyclists were assigned to intake 10 g of JP (240 mg anthocyanins) or placebo (PLA) for 7 days and performed a cycling time-to-exhaustion (TTE). A 5 s cycling sprint was performed before and after the cycling TTE. Blood oxidative stress biomarkers and lactate concentration where evaluated 1 h before (T-1), immediately after (T0), and 1 h after (T1) the cycling TTE. The mean duration time for the cycling TTE was 8.4 ± 6.0% (63 ± 17 s) longer in the JP condition (JP: 751 ± 283 s) compared to PLA (688 ± 266 s) (P < 0.019). Two-way repeated measures Analysis of variance showed an increase in the JP condition for reduced glutathione (GSH) (P = 0.049) at T0 (P = 0.039) and T1 (P = 0.029) compared to PLA with a moderate effect size at T0 (d = 0.61) and T1 (d = 0.57). Blood lactate levels increased over time in both conditions (P ≤ 0.001). No differences were observed for the post-TTE sprint fatigue index, total phenols, protein carbonyls, and glutathione peroxidase activity. Seven-day intake of JP improved cycling endurance performance and increased GSH levels but had no effect on lactate and cycling sprint-induced fatigue.

Whey Protein, Vitamins C and E Decrease Interleukin-10 in Chronic Hemodialysis Patients: A Pioneer, Randomized, Double-Blind Pilot Trial.

OBJECTIVE: To evaluate the effects of supplementation with whey protein combined with vitamins C and E on inflammatory markers in hemodialysis (HD) patients. DESIGN AND METHODS: This was a pioneer, randomized and double-blinded study. Patients were randomized into two groups and stratified by HD frequency. The supplementation group received 20 g of whey protein, 250 mg of vitamin C, and 600 IU of vitamin E; the placebo group, 20 g of rice flour, and microcrystalline cellulose capsules. The interventions were given after HD, 3 times a week, for 8 weeks. The inflammatory markers were assessed: interleukin (IL) IL-12p70, IL-10, IL-6, IL-8, and tumor necrosis factor alpha. For statistical analysis, the χ2 test, Student's t-test, Mann-Whitney test, analysis of variance for repeated two-way measurements, paired t test, and Wilcoxon test were performed. P < .05 was considered statistically significant. RESULTS: Twenty-three patients completed the study. No significant differences were found in inflammatory markers when comparing the groups postintervention. In the intragroup was a decrease in IL-10 in the supplementation group after 8 weeks (P = .0382). IL-6 tended to decrease by 810.95% in the supplementation group and increased by 732.8% (nonsignificant) in the placebo group. CONCLUSION: Whey protein combined with vitamins C and E significantly reduced IL-10 in the supplementation group and could be beneficial to reduce IL-6 in HD patients. Future studies are suggested with a larger sample size, different supplementation doses, and longer interventions.

Low to moderate adherence to 2018 diet and physical exercise recommendations of the World Cancer Research Fund/American Institute for Cancer Research is associated with prooxidant biochemical profile in women undergoing adjuvant breast cancer treatment.

Adequate adherence to the 2018 diet and exercise recommendations of the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) can possibly result in less oxidative stress, lower risk to chemo- and radiotoxicity, lower risk of relapse, and increased quality of life in breast cancer survivors. This observational study aims to investigate the influence of adherence to updated recommendations of the WCRF/AICR on oxidative stress biomarkers in women with breast cancer undergoing adjuvant treatment (AT). We hypothesized that adherence to WCRF/AICR recommendations is inversely related to oxidative damage biomarkers and directly associated with antioxidant status. Women (n = 78) were evaluated before (T0) and after AT. After collecting anthropometric, physical activity, and food consumption data, a standardized score of adherence to WCRF/AICR recommendations was applied. The sample was divided into low-medium adherence and high adherence groups. Blood samples were collected at both timepoints for oxidative stress biomarkers analysis. Multiple linear regression analyzes were applied to verify associations between WCRF/AICR score and biomarkers. We found that low-medium adherence to WCRF/AICR recommendations at T0 affected lower levels of reduced glutathione (P= .003) and higher levels of lipid hydroperoxides (P= .002) and plasma carbonylated proteins (P= .001) after AT. The WCRF/AICR score at T0 was inversely associated with changes in plasma carbonylated protein concentrations after AT (adjusted ß = -0.359; P= .01). Our findings suggest that high WCRF/AICR score before and during AT may provide greater stability of antioxidant capacity and protection against exacerbated oxidative stress.

Diet Quality Influences the Occurrence of Food Aversions in Women Undergoing Adjuvant Chemotherapy for Breast Cancer.

Food aversions in women undergoing adjuvant chemotherapy for breast cancer may be linked to oxidative stress and gastrointestinal consequences underlying it, and diet possibly plays a role in this association. This follow-up study included 73 women with breast cancer treated in Florianopolis City, Brazil. Dietary antioxidant capacity-DaC (mmol/d), diet quality-Brazilian Healthy Eating Index Revised (BHEI-R score), and oxidative stress biomarkers were accessed before the treatment, and women were asked if they developed food aversions during adjuvant chemotherapy. Red meat was the main aversion-causing food reported (37.9%, n = 9). There was no difference in DaC, BHEI-R score, or oxidative stress biomarkers between women with no food aversion occurrence and those showing food aversions. A logistic regression adjusted model showed that women exhibiting higher BHEI-R scores were 1.08 times more likely to not develop food aversions during adjuvant chemotherapy (p = 0.041). In summary, this innovative investigation showed that diet quality before adjuvant chemotherapy may influence the non-occurrence of food aversion. Considering this, the result opens new areas for early nutritional interventions, focusing on reducing the occurrence of food aversions and consequently benefiting women with breast cancer by having better outcomes in oncologic treatment.

Vitamin C decreases reduced glutathione in chronic haemodialysis patients: a pilot, randomised, double-blind trial.

PURPOSE: Whey protein has antioxidant properties through its amino acid cysteine, which enhances the biosynthesis of glutathione, the most abundant antioxidant non-protein in mammalians. Glutathione influences vitamin C recycling and increases its protective effect on oxidative stress (OS). The aim of this study was to analyse the effect of whey protein and vitamin C supplementation on OS biomarkers in chronic haemodialysis (HD) patients. METHODS: This pioneer trial was a randomised, double-blind, pilot study in patients from a dialysis clinic. Patients were randomised into three groups (1:1:1) and stratified by HD frequency (2 or 3 times/week). Sachets containing protein powder (20.0 g) with/without vitamin C (0.25 g) or placebo (20.0 g of white rice flour) with vitamin C (0.25 g) were supplemented after each HD session, 3 times/week for 8 weeks. Blood samples were collected at the baseline period and after 8 weeks for the measurement of reduced glutathione (GSH), oxidised glutathione (GSSG), the GSH:GSSG ratio, malondialdehyde, vitamin C, and glutathione peroxidase-1. RESULTS: Twenty-two patients were enrolled, of which 18 concluded the trial, 6 per group (18.2%, n = 4 losses during follow-up). The vitamin C group presented decreased GSH levels after supplementation (p = 0.053) and a decreasing tendency in the GSH:GSSG ratio (non-statistically significant), while MDA levels significantly decreased only in the whey protein-supplemented groups (p ≤ 0.05). CONCLUSION: The results suggest a pro-oxidant effect of 0.25 g of vitamin C alone in chronic HD patients. CLINICAL TRIAL REGISTRATION: https://ensaiosclinicos.gov.br/ , RBR-65b8f4.

Açaí (Euterpe oleracea Mart.) and juçara (Euterpe edulis Mart.) juices improved HDL-c levels and antioxidant defense of healthy adults in a 4-week randomized cross-over study.

OBJECTIVE: To evaluate the effects of moderate-term açaí and juçara juice intake on fasting glucose, lipid profile, and oxidative stress biomarkers in healthy subjects. METHODS: A randomized cross-over study was performed with 30 healthy adults. The subjects were assigned to drink 200 mL/day of açaí or juçara juice for four weeks with a 4-week washout period. Before and after each nutritional intervention, blood samples were obtained to evaluate the outcomes: fasting glucose, total cholesterol, triglycerides, high-density lipoprotein-cholesterol (HDL-c), low-density lipoprotein-cholesterol (LDL-c), small, dense LDL-c (sd-LDL-c), total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), uric acid, and activity of the enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). RESULTS: After four weeks, açaí and juçara juices increased the concentrations of HDL-c by 7.7% and 11.4%, respectively (P < 0.05). In addition, açaí juice intake promoted significant increases in TAC (66.7%), CAT (275.1%), GPx (15.3%), and a decrease in OSI (55.7%) compared to baseline (P < 0.05 for all). Juçara juice intake significantly increased CAT activity (~15.0%) in relation to baseline. No significant intergroup differences were observed for any outcomes (P > 0.05). CONCLUSION: The results indicated a positive impact of regular consumption of açaí and juçara juices on the HDL-c levels, as well as on the antioxidant enzyme activities, which may contribute to cardiovascular health.

Spray-Dried Yerba Mate Extract Capsules: Clinical Evaluation and Antioxidant Potential in Healthy Individuals.

The aim of the present study was to evaluate the clinical effects and antioxidant potential of spray-dried yerba mate extract (SDME) capsules in healthy individuals. Fourteen healthy volunteers consumed three capsules of SDME three times daily. Measurements were carried out at the baseline and after 7, 30, and 60 days of SDME capsules intake. Electrocardiogram, hematological, urinary, and biochemical parameters analyzed remained within the normal values during all the study. SDME capsules ingestion increased significantly serum antioxidant capacity (after 7 and 30 days) and reduced glutathione values (after 7 and 60 days), and the superoxide dismutase (after 7, 30, and 60 days), catalase (after 7 and 30 days), and paraoxonase-1 activities (after 7 days); and decreased lipid hydroperoxides (after 30 and 60 days) and thiobarbituric acid reactive substances levels (after 7 and 30 days). No change was observed for glutathione peroxidase activity after SDME capsules intake. The present study showed that SDME capsules ingestion by healthy individuals did not promote clinical changes and promoted an increase of antioxidant biomarkers with a concomitant decrease of lipid peroxidation biomarkers in a short and prolonged manner.

Effect of mate tea (Ilex paraguariensis) on the expression of the leukocyte NADPH oxidase subunit p47phox and on circulating inflammatory cytokines in healthy men: a pilot study.

Increased superoxide production by phagocytic NADPH oxidase has been associated with inflammatory conditions. Growing evidences suggest that dietary polyphenols may modulate the expression of NADPH oxidase subunits. Herein, we examined whether soluble mate tea (SMT) consumption - a polyphenol-rich beverage - affects the expression of the leukocyte NADPH oxidase protein p47phox and/or circulating biomarkers of inflammation and antioxidant biomarkers in humans. In a two-phase study, nine men were requested to drink water (control) for 8 d and then follow a second 8-d period drinking SMT. Blood samples were analysed for p47phox protein in CD16+/CD14- cells, interleukin (IL)-1ß (IL-1ß), tumour necrosis factor-alpha (TNF-α), IL-6, total phenols, and reduced and oxidised glutathione (GSH and GSSG, respectively) after each study phase. After SMT intake, CD16+/CD14- cells' p47phox protein and serum TNF-α and IL-6 levels were significantly attenuated (P < .05) while plasma phenolic compounds and blood GSH:GSSG ratio were significantly enhanced (P < .05). Consumption of SMT favourably affected leukocytes' p47phox expression and inflammatory cytokine and antioxidants levels in peripheral blood, which may help decrease oxidative stress and low-grade inflammation.

Effects of N-acetylcysteine supplementation on cellular damage and oxidative stress indicators in volleyball athletes.

The purpose of this study was to evaluate the effects of N-acetylcysteine (NAC) supplementation on cellular damage and oxidative stress indicators in volleyball athletes. Twenty male volleyball athletes at national level performed a physical training session and were divided into 2 groups, which for 7 days took the placebo substance or NAC. After 7 days the athletes repeated the same training session. In both sessions, blood samples were collected 30 min before and immediately after the training session to measure cellular damage and oxidative stress markers. The main results show that, although higher concentrations of glutathione peroxidase and superoxide dismutase were observed in post-session 1 than those in postsession 2, the other markers showed an increase in antioxidant action after supplementation of NAC, once the effect of experimental conditions (P=0.030) were observed in: time effect (P<0.001) and interaction (P=0.019) for total glutathione; time effect (P<0.001) and interaction (P<0.001) for reduced glutathione; and time effect (P<0.001) for ferric-reducing antioxidant potential. The oxidant action indicated by the protein carbonyl was higher in the placebo group than in the NAC group (P=0.028), but a time effect (P<0.001) for the thiobarbituric acid reactive substances showed lower values in presession 1 than in presession 2. For the cellular damage markers, antagonistic results between markers were found. Based in the results, the supplementation of NAC during a short period was effective in reducing oxidant action and increasing antioxidant action. However, conclusive alterations in the responses of the cellular damage markers were not obtained.

Influence of exercise on oxidative stress in patients with heart failure.

Reactive oxygen species play an important role in the pathophysiology of heart failure (HF). In contrast, regular physical exercise can promote adaptations to reactive oxygen species that are beneficial for patients with HF. We completed a systematic review of randomized controlled trials that evaluate the influence of exercise on oxidative stress in patients with HF. Articles were searched in the PubMed, Cochrane, SciELO, and LILACS databases. The search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The quality of the included studies was assessed using the Physiotherapy Evidence Database scale. We selected 12 studies with a total of 353 participants. The included patients had a left ventricle ejection fraction of < 52% and New York Heart Association functional class II or III disease. A significant increase was observed in peak oxygen consumption (between 10 and 46%) in the group that underwent training (TG). There was an improvement in the oxidative capacity of skeletal muscles in the TG, related to the positive activity of mitochondrial cytochrome c oxidase (between 27 and 41%). An increase in the expression of the enzymes glutathione peroxidase (41%), catalase (between 14 and 42%), and superoxide dismutase (74.5%), and a decrease in lipid peroxidation (between 28.8 and 58.5%) were observed in the TG. Physical training positively influenced the cardiorespiratory capacity and enhanced the benefits of oxidant and antioxidant biomarkers in patients with HF. High-intensity training promoted a 15% increase in the plasma total antioxidant capacity, whereas moderate training had no effect.

Effects of mate tea consumption on muscle strength and oxidative stress markers after eccentric exercise.

Dietary phytochemical supplementation may improve muscle recovery from exercise. In this study, we investigated the effect of mate tea (MT) consumption - a phenol-rich beverage - on muscle strength and oxidative stress biomarkers after eccentric exercise. In a randomised, cross-over design, twelve men were assigned to drink either MT or water (control; CON) for 11 d. On the 8th day, subjects performed three sets of twenty maximal eccentric elbow flexion exercises. Maximal isometric elbow flexion force was measured before and at 0, 24, 48 and 72 h after exercise. Blood samples were obtained before and at 24, 48 and 72 h after exercise and analysed for total phenolics, GSH, GSSG, GSH:GSSG ratio and lipid hydroperoxides (LOOH). After eccentric exercise, muscle strength was significantly reduced over time, regardless of treatments. However, MT improved the rate of strength recovery by 8·6 % on the 1st day after exercise (P<0·05). Plasma concentration of total phenolic compounds was higher in MT than in CON at all time points (P<0·05) but decreased significantly at 72 h after exercise in both trials (P<0·05). Blood levels of GSH were significantly decreased at 48 and 72 h after exercise in CON (P<0·05) but did not change over time in MT. No significant changes were observed for GSSG, GSH:GSSG ratio and LOOH levels. MT intake did not influence muscle strength at all time points assessed but hastened the strength recovery over 24 h after exercise. MT also favoured the concentration of blood antioxidant compounds.

Bioactive potential of Vitis labrusca L. grape juices from the Southern Region of Brazil: phenolic and elemental composition and effect on lipid peroxidation in healthy subjects.

Grapes are rich in polyphenols with biologically active properties. Although the bioactive potential of grape constituents are frequently reported, the effects of Brazilian Vitis labrusca L. grape juices ingestion have not been demonstrated in humans. This study identified the phenolic and elemental composition of red and white grape juices and the effect of organic and conventional red grape juice consumption on lipid peroxidation in healthy individuals. Concentrations of anthocyanins, flavanols and phenolic acids and the in vitro antioxidant activity were significantly higher in the organic juice. The macro-elements K, Ca, Na and Mg were the most abundant minerals in all juices. The acute consumption of red grape juices promoted significant decrease of lipid peroxides in serum and TBARS levels in plasma. It is concluded that red V. labrusca L. grape juices produced in Southern Brazil showed lipid peroxidation inhibition abilities in healthy subjects, regardless of the cultivation system.

Yerba mate (Ilex paraguariensis) enhances the gene modulation and activity of paraoxonase-2: in vitro and in vivo studies.

OBJECTIVE: Paraoxonase-2 (PON-2) is an intracellular antioxidant enzyme that can be modulated by polyphenols. The aim of this study was to verify whether yerba mate (Ilex paraguariensis), a plant species rich in phenolic compounds, modulates gene expression and the activity of PON-2 in macrophages in vitro and in monocytes from peripheral blood and monocyte-derived macrophages obtained after the ingestion of green or roasted yerba mate infusions by healthy subjects. METHODS: THP-1 macrophages were incubated with increasing amounts of yerba mate extracts or chlorogenic and caffeic acids (1-10 µmol/L). The in vivo effects of yerba mate or water (control) intakes were evaluated acutely (2 h after ingestion) and in the short term (after daily ingestion for 7 d) in 20 healthy women. RESULTS: In general, there was no difference between the two kinds of yerba mate studied. Yerba mate extracts or chlorogenic acid at 1 and 3 µmol/L increased PON-2 relative gene expression in THP-1 macrophages (P < 0.05), whereas higher concentrations (5 and 10 µmol/L) increased the activity only. Caffeic acid induced PON-2 activity only. The acute ingestion of yerba mate infusions increased relative gene expression and PON-2 activity in monocytes (P < 0.05), whereas the consumption of yerba mate for 7 d increased PON-2 relative gene expression (P < 0.05) and had a tendency to increase PON-2 activity in monocytes and monocyte-derived macrophages. CONCLUSION: It is suggested that green or roasted yerba mate modulates positively the mRNA relative expression and activity of the PON-2 enzyme in monocytes and macrophages, which may prevent cellular oxidative stress.

Association of mate tea (Ilex paraguariensis) intake and dietary intervention and effects on oxidative stress biomarkers of dyslipidemic subjects.

OBJECTIVE: To evaluate the effect of long-term ingestion of mate tea, with or without dietary intervention, on the markers of oxidative stress in dyslipidemic individuals. METHODS: Seventy-four dyslipidemic volunteers participated in this randomized clinical trial. Subjects were divided into three treatment groups: mate tea (MT), dietary intervention (DI), and mate tea with dietary intervention (MD). Biochemical and dietary variables were assessed at the beginning of the study (baseline) and after 20, 40, 60, and 90 d of treatment. Participants in the MT and MD groups consumed 1 L/d of mate tea. Those in the DI and MD groups were instructed to increase their intake of fruit, legumes and vegetables and decrease their consumption of foods rich in cholesterol and saturated and trans-fatty acids. Biomarkers of oxidative stress such as antioxidant capacity of serum (ferric reducing antioxidant potential assay), uric acid, reduced glutathione, paraoxonase-1 enzyme, lipid hydroperoxide (LOOH), and protein carbonyl were analyzed. RESULTS: Participants in the DI group showed a significant decrease in total fat and saturated fatty acid intakes. Those in the DI and MD groups presented a significant increase in vitamin C consumption. For all groups, there was a significant increase in ferric reducing antioxidant potential and reduced glutathione concentrations but no significant changes in LOOH, protein carbonyl, and paraoxonase-1 values. The reduced glutathione concentration was positively correlated with the consumption of monounsaturated fatty acids, fiber, and vitamin C, whereas levels of LOOH were inversely correlated with intakes of vitamin C and fiber. In addition, LOOH correlated positively with low-density lipoprotein cholesterol and inversely with high-density lipoprotein cholesterol, which had a positive association with paraoxonase-1. CONCLUSION: The ingestion of mate tea independently of the dietary intervention increased plasma and blood antioxidant protection in patients with dyslipidemia.

Safety assessment of yerba mate (Ilex paraguariensis) dried extract: results of acute and 90 days subchronic toxicity studies in rats and rabbits.

Acute toxicity of yerba mate dried extract (YMDE) was investigated in Wistar rats (6/sex/group) from single dose of 2g/kg body weight by intragastric administration and 14days monitoring. Subchronic toxicity was investigated in Wistar rats, by intragastric administration (10/sex/group), and in New Zealand rabbits by oral administration (3/sex/group) of 2g/kg body weight for 12weeks. Toxicological parameters included clinical signs, body weight, water, and food consumption, hematological and serum parameters, and histopathological assessment. Acute YMDE administration showed no effects on survival, clinical observations, macroscopic examination of organs, body weight or food, and water consumption. Sub-chronic administration of YMDE did not change behavior, body weight, and histopatological assessment of stomach, kidney, liver, and small gut. Moreover, most of biochemical and hematological parameters remained unchanged. In summary, the results of our preclinical toxicological investigation are indicative that the YMDE is well tolerated for both single and chronic administration.

Diphenyl diselenide decreases serum levels of total cholesterol and tissue oxidative stress in cholesterol-fed rabbits.

Hypercholesterolaemia and oxidative stress are well-known risk factors in coronary artery diseases. Diphenyl diselenide is a synthetic organoselenium compound that has been shown to have in vitro and in vivo antioxidant properties. In this study, we investigated whether diphenyl diselenide could reduce the hypercholesterolaemia and diminish the tissue oxidative stress in cholesterol-fed rabbits. Twenty-four New Zealand white male rabbits were randomly divided into four groups. Each group was fed a different diet as follows: Control group--regular chow; Cholesterol group--1% cholesterol-enriched diet; diphenyl diselenide group--regular diet supplemented with 10 ppm diphenyl diselenide; and Chol/diphenyl diselenide group--the same cholesterol-rich supplemented with 10 ppm diphenyl diselenide. After 45 days of treatment, the rabbits were killed and the blood, liver, and brain were used for laboratory analysis. The results showed that the serum levels of total cholesterol were markedly increased in cholesterol-fed rabbits and the consumption of diphenyl diselenide decreased these levels approximately twofold in Chol/diphenyl diselenide rabbits (P < 0.05). The intake of diphenyl diselenide by hypercholesterolaemic rabbits diminished the serum and hepatic thiobarbituric acid reactive substances levels as well as the production of reactive oxygen species in the blood and brain (P < 0.05) when compared to the cholesterol group. In addition, diphenyl diselenide supplementation increased hepatic and cerebral delta-aminolevulinic dehydratase activity and hepatic non-protein thiol groups levels despite hypercholesterolaemia (P < 0.05). In summary, the results showed that diphenyl diselenide reduced the hypercholesterolaemia and the oxidative stress in cholesterol-fed rabbits.

Consumption of green tea favorably affects oxidative stress markers in weight-trained men.

OBJECTIVE: This study investigated the effects of the consumption of green tea (GT) for 7 d on biomarkers of oxidative stress in young men undergoing resistance exercise. METHODS: Fourteen subjects performed a bench press exercise (four sets, 10 to 4 repetitions) after undergoing a period without (control group) or with the intake of GT (GT group; 2 g of leaves in 200 mL of water, three times per day). Blood samples were obtained before and after exercise and analyzed for total antioxidant capacity (ferric reducing ability of plasma [FRAP]), total polyphenols, reduced glutathione (GSH), lipid hydroperoxide (LH) and thiobarbituric acid-reactive substances, creatine kinase (CK), aspartate aminotransferase (AST), xanthine oxidase (XO), hypoxanthine, and uric acid (UA). RESULTS: In the control group, exercise did not affect the values of LH, thiobarbituric acid-reactive substances, and FRAP, although it did reduce the levels of GSH (P < 0.05). In addition, exercise increased CK, AST, and XO activities, although it did not change the values for hypoxanthine or UA. Green tea reduced the postexercise concentration of LH and increased the values of total polyphenols, GSH, and FRAP. GT also inhibited a significant rise in CK and XO activities induced by exercise. Furthermore, GT decreased the AST activity and hypoxanthine and UA concentrations before and after exercise. The assessment of food consumption revealed that the participants had an unbalanced diet, particularly in relation to vitamin E and carotenoids. CONCLUSION: Consumption of GT, a beverage rich in polyphenols, may offer protection against the oxidative damage caused by exercise, and dietary guidance for sports participants should be emphasized.

Aqueous extract of Ilex paraguariensis attenuates the progression of atherosclerosis in cholesterol-fed rabbits.

Ilex paraguariensis aqueous extract (mate) is an antioxidant-rich beverage widely consumed in South American countries. Here we questioned whether mate could reduce the progression of atherosclerosis in 1% cholesterol-fed rabbits. New Zealand White male rabbits (n = 32) were divided into four groups: control (C, n = 5), control-mate (CM, n = 5), hypercholesterolemic (HC, n = 11) and hypercholesterolemic-mate (HCM, n = 11). The daily water and mate extract consumption was approximately 400 ml. After 2 months of treatment, mate intake did not change the lipid profile or hepatic cholesterol content of control or hypercholesterolemic rabbits (p < 0.05). However, the atherosclerotic lesion area was considerably smaller in the hypercholesterolemic-mate group (HCM, 35.4% vs. HC, 60.1%; p < 0.05). In addition, the aortic cholesterol content was around half that of the HC group (HCM, 36.8 vs. HC, 73.9 microg/mg of protein, p < 0.05). In spite of this, the thiobarbituric acid-reactive substances (TBARS) in the atherosclerotic aorta, liver and serum, and the activity of the antioxidant enzymes in liver and aorta did not differ among groups (p > 0.05). The results showed that Ilex paraguariensis extract can inhibit the progression of atherosclerosis in cholesterol-fed rabbits, although it did not decrease the serum cholesterol or aortic TBARS and antioxidant enzymes.

Ascorbic acid interference in the measurement of serum biochemical parameters: in vivo and in vitro studies.

OBJECTIVES: To investigate the negative interference of ascorbic acid in serum biochemical tests in relation to the dose of vitamin C intake and to the time of blood collection. DESIGN AND METHODS: Healthy volunteers (n = 18) consumed daily doses of vitamin C (0.25-4.0 g) for 1 week and serum parameters were assayed prior to the experiment and on the eighth day of consumption. Blood samples were collected 4, 12 and 24 h after vitamin C intake. RESULTS: Serum levels of ascorbic acid increased significantly after vitamin C ingestion inhibiting urate and total bilirubin tests 4 and 12 h after intake (P < 0.01). A significant negative interference occurred up to 24 h after consumption of 4 g vitamin C for the urate test. In contrast, ingestion of vitamin C did not show interference in glucose, triglyceride and cholesterol tests. Addition of ascorbic acid to serum inhibited the urate test to a similar extent to that observed after vitamin C intake. However, after ingesting vitamin C, the interference for the bilirubin test was greater than that of the in vitro interference. CONCLUSIONS: Commonly taken doses of supplementary vitamin C interfered negatively with the serum urate test based on the Trinder method, and with bilirubin metabolism.

Use of Nb(2)O(5)-SiO(2) in an automated on-line preconcentration system for determination of copper and cadmium by FAAS.

A procedure for the determination of trace level of copper(II) and cadmium(II) by FAAS using an on-line preconcentration system has been proposed. In this system, copper and cadmium ions were adsorbed onto a minicolumn packed with silica gel modified with niobium(V) oxide (Nb(2)O(5)-SiO(2)), followed by nitric acid elution in reverse mode and determination on-line by flame atomic absorption spectrometry (AAS) without interference of the matrix. Chemical and flow variables as well as concomitant ions were studied in the developed procedure. The enrichment factor for copper(II) and cadmium(II) was 34.2 and 33.0, respectively, using a preconcentration time of 2min. The limit of detection for copper(II) and cadmium(II) was 0.4, and 0.1mugl(-1), respectively. The precision of the method, evaluated as the relative standard deviation in solutions containing 15mugl(-1) of copper and 10mugl(-1) of cadmium, by analyzing a series of seven replicates, was 1.8 and 1.6%, respectively. The accuracy was assessed through recovery experiments of certified material and water samples.