Increase In Plasma Antioxidant Capacity Research Articles

Improved Antioxidant Status after Diet Supplementation with Novel Natural-Based Supplement in Combat Athletes.

Intense physical activity is known to generate high levels of oxidative stress, and supplementation with bioactive products with powerful antioxidant effects is often recommended. In this context, the present study aims to evaluate the potential benefits of supplementing the diet of professional combat fighters with a new bioactive formulation based on Aronia melanocarpa (black chokeberry) and bee pollen, a natural combination with a balanced ratio of macro- and micronutrients, rich in proteins and polyphenols. A total of 31 professional combat fighters were selected to participate in this study. Due to allergic medical history, two were excluded, and the remaining 29 were divided into two groups: 14 in the control and 15 in the supplementation group. The supplemented group consumed daily 40 g of novel supplement based on a combination of dried black chokeberry and bee pollen (1:2 ratio) for 4 weeks. A statistically significant increase in plasma antioxidant capacity was observed in the supplemented group compared to control related to the time and group factors at the end of this study. During this study, a significant increase in neutrophils was recorded in both groups. Supplementation with black chokeberry and bee pollen generated no significant modifications in inflammatory markers, body composition, glycemia, maximum aerobic capacity, blood glycemia, hemoglobin or red cell line. This clinical study pointed out a positive result in terms of plasma antioxidant capacity upon administration of the novel nutraceutical formulation.

Renal Oxidative Stress May Explain Sex Differences in Blood Pressure in Adult Offspring Exposed to an Impoverished Environment

Background: Nearly 40 million people experience poverty in the United States. Poverty is linked to adverse childhood experiences (ACEs) which affects about 64% of adults in the U.S. Previous studies indicate that those who experience ACEs are at a higher risk of developing hypertension (HTN) and cardiovascular diseases (CVDs) later in life, with a greater severity and earlier onset in males. The mechanisms behind the ACEs-attributed development of sex differences in HTN later in life is unknown. One plausible mechanism for this sex difference is increased oxidative stress. One rodent model to mimic poverty as an ACE is the limited bed and nesting (LBN) model. This model simulates an impoverished and low resource environment, as observed in poverty, in which the nesting material during weaning is reduced. We hypothesize that male offspring exposed to LBN will have elevated blood pressure and oxidative stress, while females will have no change in blood pressure and reduced oxidative stress. Methods: Pregnant Sprague Dawley rats gave birth naturally and weaned their offspring for 3 weeks. During the weaning period, on Days 2-9, the dams and their respective pups were divided into 2 groups: LBN and control (CON). After LBN treatment, all rats received normal bedding. After weaning, offspring were divided by sex and experimental status: LBN male (n=5), LBN female (n=5), CON male (n=6), and CON female (n=6). At 16-17 weeks, mean arterial pressure (MAP) was measured via carotid catheterization and the kidneys, brain, heart, and plasma were collected to measure antioxidant capacity via colorimetric biochemical assays. Results: LBN males had a significant increase (18 mmHg) in MAP compared to CON males (128.17±3.93 vs 110.72± 3.93 mmHg, P>0.001), while female LBN and CON rodents displayed no differences. In males, there were no changes in antioxidant capacity in the brain, heart, and plasma. However, there was a significant 2-fold decrease in renal antioxidant capacity (233±14.0 vs 442±12.3 mM Trolox/mg protein, p>0.0001). In females, there were no changes in the kidneys, heart, and brain antioxidant capacity. Conversely, LBN females showed a trending increase in plasma antioxidant capacity compared to CON (3.33±0.16 vs 2.53±0.35 mM Trolox/mg protein, p=0.053). Conclusion: Only males exposed to an impoverished environment during weaning have elevated blood pressure, while females do not. This difference in blood pressure may be explained by decreases in renal antioxidant capacity in males only. On the other hand, females may be protected from elevated blood pressure because they experience a slight increase in systemic antioxidant capacity. Future studies will examine the role of antioxidants in blood pressure regulation in the kidneys. This study is clinically relevant because ACEs affect a large percentage of the American population with about 17% of adults experiencing 4 or more ACEs, with minorities at a greater risk. Understanding the mechanisms on how ACEs contribute to HTN may alleviate some of the racial and ethnic disparities, along with the financial burden on the healthcare system to care for people with HTN and CVDs. Perhaps, organ and sex-specific antioxidant therapies may be used to alter, prevent, or reduce the development of HTN in adults that were exposed to ACEs, such as poverty during nursing and early childhood. This research was supported by start-up funds and the American Heart Association Early Career Development Award [AHA 18CDA34110264 (Cunningham)]. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Hyperbaric Oxygen Reduces Oxidative Stress Impairment and DNA Damage and Simultaneously Increases HIF-1α in Ischemia-Reperfusion Acute Kidney Injury.

The central exacerbating factor in the pathophysiology of ischemic-reperfusion acute kidney injury (AKI) is oxidative stress. Lipid peroxidation and DNA damage in ischemia are accompanied by the formation of 3-nitrotyrosine, a biomarker for oxidative damage. DNA double-strand breaks (DSBs) may also be a result of postischemic AKI. γH2AX(S139) histone has been identified as a potentially useful biomarker of DNA DSBs. On the other hand, hypoxia-inducible factor (HIF) is the "master switch" for hypoxic adaptation in cells and tissues. The aim of this research was to evaluate the influence of hyperbaric oxygen (HBO) preconditioning on antioxidant capacity estimated by FRAP (ferric reducing antioxidant power) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assay, as well as on oxidative stress parameter 3-nitrotyrosine, and to assess its effects on γH2AX(S139), HIF-1α, and nuclear factor-κB (NF-κB) expression, in an experimental model of postischemic AKI induced in spontaneously hypertensive rats. The animals were divided randomly into three experimental groups: sham-operated rats (SHAM, n = 6), rats with induced postischemic AKI (AKI, n = 6), and group exposed to HBO preconditioning before AKI induction (AKI + HBO, n = 6). A significant improvement in the estimated glomerular filtration rate, eGFR, in AKI + HBO group (p < 0.05 vs. AKI group) was accompanied with a significant increase in plasma antioxidant capacity estimated by FRAP (p < 0.05 vs. SHAM group) and a reduced immunohistochemical expression of 3-nitrotyrosine and γH2AX(S139). Also, HBO pretreatment significantly increased HIF-1α expression (p < 0.001 vs. AKI group), estimated by Western blot and immunohistochemical analysis in kidney tissue, and decreased immunohistochemical NF-κB renal expression (p < 0.01). Taking all of these results together, we may conclude that HBO preconditioning has beneficial effects on acute kidney injury induced in spontaneously hypertensive rats.

Polyphenols and Fish Oils for Improving Metabolic Health: A Revision of the Recent Evidence for Their Combined Nutraceutical Effects.

Polyphenols and omega-3 polyunsaturated fatty acids from fish oils, i.e., eicosapentaenoic and docosahexaenoic acids, are well-recognized nutraceuticals, and their single antioxidant and anti-inflammatory properties have been demonstrated in several studies found in the literature. It has been reported that the combination of these nutraceuticals can lead to three-fold increases in glutathione peroxidase activity, two-fold increases in plasma antioxidant capacity, decreases of 50–100% in lipid peroxidation, protein carbonylation, and urinary 8-isoprotanes, as well as 50–200% attenuation of common inflammation biomarkers, among other effects, as compared to their individual capacities. Therefore, the adequate combination of those bioactive food compounds and their single properties should offer a powerful tool for the design of successfully nutritional interventions for the prevention and palliation of a plethora of human metabolic diseases, frequently diet-induced, whose etiology and progression are characterized by redox homeostasis disturbances and a low-grade of chronic inflammation. However, the certain mechanisms behind their biological activities, in vivo interaction (both between them and other food compounds), and their optimal doses and consumption are not well-known yet. Therefore, we review here the recent evidence accumulated during the last decade about the cooperative action between polyphenols and fish oils against diet-related metabolic alterations, focusing on the mechanisms and pathways described and the effects reported. The final objective is to provide useful information for strategies for personalized nutrition based on these nutraceuticals.

Consumption of Spinach and Tomato Modifies Lipid Metabolism, Reducing Hepatic Steatosis in Rats.

Non-alcoholic fatty liver disease (NAFLD) is currently a serious and growing clinical problem in developed and developing countries and is considered one of the most frequent chronic liver diseases in the world. The aim of this study was to evaluate the functionality of dietary carotenoids provided by tomato and spinach in the dietary treatment of steatosis. Twenty-two Sprague-Dawley rats with induced steatosis were grouped into three groups and fed standard diet (CD group) and two experimental diets supplemented with 12.75% (LC12.75 group) and 25.5% (HC25.5 group) of a mixture of spinach and tomato powder. Rats fed carotenoid-rich feeds showed an improvement in the plasma biomarkers of steatosis, with lower levels of glucose, total cholesterol, VLDL, TG, proteins, ALT and AST. Likewise, a decrease in oxidative stress was observed, with a significant reduction of malondialdehyde (MDA) in plasma (up to 54%), liver (up to 51.42%) and urine (up to 78.89%) (p < 0.05) and an increase in plasma antioxidant capacity (ORAC) (up to 73.41%) (p < 0.05). Furthermore, carotenoid-rich diets led to an accumulation of carotenoids in the liver and were inversely correlated with the content of total cholesterol and hepatic triglycerides, increasing the concentrations of MUFA and PUFA (up to 32.6% and 48%, respectively) (p < 0.05). The accumulation of carotenoids in the liver caused the modulation of genes involved in lipid metabolism, and we particularly observed an overexpression of ACOX1, APOA1 and NRIH2 (LXR) and the synthesis of the proteins. This study suggests that dietary carotenoids from spinach and tomato aid in the dietary management of steatosis by reversing steatosis biomarkers.

Sex differences by design and outcome in the Safety of Urate Elevation in PD (SURE-PD) trial.

To investigate whether women and men with Parkinson disease (PD) differ in their biochemical and clinical responses to long-term treatment with inosine. The Safety of Urate Elevation in Parkinson's Disease (SURE-PD) trial enrolled 75 people with early PD and baseline serum urate below 6 mg/dL and randomized them to 3 double-blinded treatment arms: oral placebo or inosine titrated to produce mild (6.1-7.0 mg/dL) or moderate (7.1-8.0 mg/dL) serum urate elevation for up to 2 years. Parkinsonism, serum urate, and plasma antioxidant capacity were measured at baseline and repeatedly on treatment; CSF urate was assessed once, at 3 months. Here in secondary analyses results are stratified by sex. Inosine produced an absolute increase in average serum urate from baseline that was 50% greater in women (3.0 mg/dL) than in men (2.0 mg/dL), consistent with expected lower baseline levels in women. Similarly, only among women was CSF urate significantly greater on mild or moderate inosine (+87% [p < 0.001] and +98% [p < 0.001], respectively) than on placebo (in contrast to men: +10% [p = 0.6] and +14% [p = 0.4], respectively). Women in the higher inosine dosing group showed a 7.0 Unified Parkinson's Disease Rating Scale (UPDRS) points/year lower rate of decline vs placebo (p = 0.01). In women, slower rates of UPDRS change were associated with greater increases in serum urate (r = -0.52; p = 0.001), and with greater increases in plasma antioxidant capacity (r = -0.44; p = 0.006). No significant associations were observed in men. Inosine produced greater increases in serum and CSF urate in women compared to men in the SURE-PD trial, consistent with the study's design and with preliminary evidence for slower clinical decline in early PD among women treated with urate-elevating doses of inosine. NCT00833690. This study provides Class II evidence that inosine produced greater urate elevation in women than men and may slow PD progression in women.

Human urine metabolomic signature after ingestion of polyphenol-rich juice of purple grumixama (Eugenia brasiliensis Lam.)

Polyphenol intake has been associated with health promotion because of its interaction with several metabolic pathways. This study investigates changes in the urine metabolome following acute intake of polyphenol-rich juice, purple grumixama juice. Grumixama (Eugenia brasiliensis Lam.) is a cherry native to Brazil that is known to be a rich source of anthocyanins and ellagitannins. In this research 15 healthy subjects consumed a single dose of grumixama juice. Urine samples were collected before grumixama juice intake, 0–1, 1–2, 2–4 h, with fasting at 24 h after intake. Plasma samples were also collected before intake, 30′ and at 1 h, 2 h and 4 h, with fasting at 24 h after juice intake. The urine primary metabolites were analysed by a metabolomic approach using gas chromatography mass spectrometry with methyl chloroformate derivatisation for amino acids and organic acids. Also, an oxygen radical absorbance capacity method was carried out to evaluate the plasma samples antioxidant capacity changes. Subjects showed increase in plasma antioxidant capacity after juice intake (p-values < .05). A total of 114 metabolites were assessed in urine (1–2 h and 2–4 h), including 17 amino acids, 47 organic acids and several other metabolites. Among the 114 metabolites, 25 were significantly changed during the first 4 h following juice intake, as shown by the Orthogonal Partial Least Squares Discriminant Analysis (0.5 > p(corr) > 0.3) and univariate analysis (p-values < .05). Some metabolites were related to mitochondrial metabolism, such as glyoxylic acid and oxalic acid. Metabolites related to amino acid metabolism were also changed, such as beta-alanine, l-phenylalanine and l-tyrosine. In conclusion, results suggest that acute intake of grumixama juice could affect amino acid metabolism and mitochondrial metabolism, but the related health implications should be explored in further studies using additional approaches.

Acute effect of Clitoria ternatea flower beverage on glycemic response and antioxidant capacity in healthy subjects: a randomized crossover trial

BackgroundClitoria ternatea L., a natural food-colorant containing anthocyanin, demonstrated antioxidant and antihyperglycemic activity. The aim of this study was to determine the effects of Clitoria ternatea flower extract (CTE) on postprandial plasma glycemia response and antioxidant status in healthy men.MethodsIn a randomized, crossover study, 15 healthy men (ages 22.53 ± 0.30 years; with body mass index of 21.57 ± 0.54 kg/m2) consumed five beverages: (1) 50 g sucrose in 400 mL water; (2) 1 g CTE in 400 mL of water; (3) 2 g CTE in 400 mL of water; (4) 50 g sucrose and 1 g CTE in 400 mL of water; and (5) 50 g sucrose and 2 g CTE in 400 mL of water. Incremental postprandial plasma glucose, insulin, uric acid, antioxidant capacities and lipid peroxidation were measured during 3 h of administration.ResultsAfter 30 min ingestion, the postprandial plasma glucose and insulin levels were suppressed when consuming sucrose plus 1 g and 2 g CTE. In addition, consumption of CTE alone did not alter plasma glucose and insulin concentration in the fasting state. The significant increase in plasma antioxidant capacity (ferric reducing ability of plasma (FRAP), oxygen radical absorbance capacity (ORAC), trolox equivalent antioxidant capacity (TEAC), and protein thiol) and the decrease in malondialdehyde (MDA) level were observed in the subjects who received 1 g and 2 g CTE. Furthermore, consumption of CTE protected sucrose-induced reduction in ORAC and TEAC and increase in plasma MDA.ConclusionsThese findings suggest that an acute ingestion of CTE increases plasma antioxidant capacity without hypoglycemia in the fasting state. It also improves postprandial glucose, insulin and antioxidant status when consumed with sucrose.Trial registrationThai Clinical Trials Registry: TCTR20170609003. Registered 09 September 2017.‘retrospectively registered’.

Lentinus squarrosulus (Mont.) mycelium enhanced antioxidant status in rat model.

AimLentinus squarrosulus is an edible wild mushroom commonly found in Asia. This species has several interesting features such as rapid mycelial growth, and hence has the potential to be used as food, functional food, and nutraceuticals. Our previous study shows that L. squarrosulus contains potent antioxidant compounds in vitro. This study aims to investigate the in vivo bioavailability of L. squarrosulus mycelium extract and its antioxidant effect on biomarkers of antioxidant defense and oxidative stress.MethodsWater extract of mycelial biomass of L. squarrosulus was analyzed for in vivo antioxidant effects, including cupric-reducing antioxidant capacity (CUPRAC), glutathione peroxidase (GPx), xanthine oxidase (XO), advanced oxidation protein products (AOPPs), and lipid hydroperoxides (LHPs) at 0 and 28 days. GPx and XO were also analyzed in liver homogenates. Normal Sprague Dawley rats were treated with 250 and 500 mg/kg of extract for 28 days.ResultsThe serum CUPRAC level increased after treatment with both concentrations, indicating that there was sufficient bioavailability of the extract which contributed to the total antioxidant capacity. GPx activity in both serum and liver was increased and this correlated with LHP level after treatment with 250 mg/kg of extract, but XO activity was significantly decreased after treatment with 500 mg/kg of the extract. Lack of difference between AOPP levels implied that there were no significant changes in oxidative damage of protein after treatment.ConclusionThis study clearly showed that L. squarrosulus mycelium antioxidant extract contains absorbable antioxidants that enter the circulating plasma and cause a significant acute increase in plasma antioxidant capacity. Thus, the water extract of L. squarrosulus mycelium, which can be obtained abundantly by liquid fermentation, may serve as an antioxidant ingredient in functional foods and nutraceuticals.

Genetic damage in patients moving from hemodialysis to online hemodiafiltration.

End-stage renal failure patients exhibit a high incidence of genetic damage and genomic instability. Part of this genetic damage is assumed to be caused by the hemodialysis (HD) procedure. To reduce these effects, different alternative HD procedures have been proposed, such as the use of high efficiency convective therapies to improve the reactive oxygen species/antioxidant ratio. To determine the efficiency of online hemodiafiltration (HDF) technique on the levels of DNA damage, we have measured the frequency of micronucleus in peripheral blood lymphocytes of 33 individuals moving from low-flux HD to post-dilution online HDF. In addition to basal levels of genetic damage, potential changes in radiosensitivity were measured as indicators of genomic instability. Plasma antioxidant capacity was also determined. Second samples were obtained after 6 months on the HDF protocol. Results indicate that moving to online HDF therapy produce a significant reduction of the basal levels of genetic damage, but does not affect the genomic instability status. In addition, a greater increase in plasma antioxidant capacity was observed. In spite of the lack of correlation between these parameters, our results confirm the usefulness of the online HDF technique as a way to reduce DNA damage in HD patients.

Consumption of extra-virgin olive oil rich in phenolic compounds has beneficial antioxidant effects in healthy human adults

Extra-virgin olive oil (EVOO) possesses beneficial health effects due to its antioxidant activity. In a controlled before-and-after supplementation trial (45 healthy adults), we examined the effects of daily consumption (30 days (d), 50 mL/d) of EVOO rich in phenolic compounds, antioxidant activity and antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX)). Participants completed for 30 d a 24-h dietary record. Anthropometric characteristics, body composition, glycemia, plasma lipid profile, plasma polyphenols, total antioxidant capacity, erythrocyte antioxidant enzyme activity, peripheral blood mononuclear cells (PBMC) gene expression were recorded. EVOO supplementation did not modify the first four parameters. Significant increases in plasma antioxidant capacity and antioxidant enzyme activity (CAT, GPX) were observed. Significant increase in SOD and decrease in CAT gene expression were detected. Daily consumption of EVOO rich in phenolic compounds by healthy adults improved their antioxidant status and modified their antioxidant gene expression levels without affecting metabolic parameters.

Absorption, Metabolism, and Effects at Transcriptome Level of a Standardized French Oak Wood Extract, Robuvit, in Healthy Volunteers: Pilot Study

The consumption of wine and spirits, traditionally aged in oak barrels, exposes humans to roburin ingestion. These molecules belong to a class of ellagitannins (ETs), and their only known source is oak wood. Very little is currently known about roburin bioavailability and biological activity. We reported for the first time human absorption of roburins from a French oak wood (Quercus robur) water extract (Robuvit) by measuring the increase of total phenols (from 0.63 ± 0.06 to 1.26 ± 0.18 μg GAE equiv/mL plasma) and the appearance of roburin metabolites (three different glucoronidate urolithins and ellagic acid), in plasma, after 5 days of supplementation. Robuvit supplementation induced also the increase of plasma antioxidant capacity from 1.8 ± 0.05 to 1.9 ± 0.01 nmol Trolox equiv/mL plasma. Moreover, utilizing a combined ex vivo cell culture approach, we assessed the effect of Q. robur metabolites (present in human serum after supplementation) on gene expression modulation, utilizing an Affymetrix array matrix, in endothelial, neuronal, and keratinocyte cell lines. The functional analysis reveals that Robuvit metabolites affect ribosome, cell cycle, and spliceosome pathways.

Consumption of Mesona chinensis Attenuates Postprandial Glucose and Improves Antioxidant Status Induced by a High Carbohydrate Meal in Overweight Subjects

Edible plants constitute a potential source for controlling postprandial hyperglycemia and oxidative stress. The objective of this study was to investigate in vitro antioxidant and intestinal α-glucosidase inhibitory activities of Mesona chinensis (MC). In addition, the acute effect of MC on postprandial glucose and plasma antioxidant status after the consumption of a high carbohydrate (HC) meal by overweight subjects was also determined. The results showed that total phenolic and flavonoid contents in the extract were 212.37 ± 5.64 mg gallic acid equivalents/g dried extract and 23.44 ± 2.50 mg catechin equivalents/g dried extract, respectively. MC extract markedly inhibited the intestinal maltase and sucrose with the IC50 values of 4.66 ± 0.22 mg/mL and 1.30 ± 0.43 mg/mL, respectively. However, MC extract had no inhibitory activity against pancreatic α-amylase. In addition, MC extract had antioxidant properties including DPPH radical scavenging activity, superoxide radical scavenging activity (SRSA), hydroxyl radical scavenging activity (HRSA), trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and ferrous ion cheating activity (FICP). The significant decrease in postprandial plasma glucose, triglyceride and malondialdehyde levels, and the increase in plasma antioxidant capacity (FRAP and ORAC) were observed in overweight subjects receiving a HC meal together with MC extract (1 g). The finding supports that MC helps normalize and enhance antioxidant defense induced by a HC meal, suggesting that MC may have the potential for the prevention of chronic conditions and diseases associated with overweight and obesity.

The inhibitory effect of milk on the absorption of dietary phenolic acids and the change in human plasma antioxidant capacity through a mechanism involving both milk proteins and fats

We assessed the effects of milk proteins and fats, alone and in combination, on the absorption of phenolic acids and the change in plasma antioxidant capacity after jujube juice intake in humans. Twenty volunteers received the following four treatments each in a 4 × 4 Latin square design with a minimum 1 week interval: 200 mL of jujube juice plus 200 mL of (1) water; (2) whole milk; (3) skimmed milk; or (4) milk fat. The results showed that skimmed milk extended the time to reach maximum increase of plasma phenolic acids concentrations and plasma antioxidant capacity. However, neither the skimmed milk nor the milk fat had a significant effect on the absorption of phenolic acids. In contrast, whole milk significantly reduced the absorption of phenolic acids and the increase in plasma antioxidant capacity (p < 0.05). In vitro results suggested the formation of complexes during digestion that involved milk proteins, milk fats, and phenolic acids, which were responsible for the inhibitory effect of whole milk. Milk proteins and fats together, but not alone, are responsible for the inhibitory effect of milk on the absorption of phenolic acids and the change in plasma antioxidant capacity.

Milk protein and fat play different roles in affecting the bioavailability and the antioxidant activity of jujube juice phenolics in rats

In this study, we intend to clarify the role that milk proteins and fat may play in affecting the bioavailability and the antioxidant activity of jujube juice phenolics. Three milk preparations-skimmed milk, milk fat, and whole milk were produced to represent milk protein, milk fat, and milk protein and fat together, respectively. The bioavailability of phenolics and the rat plasma antioxidant capacity were measured for 8 h after the consumption of jujube juice with and without milk preparations. The addition of skimmed milk to jujube juice resulted in significant changes in the plasma kinetics profile of phenolics, rather than affecting the overall absorption. Milk fat did not interact with jujube juice phenolics. However, when jujube juice was ingested with whole milk, a significant reduction of the bioavailability of phenolics and the maximum increase in plasma antioxidant capacity was observed. Moreover, a consistent increase in the median diameters of the emulsions indicated the formation of complexes of proteins, fat, and phenolics during digestion. The present study suggests that when ingested with jujube juice, milk proteins and fat play different roles in affecting the bioavailability and the antioxidant activity of jujube juice phenolics.

Effect of New Zealand blueberry consumption on recovery from eccentric exercise-induced muscle damage

BackgroundExercise-induced muscle damage (EIMD) is accompanied by localized oxidative stress / inflammation which, in the short-term at least, is associated with impaired muscular performance. Dietary antioxidants have been shown to reduce excessive oxidative stress; however, their effectiveness in facilitating recovery following EIMD is not clear. Blueberries demonstrate antioxidant and anti-inflammatory properties. In this study we examine the effect of New Zealand blueberries on EIMD after strenuous eccentric exercise.MethodsIn a randomized cross-over design, 10 females consumed a blueberry smoothie or placebo of a similar antioxidant capacity 5 and 10 hours prior to and then immediately, 12 and 36 hours after EIMD induced by 300 strenuous eccentric contractions of the quadriceps. Absolute peak and average peak torque across the knee, during concentric, isometric, and eccentric actions were measured. Blood biomarkers of oxidative stress, antioxidant capacity, and inflammation were assessed at 12, 36 and 60 hours post exercise. Data were analyzed using a two-way ANOVA.ResultsA significant (p < 0.001) decrease in isometric, concentric and eccentric torque was observed 12 hours following exercise in both treatment groups. During the 60 hour recovery period, a significant (p = 0.047) interaction effect was seen for peak isometric tension suggesting a faster rate of recovery in the blueberry intervention group. A similar trend was observed for concentric and eccentric strength. An increase in oxidative stress and inflammatory biomarkers was also observed in both treatment groups following EIMD. Although a faster rate of decrease in oxidative stress was observed in the blueberry group, it was not significant (p < 0.05) until 36 hours post-exercise and interestingly coincided with a gradual increase in plasma antioxidant capacity, whereas biomarkers for inflammation were still elevated after 60 hours recovery.ConclusionsThis study demonstrates that the ingestion of a blueberry smoothie prior to and after EIMD accelerates recovery of muscle peak isometric strength. This effect, although independent of the beverage’s inherent antioxidant capacity, appears to involve an up-regulation of adaptive processes, i.e. endogenous antioxidant processes, activated by the combined actions of the eccentric exercise and blueberry consumption. These findings may benefit the sporting community who should consider dietary interventions that specifically target health and performance adaptation.

Effects of Açai (Euterpe oleracea Mart.) berry preparation on metabolic parameters in a healthy overweight population: A pilot study

BackgroundThe purpose of this study was to evaluate the effect of açai fruit pulp on risk factors for metabolic disorders in overweight subjects. The açaí palm (Euterpe oleracea Mart.), which is native to South America, produces a small, black-purple fruit which is edible. The fruit has recently become popular as a functional food due to its antioxidant potential. Although several studies have been conducted in vitro and with animals, little is known about the potential health benefits in humans aside from an increase in plasma anti-oxidant capacity. Metabolic syndrome is a condition which is defined by a cluster of risk factors for cardiovascular disease and/or type-2 diabetes. Preliminary studies indicate that a reduction in reactive oxygen species can assist in the normalization of the metabolic pathways involved in this syndrome.MethodsThis was an open label pilot study conducted with 10 overweight adults (BMI ≥ 25 kg/m2 and ≤ 30 kg/m2) who took 100 g açai pulp twice daily for 1 month. The study endpoints included levels of fasting plasma glucose, insulin, cholesterol, triglycerides, exhaled (breath) nitric oxide metabolites (eNO) and plasma levels of high sensitivity C-reactive protein (hs-CRP). The response of blood glucose, blood pressure and eNO to a standardized meal was determined at baseline and following the 30 day treatment.ResultsCompared to baseline, there were reductions in fasting glucose and insulin levels following the 30 day treatment (both p < 0.02). There was also a reduction in total cholesterol (p = 0.03), as well as borderline significant reductions in LDL-cholesterol and the ratio of total cholesterol to HDL-cholesterol (both p = 0.051). Compared to baseline, treatment with açai ameliorated the post-prandial increase in plasma glucose following the standardized meal, measured as the area under the curve (p = 0.047). There was no effect on blood pressure, hs-CRP or eNO.ConclusionIn this uncontrolled pilot study, consumption of açai fruit pulp reduced levels of selected markers of metabolic disease risk in overweight adults, indicating that further studies are warranted.

Bioavailability and antioxidant potential of rooibos flavonoids in humans following the consumption of different rooibos formulations

In a complete crossover design, a human study with twelve healthy male volunteers has been conducted using a placebo and different rooibos drinks (rooibos tea and an isolated active fraction) from unfermented rooibos (Aspalathus linearis). Blood and urine samples were collected before and up to 24h after consumption of the drinks.By HPLC–MS/MS, seven metabolites of aspalathin and nothofagin were identified in urine samples, as well as intact aspalathin and nothofagin. Moreover, sulphated, glucuronidated, methylated, both glucuronidated and methylated aspalathin, and glucuronidates of the aglycones of aspalathin and nothofagin were detected. The main metabolite excreted was methylated aspalathin. Most of the metabolites were detected after administration of both rooibos formulations. In plasma samples characteristic unchanged flavonoids derived from unfermented rooibos (e.g. aspalathin) were detected in trace quantities this is due to the changes in Table 5 after ingestion of both rooibos formulations. On average a total of 0.76nmol of flavonoids were detected during their peak concentration after intake of the rooibos tea, accounting for 0.26% compared to the total amount of flavonoids ingested. Despite the comparable intake of total flavonoids, only an overall 0.41nmol of flavonoids could be detected after ingestion of the isolated active fraction. No significant increase in plasma antioxidant capacity was observed using the ORAC assay giving rise to the assumption that the effects of rooibos flavonoids have to be detected using other endpoints.

Effects of Controlled-Release Alpha Lipoic Acid in Lean, Nondiabetic Patients with Polycystic Ovary Syndrome

The purpose of this study was to determine whether a preparation of controlled-release alpha lipoic acid (CRLA) influences features of the polycystic ovary syndrome (PCOS). We administered CRLA 600 mg twice daily for 16 weeks to six lean, nondiabetic patients with PCOS. Insulin sensitivity was measured by the euglycemic, hyperinsulinemic clamp. Plasma lipids were measured by vertical ultracentrifugation. Oxidative stress markers were measured in serum. At the end of 16 weeks of CRLA treatment, there was a 13.5% improvement in insulin sensitivity as determined by the euglycemic, hyperinsulinemic clamp (p < .03). There was also a lowering of triglyceride levels (p < .04) and a shift in the distribution of low-density lipoprotein (LDL) particles toward the larger, more buoyant LDL subclass fraction. Two of the subjects who were not on oral contraception had an increased number of menstrual cycles. Controlled-release alpha lipoic acid treatment, however, was neither associated with an increase in plasma antioxidant capacity nor with a reduction in plasma lipid oxidation products. These data suggest that the CRLA has positive effects on the PCOS phenotype. The effects of CRLA, however, may have been exerted through a mechanism not involving changes in oxidative stress.

Uric Acid and Antioxidant Effects of Wine

The aim of this article is to review the role of uric acid in the context of antioxidant effects of wine and its potential implication to human health. We described and discussed the mechanisms of increase in plasma antioxidant capacity after consumption of moderate amounts of wine. Because this effect is largely contributed by acute elevation in plasma uric acid, we paid special attention to wine constituents and metabolic processes that are likely to be involved in uric acid elevation.