Oxidative Stress In Healthy Men Research Articles

Effect of Repeated Bolus and Continuous Glucose Infusion on DNA Damage and Oxidative Stress Biomarkers in Healthy Male Volunteers.

Glucose variability (GV), which describes fluctuations in blood glucose levels within the day, is a phenomenon that is increasingly becoming the target of scientific attention when it comes to increased risk of coronary heart disease. Effects of GV may contribute to the development of metabolic syndrome and type 2 diabetes. Hyperglycemia can lead to oxidative stress resulting in molecular damage due to accumulation of reactive oxygen species (ROS). To discover more about the immediate effects of GV, continuous vs. bolus intravenous glucose administration was applied to 10 healthy men aged 21-30 years over a time frame of 48 h. Whole blood and plasma were analyzed for DNA damage using a comet assay with 3 different treatments (lysis buffer, H2O2, and the lesion-specific enzyme formamidopyrimidine DNA glycosylase (FPG)) as well as for the oxidative stress markers protein carbonyls (PC), unconjugated bilirubin (UCB), and ferric reducing antioxidant power (FRAP). A significant time effect was found in the three DNA damage treatments as well as in PC and UCB possibly due to circadian changes on oxidative stress, but no intervention group effect was observed for any of the markers. In conclusion, bolus vs. continuous glucose administration had no significant acute effect on DNA damage and markers of oxidative stress in healthy men.

Relationship Between Composition of Fatty Acid in Platelet Phospholipid Membrane and Markers of Oxidative Stress in Healthy Men and Men After a Myocardial Infarction.

BackgroundOxidative stress (OS) is known to be extremely damaging for phospholipids in cell membranes, especially their polyunsaturated fatty acids (PUFAs). OS is known to be associated with increased platelet activation and thrombosis, which lead to cardiovascular lesions. The aim of this study was to investigate how changes in the composition of fatty acids (FAs) in the platelet phospholipid membrane correlate with OS in healthy men and in men who have experienced a myocardial infarction (post-MI men).Material/MethodsFA methyl esters from the platelet phospholipid membrane of 79 apparently healthy and 20 post-MI men were identified using gas chromatography/mass spectrometry. Malondialdehyde (MDA) was measured in the blood serum using high-performance liquid chromatography, and platelet-white blood cell aggregates (PWAs) were analysed based on whole-blood flow cytometry. The composition of platelet membrane FAs was compared to MDA concentration (μg/l) and the percentage of PWA formation between healthy men and individuals who had suffered a myocardial infarction (MI).ResultsStatistically, post-MI patients had a significantly higher concentration of blood serum MDA than those in the control group (p=0.000). The level of PUFAs was also higher in the platelet phospholipid membrane of post-MI patients than in healthy individuals (p=0.016). However, the percentage of PWA formation was lower in patients compared with the control group (p<0.05).ConclusionsA higher level of blood serum MDA concentration due to OS stimulates platelets to incorporate more PUFAs into the phospholipid membrane, thereby affecting platelet activation. This may lead the individual to develop cardiovascular diseases in the future.

Association of Platelet Membrane Fatty Acid Composition with Markers of Oxidative Stress in Healthy Men

BackgroundPlatelet membranes are extremely susceptible to peroxidation, forming a variety of lipid peroxides, including malondialdehyde (MDA), which has been implicated in the etiology of cardiovascular diseases. Moreover, platelet-leukocyte aggregates (PLAs) are known to contribute to advanced endothelial injury and atherogenesis.Material/MethodsFatty acid (FA) methyl esters of the platelet membranes of 79 apparently healthy men without any acute clinical condition at the time of the study were identified by GC/MS. MDA was measured by HPLC in blood serum, and PLAs were analyzed by whole-blood flow cytometry. Individuals were divided into quartiles according to MDA concentration and percentage of PLAs formation. The composition of platelet membrane FAs was compared to MDA concentration and the percentage of PLAs formation in apparently healthy individuals.ResultsIn quartiles (Q) with higher MDA concentration, percentage of C 16: 1ω7 (Q1 vs. Q3, p=0.021), C 20: 1ω9 (Q2 vs. Q4, p=0.028) and C 20: 5ω3 (Q2 vs. Q4, p=0.046) was lower. However, C 22: 5ω3 (Q1 vs. Q4, p=0.038) and total ω3 (Q1 vs. Q2, p=0.024) were higher.ConclusionsMDA and the formation of platelet-monocyte aggregates stimulate the incorporation of monounsaturated fatty acids and polyunsaturated fatty acids in platelet phospholipid membranes, which may be a hallmark for a changed level of biologically active compounds required for the activation of future platelets.

Taurine and magnesium supplementation enhances the function of endothelial progenitor cells through antioxidation in healthy men and spontaneously hypertensive rats.

Endothelial damage is repaired by endothelial progenitor cells (EPCs), which are pivotal in preventing cardiovascular diseases and prolonging lifespan. The WHO Cardiovascular Diseases and Alimentary Comparison Study demonstrated that dietary taurine and magnesium (Mg) intake suppresses cardiovascular diseases. We herein evaluate the effects of taurine and Mg supplementation on EPC function and oxidative stress in healthy men and spontaneously hypertensive rats (SHRs). Healthy men received taurine (3 g per day) or Mg (340 mg per day) for 2 weeks. SHRs and Wistar-Kyoto (WKY) rats were housed with high-salt drinking water (1% NaCl). The SHRs received 3% taurine solution and/or a high-Mg (600 mg per 100 g) diet for 4 weeks. Their peripheral blood mononuclear cells were separated to quantify EPC colony formation. Oxidative stress markers in their peripheral blood were evaluated using a free radical analytical system and a thiobarbituric acid reactive substance (TBARS) assay. Taurine and Mg supplementation significantly increased EPC colony numbers and significantly decreased free radical levels and TBARS scores in healthy men. Taurine and Mg supplementation significantly increased EPC colony numbers and significantly decreased TBARS scores and free radical levels in SHRs. Nicotinamide adenine dinucleotide phosphate oxidase component mRNA expression was significantly higher in the renal cortex of salt-loaded SHRs than in WKY rats, in which it was suppressed by taurine and Mg supplementation. Taurine and Mg supplementation increased EPC colony formation in healthy men and improved impaired EPC function in SHRs through antioxidation, indicating that the dietary intake of taurine and Mg may prolong lifespan by preventing the progression of cardiovascular diseases.

Abstract 3244: Supplementation with selenium-enriched yeast but not selenomethionine reduces oxidative stress in healthy men in a randomized clinical trial

Abstract Epidemiological and laboratory studies indicate that dietary selenium is protective against prostate cancer. Results from clinical trials suggest that selenium-enriched yeast (SY) but not selenomethionine (SeMet) may be effective at reducing prostate cancer risk. Our objectives were to directly compare for the first time the effects of SeMet and SY on prostate cancer relevant biomarkers in men. We performed a randomized double blind, placebo-controlled trial of SY (200 or 285 μg/day) and SeMet (200 μg/day) administered for 9 months in 69 healthy adult males. Biomarkers including blood selenium, glucose, PSA and glutathione (GSH) and urine 8-hydroxy-2’-deoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F2α (8-iso-PGF2α) were measured at baseline and various times thereafter. Compliance was high in all groups (&amp;gt;95%). Plasma selenium levels were increased 93%, 54%, and 86% after 9 months in the SeMet and low and high dose SY groups, respectively, and returned to baseline levels after a 3 month washout (P&amp;lt;0.05). Urinary biomarkers of oxidative stress, 8-OHdG and 8-iso-PGF2α, were decreased 34% and 28%, respectively, after 9 months in the high dose SY group (P&amp;lt;0.05). Decreases in oxidative stress biomarkers were greatest in individuals with low baseline plasma levels of selenium (&amp;lt;127 ng/ml). No changes in serum PSA or blood glucose and GSH were observed. We showed for the first time reductions in biomarkers of oxidative stress following supplementation with SY but not SeMet in healthy men. These findings suggest that selenium-containing compounds other than SeMet may be responsible for the decrease in oxidative stress and possibly cancer risk. This work was supported a National Cancer Institute grant (R01CA127729). Citation Format: Matt G. Kaag, John P. Richie, Arun Das, Ana Calcagnotto, Raghu Sinha, Wanda Neidig, Jiangang Liao, Eugene J. Lengreich, Arthur Berg, Terryl J. Hartman, Amy Ciccarella, Aaron Baker, Telih Boyiri, Susan Goodin, Robert S. DiPaola, Karam El-Bayoumy. Supplementation with selenium-enriched yeast but not selenomethionine reduces oxidative stress in healthy men in a randomized clinical trial. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3244. doi:10.1158/1538-7445.AM2014-3244

A 21 Day Daniel Fast Favorably Impacts Biomarkers of Oxidative Stress in Healthy Men and Women

Background: The Daniel Fast is based on the Biblical book of Daniel and involves a 21 day ad libitum food intake period, devoid of animal products, additives, preservatives, caffeine and alcohol, and inclusive of fruits, vegetables, whole grains, legumes, nuts, seeds, and oil. We have recently reported this plan to be associated with improvements in several markers of cardiovascular health when adhered to by healthy men and women. PURPOSE: To determine the impact of the Daniel Fast on biomarkers of oxidative stress and antioxidant capacity. METHODS: 43 subjects (13 men; 30 women; 35±1 yrs; range: 20-62 yrs) completed a 21 day period of modified food intake in accordance with guidelines provided by investigators. All subjects purchased and prepared their own food. Following initial screening, subjects were given one week to prepare for the fast, after which time they reported to the lab for their pre-fast assessment (day 1). After the 21 day fast, subjects reported to the lab for their post-fast assessment (day 22). For both visits, subjects reported to the lab in a 12 hr fasted state, performing no strenuous physical activity during the preceding 48 hrs, and blood was collected for determination of malondialdehyde (MDA), hydrogen peroxide (H2O2), nitrate/nitrite (NOx), and Trolox Equivalent Antioxidant Capacity (TEAC). RESULTS: From pre- to post-fast, a significant decrease was noted in MDA (0.66±0.0.03 vs. 0.56±0.02 μmol·L-1; p=0.007), while H2O2 followed a trend for decrease (4.42±0.32 vs. 3.78±0.21 μmol·L-1; p=0.095). Both NOx (18.79±1.92 vs. 26.97±2.40 μmol·L-1; p=0.009) and TEAC (0.47±0.01 vs. 0.51±0.01 mmol·L-1; 0.039) increased significantly from pre to post fast. CONCLUSION: A 21 day Daniel Fast favorably impacts blood markers of oxidative stress and antioxidant capacity in a sample of healthy men and women. Larger scale randomized studies inclusive of a longer time period of dietary modification are needed to extend these findings.

Positive correlation between plasma nitrite and performance during high-intensive exercise but not oxidative stress in healthy men

Several studies suggest that exercise is associated with elevated oxidative stress which diminishes NO bioavailability. The aim of the present study was to investigate a potential link between NO synthesis and bioavailability and oxidative stress in the circulation of subjects performing high-intensive endurance exercise. Twenty-two male healthy subjects cycled at 80% of their maximal workload. Cubital venous blood was taken before, during and after exercise, and heparinized plasma was generated. Plasma concentrations of nitrite and nitrate were quantified by GC–MS and of the oxidative stress biomarker 15( S)-8 -iso-PGF 2α by GC–MS/MS. pH and pCO 2 fell and HbO 2 increased upon exercise. The duration of the 80% phase (d80) was 740 ± 210 s. Subjects cycled at 89.2 ± 3.3% of their peak oxygen uptake. Plasma concentration of nitrite ( P < 0.01) and 15( S)-8 -iso-PGF 2α ( P < 0.05) decreased significantly during exercise. At the end of exercise, plasma nitrite concentration correlated positively with d80 and performed work (w80) (each P < 0.05). Changes in nitrate concentration also correlated positively with d80 ( P < 0.05) and w80/kg ( P < 0.01). These findings provide evidence of a favorable effect of nitrite on high-intensive endurance exercise. The lack of association between 15( S)-8 -iso-PGF 2α and NO bioavailability (nitrite concentration) and NO biosynthesis (nitrate concentration) suggest that oxidative stress, notably lipid peroxidation, is not linked to the l-arginine/NO pathway in healthy male subjects being on endurance exercise.

Effect of 4 days of intermittent hypoxia on oxidative stress in healthy men

Periodic occlusion of the upper airway in patients with obstructive sleep apnea (OSA) leads to intermittent hypoxia (IH). IH is characterized by repeated episodes of hypoxia/reoxygenation, which is known to increase the production of reactive oxygen species (ROS). Causal relationships between OSA, IH and oxidative stress have not been established because of confounding effects of medical co‐morbidities and obesity which are frequently associated with OSA. The aim of this study was to determine if IH changes oxidative stress in healthy volunteers. Nine men (29.3 ± 1.7 years; BMI, 25.0 ± 0.4 kg.m−2; mean±SD) were studied. Following baseline measurements breathing room air (day zero (D0)), all subjects were exposed to 4 days (D1 to D4) of IH while awake (2 min at PetO2 = 45 Torr and 2 min at PetO2 = 88 Torr) 6 hours.d−1. Lipid peroxidation (malondialdehides, MDA), DNA oxidation (8‐Hydroxy‐2′‐deoxyguanosine, 8‐OHdG) and oxidation protein products (AOPP) were assessed in plasma. MDA increased significantly between baseline (D0) and D1 (+39%: 3.48 ± 1.17 vs 4.85 ± 0.90 μmol.l−1) and then tended to return to baseline levels. 8‐OHdG increased significantly between D0 and D1 (+51%: 53.84 ± 54.63 vs 83.30 ± 45.49 μmol.l−1) and remained elevated until D4 (+67%: 53.84 ± 54.63 vs 89.71 ± 36.06 μmol.l−1). These findings demonstrate that IH increases oxidative stress and suggest that IH may contribute to ROS overproduction in OSA.Supported by the Alberta Heritage Foundation for Medical Research and the Heart &amp; Stroke Foundation of Canada.

Effect of hyperbaric oxygen and vitamin C and E supplementation on biomarkers of oxidative stress in healthy men

The objectives of the present study were to evaluate the effect of normobaric and hyperbaric O2 (HBO) on plasma antioxidants and biomarkers of oxidative stress in plasma and urine and to investigate the effect of a 4-week vitamin C plus E supplementation on HBO-induced oxidative stress. Nineteen healthy men were exposed to HBO (100 % O2; 240 kPa) before and after 4 weeks' supplementation with 500 mg vitamin C plus 165 mg alpha-tocopherol equivalents. Exposure to 21 % O2 at 100 kPa served as intra-individual controls (control). Samples for the analysis of plasma antioxidants and oxidative stress biomarkers were collected before and immediately after each treatment. The present results showed that when compared with 'control', a single exposure to HBO resulted in a decrease of plasma vitamin C (P = 0.027) and an increase of lipid peroxides (P = 0.0008) and urinary 8-oxo-deoxyguanosine (8-oxodG) excretion (P = 0.006). Oxidative stress was not prevented by a 4-week supplementation with vitamins C and E. HBO-induced changes in plasma parameters correlated with basal antioxidant levels. The increase of urinary 8-oxodG after HBO plus supplementation correlated negatively with vitamin E intake (P = 0.023). We concluded that in healthy men HBO caused oxidative stress, which could not be prevented by dietary vitamin C plus E supplementation. The present data support the idea that HBO is a suitable model for oxidative stress in healthy volunteers.