Erythrocyte Glutathione Peroxidase Research Articles

Selenium levels and glutathione peroxidase activity in patients with ataxia-telangiectasia: association with oxidative stress and lipid status biomarkers

IntroductionAtaxia-Telangiectasia (A-T) is a multi-system disorder that may be associated with endocrine changes, oxidative stress in addition to inflammation. Studies suggest that selenium is a trace element related to protection against damage caused by oxidative stress.ObjectiveTo describe the plasma levels of selenium and erythrocyte glutathione peroxidase activity in A-T patients and to relate them to oxidative stress and lipid status biomarkers.MethodsThis is a cross-sectional and controlled study evaluating 22 A-T patients (age median, 12.2 years old) matched by gender and age with 18 healthy controls. We evaluated: nutritional status, food intake, plasma selenium levels, erythrocyte glutathione peroxidase activity, lipid status, inflammation and oxidative stress biomarkers.ResultsAdequate levels of selenium were observed in 24/36 (66.7%) in this evaluated population. There was no statistically significant difference between the groups in selenium levels [47.6 μg/L (43.2–57.0) vs 54.6 (45.2–62.6) μg/dL, p = 0.242]. Nine of A-T patients (41%) had selenium levels below the reference value. The A-T group presented higher levels of LDL-c, non-HDL-c, oxidized LDL, Apo B, Apo-B/Apo-A-I1, LDL-c/HDL-c ratio, malondialdehyde [3.8 µg/L vs 2.8 µg/L, p = 0.029] and lower Apo-A-I1/HDL-c and glutathione peroxidase activity [7300 U/L vs 8686 U/L, p = 0.005]. Selenium levels were influenced, in both groups, independently, by the concentrations of oxidized LDL, malonaldehyde and non-HDL-c. The oxidized LDL (AUC = 0.849) and ALT (AUC = 0.854) were the variables that showed the greatest discriminatory power between groups.ConclusionIn conclusion, we observed the presence of selenium below the reference value in nearly 40% and low GPx activity in A-T patients. There was a significant, inverse and independent association between selenium concentrations and oxidative stress biomarkers. Those data reinforce the importance of assessing the nutritional status of selenium in those patients.

The relationship of folate deficiency, hyperhomocysteinemia and glutathione metabolism in hypertensive patients

Hypertension (HTN) is often accompanied by folic acid (FA) deficiency and hyperhomocysteinemia (HHcy). Reduced glutathione (GSH) and dependent enzymes determine the state of cellular antioxidant and redox systems in cardiovascular pathology. The aim of our work is to assess the relationship between the status of FA and the presence of HHcy with enzymes of glutathione metabolism and the redox state of erythrocyte glutathione in HTN. Design and methods. In blood plasma samples from 43 HTN patients admitted to the clinic of Pavlov University, the concentration of FA and total homocysteine (oHcy) was determined. We also evaluated the level of GSH, the activity of glutathione peroxidase and glutathione reductase (GR) in erythrocytes. Results. In the whole group, GR activity positively correlated with the concentration of FA (R = 0,415; p = 0,001). A significant decrease in GR activity (U/g Hb) was found in the subgroup with the low level of FA [0,8 (0,5–1,1)] compared with the subgroup without a FA deficiency [1,2 (0,9–2,0)]. The GSH level (μM/g Hb) was also lower (p < 0,018) in the subgroup with FA deficiency [1,3 (0,9–2,1)] compared with the subgroup with normal FA levels [1,8 (1,5–4,6)]. A significant decrease in the level of GSH and GR activity in the subgroup with HHcy was found compared with the corresponding parameters in the subgroup without HHcy. However, even in the absence of HHcy patients with FA deficiency demonstrated a significant decrease in GR activity compared to patients without FA deficiency. In this case, GR positively correlated with FA (R = 0,564; p = 0,03). Conclusions. The deficiency of FA can increase the deficiency of GR activity, regardless of the level of oHcy. The indicator of GR activity in erythrocytes can be considered as a possible marker of functional deficiency of FA in the absence of HHcy.

Oxidative Stress Risk Is Increased with a Sedentary Lifestyle during Aging in Mexican Women.

Oxidative stress (OS) increases during the human aging process, and the sedentary lifestyle could be a prooxidant factor. In this study, we determine the effect of sedentary lifestyle on OS during the aging process in Mexican women. A longitudinal study of two-year follow-up was carried out with 177 community-dwelling women (40-69 y) from Mexico City. We measured as OS markers plasma malondialdehyde, erythrocyte glutathione peroxidase (GPx) and superoxide dismutase (SOD), total plasma antioxidant status, uric acid level, antioxidant gap, and SOD/GPx ratio. To define OS using all the markers, we defined cut-off values of each parameter based on the 90th percentile of young healthy subjects and, we calculated a stress score (SS) ranging from 0 to 7, which represented the intensity of the marker modifications. All the women answered a structured questionnaire about prooxidant factors, including physical activity specially the type of activity, frequency, and duration, and they answered Spanish versions of self-assessment tests for establishing dysthymia and insomnia as potential confounders. Principal component and Poisson regression analysis were used as statistical tools, being two-year OS the primary outcome. The OS was considerate as SS ≥ 4 and sedentary lifestyle as <30 min/day of physical activity, beside several prooxidant factors and age that were covariables. SS is higher in sedentary lifestyle women after the two-year follow-up; although, the difference was statistically significant only in older women. Four principal components were associated with the OS, and 7 out of 8 prooxidant factors were important for the analysis, which were included in the Poisson model. The predictive factors for OS were the sedentary lifestyle (adjusted PR = 2.37, CI95%: 1.30–4.30, p < 0.01), and age, in which the risk increases 1.06 (CI95%:1.02–2.11, p < 0.01) by each year of age. Our findings suggest that a sedentary lifestyle increases the OS during the aging in Mexican women.

Association between Vitamin D Supplements, Oxidative Stress Biomarkers, and Hyperbaric Therapy in Patients with Sudden Sensorineural Hearing Loss.

The effect of vitamin D supplementation to patients with sudden sensorineural hearing loss (SSNHL), treated with hyperbaric oxygen (HBO) therapy, on the markers of the oxidant-antioxidant equilibrium was investigated. Patients were divided into two groups: those who did and did not receive vitamin D (cholecalciferol at 4000 IU/24 h). Concentrations of the following compounds, thiobarbituric acid reactive substances (TBARS), malondialdehyde (MDA), conjugated dienes (CD) in plasma and erythrocytes and activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in erythrocytes, were determined. Haemoglobin (HGB) and haematocrit (HCT) were measured. Blood for analyses was collected from the basilic vein at three time points: before the first HBO procedure, up to 5 min after the first procedure, and after 14 procedures. No statistically significant differences in parameters tested were found between patients who did and did not receive vitamin D. In patients without supplementation, an increase of 53.2% (P ≤ 0.05) in erythrocyte TBARS was observed after the first HBO treatment. In patients receiving vitamin D, a reduction of 27.6% (P ≤ 0.05) was observed in erythrocyte MDA after 14 HBO treatments vs. that after the first treatment. In both groups, a decrease of 33.3% in plasma CD was observed after 14 treatments vs. that after the first treatment (P ≤ 0.05 and P ≤ 0.01, respectively). No statistically significant changes were observed in the erythrocyte SOD, GPx, and CAT activities and in HCT. A reduction of HGB concentration of 10.9% (P ≤ 0.05) was demonstrated in nonsupplemented patients after 14 treatments compared with baseline. The results confirm that the effect of HBO therapy on oxidative stress markers is inconclusive and complex. Repeated HBO procedures can induce adaptive changes which protect against disruption of the oxidant-antioxidant equilibrium. It is possible that vitamin D supplementation inhibits the process of lipid peroxidation in erythrocytes.

Parameters of Oxidative Stress, Vitamin D, Osteopontin, and Melatonin in Patients with Lip, Oral Cavity, and Pharyngeal Cancer.

Lip, oral cavity, and pharyngeal cancers (LOCP) constitute a group of rare neoplasms with unfavorable prognosis. So far, not much is known about the role of vitamin D and oxidative stress in the pathogenesis of LOCP in the European population. The aim of the study was to determine the concentrations of vitamin D, osteopontin, melatonin, and malondialdehyde (MDA) as markers of oxidative stress and/or inflammation, as well as the activities of antioxidant enzymes in the course of LOCP. The vitamin D, melatonin, and osteopontin concentrations in blood serum, the MDA levels in erythrocytes and blood plasma, and the activities of superoxide dismutase (SOD-1), catalase (CAT), and glutathione peroxidase (GPx) in erythrocytes were measured in blood samples taken from 25 LOCP patients of middle age (YCG), 20 LOCP elderly patients (OCG), and 25 healthy middle-aged volunteers. In both cancer groups, decreases in vitamin D and CAT, as well as increases in osteopontin and blood plasma MDA, were observed. An increase in GPx activity in YCG and a decrease in melatonin level in OCG were found. The results indicate the vitamin D deficiency and disturbed oxidant-antioxidant homeostasis in LOCP patients. Osteopontin seems to be associated with LOCP carcinogenesis and requires further research.

Evaluations of Antioxidant Enzyme Activities, Total Sialic Acid and Trace Element Levels in Coronary Artery Bypass Grafting Patients.

IntroductionIn this study, patients before and after cardiac surgery with cardiopulmonary bypass (CPB) and control subjects were evaluated for erythrocyte glutathione peroxidase, catalase and superoxide dismutase enzyme activities, in addition to glutathione, malondialdehyde, serum total sialic acid, lipid-bound sialic acid, total antioxidant status, trace elements and mineral levels. The correlation of these variables with coronary artery disease (CAD) was also assessed.MethodsA total of 30 CAD patients and 30 control subjects were included in the study. CAD patients were divided into three groups: before surgery (BS), first day after surgery (1st day AS) and seventh day after surgery (7th day AS).ResultsMalondialdehyde (MDA) and total sialic acid (TSA) levels were significantly higher in CAD (BS) than in the control group (P<0.05, P<0.05). In addition, GSH and TAS levels were significantly lower in the 1st day AS group than in the control group (P<0.001, P<0.01). Moreover, Co, Cu, Mg, Se, V and Zn levels were significantly lower in CAD (BS) group than in the control group (P<0.01, P<0.01, P<0.01, P<0.01, P<0.05, P<0.001).ConclusionsIt was concluded that the levels of LDL-C, total cholesterol, triglycerides and CRP significantly associated with parameters, as well as Cu, Ca and SOD activity, should be measured together to monitor CAD. It is also considered that measuring TSA and MDA might be an appropriate choice for biomarkers of CAD.

Estimation of serum superoxide dismutase and glutathione peroxidase levels in tobacco chewers and smokers: A comparative study

Introduction: Habitual tobacco use is known to cause various health hazards by initiating oxidative stress through the release of free radicals. The free radicals induce cellular damage that is reflected through alterations in antioxidant enzymes levels like superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) within circulating erythrocytes. Therefore, it is important to estimate the erythrocytic SOD and GPx levels to assess tobacco induced oxidative stress. Aim: The aim of the present study is to assess the effect of tobacco chewing and smoking on serum antioxidant enzymes superoxide dismutase and glutathione peroxidase levels. Materials and Methods: The present study comprised of 4 study groups including healthy control (n=25), tobacco smokers (n=25), tobacco chewers (n=25) and combination habit group (n=25). The case subjects were further sub-divided depending upon the frequency of habits i.e. > 10 times/day and 10 years and Result: Mean erythrocytic SOD levels were significantly decreased in cases compared to control group whereas mean erythrocytic GPx level was significantly increased in cases compared to controls. When SOD and GPx were compared for the frequency and duration of habits, GPx levels were significantly increased among smokers who smoked Conclusions: The present study confirmed the relationship between antioxidative enzymes activity, oxidative stress and tobacco. Frequency and duration of tobacco consumption were shown to alter antioxidant enzymes levels. Therefore, estimation of these enzyme levels will help in early intervention of tobacco habit by patient education and motivation and can minimize the risk of tobacco induced lesions. Keywords: Tobacco, Erythrocytic superoxide dismutase (SOD), Glutathione peroxidase (GPx), Oxidative stress.

Biological Effects of Scattered Versus Scanned Proton Beams on Normal Tissues in Total Body Irradiated Mice: Survival, Genotoxicity, Oxidative Stress and Inflammation.

Side effects of proton therapy are poorly studied. Moreover, the differences in the method of dose delivery on normal tissues are not taken into account when proton beams are scanned instead of being scattered. We proposed here to study the effects of both modalities of proton beam delivery on blood; skin; lung and heart in a murine model. In that purpose; C57BL/6 mice were total body irradiated by 190.6 MeV proton beams either by Double Scattering (DS) or by Pencil Beam Scanning (PBS) in the plateau phase before the Bragg Peak. Mouse survival was evaluated. Blood and organs were removed three months after irradiation. Biomarkers of genotoxicity; oxidative stress and inflammation were measured. Proton irradiation was shown to increase lymphocyte micronucleus frequency; lung superoxide dismutase activity; erythrocyte and skin glutathione peroxidase activity; erythrocyte catalase activity; lung; heart and skin oxidized glutathione level; erythrocyte and lung lipid peroxidation and erythrocyte protein carbonylation even 3 months post-irradiation. When comparing both methods of proton beam delivery; mouse survival was not different. However, PBS significantly increased lymphocyte micronucleus frequency; erythrocyte glutathione peroxidase activity and heart oxidized glutathione level compared to DS. These results point out the necessity to take into account the way of delivering dose in PT as it could influence late side effects.

Anti-Acute Monocytic Leukemia Activities of Selenium Nanoparticles Embedded in Nanotube Consisted of Triple-Helix β-D-Glucan

Acute monocytic leukemia (AML-M5) is a subtype of acute myeloid leukemia (AML) which has the characteristics of high degree of malignancy, prone to extramedullary infiltration, poor efficacy of conventional chemotherapy, easy recurrence, etc. Besides, chemotherapy has large side effects and high cost. Therefore, it is urgent to find natural, non-toxic and cheap drugs for the treatment of AML-M5. Polysaccharide is a class of natural macromolecular substances with biological activities such as immune regulation, anti-tumor, anti-oxidation, anti-virus, and hypoglycemic activity. Selenium is a component of human erythrocyte glutathione peroxidase, it participates in the metabolism of peroxide and iodine in the body, regulates the level of iodine and free radicals in the organism, and can enhance the body's ability to prevent and resist diseases. LNT-Se has the activity of SeNPs and the physiological function of polysaccharide.Due to the self-assembly behavior of rigid triple helix β-glucan (LNT) extracted from Lentinus edodes in aqueous solution, Selenium nanoparticles (SeNPs) could be encapsulated in the cavities of hollow nanotubes consisted of LNT to form stable complexes (LNT-Se) with high dispersity and biocompatibility. It could significantly improve the safety, biocompatibility and anti-tumor activity of SeNPs, and had powerful applications in the field of nanomaterials. In this study, we found that LNT-Se could inhibit the proliferation of AML-M5 cell lines such as THP-1, Molm-13, MV-4-11 and greatly promote the apoptosis of AML-M5 cell lines and M5 patient cells, and obviously block cells in the G2/M phase. It had little toxicity to normal cell lines, hematopoietic stem cells (HSC) and healthy human peripheral blood mononuclear cells (PBMC). Besides, we used a novel optofluidics chips wth diffused total internal reflection (TIR) method to capture single Molm-13 GFP + cell, and at the same time detected the signal intensity changes of GFP at different drug concentrations. At the single-cell level, We also observed the swelling, lysis and fluorescence intensity of the cells after treatment. Therefore, it's a promising drug for the treatment of AML-M5. These findings indicate that LNT-Se inhibit theproliferation of leukemia cell and it can be a natural inducer for therapy of AML. Disclosures No relevant conflicts of interest to declare.

Biomarkers of inflammation and oxidative stress in smokers and severe chronic obstructive pulmonary disease patients

Identification of biomarkers for the novel therapeutics targets of Chronic obstructive pulmonary disease (COPD) is an important area of current research. In this study, the level of inflammatory cytokines was investigated and correlated these levels with erythrocytic antioxidant activities in COPD patients with smokers and without smokers and parameters of severity.Plasma levels of Interleukin (IL)-6, IL-8 and IL-10 concentrations were assayed by means of Enzyme-linked Immunosorbent Assay (ELISA) and erythrocytic glutathione-s-transferase (GST) and glutathione peroxidase (GPx) activities were estimated by spectrophotometric method.Both IL-6 and IL-8 plasma levels showed a statistically significantly higher in COPD patients as compared to healthy controls (p&amp;#60;0.001; p&amp;#60;0.05). In contrast, the IL-10 was lower in COPD patients as compared to control group (p&amp;#60;0.05). FEV1 was significantly negatively correlated with plasma IL-6 (r= - 0.565, p&amp;#60; 0.001) and IL-8 (r= -0.453, p &amp;#60;0.05). Plasma IL-6 was found negative association with erythrocytic GST (r= - 0.018, p&amp;#62;0.05) and GPx activities (r= - 0.080, p&amp;#62;0.05). Similarly IL-8 was also found negative association with GST (r= - 0.260, p&amp;#62;0.05) and GPx activities (r= - 0.268, p&amp;#62;0.05). Whereas, a significant positive association was observed between IL-10 and erythrocytic GST (r= 0.494, p &amp;#60;0.05) and GPx activities (r= 0.546, p &amp;#60; 0.001).In conclusion, Plasma levels of inflammatory cytokines IL-6 and IL-8 are related with severity of COPD and IL-10 and oxidative stress markers GST and GPx are co-dependent and strongly interrelated processes and may be used as a potential marker for the evaluation of COPD.

Serum concentration of thyroxine and triiodothyronine in newborn calves from cows supplemented with barium selenate

Background: Barium selenate is an inorganic source of selenium (Se) used in prolonged-release preparations to treat selenium deficiency in bovines. Objective: To evaluate serum concentrations of triiodothyronine (T3) and thyroxine (T4) hormones in newborn calves from mothers supplemented with barium selenate during prepartum. Methods: Six black Frisian pregnant cows were supplemented with barium selenate subcutaneously during the last two months of gestation, until calving. Six cows were used as controls. All cows were subjected to a low Se diet, consisting of hay from natural pasture and commercial concentrate lacking Se. The Se balance was measured through the activity of erythrocyte glutathione peroxidase (GPx). Serum concentration of T3 and T4 in calves was determined by electrochemiluminescence. Results: Se supplementation during prepartum increased GPx activity in cows from day 45 post-supplementation (p&lt;0.05). Calves from supplemented mothers showed higher average serum Se concentration than calves from non-supplemented mothers. The average concentration of T3 in the calves from supplemented mothers was lower in the first hour of life (p&lt;0.05) compared with calves from mothers of the non-supplemented group. A decrease (p&lt;0.05) in T4 serum concentrations was observed in both groups at seven days of age. Conclusions: Administration of barium selenate to cows during prepartum generates a reduction in serum concentration of T3 in the first hour of life of calves.

Evaluation of Oxidative Stress in Patients with Difficult-to-Heal Skin Wounds Treated with Hyperbaric Oxygen.

Objective To determine the concentration of thiobarbituric acid reactive substances (TBARS) in erythrocytes and blood plasma, and the activities of selected antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in erythrocytes in patients receiving hyperbaric oxygen (HBO) treatment due to difficult-to-heal “skin wounds”. Material and Methods. Indices of oxidative stress were assessed in venous blood taken from 23 patients three times: immediately before HBO procedure, approx. 5 minutes after leaving the hyperbaric chamber, and after 25 HBO procedures. Moreover, selected blood counts were measured in the collected material two times: prior to treatment and after 25 HBO procedures. Results A statistically significant positive correlation between the CAT activity and the TBARS concentration in the erythrocytes of patients was found before treatment in the hyperbaric chamber (r = 0.394; P ≤ 0.05). No statistically significant changes in the TBARS concentration in erythrocytes and blood plasma were observed both after the first HBO procedure and after 25 procedures. No statistically significant changes in the activities of CAT, SOD, and GPx were noted. Platelet count decreased by 18.7% (P ≤ 0.05) after 25 HBO procedures. Granulocyte count decreased by approx. 21% (P ≤ 0.05), and granulocyte percentage by 11.8% (P ≤ 0.01). In turn, the percentage of lymphocytes and monocytes increased after the treatment by 16.6% (P < 0.05) and 16.4% (P < 0.05), respectively. Conclusions Exposure to HBO due to difficult-to-heal skin wounds does not significantly affect the levels of oxidative stress in the peripheral blood of patients and, from the point of view of oxidation–reduction processes, appears to be a safe therapeutic method for the treatment of chronic wounds.

Effect of dietary sorbitol supplementation on performance of crossbred dairy cattle during winter season in Jammu

The effect of sorbitol supplementation on physiological, hemato-biochemical and milk production parameters was studied for a period of 12 weeks during winter on 12 crossbred dairy cattle, aged 4–5 years, average body weight 420–500 Kg and producing 10–15 kg of milk/day. The animals were randomly divided into two groups (T1 and T2) of six each. The T1 group served as control and T2 group was supplemented with sorbitol @100gm/animal/day. During the experiment, the minimum temperature, maximum temperature, wind velocity, Wind Chill Temperature (WCT) and Relative Humidity (RH) ranged from 8.00±0.44 to 15.29±0.42°C; 20.43±0.87 to 25.00±0.49°C, 2.42±0.37 to 4.48±0.77 km/hr, 5.67±0.51 to 13.68±0.62°C and 79.14±2.40 to 88.43±1.78%, respectively. Dietary supplementation of sorbitol significantly (P<0.05) increased the rectal temperature (°C) of T2 (36.12±0.04, 38.03±0.11) over T1 (35.86±0.04, 37.73±0.12) both at 6: 00 hrs and 14: 00 hrs. Glucose level (mg/dl) was significantly (P<0.05) higher in T2 (69.60±0.38) than T1 (68.07±0.20). Significantly (P<0.05) higher milk yield (Kg) was recorded in T2 (9.60±0.28) than T1 (8.31±0.27). The respiration rate, pulse rate, hemoglobin (Hb), packed cell volume (PCV), erythrocyte sedimentation rate (ESR), aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutathione peroxidase (GPx) and superoxide dismutase (SOD), dry matter intake (DMI), water intake (WI), rumination number (R. No) did not differ significantly between T1 and T2. Thus it is concluded that, dietary supplementation of sorbitol to crossbred dairy cattle during winter has beneficial effect on increasing the rectal temperature, blood glucose level and milk production.

Ratlarda böbrek iskemi-reperfüzyon hasarında proflaktik kalsiyum dobesilatın etkinliği

Aim: In this study, the objective was to investigate the protective effect of calcium dobesilate, which has antioxidant and anti-inflammatory properties, on the experimental renal ischemia-reperfusion injury (IRI). Methods: Twenty-four male Wistar-Albino rats were divided into three groups: Sham group (Group 1), ischemia-reperfusion group (Group 2), and treatment group (Group 3). Before the ischemia-reperfusion procedure, rats in Group 3 received calcium dobesilate through gavage (100mg/kg/day) for 10 days. Groups other than the sham group underwent ischemia for 45 minutes and reperfusion for 24 hours. Plasma urea and creatinine levels, erythrocyte superoxide dismutase and glutathione peroxidase enzyme activity levels were measured. In addition, histopathological changes that may be related to ischemia-reperfusion injury in the renal tissue, were investigated.Results: The median glutathione peroxidase and superoxide dismutase enzyme levels were higher in Group 2 compared to Groups 1 and 3. However, the differences were not statistically significant. The creatine levels were statistically lower in Group 3 compared to Group 1 and Group 2. The median urea levels were lower in Group 3 than in Group 1 and Group 2, but the differences were not statistically significant. The histopathological examination showed that parameters such as cellular necrosis, flattened tubular epithelial cells, cytoplasmic vacuolization, tubular lumen obstruction, and chronic inflammation, which are indicators of the ischemia-reperfusion injury, were statistically less common in the treatment group compared to the control group. Conclusion: Our study demonstrated that prophylactic calcium dobesilate had a protective effect on ischemia-reperfusion injury.

Changes in Oxidative Stress, Inflammation, and Muscle Damage Markers Following Diet and Beetroot Juice Supplementation in Elite Fencers.

The aim of this study was to assess the impact of diet and active substances in beetroot juice on the parameters of oxidative stress, inflammation, and muscle damage as well as on the maximum rate of oxygen uptake (VO2max) in elite fencers (10 women, 10 men). Athletes during four weeks realized dietary recommendations (ID) and, after that, diet with freeze-dried beetroot juice supplementation (ID&BEET). At baseline and after each stage, fasting antioxidants, biomarkers of oxidative stress, inflammation, and skeletal muscle damage were measured, and a VO2max test was performed. Only after ID&BEET was a significant increase of VO2max observed, and changes of this parameter were negatively related with changes of serum lactate dehydrogenase (∆LDH) activity, as well as with serum ∆β-carotene and malondialdehyde concentration (∆MDA). Additionally, positive relationships were observed between ∆β-carotene versus changes of the serum concentration of advanced oxidation protein products (∆AOPP), changes of serum glutathione peroxidase activity (∆GPx3) versus both changes of physical activity level and ∆LDH, as well as erythrocyte glutathione peroxidase activity (∆GPx1) versus ∆LDH. To summarize, we showed that long-term beetroot juice supplementation increases lipid peroxidation, and improvement of VO2max after ID&BEET seems to be dependent on LDH activity, as well as on the serum concentration of MDA and β-carotene.

Influence of Long-Term Fasting on Blood Redox Status in Humans.

Fasting is increasingly practiced to improve health and general well-being, as well as for its cytoprotective effects. Changes in blood redox status, linked to the development of a variety of metabolic diseases, have been recently documented during calorie restriction and intermittent fasting, but not with long-term fasting (LF). We investigated some parameters of the blood redox profile in 109 subjects before and after a 10-day fasting period. Fasting resulted in a significant reduction in body weight, improved well-being and had a beneficial modulating effect on blood lipids and glucose regulation. We observed that fasting decreased lipid peroxidation (TBARS) and increased total antioxidant capacity (TAC) in plasma, concomitant with a uric acid elevation, known to be associated with fasting and did not cause gout attacks. Reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx) and catalase in erythrocytes did not show significant changes. In addition, reduction in body weight, waist circumference, and glucose levels were associated to a reduced lipid peroxidation. Similar results were obtained by grouping subjects on the basis of the changes in their GSH levels, showing that a period of 10 days fasting improves blood redox status regardless of GSH status in the blood.

Effects of pomegranate (Punica granatum L.) peel extract supplementation on serum lipid profile and oxidative stress in obese women with knee osteoarthritis: A double blind, randomized, placebo controlled study

ObjectiveDyslipidemia and subsequent oxidative stress may be involved in the progression of osteoarthritis (OA). The aim of the study was to investigate the effects of pomegranate peel extract (PPE) supplementation on serum lipid profile and antioxidant status in obese women with knee OA. MethodsThis randomized, double-blind placebo-controlled clinical trial was conducted on 66 obese women aged 38–60 years old with knee OA. Participants were allocated into two groups. Subjects in the intervention group (n = 33) received PPE capsules (500 mg) twice daily for 8 weeks along with standard drug therapy and control group (n = 33) received placebo for the same period. Fasting blood samples, anthropometric measurements, dietary intakes data, and physical activity levels were collected at the baseline and end of the study. ResultsPPE supplementation significantly decreased serum total cholesterol, triglyceride and malondialdehyde levels (all, p < 0.05) and increased erythrocyte superoxide dismutase, glutathione peroxidase and serum total antioxidant capacity compared to the control group at the end of study (p < 0.05). No significant differences were observed between two groups in serum low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and body mass index at the end of the trial (p > 0.05). ConclusionResults indicated that short term PPE supplementation had useful effects on serum levels of total cholesterol and triglyceride and antioxidant status in obese women with knee OA.

Recovery and identification bioactive peptides from protein isolate of Spirulina platensis and their in vitro effectiveness against oxidative stress-induced erythrocyte hemolysis.

Spirulina platensis is recognized as one of the most nutritious foods, containing a high protein content of up to 70%. Meanwhile, he interest in using natural protein resources to develop bioactive peptides is steadily increasing. Therefore, this study released the bioactive peptides from S. platensis by enzymatic hydrolysis using pepsin (1:3000 U g-1 ), and their amino acid sequences were determined by de novo sequencing. On this basis, the antioxidant activities of synthesized bioactive peptides were comprehensively evaluated by 2,2'-azinobis-3-ethylbenzothiazolin-6-sulfonic acid assay, 1,1-diphenyl-2-picryhydrazyl assay, and cell hemolysis assay induced by 2,2'-azobis-(2-amidino-propane) dihydrochloride (AAPH). The degree of hydrolysis and recovery percentage of pepsin hydrolysis were 172 and 825 g kg-1 respectively, and FFEFF (P1: m/z 736.4, 8%), EYFDALA (P2: m/z 828.4, relative intensity 18.5%), and VTAPAASVAL (P3: m/z 899.5, relative intensity 17.3%) were purified and identified. P2 possessed an excellent radical scavenging activity compared with P1, P3, and vitamin C, which was contributed to by its high β-sheet conformation and specific amino acid compositions. Moreover, P2 significantly attenuated AAPH-induced oxidative hemolysis of erythrocytes and protected the erythrocytes, because it reduced the formation of malondialdehyde and increased the enzyme activities of superoxide dismutase, catalase, and glutathione peroxidase in erythrocytes. This study provided insights into the potential antioxidant function of the synthesized peptides originated from the bioactive peptides of S. platensis proteins, which would contribute to the development of natural antioxidant from new protein resources. © 2020 Society of Chemical Industry.

Near‐Infrared Fluorescence Hydrogen Peroxide Assay for Versatile Metabolite Biosensing in Whole Blood

In emergency medicine, blood lactate levels are commonly measured to assess the severity and response to treatment of hypoperfusion-related diseases (e.g., sepsis, trauma, cardiac arrest). Clinical blood lactate testing is conducted with laboratory analyzers, leading to a delay of 3 h between triage and lactate result. Here, a fluorescence-based blood lactate assay, which can be utilized for bedside testing, based on measuring the hydrogen peroxide generated by the enzymatic oxidation of lactate is described. To establish a hydrogen peroxide assay, near-infrared cyanine derivatives are screened and sulfo-cyanine 7 is identified as a new horseradish peroxidase (HRP) substrate, which loses its fluorescence in presence of HRP and hydrogen peroxide. As hydrogen peroxide is rapidly cleared by erythrocytic catalase and glutathione peroxidase, sulfo-cyanine 7, HRP, and lactate oxidase are encapsulated in a liposomal reaction compartment. In lactate-spiked bovine whole blood, the newly developed lactate assay exhibits a linear response in a clinically relevant range after 10 min. Substituting lactate oxidase with glucose and alcohol oxidase allows for blood glucose, ethanol, and methanol biosensing, respectively. This easy-to-use, rapid, and versatile assay may be useful for the quantification of a variety of enzymatically oxidizable metabolites, drugs, and toxic substances in blood and potentially other biological fluids.

Urinary levels of environmental phenols and parabens and antioxidant enzyme activity in the blood of women

BackgroundThe balance between oxidative stress and antioxidant enzymes is one biological mechanism by which environmental and lifestyle exposures affect health outcomes. Yet, no studies have examined the relationship between environmental phenolic compounds and parabens or their mixtures in relation to antioxidant enzyme activity in women of reproductive age. MethodsSixteen environmental phenols and parabens were measured in urine 2–5 times across two months of follow-up in 143 women aged 18–44 years. Four antioxidant enzymes, erythrocyte and plasma glutathione peroxidase (eGPx, pGPx), glutathione reductase (GSHR), superoxide dismutase (SOD) were measured in plasma. Linear mixed models were adjusted for age, body mass index, race, and creatinine and were weighted with inverse probability of exposure weights. Multi-chemical exposures were estimated using hierarchical principal component analysis (PCA). ResultsIn line with our hypothesis that environmental phenols and parabens would be associated with decreased antioxidant enzymes, butyl, benzyl, ethyl, and propyl parabens were associated with lower levels of eGPx. Methyl paraben, 2,4-dichlorophenol and 2,5-dichlorophenol were associated with reduced SOD. 2,4,6-trichlorophenol was associated with increased levels of pGPx and GSHR. Several parabens were associated with modest decreases in eGPx and SOD, biomarkers of antioxidant defense. Increases in pGPx and GSHR were noted in relation to butyl and ethyl parabens. Co-exposures to parabens were associated with decreased eGPx (β = −1.08, 95% CI: −1.74, −0.43) in principal components mixed models, while co-exposure to benzophenones-3 and -1 were associated with increased eGPx (β = 0.92, 95% CI: 0.20, 1.64). ConclusionThese findings indicate that nonpersistent chemicals altered antioxidant enzyme activity. Further human studies are necessary to delineate the relationship between environmental phenol and paraben exposures with erythrocyte and plasma activities of antioxidant enzymes.