Red Blood Cell Glutathione Peroxidase Research Articles

Molecular docking and in vivo protective effects of okra (Abelmoschus esculentus) against metabolic dysfunction in high-fat, high-sodium diet-fed rats.

Okra pods (Abelmoschus esculentus L. Moench) have been used as a functional vegetable as they contain polysaccharides, flavonoids, and other bioactive molecules that protect the body from several chronic diseases. The purpose of this study was to look at the involvement of okra constituents (mucilage and flesh) in the prevention of metabolic dysfunctions induced in a rat model by a high-fat, high-salt (HF/NaCl) diet. Okra mucilage was extracted using an ultrasonic method, freeze-dried, characterized using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM), and tested for swelling ratio and radical scavenging activity. Okra flesh (skin and seeds) was separated from pods; characterized using SEM; and tested for dietary fiber content, phenolic profile, and radical scavenging activity. The significance of okra bioactive compounds in inhibiting human salivary amylase, glutamine : fructose-6-phosphate amidotransferase (GFAT), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) was investigated using molecular docking. Rats were fed an HF/NaCl diet and orally treated daily with freeze-dried okra mucilage or flesh (100 mg per kg body weight) for 8 weeks. Glucose, insulin, inflammatory indicators (CRP, TNF-α, and interleukin 6), oxidative markers (red blood cell lipid peroxidation, glutathione peroxidase, nitric oxide, and superoxide dismutase), lipid profile, estradiol, feces lipids as well as femur and urine calcium were measured. The molecular docking findings showed the interaction of quercetin and chlorogenic acid, which are the most abundant phenolic compounds in okra pods, with the studied proteins, which gives an indication of the mechanism of okra's anti-diabetic, anti-oxidant, and anti-inflammatory effects. Okra mucilage and flesh significantly reduced glucose, insulin, cholesterol, lipid peroxidation, CRP, TNF-α, IL-6, and urine calcium levels while significantly increasing feces lipid and femur calcium levels. The findings suggested that okra mucilage and flesh seem to be promising candidates for protection against metabolic dysfunction.

Effect of Zinc Oxide Nanoparticles as Feed Additive on Blood Indices, Physiological, Immunological Responses, and Histological Changes in Broiler Chicks

A feeding trial of 5-week duration was performed to assess the response of broiler chicks to dietary supplementation with different doses of myco-fabricated zinc oxide nanoparticles (ZONPs) on blood indices, physiological, immunological response, antioxidant status, intestinal microbial count, and histological changes in immune organs. A total of 162 3-day-old Ross 308 broiler chicks were weighed individually and distributed equally into 3 dietary treatments with 6 replicate of 9 chicks in each in a completely randomized design. Chicks were fed ad libitum a basal ration prepared as starter, grower, and finisher supplemented with 0 (T1, control), 40 (T2), and 60 (T3) mg zinc oxide nanoparticles (ZONPs)/kg feed. Results showed that supplementing with ZONPs at both studied levels increased the relative weights of the spleen, bursa, thymus, and liver and decreased the relative weight of the kidney, gizzard, and intestine. A significant increase in the concentrations of hemoglobin (Hb), hematocrit (PCV%), red and white blood cell counts, total protein (TP), globulin (GLOB), aspartate transferase (AST), alanine transferase (ALT), alkaline phosphatase (ALP), superoxide dismutase (SOD), glutathione peroxidase (GPx), and total antioxidant capacity (TAC) and a significant decrease in malonaldehyde (MDA), uric acid, and creatinine concentration were observed. Furthermore, all immunological organs showed histological alteration and increased both types of immunity in ZONPs groups with more pronounced effects in the T2 group.

Tryptophan can alleviate the inhibition in growth and immunity of tilapia (GIFT Oreochromis spp.) induced by high dietary soybean meal level

A 85-day feeding trial was designed to verify the effects of soybean meal on growth, feed utilization, antioxidants, and immune response of tilapia (GIFT Oreochromis spp.), and evaluated the effects of dietary tryptophan on alleviating the negative responses induced by high inclusion of soybean meal. Five experimental diets, two of which substituted 15 % and 45 % of the fish meal with soybean meal, the others supplemented with 0.2 %, 0.4 % and 0.6 % L-tryptophan on the basis of 45 % soybean meal, respectively, were fed 400 juvenile fish (initial weight: 2.98 ± 0.04 g). The results showed that the crude ash content, red blood cell count (RBC), lipase (LPS) and glutathione peroxidase (GSH-Px) activities of tilapia significantly decreased when the soybean meal replaced fish meal by 45 % (p < 0.05). Although the growth performance values of replacing 45 % soybean meal were slightly lower than that of replacing 15 % soybean meal, while there was no significant difference between them (p > 0.05). However, supplementation with tryptophan in the high soybean meal replacement groups significantly improved the final weight, weight gain rate (WGR), specific growth rate (SGR), phagocytosis index (PI), RBC, trypsin (TPS), LPS and GSH-Px activities of tilapia (p < 0.05), and the apparent digestibility and feed coefficient of tilapia were significantly decreased (p < 0.05). Taken together, these results suggested that excessive soybean meal inhibited the feed utilization and immunity of tilapia to a certain extent, while the inclusion of 0.2 %−0.4 % tryptophan in the diet could alleviate the negative effects of high soybean meal diet in tilapia. This study will provide ideas and a theoretical basis for further expanding the application of soybean meal in tilapia feed.

Effects of Dietary Glycine Supplementation on Growth Performance, Immunological, and Erythrocyte Antioxidant Parameters in Common Carp, Cyprinus carpio.

The effects of dietary glycine supplementation, 0 (control), 5 (5 GL), and 10 (10 GL) g/kg, have been investigated on growth performance, hematological parameters, erythrocyte antioxidant capacity, humoral and mucosal immunity in common carp, Cyprinus carpio. After eight weeks feeding, the 5 GL treatment exhibited significant improvement in growth performance and feed efficacy, compared to the control treatment. Red blood cell (RBC) and white blood cell (WBC) counts, hemoglobin, hematocrit, neutrophil and monocyte counts/percentages, RBC reduced glutathione (GSH) content, and skin mucosal alkaline phosphatase, peroxidase, protease, and lysozyme activities were similar in the glycine-treated fish and significantly higher than the control treatment. Blood lymphocyte percentage decreased in the glycine-treated fish, but lymphocyte count increased, compared to the control fish. RBC glutathione reductase activities in the glycine-treated fish were similar and significantly lower than the control treatment. The highest plasma lysozyme and alternative complement activities were observed in GL treatment. The glycine-treated fish, particularly 5 GL, exhibited significant improvement in RBC osmotic fragility resistance. Dietary glycine had no significant effects on RBC glutathione peroxidase activity, plasma immunoglobulin, eosinophil percentage/count, and hematological indices. In conclusion, most of the benefits of dietary glycine supplementation may be mediated by increased glutathione synthesis and antioxidant power.

Use of antioxidant nanoparticles to reduce oxidative stress in blood storage.

Oxidative damage by free radicals has a negative effect on blood quality during storage. Antioxidant nanoparticles can prevent oxidative stress. We use SOD-CAT-Alb-PEG-PLGA- nanoparticles to reduce the effects of oxidative stress in blood storage. Electrospray was employed to prepare nanoparticles. Nanoparticles entered the test bags and were kept for 35 days from the time of donation under standard conditions. On target days, experiments were performed on the samples taken. The examination included blood smear, red blood cells count, hemoglobin, hematocrit, K, Fe, glutathione peroxidase, glutathion reductase, glucose-6-phosphate dehydrogenase, prooxidant-antioxidant balance, malondialdehyde, and flow cytometric assay for phosphatidylserine. The repeated measures analysis was performed on samples every week. Morphological changes were less in the test group compared to the control. The quantitative hemolysis profile test showed significant changes in the test and control groups (p < 0.05) in consecutive weeks except for K and Fe. Oxidative stress parameters too showed a significant change during the target days of the examination (p < 0.05). Also, the phosphatidylserine expression was increased in control groups more than test in consecutive weeks (p < 0.05). It seems that the use of antioxidant nanoparticles improves the quality of stored red blood cells and can prevent posttransfusion complications and blood loss by reducing oxidative stress.

The protective effect of olive cake treatment on oxidant/antioxidant biomarkers, on serum, red blood cells and liver, in streptozotocin-induced diabetic rats fed cholesterol-enriched diet

PurposeThe purpose of this study is to determine the effect of olive cake (OC) on lipid peroxidation as well as antioxidant enzymes activities of serum, red blood cells (RBCs) and liver, in streptozotocin (STZ)-induced-diabetic rat fed cholesterol-enriched diet.Design/methodology/approachHypercholesterolemic male rats were rendered diabetic (HC-D) by a single intraperitoneal injection dose of STZ (35 mg/kg BW). HC-D rats were divided into two groups fed for 28d a diet supplemented with OC at 7.5 percent (HC-D-OC) or not (HC-D). A control group (C) was submitted to standard diet containing 20 per cent casein for the same experimental period.FindingsRBCs, serum and liver thiobarbituric acid reactive substances (TBARS) contents were significantly increased in HC-D, compared to C group (p = 0.04, p = 0.02 and 0.03). These values were significantly decreased (48 per cent and 64 per cent; p = 0.02 and p = 0.0007) in serum and liver of HC-D-OC vs HC-D group. In RBCs, superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) activities were, respectively, 1.5, 2- and 1.7-fold higher (p = 0.03, p = 0.008 and p = 0.03) in HC-D group compared to HC group. In serum and liver, SOD, CAT and GST activities were, respectively, 1.3-, 2.6- and 1.6-fold increased (p = 0.03, p = 0.007 and p = 0.02). In HC-D-OC compared to HC-D group, RBCs glutathione peroxidase (GSH-Px), CAT and GST activities were, respectively, 2.1-, 3.3- and 2.1-fold higher (p = 0.04, p = 0.0009 and p = 0.03). In serum, SOD and CAT activities were, respectively, 1.5- and 1.9-fold increased (p = 0.02, p = 0.02). In liver, SOD, GSH-PX, CAT and GST activities were significantly increased (p = 0.005, p = 0.03, p = 0.02 and p = 0.04).Originality/valueIn diabetic rats-fed cholesterol-enriched diet, OC was able to reduce oxidative stress by decreasing lipid peroxidation and increasing antioxidant enzymes activities in serum, RBCs and liver.

Biomarkers of selenium status and antioxidant effect in workers occupationally exposed to mercury

The present observation based research was designed to evaluate the influence of occupational human exposure to metallic mercury (Hg°) vapor on the biomarkers of selenium status involved in the antioxidant defense system. For this purpose we determined Hg and selenium (Se) concentrations in body fluids, the markers of antioxidant effect measured as an activity of Se-dependent enzymes (red blood cell and plasma glutathione peroxidase: GPx1-RBC and GPx3-P), concentration of selenoprotein P in the plasma (SeP-P) and total antioxidant activity in the plasma (TAA-P) in 131 male workers from a chloralkali plant exposed to Hg° and 67 non-exposed males (control group). The mRNA expression levels of glutathione peroxidases (GPX1, GPX3), selenoprotein P (SEPP1), thioredoxin reductase 1 (TRXR1), thioredoxin 1 (TRX1), peroxiredoxins (PRDX1, PRDX2) were also examined in the leukocytes of peripheral blood. Hg concentration in the blood (Hg-B) and urine (Hg-U) samples was determined using the thermal decomposition amalgamation/atomic absorption spectrometry (TDA-AAS) method and Se concentrations in plasma (Se-P) and urine (Se-U) using the inductively coupled plasma mass spectrometry (ICP-MS) method. Activities of GPx1-RBC, GPx3-P and TAA-P were determined using the kinetic and spectrophotometric method, respectively. Gene expression analysis was performed using the quantitative Real-Time PCR.The results showed significant higher Hg levels among the Hg°–exposed workers in comparison to control group (12-times higher median for Hg-B and almost 74-times higher median for Hg-U concentration in chloralkali workers). Se-P was also significantly higher (Me (median): 82.85 μg/L (IQR (interquartile range) 72.03–90.28 μg/L) for chloralkali workers vs. Me: 72.74 μg/L (IQR 66.25-80.14 μg/L) for control group; p = 0.0001) but interestingly correlated inversely with Hg-U in chloralkali workers suggesting depletion of the Se protection among the workers with the highest Hg-U concentration. The mRNA level for GPX1, PRXD1 were markedly but significantly higher in the workers compared to the control group. Moreover, concentrations of Hg-B and Hg-U among the workers were significantly positively correlated with the levels of selenoprotein P at both the mRNA and selenoprotein levels. In the multivariate model, after adjusting to cofounders (dental amalgam fillings, age, BMI, job seniority time, smoking), we confirmed that Hg-U concentration was inversely correlated with genes expression of TRXR1.This is the first comprehensive assessment of the impact of occupational exposure of workers to Hg° at both the mRNA and selenoprotein levels, with investigation of fish intake obtained by means of a questionnaire. These findings suggest that exposure to Hg° alters gene expression of the antioxidant enzymes and the level of Se-containing selenoproteins.

Relationship Between Aerobic Capacity With Oxidative Stress and Inflammation Biomarkers in the Blood of Older Mexican Urban-Dwelling Population.

The maximal oxygen uptake (VO2max) constitutes an indicator of an organism’s capacity to integrate oxygen into the metabolism to obtaining energy. The aim of this study was to determine the relationship between VO2max and oxidative stress (OxS) and chronic inflammation in the elderly individuals. A cross-sectional and exploratory study was conducted in a sample of 52 older persons. We measured plasma lipid peroxides (LPO), red blood cell glutathione peroxidase, red blood cell superoxide dismutase, and total antioxidant status. The interleukin 10 and tumor necrosis factor-α (TNF-α) were measured in serum by ELISA. The VO2max was determined by the Rockport aerobic test, and the energy expenditure (caloric expenditure and metabolic equivalence unit (MET) per day) was measured by a 3-day activity record. We observed a positive correlation between VO2 max with IL-10, MET/day•day-1 and kcal•day-1 (r = 0.31, P < .05, r = 0.44, P < .01, and r = 0.29, P < .05, respectively), and a negative correlation with the body mass index, TNF-α, and LPO (r = −0.27, P < .05, r = −0.29, P < .05, and r = −0.40, P < .01 respectively). Our findings suggest that there is an inverse relationship between the aerobic capacity and the OxS and chronic inflammation biomarkers in the blood in older Mexican adults.

Antioxidant response to artichoke leaf extract supplementation in metabolic syndrome: A double-blind placebo-controlled randomized clinical trial

Oxidative stress is associated with most components and complications of Metabolic Syndrome (MetS). Artichoke Leaf Extract (ALE) has demonstrated anti-oxidant properties in both laboratory and animal studies. This study was designed to examine the effects of ALE on oxidative stress indices in patients with MetS. In the current double-blind placebo-controlled randomized clinical trial, 80 patients with MetS were randomly allocated to either "ALE group" (received 1800mg ALE as four tablets per day) or "Placebo group" (received placebo containing cornstarch, lactose and avicel as four tablets per day) for 12 weeks. Serum levels of malondialdehyde (MDA), total antioxidant capacity (TAC), oxidized-LDL (ox-LDL), red blood cell glutathione peroxidase (GPx) and superoxidase dismutase (SOD), as well as dietary intakes were assessed at baseline and at the end of the study. A total number of 68 patients completed the study (ALE group=33; placebo group=35). Dietary intakes of energy, macronutrients, and micronutrients were not significantly different between two groups throughout the trial, with the exception of zinc (p<0.05). The concentration of ox-LDL decreased significantly in ALE group in comparison to the placebo group (-266.8±615.9 vs-129.5±591.2ng/L; p<0.05). However, no significant inter- and intra-group changes in MDA, SOD, GPx, and TAC concentrations were observed. ALE decreased serum ox-LDL level in patients with MetS, with no beneficial effects on other antioxidant indices. IRCT201409033320N9.

Lead Induced Hepato-renal Damage in Male Albino Rats and Effects of Activated Charcoal.

Lead is a multi-organ toxicant implicated in various cancers, diseases of the hepatic, renal, and reproductive systems etc. In search of cheap and readily available antidote this study has investigated the role of activated charcoal in chronic lead exposure in albino rats. Eighteen mature male albino rats were used, divided into three groups of six rats per group. Group 1 (control rats) received deionised water (10 ml/kg), group 2 was given lead acetate solution 60 mg/kg and group 3 rats were given lead acetate (60 mg/kg) followed by Activated charcoal, AC (1000 mg/kg) by oral gavage daily for 28 days. Rats in group 2 showed significant increases in serum Aspartate aminotransferase, Alkaline phosphatase, Alanine aminotransferase, urea, bilirubin, total cholesterol, triglycerides, Low Density Lipoprotein, Very Low Density Lipoproteins, Total White Blood Cell Counts, Malondialdehyde, Interleukin-6, and decreases in Packed Cell Volume, hemoglobin concentration, Red blood cell count, total proteins, albumins, superoxide dismutase, glutathione peroxidase and total glutathione. Co-administration of AC significantly decreased these biomarkers with the exception of the sperm parameters. Histopathology of liver and kidney also confirmed the protective effective of AC against lead induced hepato-renal damage. AC may be beneficial in chronic lead induced liver and kidney damage.

Dietary selenium and prolonged exercise alter gene expression and activity of antioxidant enzymes in equine skeletal muscle.

Untrained Thoroughbred horses (6 mares and 6 geldings; 11 yr [SE 1] and 565 kg [SE 11]) were used to evaluate antioxidant gene expression and enzyme activity in blood and skeletal muscle in response to prolonged exercise after receiving 2 levels of dietary selenium for 36 d: 0.1 (CON; = 6) or 0.3 mg/kg DM (SEL; = 6). Horses were individually fed 1.6% BW coastal bermudagrass hay, 0.4% BW whole oats, and a mineral/vitamin premix containing no Se. Sodium selenite was added to achieve either 0.1 or 0.3 mg Se/kg DM in the total diet. On d 35, horses underwent 2 h of submaximal exercise in a free-stall exerciser. Blood samples were obtained before (d 0) and after 34 d of Se supplementation and on d 35 to 36 immediately after exercise and at 6 and 24 h after exercise. Biopsies of the middle gluteal muscle were obtained on d 0, before exercise on d 34, and at 6 and 24 h after exercise. Supplementation with Se above the NRC requirement (SEL) increased serum Se ( = 0.011) and muscle thioredoxin reductase (TrxR) activity ( = 0.051) but had no effect on glutathione peroxidase (GPx) activity in plasma, red blood cell (RBC) lysate, or muscle in horses at rest. Serum creatine kinase activity increased ( < 0.0001) in response to prolonged exercise but was not affected by dietary treatment. Serum lipid hydroperoxides were affected by treatment ( = 0.052) and were higher ( = 0.012) in horses receiving CON than SEL immediately following exercise. Muscle expression of was unchanged at 6 h but increased ( = 0.005) 2.8-fold 24 h after exercise, whereas muscle TrxR activity remained unchanged. Glutathione peroxidase activity increased in plasma (P < 0.0001) and decreased in RBC lysate ( = 0.010) after prolonged exercise. A Se treatment × time interaction was observed for RBC GPx activity (P = 0.048). Muscle and expression and GPx activity did not change during the 24-h period after exercise. Level of dietary Se had no overall effect on expression of , , , , , , or in muscle following exercise. The impact of prolonged exercise on the activities of antioxidant enzymes varied. Furthermore, changes in enzyme activity did not necessarily align with enzyme gene expression following exercise. A higher level of Se intake elevated Se status of untrained horses, increased GPx activity, and lessened lipid peroxidation following exercise, suggesting that Se may be beneficial for mitigating oxidative muscle damage and aiding in postexercise recovery.

Growth, antioxidant capacity and muscle histochemistry of yellowtail kingfish (Seriola lalandi Valenciennes 1883): Selenium and temperature interaction

The aim of this study was to investigate the interactive effects of temperature and dietary selenium concentrations on antioxidant capacity, muscle histochemistry and the growth, of juvenile yellowtail kingfish (Seriola lalandi). The yellowtail kingfish were exposed to two temperatures (21°C or 26°C) and three selenium levels (0.0, 2.0 or 4.0mgSekg−1 of feed) for 30 days. Final weight and specific growth rate (SGR) were significantly affected by water temperature (ρ<0.001) and dietary Se (ρ<0.001) supplementation, and there were significant differences in the interaction between these two factors. Juvenile yellowtail kingfish fed Se-supplemented diets, attained a higher final weight and SGR than those without Se supplementation at 21°C, but not at 26°C. Regardless of the temperature, the red blood cell (RBC) glutathione peroxidase (GPx) activity of yellowtail kingfish fed Se-supplemented diets was significantly higher (ρ<0.05) than with the control diet. However, GPx activity of yellowtail kingfish when fed either 2.0mgSekg−1 or 4.0mgSekg−1 showed no significant difference (ρ>0.05). Se concentration in the muscles of juvenile yellowtail kingfish fed Se-supplemented diets was higher than that of the yellowtail kingfish that were fed the control diet. A histopathological test confirmed that 20.3% of fish muscles exhibited lesions, which occurred in the absence of dietary Se. The outcome of the present study helps in understanding the interactive effects of dietary Se concentrations and the temperature in the farming of yellowtail kingfish.

Selenium and vitamin E interaction in the nutrition of yellowtail kingfish (Seriola lalandi): physiological and immune responses

Six dietary treatments were prepared in a 3 × 2 factorial design (unsupplemented or supplemented with Se at 1 or 2 mg kg-1 × supplemented with vitamin E at 40 or 180 mg kg-1) and fed to yellowtail kingfish (Seriola lalandi) for 6 weeks to evaluate the effects of dietary Se and vitamin E on growth performance, immune and antioxidant responses and to investigate the potential interaction between these two micronutrients in this species. The results have revealed significantly interactive effects with positive physiological responses. Se significantly increased weight gain of fish fed diets low in vitamin E, but not high in vitamin E, whereas serum lysozyme activity was significantly improved by Se in diets high in vitamin E, but not low in vitamin E. Moreover, there was evidence of myopathy in fish deficient in both Se and vitamin E, but not single deficiency. There was no significant effect of dietary Se, vitamin E or their interaction on survival, antibody titre, feed intake, feed conversion ratio and fillet proximate composition; however, fillet Se and vitamin E were significantly responsive to dietary Se and vitamin E, respectively, and higher dietary Se intakes produced significantly higher red blood cell glutathione peroxidase activity.

Bioavailability of selenium from different dietary sources in yellowtail kingfish (Seriola lalandi)

Different forms of selenium (Se) were supplemented to a fishmeal-based diet to investigate the digestibility and bioavailability of Se in yellowtail kingfish (Seriola lalandi). Five groups of fish in triplicate were fed a basal diet (containing 3.31mg/kg Se) either unsupplemented or supplemented with 2mg/kg Se from selenite, selenocystine (SeCys), selenomethionine (SeMet) or Se-yeast for 6 weeks. The basal unsupplemented diet resulted in significantly lower weight gain, red blood cell glutathione peroxidase (GPx) and bactericidal activities than the supplemented diets. Muscle Se concentration was increased by Se supplementation from SeCys, SeMet or Se-yeast, but not selenite. There was no difference in GPx activity of fish fed with any supplemented diets. The bioavailability of Se from SeMet and Se-yeast was similar for all measurements. The most digestible sources of Se were from SeMet and Se-yeast, whereas the least was from fishmeal. Se from SeMet or Se-yeast produced more weight gain, higher Se accumulation in muscle tissues and bactericidal activity in yellowtail kingfish than Se from SeCys or selenite. This study shows that SeMet and Se-yeast are the most bioavailable sources of Se to yellowtail kingfish and are recommended to be supplemented to fishmeal-based formulated diets for yellowtail kingfish.

Effects of Supplementation with Selenium, as Selenized Yeast, in a Healthy Male Population from New Zealand

Selenium (Se) supplementation was tested in a group of healthy men from Auckland, New Zealnd with selenized yeast (Selplex, 200 μg/day) as the supplementation mode. A set of biomarkers, including DNA damage levels and seleno-antioxidant enzyme levels, were evaluated at pre- and postsupplementation time points. Supplementation produced significant increases in serum Se levels, red blood cell (RBC) thioredoxin reductase (TR) activity and peroxide-induced DNA damage, when the mean baseline serum Se level was 110 ng/ml. Those with higher baseline serum Se levels gained less serum Se and showed a significant reduction of RBC glutathione peroxidase (GPx) activity by supplementation. The optimum benefits of supplementation on DNA stability are observed when the serum Se level reaches between >120 and <160 ng/ml. However, the most significant observation was that those with highest baseline DNA damage benefit the most from Se supplementation, whereas those having lower baseline DNA damage are disadvantaged. A dose of 200 μg/day selenized yeast was also shown to be a safer supplementation option compared to a similar dose of selenomethionine (SeMet). This study highlights the requirement for prestratification of a population by standing serum Se level and baseline DNA damage level, before any Se supplementation is carried out.

Effect of long-term onion (Allium cepa) feeding on antioxidant enzymes in goat erythrocyte

The effect of long-term onion consumption on red blood cell antioxidant enzymes (glucose-6-phosphate dehydrogenase (G6PD), superoxide dismutase (SOD) and glutathione peroxidase (GPx)), were measured. The relationship of these enzymes with PCV and hemoglobin (Hb) concentrations was also determined. Twelve adult female goats were used for the experiment and randomly assigned to three groups. Animals of group 1 and 2 received diets containing 30% and 60% spring onions (DM basis) for 60 days, respectively. Goats of group 3 served as control and were fed whole alfalfa hay. Blood samples were obtained before feeding onion and every 10 days up to 80 days. In the onion groups, PCV amounts decreased from day 10 and reached the lowest value at day 40. Although onion consumption reduced PCV, the measures were within the normal range for goats. G6PD activity decreased from day 10 and the lowest value was detected at day 40. After day 40, a slow and gradual return toward the baseline values was seen. In the onion groups, SOD showed a negative correlation with PCV and Hb (P<0.01). On the other hand, there was a positive correlation between G6PD and Hb (P<0.01). It seems that up to 60% of onions in diet can be consumed by goats without noticeable clinical anaemia. Moreover, it seems that SOD has a compensatory role in protection of erythrocytes against oxidative stress induced by onion consumption in goats.

Relationship between intensity of night shift work and antioxidant status in blood of nurses

PurposeLight-at-night exposure can disrupt the human circadian rhythm via clock gene expressions. The circadian rhythm influences antioxidant enzymes’ activity and cellular mRNA levels of these enzymes. The employees working based on a shift system adjust to the changes occurring both on the cell level and on the level of the whole organism. Therefore, a question should be answered whether shift work disturbs oxidant–antioxidant balance and/or generates oxidative stress.MethodsA cross-sectional study was conducted among nurses selected from the Local Registry of the Chamber of Nurses and Midwives in Lodz: 359 nurses worked daily only and 349 working rotating night shifts. These two groups differed significantly in respect of age (p < 0.0001), menopausal status (p < 0.0001), and current smoking habit (p = 0.02). The average total work duration was significantly shorter (12.4 years) in nurses working currently rotating night shifts who worked significantly longer on night shifts than day-workers (26.6 years).ResultsWe found statistically significant higher red blood cell glutathione peroxidase in nurses working on night shifts (21.0 ± 4.6 vs. 20.0 ± 5.0 U/g Hb, p < 0.009) after adjusting for age, oral contraceptive hormone use, smoking, and drinking alcohol during last 24 h. Statistically significant lower vitamin A and E levels were found in the premenopausal women working in rotating system (0.690 ± 0.238 vs. 0.786 ± 0.262 μg/ml, p < 0.0001 for vitamin A and 10.93 ± 4.15 vs. 12.78 ± 4.75 μg/ml, p < 0.0001 for vitamin E). The marker of lipid peroxidation (TBARS concentration) was significantly lower in the premenopausal nurses than postmenopausal ones working day shifts only (2.06 ± 0.76 vs. 2.21 ± 0.80 nmol/ml, p < 0.038). We observed that erythrocyte GSH-Px activity rose statistically significant in nurses working more night shifts per month (p < 0.01).ConclusionsThe results quoted above seem to support the existence of an association between light-at-night exposure and blood glutathione peroxidase activity in female shift workers. Nevertheless, in order to explain the mechanisms of this association, we need more studies.

Dietary Total Antioxidant Capacity Is Associated with Diet and Plasma Antioxidant Status in Healthy Young Adults

Dietary total antioxidant capacity (TAC), based on the cumulative antioxidant activities of all the antioxidants present in food, has been shown to be inversely associated with risks of chronic diseases. However, dietary TAC has not been validated for its relevance in a healthy young population or for reliability and predictability for antioxidant status. Our study aimed to validate TAC as a tool in assessing antioxidant intake and to investigate whether dietary TAC predicts plasma antioxidant status in a healthy young population. Sixty healthy, nonsmoking college students at the University of Connecticut ages 18 to 25 years were recruited. Thirty-day food records and two 12-hour fasting blood samples were collected for dietary and plasma antioxidant assessments. After adjustment for total energy intake, TAC from diet and supplement was positively correlated with intakes of carotenoids (P<0.01), beta carotene (P<0.05), β-cryptoxanthin (P<0.05), flavonoids (P<0.0001), isoflavones (P<0.01), flavan-3-ols (P<0.01), flavones (P<0.05), and flavonols (P<0.0001). Dietary TAC was an independent predictor of plasma TAC determined by vitamin C equivalent antioxidant capacity (P<0.01) and by ferric-reducing ability of plasma (P<0.0001), plasma glutathione peroxidase (P<0.01), red blood cell glutathione peroxidase (P<0.05), α-tocopherol (P<0.05), and lutein (P<0.05). Results were similar for TAC from diet sources only. The findings suggest that dietary TAC is a good predictor of dietary and plasma antioxidant status in this sample of young adult men and women.

Relationship between antioxidant enzyme genotype and activity and kidney function: a case-control study

Oxidative stress is associated with the progression of chronic kidney disease (CKD). Links between antioxidant enzyme SNPs such as superoxide dismutase (SOD) Ala16Val, glutathione peroxidase (GPx) Pro197Leu and catalase C- 262T and CKD have not been investigated. This study compared antioxidant genotypes and activities of CKD patients with population controls, and determined their relationship to kidney function. CKD patients (n = 230) and controls (n = 224) were screened for the GPx, SOD and catalase SNPs. Plasma and red blood cell (RBC) GPx, RBC SOD and RBC catalase activities, and estimated glomerular filtration rate (eGFR) were measured. Significantly more CKD patients (n = 5) had the GPx Leu/Leu genotype compared to controls (n = 0), and had lower eGFR (p = 0.054). CKD patients had significantly lower plasma GPx and RBC catalase activities compared to controls, whereas RBC GPx and RBC SOD activities were significantly higher in CKD patients (p < 0.001). CKD is associated with reduced plasma GPx and catalase activities and enhanced RBC GPx and SOD activities. Although, genotype frequencies were similar for both groups, lower eGFR was associated with the GPx Leu/ Leu genotype.

An automated system to control and manipulate the flight activity of captive birds

Biologists have long been interested in the behavioural and physiological mechanisms that regulate flight. The manipulation of physical activity of birds under captive conditions, however, faces the experimenter with some technical problems. In this article, we describe a simple automated system that allows control and manipulation of the flight activity of captive birds and use it for the first time to induce blood oxidative stress in male zebra finches (Taeniopygia guttata). Finches subjected to a short-term flight effort regime had an increase of plasma oxidative damage and a decrease of thiol concentration in red blood cells and of body mass, respectively. However, no change in red blood cell glutathione peroxidase was observed. This simple experiment shows that our automated system may be successfully used to induce changes in the physiological state of small birds.