Plasma Glutathione Peroxidase Activity Research Articles

Oxidative stress and other risk factors associated with diabetic nephropathy in type 2 diabetes mellitus

<p>Introduction. The aim of the study was to examine whether biomarkers of oxidative stress and antioxidant enzyme activities are among other risk factors for diabetic nephropathy (DN). Methods. The study involved 70 patients with type 2 diabetes (37 males, aged 41 to 81 years) allocated to two groups: one of 32 patients with DN and the other of 38 patients without DN. In the study of oxidative stress 15 healthy persons were included. All examined patients were interviewed and underwent objective examination. Their serum and urine samples were analyzed in order to estimate the quality of glycoregulation and kidney function. Protein thiol groups (P-SH), antioxidant enzyme activities [superoxide dismutase (SOD) and glutathione peroxidase (GPX)] were determined in plasma spectrophotometrically and malondialdehyde-adducts (MDA) by enzyme immunoassay. Results. No significant differences were found between the two groups for demographic characteristics, duration and treatment of diabetes, blood pressure, fasting glucose level and HbA1c. Patients with DN had a higher body mass index, lower estimated glomerular filtration rate (eGFR) and higher albuminuria and proteinuria. Plasma activity of GPX and SOD as well as levels of MDA adducts and P-SH groups were similar in patients with and without DN, but GPX and SOD plasma activities were significantly lower and plasma level of MDA significantly higher in all patients than in healthy controls. Patient gender, age, BMI, HbA1c and plasma level of P-SH and MDA were selected as significant predictors of DN. Patient age, duration of diabetes, serum phosphorus, uric acid levels and plasma SOD activity were negatively associated with eGFR. Patient age, serum levels of protein and albumin and plasma GPX activity were negatively, while systolic BP, serum levels of uric acid and cholesterol were positively associated with proteinuria. Conclusion. Biomarkers of oxidative protein and lipid damage were selected as risk factors for DN, besides several other well known risk factors.</p>

Growth Performance, Biochemical Indices and Antioxidant Status of Grey Mullet (Mugil cephalus Linnaeus, 1758) Under Dietary L-Carnitine Supplementation

The present research evaluated the use of dietary carnitine supplementation and its effects on the growth, body composition, fatty acids, biochemical parameters, Insulin-like growth factor 1 (IGF-1) level and antioxidant activity, in grey mullet. Four experimental diets were prepared by adding carnitine at concentrations of 0, 400, 800, and 1200 mg kg−1 diet (C0, C400, C800 and C1200 respectively). After 9 weeks of the feeding trial, a significant increase in growth performance (except for Daily Growth Rate or DGR), carcass quality (crude protein and crude lipid), biochemical parameters (cholesterol, triglyceride, total lipid, free fatty acid or FFA, total protein, albumin, and globulin), plasma superoxide dismutase and glutathione peroxidase activities was detected in the fish fed on C800 diet, as compared to those fed on the other diets (P 0.05) differences were observed in moisture and crude ash contents among groups. Barring the C1200 diet, there was also a positive correlation between the plasma IGF-1 level and DGR. The results showed that the diet containing 800 mg kg−1 L-carnitine enhanced growth yield, feed utilization, and carcass quality; as well as biochemical and antioxidant activity of grey mullet. The authors concluded that the maximum recommended levels of L-carnitine in diets for grey mullet (Mugil cephalus) can be established at 800 mg kg−1.

Roles of selenoprotein K and selenium status in the etiopathogenesis of preeclampsia: Their relationships with maternal lipid peroxidation, oxidative DNA damage, and glutathione peroxidase

Abstract. Objective: Preeclampsia (PE) is a complex disease and the underlying mechanisms are not known yet. It is well known that selenium and oxidative stress play a role in the pathogenesis of various diseases as well as PE. The aim of the study was to investigate the changes in selenium status, as an essential trace element, and selenoprotein K (SelK), a newly described selenoprotein which has been suggested to have an antioxidant function in some tissues in patients with preeclampsia. We also aimed at investigating their relationships with maternal lipid peroxidation, oxidative DNA damage, and glutathione peroxidase (GPx) activities. Materials and methods: 38 healthy pregnant and 48 pregnant women with PE were included in the study. Serum selenium levels were measured by graphite-furnace atomic absorption spectrophotometry. Plasma TBARS levels were analyzed by spectrophotometric method; GPx activities, 8OHdG, and SelK levels were determined by ELISA. Results: Plasma TBARS and 8OHdG levels were found to be increased in the PE group compared to the healthy pregnant group. Plasma SelK levels and GPx activities were found to be lower in the PE group than in the healthy control group. However, there was no significant difference in serum selenium levels between two groups. Furthermore, a significant correlation was determined between plasma SelK levels and GPx activities in PE patients group (r = 0.743; p < 0.01). Likewise, a significant positive correlation was found between plasma 8OHdG and TBARS levels (r = 0.457; p < 0.01), serum selenium levels and plasma GPx activities (r = 0.663; p < 0.01), serum selenium and plasma SelK levels (r = 0.851; p < 0.01) in PE. Conclusion: Our findings indicated that a selenoprotein SelK and a selenoenzyme GPx play a role in the etiopathogenesis of PE. Decreases in these antioxidant systems were associated with increase in lipid and DNA oxidation in PE patients. Underlying mechanisms of SelK and its interactions with selenium status and GPx in PE should be clarified in details with further studies.

Injectable trace minerals (selenium, copper, zinc, and manganese) alleviate inflammation and oxidative stress during an aflatoxin challenge in lactating multiparous Holstein cows

Trace minerals are vital in the antioxidant response during oxidative stress; however, limited research is available on the effects of trace mineral supplementation during an aflatoxin (AF) challenge. The objective of the study was to determine the effects of 2 subcutaneous injections of 15 mg/mL of Cu, 5 mg/mL of Se, 60 mg/mL of Zn, and 10 mg/mL of Mn (Multimin 90, Multimin North America, Fort Collins, CO) given at 1 mL/90.7 kg of average body weight in response to an AF challenge. Fifty-eight Holstein cows [body weight (mean ± SD) = 734 ± 6 0kg; days in milk = 191 ± 93] were assigned to 1 of 3 treatments in a randomized complete block design. The experimental period (63 d) was divided into an adaptation phase (d 1-56) and a measurement phase (d 57-63). From d 57 to 59, cows received an AF challenge that consisted of 100 μg of aflatoxin B1/kg of dietary dry matter intake (DMI) administered orally via balling gun. Treatments were saline injection and no AF challenge (NEG), saline injection and AF challenge (POS), and trace mineral injection and AF challenge (MM). Injections were performed subcutaneously on d 1 and 29. Milk was sampled 3 times daily from d 56 to 63, blood was sampled on d 0, 56, 60, and 63, and liver samples were taken on d 0 and 60. Two treatment orthogonal contrasts [CONT1 (NEG vs. POS) and CONT2 (POS vs. MM)] were made. Cows in NEG had lower AF excretion in milk and greater 3.5% fat-corrected milk (32.1 ± 1.37 kg/d) compared with cows in POS (28.6 ± 1.43 kg/d). Feed efficiencies (3.5% fat-corrected milk/DMI, energy-corrected milk/DMI, and milk/DMI) were greater for cows in NEG (1.42 ± 0.07, 1.46 ± 0.07, and 1.45 ± 0.07, respectively) than cows in POS (1.16 ± 0.08, 1.18 ± 0.08, and 1.22 ± 0.07, respectively). Cows in POS had greater milk urea nitrogen and blood urea nitrogen than cows in MM. Liver concentrations of Se and Fe were greater for cows in MM compared with cows in POS. Cows in MM tended to have greater plasma glutathione peroxidase activity compared with cows in POS. An upregulation of liver GPX1 was observed for cows in POS compared with cows in MM. In conclusion, subcutaneous injection of trace minerals maintained an adequate antioxidant response when an AF challenge was present.

A novel Se-polysaccharide from Se-enriched G. frondosa protects against immunosuppression and low Se status in Se-deficient mice

In this study, a Se-deficient mice model was successfully developed by feeding a Se-deficient diet (0.02 mg Se/kg diet) for 4 weeks, and Se supplementation by Se-polysaccharides (Se-GFP-22) was lasted for 4 weeks. The immunomodulatory activity and Se supplementation of Se-GFP-22 from Se-enriched G. frondosa was investigated. Results showed that Se-GFP-22 remarkably enhanced glutathione peroxidase (GSH-Px) and thioredoxin reductase (TrxR) activities in liver, kidney and plasma, and serum, liver, spleen and kidney Se levels of Se-deficient mice. Se-GFP-22 increased the thymus and spleen indices, phagocytic index, co-mitogenic (ConA- or LPS-stimulated) activities on splenocytes and DTH reaction. Se-GFP-22 caused significant increments in cytokine (IL-1β, TNF-α and IFN-γ) levels and Ig G, Ig A, Ig M and Ig E levels. Se-GFP-22 exhibited superior immunomodulatory effects than GFP-22. These findings indicated that Se-GFP-22 promote the protective effects against Se deficiency-induced immunosuppression and could be a potential immunomodulatory agent and a dietary Se-supplement.

Sulforaphane prevents maleic acid-induced nephropathy by modulating renal hemodynamics, mitochondrial bioenergetics and oxidative stress

Maleic acid (MA)-induced nephropathy that is characterized by proteinuria, glycosuria, phosphaturia and a deficient urinary acidification and concentration. Sulforaphane (SF) is an indirect antioxidant that shows nephroprotective effects. The aim of the present work was to test the pre-treatment with SF against the MA-induced nephropathy.Wistar rats (230–260 g) were separated in the following groups: control, MA (which received 400 mg/kg of MA), SF + MA (which received MA and 1 mg/kg of SF each day for four days) and SF (which only received SF). MA induced proteinuria, an increase in urinary excretion of N-acetyl-β-d-glucosaminidase, and a decrease in plasma glutathione peroxidase activity, renal blood flow, and oxygenation and perfusion of renal cortex. All these impairments correlated with higher levels of oxidative damage markers and exacerbated superoxide anion production on renal cortex. Moreover, MA impaired mitochondrial bioenergetics associated to complex I, mitochondrial membrane potential and respiratory control index and increased the mitochondrial production of hydrogen peroxide. Further it disrupted mitochondrial morphology. SF prevented all the above-described alterations.In conclusion, the protective effect of SF against MA-induced nephropathy is associated with preservation of mitochondrial bioenergetics, amelioration of oxidative stress and improvement of renal hemodynamics and renal cortex oxygenation.

Organic zinc and copper supplementation on antioxidant protective mechanism and their correlation with sperm functional characteristics in goats.

Trace minerals feeding had significant effects on sperm production and fertility with better absorption and proper utilization within the body for optimum reproductive function. Several studies have shown that more influenced trace elements in the diets of animals are copper (Cu) and zinc (Zn). Bucks showing deficiency of this mineral might affect the quality of semen production which in turn would affect the fertility. This experiment was thus designed to test the effects of organic Cu and Zn supplementation on antioxidants enzyme activities and sperm functional attributes in fresh semen of bucks. Forty bucks (n=40, Aged 5months) were assigned to ten groups of four animals in each group, supplemented (for a period of 8months) with different levels of organic Zn: 20mg (T2), 40mg (T3) and 60mg (T4), organic Cu: 12.5mg (T5), 25mg (T6), 37.5mg (T7) and combined organic Zn and Cu: 20+12.5mg (T8), 40+25mg (T9), 60+37.5mg (T10), respectively, per kg dry matter and no additional mineral diet (control; T1). One hundred and sixty semen samples were collected through electro-ejaculator and analysed for sperm quantity, quality, acrosome intactness and plasma membrane integrity and correlated with the catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase enzyme activities in seminal plasma. The results indicated organic Cu and zinc supplemented bucks produced more sperm cells, had higher sperm concentrations, maintained higher (p<.01) sperm livability, plasma membrane and acrosome integrities, more motility and velocity. The increased antioxidant enzyme activities, reduced oxidative stress and lowered lipid peroxidation were positively correlated (p<.05) with the sperm functional attributes. In conclusion, organic Cu and Zn supplement to male goats showed protective roles against oxidative damage and maintained better fresh semen characteristics.

Effect of different levels of sunflower meal and multi-enzyme complex on performance, biochemical parameters and antioxidant status of laying hens

This study was designed to evaluate the effects of different sunflower meal ( Helianthus annus ; SFM) levels and a multi-enzyme complex (Natuzyme P 50 ) on performance, biochemical parameters and antioxidant status of laying hens. A total of 288 Hy-Line W-36 laying hens (39-wk-old) were divided into six groups with six replicates per group (eight birds per replicate) and fed one of the six experimental diets. A corn-soybean meal-based diet was formulated and used as control diet. The experimental treatments consisted of three levels of SFM (0, 10, and 20%) and two levels of multi-enzyme complex (0 and 250g/ton). The feeding trial lasted 10 weeks. The results showed that the egg production, egg weight and mass, egg specific gravity, shell strength and thickness, Haugh unit, shape index, triglyceride content, plasma glutathione peroxidase (GSH) activity, and malondialdehyde (MDA) were not influenced by dietary treatments; however, the feed consumption, yolk cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol were significantly affected by feeding SFM compared to the control. In conclusion, the supplementation of SFM up to 20% in diet with multi-enzyme complex in laying hens did not appear to cause any adverse effects on egg production and quality as well on antioxidant status in laying hens. Keywords: Enzymes, laying hen, performance, sunflower meal, yolk cholesterol

Effects of season on boar semen parameters and antioxidant enzymes in the south subtropical region in Brazil.

Although boar semen productivity is affected by seasonality, its effects are not equal among different regions which raise concerns regarding the profitability of boar stud farms. Therefore, the goals of this study were (i) to evaluate the seasonal effect on semen production in a commercial boar stud farm located in a subtropical climate region and (ii) to verify whether the activities of superoxide dismutase and glutathione peroxidase in spermatozoa and seminal plasma were associated with seminal traits of fresh and cooled semen. Nine boars were collected twice per season, and routine seminal parameter analyses were performed together with superoxide dismutase and glutathione peroxidase activities in seminal plasma and spermatozoa. Despite a reduction in sperm concentration in spring and summer, most seminal parameters were constant year-round. Temperature-humidity index was higher in the summer compared to spring, autumn and winter (p<.05). Superoxide dismutase activity in spermatozoa was increased in summer compared to autumn and winter (p<.05). The activities of both enzymes in seminal plasma and spermatozoa glutathione peroxidase remained unaltered throughout the seasons. In conclusion, seasonality showed little influence in overall boar seminal parameters despite microclimatic differences among seasons, and spermatozoa collected during summer increased superoxide dismutase activity.

CONDITION OF LIPID PEROXIDE OXIDATION AND ANTIOXIDANT SYSTEM IN PATIENTS WITH INFECTIOUS MONONUCLEOSIS

The indicators of the activity of lipid peroxidation and the antioxidant system were studied in dynamics in 158 patients with infectious mononucleosis depending on the severity of the clinical course of the disease. It is proved that lipid peroxidation is significantly activated in patients with infectious mononucleosis as the severity of the disease increases and therefore increases the oxidative activity of blood plasma, the concentration of dyne conjugates and malondialdehyde in the blood, decreases the activity of antioxidant enzymes of erythrocytes (catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase), glutathione peroxidase and glutathione reductase activity in plasma and lowering the concentration of total and reduced glutathione in the blood, as well as reduce the antioxidant activity of blood plasma and erythrocytes. Lipid peroxidation significantly increase and the activity of the antioxidant system decrease in patients with infectious mononucleosis in the acute period of the disease, as evidenced by the increased concentration of dyne conjugates, malonic dialdehyde and total oxidative plasma activity in the blood, reduced activity of the total antioxidant activity of plasma and erythrocytes, the decrease in the activity of antioxidant enzymes of erythrocytes catalase, superoxide dismutase, glutathione peroxidase, glutathione peroxidase and glutathione reductase of blood plasma, the decrease in the concentration of glutathione in the blood. The most pronounced disorders of lipid peroxidation and antioxidant system activity were found in patients with moderate-severe and severe infectious mononucleosis. The development of cytolytic syndrome in infectious mononucleosis is associated with the action of reactive oxygen forms species and lipid hydroperoxide.

Dietary l-arginine supplementation improves semen quality and libido of boars under high ambient temperature

l-Arginine is a nutritionally essential amino acid for spermatogenesis and plays versatile roles in animal health and can be utilized as a potential agent to improve reproductive performance of boars under high ambient temperature. The present study aimed to determine whether dietary l-arginine could alleviate heat stress-induced infertility in boars. In all, 20 boars (PIC 1040; 248.59±3.84 kg BW and 407.65±6.40 days of age) were selected and randomly assigned to four groups (group 0.0%, basal diet; group 0.6%, 0.8% or 1.0%, basal diet added with 0.6%, 0.8% or 1.0% l-arginine (wt:wt), respectively.) The four diets were made isonitrogenous by addition of appropriate amounts of l-alanine. Boars were pre-fed the corresponding experimental diet for 42 days. Then, the semen characteristics and libido were accessed for 6 weeks during the hot summer period (25.5° to 33.0°C). Results show that dietary l-arginine remarkably improved sperm motility, normality, total sperm number and effective total sperm number. Also, dietary l-arginine improved semen antioxidant capacity, such as decrease of malondialdehyde and 8-Hydroxy-2'-deoxyguanosine content in sperm (P<0.05), increase of the ratio of glutathione and oxidized glutathione, total antioxidant capacity, glutathione peroxidase and catalase activities in seminal plasma (P<0.05). Most of mitochondria contained intact ultrastructure in l-arginine-supplemented group which also accompany with higher ATP content than the 0.0% group. The boars fed 0.8% l-arginine show increased levels of estradiol-17β and testosterone and exhibit improved libido performance than boars in the 0.0% group. Adding dietary l-arginine linearly increased (P=0.002) nitric oxide content (as l-arginine increased). The scrotal surface temperature in the 0.6%, 0.8% and 1.0% group were decreased by 0.9°C, 0.9°C and 0.4°C, respectively, compared with the 0.0% group. l-Arginine levels caused linear effect on semen quality and antioxidant capacity, also caused quadratic effect on libido performance. During the hot summer months, the predicted optimal l-arginine levels for best semen quality and antioxidant capacity was 0.8% to 1.0% and for best libido performance was 0.8%. It can be concluded that l-arginine can be used as an effective agent to alleviate heat stress-induced infertility of boar, and that 0.8% to 1.0% can be considered as the optimum dosage.

Effects of adding essential oils of rosemary, dill and chicory extract to diets on performance, egg quality and some blood parameters of laying hens subjected to heat stress

ABSTRACTTo determine the effects of adding essential oils of rosemary, dill and chicory extract to diets on performance, egg quality and enzyme activity of laying hens subjected to heat stress, a total of 240 laying hens were used and based on a 2 × 2 × 2 factorial, eight diets, with five replicates, including basal diet with two levels of rosemary essential oil (0, 20 ml/100 kg), two levels of dill essential oil (0, 15 ml/100 kg) and two levels of chicory extract (0, 250 ml/100 kg) were fed to the experimental birds. Dietary dill had a significant effect on egg index under heat stress condition. The birds given rosemary, dill and chicory alone exhibited lower serum cholesterol and triglycerides concentration under thermoneutral and heat stress condition compared to those fed the basal diet (P < 0.05). Synergistic effects between dietary rosemary, dill and chicory significantly increased plasma glutathione peroxidase activity compared to those that received only rosemary, dill or chicory, which has been never reported (P < 0.05). In conclusion, the addition of single or combination of rosemary, dill and chicory can improve at least some production performance and antioxidant enzyme activity (glutathione peroxidase) in heat-stressed laying hens.

Dietary levels and sources of selenium for post weaning piglets

ABSTRACT: An experiment was conducted to study the effects of two sources and dietary levels of selenium (Se) on performance, Se concentration and glutathione peroxidase activity in plasma and liver of piglets post weaning. A total of 126 weaned pigs male and female Large White × Landrace, at average body weight of 7.2±0.67kg were allotted to seven treatments in a randomized block design, with two Se sources (organic and inorganic), inclusion levels, two levels for the inorganic source (0.30 and 0.60ppm) and four for the organic source (0.15, 0.30, 0.45 and 0.60ppm) and one control diet without Se supplementation containing 0.095ppm, and six replicates of three animals per pen. The experimental period was 35 days post-weaning. The organic source contained 0.2067% (Se-yeast), and the inorganic 45.86% (sodium selenite) analyzed. Piglets that received supplemental Se had lower feed intake compared to those not supplemented. Furthermore, feed conversion was better with dietary supplementation of Se, and the organic source was better than the inorganic source at level of 0.30ppm. Plasma concentration of Se was higher (35.53%) in animals receiving dietary supplementation of this mineral, regardless of the sources studied. There was no effect of sources on plasma and hepatic Se, with the lowest values observed for the non-supplementation and organic Se at dietary level of 0.15ppm. There was a linear reduction of plasma GSH-Px activity with increased supplementation levels of organic Se, and the hepatic GSH-Px activity increased linearly with the increased supplementation, regardless of the source studied.

Glutathione, the Major Redox Regulator, in the Prefrontal Cortex of Individuals at Clinical High Risk for Psychosis.

IntroductionOxidative stress and glutathione dysregulation have been implicated in the etiology of schizophrenia. To date, most in vivo studies have investigated alterations in cerebral glutathione levels in patients in which the disorder is already established; however, whether oxidative stress actually predates the onset of psychosis remains unknown. In the current study, we investigated cerebral glutathione levels of antipsychotic-naïve individuals at clinical high risk for psychosis. As exploratory analyses, we also investigated the associations between cerebral glutathione levels and peripheral glutathione peroxidase activity and clinical and neuropsychological measures.MethodsGlutathione levels were measured in the medial prefrontal cortex of 30 clinical high risk (n=26 antipsychotic naïve) and 26 healthy volunteers using 3T proton magnetic resonance spectroscopy. Each participant was assessed for glutathione peroxidase activity in plasma and genotyped for the glutamate cysteine ligase catalytic subunit polymorphism.ResultsNo significant differences were observed in glutathione levels between clinical high risk and healthy volunteers in the medial prefrontal cortex (F(1,54)=0.001, P =0.98). There were no significant correlations between cerebral glutathione levels and clinical and neuropsychological measures. Similarly, no significant differences were found in peripheral glutathione peroxidase activity between clinical high risk and healthy volunteers (F(1,37)=0.15, P =0.70). However, in clinical high risk, we observed a significant effect of lifetime history of cannabis use on glutathione peroxidase activity (F(1,23)=7.41, P =0.01).DiscussionThe lack of significant differences between antipsychotic naïve clinical high risk and healthy volunteers suggests that alterations in glutathione levels in medial prefrontal cortex are not present in the clinical high risk state.

Antioxidant status and thigh meat quality of broiler chickens fed diet supplemented with α-tocopherolacetate, pomegranate pomace and pomegranate pomace extract

The effects of supplementation with α-tocopherol acetate (α-Toc), pomegranate pomace extract (PPE) and pomegranate pomace (PP) into chicken feed on antioxidant status, oxidation susceptibility and quality of the thigh meat during refrigeration were investigated. During six weeks broiler chickens were fed eight dietary treatments, which included: control diet, α-tocopherol diet (200 mg kg−1), PPE diets (0.1, 0.2 and 0.3 g kg−1) and PP diets (1, 2 and 3 g kg−1). Feed efficiency was significantly improved by supplementing chickens fed diet with 0.2 g kg−1 PPE. Long chain polyunsaturated fatty acids (LC PUFA) n-3 level was higher in the thigh of broilers fed with α-Toc and PPE diets (except 0.1 g kg−1) than in chickens fed control and PP diets (p < .05). Total phenolic content, lipid peroxidation level and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity in the thigh meat were significantly improved when chickens were fed diets containing α-Toc and PPE (p < .05). Supplementation of different antioxidant preparations into diets had no influence on plasma superoxide dismutase and glutathione peroxidase activities, in contrast, serum lipid peroxidation level was reduced in chickens fed diets supplemented with PPE (except 0.1 g kg−1) and α-Toc. In conclusion, the broiler thigh meat may be successfully enriched with LC PUFA n-3 and its antioxidant potential and quality characteristics may be improved by supplementing diets with 0.2 and 0.3 g kg−1 PPE. Moreover, the antioxidant potential of PPE supplementation was equal to that of α-tocopherol acetate in refrigerated meat.

Selenium status and fungi in the protein-losing enteropathy of persistent diarrhea.

A vicious cycle of infection, malabsorption, and malnutrition has been implicated in the perpetuation of diarrheal disease. This study examined whether persistent diarrhea is associated with changes in selenium status and stool alpha-1 antitrypsin (AAT) concentration. This cross-sectional study included 30 children aged 1-12 years with persistent diarrhea who were hospitalized in Cipto Mangunkusumo Hospital and Fatmawati Hospital, Jakarta, and 30 apparently healthy children who were matched by age and sex and lived in a rural area of Jakarta. Clinical examinations, blood routine tests, erythrocyte glutathione peroxidase (GPX) activity and plasma selenium levels as well as AAT in fresh stool samples were performed in all the subjects. Of 30 children with persistent diarrhea, 17 had moderate malnutrition and 13 had severe malnutrition. The mean plasma selenium was significantly lower in children with persistent diarrhea than in children without diarrhea (86.0 μg/L [95% CI: 76.1-95.9] vs 110 μg/L [95% CI: 104-116, p<0.0001). The mean stool AAT concentration was significantly higher in children with persistent diarrhea than in those without diarrhea (115 mg/dL [95% CI: 38.5-191] vs 16 mg/dL [95% CI: 4.0-13.5, p<0.0001]). Selenium correlated with AAT (p=0.05). Fecal fungi were persistently present. Although selenium status in both groups was optimal for the obtained plasma GPX activity, children with persistent diarrhea exhibited lower plasma selenium levels. This study suggests that the decrease in the plasma selenium level may be the consequence of protein loss and that fungi may be involved.

Minimum Selenium Requirements Based on Muscle and Kidney Glutathione Peroxidase Activity in the Turkey

Liver and blood glutathione peroxidase (GPX) activities have been used extensively as biomarkers of selenium (Se) status in laboratory and livestock animals. In livestock species used for meat, selenoenzyme activity in the muscle should be considered when setting Se requirements. We recently reported that the Se requirement in rapidly growing young turkey poults is 0.3 μg Se/g diet, based on plasma and liver GPX activity (PLOS ONE 11:e0151665), vs. the published requirement of 0.2 μg Se/g diet (NRC 1994). To examine Se requirements based on breast and thigh muscle, cardiac muscle, and kidney (a tissue with high GPX activity), we fed day‐old male poults (n=50) 10 graded levels of Se (0–1.0 μg/g) for 28 d, and measured GPX1 and GPX4 activity, and transcript expression of all 24 turkey selenoproteins in each tissue. Se response curves and plateau breakpoints were plotted to determine extent of deficiency and minimum Se requirements for each biomarker. The minimum dietary Se requirement for growth was 0.05 μg Se/g. Poults receiving 0 μg Se/g diet had 1 and 8% of plateau GPX1 activity in kidney and heart, respectively, and minimum Se requirements were 0.30 and 0.34 μg Se/g diet, respectively. Breast and thigh GPX1 activity Se response curves were hyperbolic but did not reach well defined plateaus, as GPX1 activity was significantly higher in poults fed 1.0 μg Se/g vs. 0.4 μg Se/g. GPX4 activities in Se‐deficient poults were 9, 22, 8, and 27% of GPX4 plateau activities in kidney, heart, breast and thigh, respectively, and minimum Se requirements were 0.25, 0.31, 0.32 and 0.30 μg Se/g diet, respectively. qPCR of total RNA from each tissue showed that 2–6 transcripts out of 24 total selenoprotein transcripts were significantly downregulated by Se deficiency to 31–73% of Se‐adequate plateaus, with GPX1 and SELH transcripts downregulated in every tissue studied; minimum Se requirements based on transcript expression were 0.08–0.19 μg Se/g diet, and no selenoprotein transcript was up‐ or downregulated significantly by supernutritional Se. This study shows that the turkey minimum dietary Se requirement is 0.3 μg Se/g diet based on heart and kidney GPX activity and on breast and thigh GPX4 activity, just as determined previously based on gizzard, liver and plasma GPX activities. The hyperbolic Se response curves for breast and thigh GPX1 activity suggest that 0.4 μg Se/g diet may be warranted for the 0–4 wk old rapidly growing poult.Support or Funding InformationUSDA NIFA (Hatch 233618 and 1004389), and by the Wisconsin Alumni Foundation Selenium Nutrition Research Fund (No. 2046295).

Antioxidant status of sportsmen performing measured physical loading during recreational periods

The purpose of the current scientific work was to study the condition of antioxidant status in sportsmen of different specializations and degree of training during measured physical training and recreational periods. 71 male sportsmen (18-25 years old) were studied. The control group included 15 practically healthy student volunteers of the same age who did not train. Physical loading was a cardiac stress test. Blood was taken by means of venipuncture in the condition of rest 5 and 30 minutes after work on a biological display stand in the volume of 13 500-27 000 kgf×m. Biochemical investigations were performed in blood plasma and erythrocytes. They included measuring of ascorbic acid, α-tocopherol, caeruloplasmin, antiradical activity, intensity of chemiluminescence in consider of general antioxidant activity, enzymatic activity of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. Comprehensive analysis of lipoprotein fractions was performed taking into consideration diagnostic rates. Dependence of the antioxidant status of sportsmen on the degree of training and specializations was determined. Thus, at rest higher content of blood plasma ascorbic acid in well-trained sportsmen (more than 23.2% in acyclic kinds of sports and 11.9% in cyclic kinds of sports) was revealed. In highly qualified sportsmen the content of this vitamin was lower by 19.6%. Also the well-trained sportsmen have lower values of erythrocyte antioxidant enzyme activities. α-tocopherol blood plasma level and glutathione peroxidase activity as well as antioxidant enzyme activity in general corresponded with blood plasma content of ascorbic acid. Blood plasma decrease of ascorbic acid in all studied groups and α-tocopherol in nontrained group was noted after dosage physical loading and recreational periods. At the background of changes of various sorts of activity of enzyme antioxidants and indicators of deep analysis of lipoprotein spectrum protection was stressed. Recommendations on sport nutrition enrichment with vitamins and mineral substances of antioxidant action were developed.

Alterations of erythrocyte rheology and cellular susceptibility in end stage renal disease: Effects of peritoneal dialysis.

In this study, we investigated the effects of peritoneal dialysis on hemorheological and hematological parameters and their relations with oxidant and antioxidant status of uremic patients. Hemorheological parameters (erythrocyte deformability, erythrocyte aggregation, osmotic deformability, blood and plasma viscosity) were measured in patients with renal insufficiency undergoing peritoneal dialysis (PD) and volunteers. Erythrocyte deformability, osmotic deformability and aggregation in both autologous plasma and 3% dextran 70 were measured by laser diffraction ektacytometry. Enzyme activities of glutathione peroxidase, superoxide dismutase and catalase were studied in erythrocytes; lipid peroxidation was studied by measuring the amount of malondialdehyde in both erythrocytes and plasma samples. Blood viscosity at native hematocrit was significantly lower in PD patients at all measured shear rates compared to controls, but it was high in PD patients at corrected (45%) hematocrit. Erythrocyte deformability did not show any difference between the two groups. Osmotic deformability was significantly lower in PD patients compared to controls. Aggregation index values were significantly high in PD patients in plasma Catalase and glutathione peroxidase activities in erythrocytes were decreased in PD patients whereas superoxide dismutase activity was increased compared to controls. Malondialdehyde was significantly increased in erythrocytes and plasma samples of PD patients which also shows correlations with aggregation parameters. It has been concluded that erythrocytes in PD patients are more prone to aggregation and this tendency could be influenced by lipid peroxidation activity in patient’s plasma. These results imply that uremic conditions, loss of plasma proteins and an increased risk of oxidative stress because of decreasing levels of antioxidant enzymes affect erythrocyte rheology during peritoneal dialysis. This level of distortion may have crucial effects, impairing the blood flow dynamics and causing inadequate microcirculatory perfusion.

Oxidative stress status and sperm DNA fragmentation in fertile and infertile men.

Evidence suggests that disturbing the balance between reactive oxygen species levels and antioxidant contents in seminal plasma leads to oxidative stress resulting in male infertility. This study was carried out to identifying clinical significance of seminal oxidative stress and sperm DNA fragmentation in treatment strategies of male infertility in southwest Iran. Sperm parameters, lipid peroxidation and activity of antioxidant enzymes were assessed in fertile (n=105) and infertile (n=112) men. Malondialdehyde (MDA) levels in seminal plasma were found to be higher significantly (p<.001) in patients. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in seminal plasma were significantly (p<.001) lower in infertile men. Significant negative correlations were observed between MDA levels and sperm motility and normal morphology. Spermatozoa with fragmented DNA were higher (p<.001) in infertile men and significantly correlated with MDA levels and SOD and GPx activities. MDA of 4.2nmol/ml, SOD of 4.89U/ml and GPx of 329.6mU/ml were optimum cut-off limits to discriminate infertile patients from fertile men. The results show the leading role of oxidative stress in aetiology of male infertility in southwest Iran and indicate that evaluation of seminal antioxidant status and DNA integrity can be helpful in men attending infertility clinics during fertility assessment.