Red Cell Glutathione Peroxidase Research Articles

Quail (Coturnix japonica) egg attenuated 2-butoxyethanol-induced enzymatic dysregulation, disseminated thrombosis and hemolytic impairment in female wistar rats

Influence of quail egg on pathologies has increased research interests and series of investigations are currently being done on its influence against these pathologies. The influence of quail egg against 2-butoxyethanol induced hemolysis and disseminated thrombosis was investigated to determine the enzymatic regulations that ensue in the amelioration of deleterious hemolytic and disseminated thrombosis displayed in female Wistar rats. Quail egg was separated into three (3) components (extracts)-quail egg yolk water soluble (QYWS) and fat soluble (QYFS), and albumen extract (QA) and the inorganic and organic compositions were characterized. Depranocytotic assaults was achieved by 250 mg/kg of 2-Butoxyethanol administered for 4 days, the clinical observation revealed a dark purple-red discoloration on the distal tails of the rats and therapeutic applications followed with 1000 mg/kg BWT of QYWS, QYFS and QA, and 15 mg/kg BWT of hydroxyurea. Morphological evaluation, haematological estimations and biochemical evaluations of the influence on the activities of sphingosine kinase-1, RNase, red cell carbonic anhydrase, lactate dehydrogenase, glutathione peroxidase and caspase-3, vis a vis the concentrations of sphingosine-1 phosphate, selenium and zinc (plasma and urine). In vitro anti-inflammatory influence of quail egg components were investigated against hemolysis and key enzymes of inflammation-cycloxygenase, lipoxygenase and β-glucuronidase. The in vitro anti-inflammatory effects of QYWS, QYFS and QA were concentration dependent from 200 to 800 μg/ml against hemolysis and the key enzymes of inflammation. The characterization of inorganic and organic bioactive composition of the yolk and albumen revealed the presence of folic acid, cobalamin, pyridine, riboflavin, ascorbic acid as well as vitamins D and E, selenium, zinc, iron and calcium. These had reflected in the attenuation of the induced hemolytic and disseminated thrombosis by regulations of enzymes linked to the infarction, apoptosis and oxidative stress characterized in sickle cell index.

A Case–Control Study Examining the Effects of Active Versus Sedentary Lifestyles on Measures of Body Iron Burden and Oxidative Stress in Postmenopausal Women

Approximately half of the Canadian adults have sedentary lifestyles that increase their risk of developing cardiovascular disease (CVD). Women are 10 times more likely to die from CVD than from any other disease. Their risk almost doubles with the onset of menopause, which may result in increased body iron burden and oxidative stress in sedentary women. Body iron burden may catalyze the production of cytotoxic oxygen species in vivo. We hypothesized that postmenopausal women who engage in moderate forms of aerobic exercise for at least 30 min three or more times per week would have significantly (i) lower levels of body iron burden, (ii) increased glutathione peroxidase (GPx) activity, and (iii) decreased oxidative stress in comparison to sedentary controls. An age-matched, case-control study was employed to examine the effects of active (N = 25) versus sedentary (N = 25) lifestyles in women aged 55-65 years on measures of body iron burden as quantified by total serum iron, transferrin saturation, and serum ferritin levels; GPx activity; and oxidative stress as quantified by 4-hydroxynonenal, malondialdehyde, and hexanal. Measures of body iron burden were significantly elevated in sedentary women in comparison to active women (p < .001). Red cell GPx activity was higher in active women compared to sedentary women (p < .001). Measures of oxidative stress were significantly higher in sedentary versus active women (p < .001). These findings suggest that aerobic forms of exercise may mitigate the risk of developing CVD in postmenopausal women by improving antioxidant capacity and decreasing body iron burden.

Red cell antioxidant enzymes and prognostic indexes in patients with burns

Red cell superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) were measured in 66 burned patients (57 men, 9 women, age 16–78 years). BSAB varied from 15 to 93% and ABSI from 3 to 14 points. In the first week after injury the activity of SOD was significantly decreased as compared with the activity of the enzymes in the control group and was also below the reference values. Later the activity of SOD increased up to the normal range. The activity of CAT followed a similar pattern but the differences were not significant. No significant changes in red cell GPX were found during the monitored period. We did not find any significant association between the antioxidant enzyme activities and the markers of burns severity. On the other side there was a significant indirect association between the change of SOD activity (calculated as a difference between the first week values after the injury and the activities measured later) and BSAB.

Oxidant/antioxidant status in obese children compared to pediatric patients with type 1 diabetes mellitus

Type 1 diabetes (T1D) mellitus and obesity are recognized risk factors for cardiovascular disease (CVD). A common mechanism underlying an increased risk for endothelial dysfunction in these two metabolic diseases is oxidative stress. To evaluate and compare the oxidant/antioxidant defense systems in children affected with T1D or obesity in order to determine the importance of oxidative stress before the emergence of complications. Children with T1D (n = 20) or obesity (n = 22), without comorbidities, and age- and sex-matched controls (n = 16). We assessed lipid peroxidation by circulating levels of lipoperoxides and malondialdehyde, as well as protein oxidation by the concentration of plasma carbonyl groups. The endogenous antioxidative defense system was evaluated by the red cell glutathione peroxidase and reduced glutathione. The serum levels of alpha-tocopherol and beta-carotene were determined to assess exogenous antioxidants. Lipid peroxidation was significantly higher in both T1D and obese children when compared with control children. However, T1D patients showed a more elevated level, because their malondialdehyde values were significantly increased with respect to obese children. Protein oxidation was present in both groups of children and did not differ between them. With respect to obese children, the glutathione peroxidase activity and exogenous antioxidants were decreased in T1D patients. Oxidative stress is present in both children with T1D and obesity, although it is more pronounced in the former. Obese children may suffer an additional oxidative stress in the case of developing impaired glucose metabolism.

Monitoring antioxidant enzymes in red cells during allergen immunotherapy

The aim of this report was to answer the question how specific immunotherapy influences the antioxidant enzyme system in patients with respiratory allergy and in longer perspective to find markers suitable to assess the efficacy of treatment. In open prospective randomised study 28 patients (18 females and 10 males, age 14-48 years) with seasonal respiratory allergy were treated with allergen immunotherapy. Subjects received subcutaneous therapy with allergens absorbed on calcium phoshate or aluminium hydroxide and were analyzed by the established protocol at the beginning, after three and 12 month of the treatment. In all treatment group red cell superoxide dismutase and glutathione peroxidase activities were in the normal range in allergic patients both before and during the treatment. Catalase activity in the allergic patients was lower as compared with controls and a significant increase of the enzyme activity occurred during and at the end of the treatment. In patients treated with calcium phosphate adsorbed allergen there was a continous increase of catalase activity from beginning up to the end of observation. In the case of the aluminium hydroxide treatment there was an increase from the baseline values up in the third month of the treatment and a decrease on the 12th month. In summary, the present results open the question that allergen immunotherapy may cause imbalance of oxidants and antioxidants. To support our findings larger controlled field studies are needed.

Selenium, glutathione and glutathione peroxidases in blood of patients with chronic liver diseases.

Disturbances in the antioxidant system could play a role in pathogenesis of chronic liver disease. The aim of our study was to evaluate the levels/activities of antioxidants in blood of patients with chronic liver disease. We estimated selenium and glutathione concentrations and glutathione peroxidase activities in blood of 59 patients with chronic hepatitis B or C virus infection (group 1) and 64 patients with alcoholic, autoimmune or cryptogenic chronic liver disease (group 2). The results were compared with 50 healthy controls. Whole blood and plasma selenium and red cell glutathione concentrations were significantly lower in the patients compared with the controls. Red cell glutathione peroxidase activity was slightly reduced in both subgroups of group 1 and in group 2 with normal alanine aminotransferase values. Plasma glutathione peroxidase activity was slightly but significantly higher in patients with elevated aminotransferase values. The findings suggest that disturbances in antioxidant parameters in blood of patients with chronic liver disease may be the cause of the peroxidative damage of cells.

Selenium, glutathione and glutathione peroxidases in blood of patients with chronic liver diseases.

Disturbances in the antioxidant system could play a role in pathogenesis of chronic liver disease. The aim of our study was to evaluate the levels/activities of antioxidants in blood of patients with chronic liver disease. We estimated selenium and glutathione concentrations and glutathione peroxidase activities in blood of 59 patients with chronic hepatitis B or C virus infection (group 1) and 64 patients with alcoholic, autoimmune or cryptogenic chronic liver disease (group 2). The results were compared with 50 healthy controls. Whole blood and plasma selenium and red cell glutathione concentrations were significantly lower in the patients compared with the controls. Red cell glutathione peroxidase activity was slightly reduced in both subgroups of group 1 and in group 2 with normal alanine aminotransferase values. Plasma glutathione peroxidase activity was slightly but significantly higher in patients with elevated aminotransferase values. The findings suggest that disturbances in antioxidant parameters in blood of patients with chronic liver disease may be the cause of the peroxidative damage of cells.

The secondary alcohol and aglycone metabolites of doxorubicin alter metabolism of human erythrocytes.

Anthracyclines, a class of antitumor drugs widely used for the treatment of solid and hematological malignancies, cause a cumulative dose-dependent cardiac toxicity whose biochemical basis is unclear. Recent studies of the role of the metabolites of anthracyclines, i.e., the alcohol metabolite doxorubicinol and aglycone metabolites, have suggested new hypotheses about the mechanisms of anthracycline cardiotoxicity. In the present study, human red blood cells were used as a cell model. Exposure (1 h at 37 C) of intact human red blood cells to doxorubicinol (40 M) and to aglycone derivatives of doxorubicin (40 M) induced, compared with untreated red cells: i) a ~2-fold stimulation of the pentose phosphate pathway (PPP) and ii) a marked inhibition of the red cell antioxidant enzymes, glutathione peroxidase (~20%) and superoxide dismutase (~60%). In contrast to doxorubicin-derived metabolites, doxorubicin itself induced a slighter PPP stimulation (~35%) and this metabolic event was not associated with any alteration in glutathione reductase, glutathione peroxidase, catalase or superoxide dismutase activity. Furthermore, the interaction of hemoglobin with doxorubicin and its metabolites induced a significant increase (~22%) in oxygen affinity compared with hemoglobin incubated without drugs. On the basis of the results obtained in the present study, a new hypothesis, involving doxorubicinol and aglycone metabolites, has been proposed to clarify the mechanisms responsible for the doxorubicin-induced red blood cell toxicity.

Blood glutathione peroxidase and selenium in abortion

This study was carried out to estimate the levels of glutathione peroxidase and selenium in blood of abortion cases. Glutathione peroxidase and selenium were determined in 52 abortion cases (22 in 1(st) trimester, 30 in second trimester), 45 normal pregnant cases and 25 nonpregnant control cases. The selenium concentration in whole blood and plasma in abortion cases was almost the same as in normal pregnant women but significantly low when compared with the control non-pregnant group. The glutathione levels was higher in abortion cases when compared with normal pregnant and non-pregnant control groups. Red cell and plasma glutathione peroxidase activities of women who had abortion were significantly lower compared with both non-pregnant control group and normal pregnancies.

Red blood cell antioxidant levels in Wuchereria bancrofti infection

The elimination of microfilariae of Wuchereria bancrofti is probably mediated by free radicals. Red cell catalase (C), glutathione peroxidase (GPX), and superoxide dismutase (SOD) activity levels were measured as an indirect method of assessing blood oxidant status in 29 asymptomatic microfilaraemics, 29 “endemic normals”, and 29 controls living in a non-endemic area. Changes in the activity of these enzymes were also compared over a one month period in 22 asymptomatic microfilaraemics randomised to receive either single dose or 14 day treatment with diethyl carbamazine citrate (DEC). Red cell GPX activity levels were significantly higher in “endemic normals” when compared to mf positive cases and non-endemic controls. An early and significant increase in GPX activity (on days 3, 7 and 14 compared to pretreatment levels, p<0.01) was observed after DEC in both treatment groups. Increases in the activity of catalase and SOD became significant only on days 14 and 30 respectively. The percentage reduction in microfilaraemia correlated significantly with the percentage increase in GPX activity levels ( R 2=0.58, p=0.6×10 −5 ). Our results may suggest a role for GPX related oxidant species in the elimination of microfilariae.

Effect of vitamin E on plasma malondialdehyde, antioxidant enzyme levels and the rates of wound closures during wound healing in normal and diabetic rats.

Vitamin E is composed of various subfamilies that include tocopherols and tocotrienols. These compounds have antioxidant properties but differ in structure, dietary source and potency. In this study we evaluated the efficacy of alpha-tocopherol as an antioxidant and its role in wound closure in normal and streptozotocin-induced diabetic rats. The healing of 6 cm linear incisions created on the back of each male Sprague-Dawley rat (250-300 g) was monitored by measuring the length of the wounds daily. The rats were divided into two categories; normal and streptozotocin-induced diabetic rats. For each category, the animals were further divided into two groups; those untreated and those receiving 200 mg/kg bodyweight alpha-tocopherols daily by oral gavage. All rats were fed standard food and water ad libitum. Blood samples were taken at 0, 5 and 10 days after the wounds were created for the determination of malondialdehyde levels and red cell superoxide dismutase, catalase and glutathione peroxidase activities. The results showed that alpha-tocopherol reduced plasma malondialdehyde levels, increased glutathione peroxidase activity and accelerated the rate of wound closure in treated rats.

Ascorbic Acid Therapy in Lead Exposed Jewellery Workers of Bangladesh

A total of 32 male jewellery workers who had been exposed to the fumes and dust of lead for the previous 10 to 25 years and 22 controls matched for age and economic status were compared with respect to lipid peroxidation, antioxidant levels and copper, zinc status in relation to lead toxicity. Effects of ascorbic acid on these parameters were also noted. Blood haemoglobin, serum copper, zinc and vitamin E, and red cell superoxide dismutase were found to be diminished, with no changes observed in red cell glutathione peroxidase and serum glutathione reductase. Lipid peroxidation product levels were very high. Ascorbic acid supplement, an antioxidant, could partially restore the serum copper and zinc levels and red cell superoxide dismutase, leading to a significant decrease in the mean blood lead concentra- tion of jewellery workers. Dietary supplementation with ascorbic acid can complement other efforts to prevent lead exposure and reduce lead toxicity.

Selenium, glutathione peroxidases, and some other antioxidant parameters in blood of patients with chronic renal failure

In the present study several parameters associated with oxidative stress were examined in the blood of 25 chronic renal failure (CRF) patients and the results were compared with 18 healthy subjects. Mean creatinine concentration in patients was 1216 ± 292 μmol/l. Selenium (Se) concentration in red cells, whole blood and in plasma of CRF patients (106 ± 32.5, 59.0 ± 16.7 and 42.4 ± 13.8 ng/ml, respectively) was significantly (0.0001 < P < 0.01) lower (by 20–42%) compared with the controls. Red cell and plasma glutathione peroxidase (GSH-Px) activities (16.6 ± 3.4 U/g Hb and 93.7 ± 32.9 U/l plasma) were lower by 12 and 53% (P < 0.05 and < 0.0001, respectively) in patients than in healthy subjects. GSH concentration in red cells of patients (2.81 ± 0.45 mmol/l) was significantly (P < 0.001) higher (by 20%) than in control group. Malonyldialdehyde (MDA) concentration (expressed as thiobarbituric acid-reactive substances) in red cells of patients (725 ± 155 nmol/g Hb) was significantly (P < 0.001) higher (by 28%) than in control group. No significant difference was observed in the activity of superoxide dismutase in plasma between the two groups. In conclusion, our results confirm that the alterations in Se levels in blood components and in GSH-Px activity in plasma show that the kidney plays an important role in Se homeostasis and in plasma GSH-Px synthesis.

Altered anti-oxidant status and increased lipid peroxidation in marasmic children.

Protein energy malnutrition (PEM) is a common pediatric health problem in developing countries. Although the clinical features of PEM are well known, its pathophysiology is still unclear. Free radicals have been implicated in pathogenesis of PEM. In the present study, oxidant/anti-oxidant status in marasmus was investigated. Red cell glutathione, glutathione peroxidase and superoxide dismutase and their related cofactors, serum selenium and copper, were studied in marasmic and control children. Serum lipid peroxidation was also evaluated to assess oxidative stress. The red cell glutathione levels and glutathione peroxidase activities were found to be significantly lower in the marasmic children than in the controls. Red cell superoxide dismutase (SOD) activity was not different between two groups. Serum selenium and copper concentrations were significantly lower in the marasmic children than in the control subjects. The malondialdehyde concentration, which is an index of lipid peroxidation, was significantly higher in the marasmic group compared with the controls. The anti-oxidant defense system was affected in marasmic children. Reduced anti-oxidant status and increased oxidative stress occurs in marasmic children.

Free radicals antioxidant enzymes and lipid peroxidation in different types of leukemias

Free radicals are highly reactive species that have been implicated in the pathogenesis of many diseases. Reactive oxygen species can initiate lipid peroxidation and DNA damage leading to mutagenesis, carcinogenesis and cell death, if the antioxidant system is impaired. This study was undertaken to examine the prevalence of oxidative stress and the role of antioxidant defence in untreated leukemia patients. The generation of superoxide anion and hydrogen peroxide by leukocytes, plasma malondialdehyde levels, red cell copper zinc superoxide dismutase (Cu–Zn SOD) and glutathione peroxidase (GSH-PX) activities were determined in 30 patients with different types of leukemias prior to therapy. The superoxide anion generation by polymorphonuclear leukocytes was found to be significantly increased in leukemia patients especially those with acute lymphocytic and nonlymphocytic leukemias, while the hydrogen peroxide levels were comparable to the control values. Plasma lipid peroxidation products in untreated leukemia patients were in the normal range. Red cell Cu–Zn SOD and GSH-PX activities were significantly increased and showed no correlation with the hemoglobin content. Although superoxide generation was high, lipid peroxide levels were normal in these patients. This might be due to the increased activities of the antioxidant enzymes (SOD, GSH-PX) which counteract lipid peroxidation. Increased free radical generation, especially superoxide anion in leukemia patients and increased antioxidant defence enzymes, which is an adaptive protective response, are indicative of mild oxidative stress. There were no significant differences for the parameters cited above between different types of leukemias, suggesting that the changes are not specific to the type of leukemia.

Antioxidant enzyme activities and trace element concentrations in ischemia-reperfusion.

In this study, we investigated the impact of ischemia-reperfusion on antioxidant enzyme activities and trace element concentrations. For this purpose, ischemia was initiated by clamping superior mesenteric artery of Wistar (albino) rats for 30 min, followed by reperfusion for 20 min. Immediately after reperfusion, blood samples were taken and examined for red cell copper-zinc superoxide dismutase (Cu-Zn-SOD), catalase (CAT), and glutathione peroxidase (GPx) activities spectrophotometrically and plasma zinc, copper, and magnesium concentrations by atomic absorption spectrophotometer. In the ischemia-reperfusion group, red cell Cu-Zn-SOD activity and plasma zinc and copper concentrations were increased significantly (p < 0.001) when compared to the control group; however, the increases in GPx activity and plasma magnesium concentration were not significant (p > 0.05). We also found a significant (p < 0.01) decrease in catalase activity. Free radicals released as a consequence of ischemia-reperfusion caused significant alterations in antioxidant enzymes and in the concentrations of trace elements.

Population genetics of Glutathione peroxidase (GPX1) in Central Portugal

The isoenzymes of red cell glutathione peroxidase (GPX1) was investigated in the population of Central Portugal. A variant of GPX1 with mobility consistent with GPX1*2 was detected with a frequency of: GPX1*2=0,005 (N=221).

Selenium Supplementation (Se+) does not Modulate Early Anemia of Prematurity† 1569

Several investigators have documented low levels of selenium in serum and erythrocytes of low-birth weight (LBW) infants at birth or in the early postnatal period. Longitudinal studies during subsequent weeks or months have shown persistently low, and in some cases decreasing levels, of both Se and Se-dependent glutathione peroxidase (GPx) enzymes in premature infants not receiving supplementary selenium. It has been suggested that inadequate Se intake and low activity of red cell GPx might play a role in the development of early anemia of prematurity. However, there have been no published data on the effect of Se supplemented (Se+) infant formulas on anemia in prematures. We had previously documented a significant improvement in Se status of LBW infants (1.0-1.75kg B.Wt.) receiving Se+ formulas (Se content 24-29μg/L) compared with a standard (Se-) formula (Se=7.5-9μg/L) during a 20 week postnatal follow-up. Mean estimated Se intakes by 4 wks. were: Se-, 1.7μg/kg/day; Se+, 4.9μg/kg/day. We have evaluated the hematologic status of these infants as presented in the table below. Data were analyzed as “intent-to-treat” so as to include“drop-outs” until the time of their withdrawal. Reasons for withdrawal from further study included need for blood transfusion, significant illness, feeding other food (cereal.)

Antioxidant systems of blood plasma in the pathogenesis of diabetic microangiopathies

The parameters of lipid peroxidation and enzymatic and low-molecular antioxidant systems of blood plasma were studied in 114 patients with insulin-dependent diabetes mellitus and 51 donors (control group). The activities of extracellular superoxide dismutase, catalase, concentrations of plasma selenium, the activity of red cell glutathione peroxidase, and the level of uric acid were measured. Oxidant stress was found to involve no changes of the enzymatic component of antiperoxide defense in patients both at the debut of the disease and with diabetic angiopathies. Evidently, the cell protection is performed not by the enzymatic, but by the low-molecular antioxidant system. The level of total antioxidant activity of the plasma is increased in newly diagnosed diabetes and normalizes by the time of formation of microangiopathies. The concentration of uric acid - one of the plasma antioxidants - is reliably decreased in comparison with the control, which may be significant in the pathogenesis of microangiopathies.

Selenium status of New Zealand infants fed either a selenium supplemented or a standard formula

New Zealand soils are deficient in the essential micronutrient, selenium. New Zealand infants have low selenium levels at birth and experience a further decline if fed cows milk based formula. This study examined the selenium status of infants fed with a new commercially available selenium supplemented formula. Forty-four newborn infants, whose mothers wished to formula feed, were randomized in an open controlled trial to be fed a commercially available selenium supplemented cows milk formula (containing 17 micrograms Se/L) or an unsupplemented formula (containing 4.6 micrograms Se/L). Cord, 1 and 3 month blood samples were obtained for selenium status (plasma and red cell selenium and glutathione peroxidase) and thyroid function. Mean plasma selenium and glutathione peroxidase values were significantly higher in supplemented than unsupplemented infants at 1 month (unpaired t-tests; P < 0.0001 and P = 0.001 respectively) and 3 months (P < 0.0001 and P = 0.0005). Analysis within treatment groups between time points (paired t-tests) showed that selenium supplementation prevented the fall in plasma selenium from birth to 1 month seen in unsupplemented infants and was associated with a rise in levels between 1 and 3 months (P = 0.002). Supplementing cows milk formula with selenium to replicate the levels found in breast milk is nutritionally sound. Feeding from a few days of age with a formula containing 17 micrograms Se/L in infants with low selenium status at birth is sufficient to cause a rise to 80% of adult levels at 3 months of age.