Enzyme Activity In Erythrocytes Research Articles

Magnesium, selenium and zinc deficiency compromises antioxidant defense in women with obesity.

Studies have shown that deficiencies in magnesium, selenium, and zinc in individuals with obesity compromise the endogenous antioxidant defense system. This study aimed to evaluate the impact of mineral deficiency on enzymatic antioxidant defense in women with obesity. The study involved 63 women with obesity (BMI ≥ 35kg/m2) and 77 eutrophic women (BMI between 18.5 and 24.9kg/m2). Variables such as fasting glucose, glycated hemoglobin, fasting insulin, and serum lipids were analyzed. Insulin resistance was measured using the homeostasis assessment model (HOMA-IR) and beta cell function using the homeostasis assessment model (HOMA-β). Dietary intake of energy, macronutrients (including magnesium, zinc, and selenium), and plasma, erythrocyte, and urinary concentrations of these minerals were measured and analyzed. Serum cortisol, plasma leptin, plasma thiobarbituric acid reactive substances, and the activity of erythrocyte superoxide dismutase (SOD), erythrocyte glutathione peroxidase (GPX), and erythrocyte catalase were also analyzed. Women with obesity had reduced plasma and erythrocyte concentrations and greater urinary excretion of all minerals compared to normal weight women (p < 0.05). There was a positive association between erythrocyte concentrations of zinc and selenium and the activity of the GPX and SOD enzymes in erythrocytes in women with obesity (p < 0.05), in addition to a positive association between serum insulin and the enzyme GPX, which is dependent on dietary selenium (p < 0.05). Individuals with obesity are deficient in magnesium, selenium, and zinc, which appears to impair the antioxidant defense system and contribute to important metabolic disorders such as oxidative stress in these patients.

Inhibitory Effects of Aspirin and Ibuprofen Overdose on Cholinesterase Activity: In Vivo and In Vitro Studies.

In recent years, it has been reported that long-term use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) may have protective effects against neurodegenerative diseases by inhibiting the activity of cholinesterase enzymes. The exact biological mechanism of these protective effects is not yet known. This study aims to assess the in vivo and in vitro effects of aspirin and ibuprofen injection on the activity of acetylcholinesterase and butyrylcholinesterase. In this experimental study, 70 adult male mice (20-25 g) were divided randomly into 7 groups (n= 10) including a control group that received normal saline and other groups that received different dosages of aspirin and ibuprofen (100, 200, and 300 mg/kg) in the form of intraperitoneal injection. Mice were anesthetized by ether, and blood samples were taken from the heart. Ellman´s methods were used to measure cholinesterase, erythrocytes, and serum, respectively. The activity of cholinesterase enzymes in serum and erythrocytes decreased significantly (P<0.0001) in treated groups with aspirin and ibuprofen compared to the control samples after 3 and 24 hours. However, these inhibitory effects were variable depending on the dose of the injected drugs, and they were statistically significant at higher injection doses in vitro and in vivo analysis. The result of this study showed that non-steroidal anti-inflammatory drugs can inhibit the activity of the cholinesterase enzymes in both in vivo and in vitro conditions compared to the control group.

Erythrocyte Oxidative Status in People with Obesity: Relation to Tissue Losses, Glucose Levels, and Weight Reduction.

This study aimed to investigate the impact of reductions in various body mass components on the erythrocyte oxidative status and glycemic state of people with obesity (PWO). A total of 53 PWO followed a six-month individualized low-calorie diet with exercise, during which anthropometric, biochemical, and oxidative parameters were measured. The participants were divided into groups based on weight (W), visceral fat area (VFA), total body water (TBW), and skeletal muscle mass (SMM) losses, as well as normoglycemia (NG) and hyperglycemia (HG). Weight reduction normalized glycemia and influenced erythrocyte enzyme activity. Regardless of the tissue type lost (VFA, TBW, or SMM), glutathione peroxidase activity decreased in all groups, accompanied by an increase in glutathione reductase activity. Lipofuscin (LPS) and malondialdehyde (MDA) concentrations decreased regardless of the type of tissue lost. The α-/γ-tocopherol ratio increased in those losing >10% body weight, >15% VFA, and >5% TBW. In the NG group, compared to the HG group, there was a decrease in glutathione peroxidase and an increase in glutathione reductase, with these changes being stronger in the HG group. The LPS and MDA concentrations decreased in both groups. Significant correlations were observed between glucose reduction and changes in catalase, retinol, and α-tocopherol, as well as between VFA reduction and changes in vitamin E, L-LPS, and the activities of L-GR and L-GST. This analysis highlights the complex interactions between glucose metabolism, oxidative state, and erythrocyte membrane integrity, crucial for understanding diabetes and its management. This study shows the significant metabolic adaptability of erythrocytes in response to systemic changes induced by obesity and hyperglycemia, suggesting potential therapeutic targets to improve metabolic health in obese individuals.

Overexpressing the PRSS1 Protein Specifically in the Pancreatic Islets by Nano-Celery Provided Protection against Streptozotocin-Induced Diabetes Mellitus in Male Rat

The goal of this study was to find out how giving whole barley grain to rats that had been given streptozotocin (STZ) affected lipid peroxidation (LPO), the activities of antioxidant enzymes in erythrocytes, and the production of insulin genes in the pancreas. A single shot of STZ (60 mg/kg, i.p.) caused diabetes in the experiment. The oxidative stress was measured by the amount of LPO in the tissue, the amount of reduced glutathione (GSH), and the activities of SOD, CAT, GPx, and GR enzymes in erythrocytes. The most important things that were seen in diabetic control rats were higher blood sugar and LPO levels, lower GSH levels, and lower enzyme functions. When diabetic rats (group G2) were given barley seed whole grain by mouth for 30 days, their LPO level dropped significantly compared to rats that were given STZ (group G3). Furthermore, diabetic rats (group G4) that were fed barley had higher levels of both enzyme- and non-enzymatic antioxidants, as well as higher levels of insulin and regeneration (PRSS1) genes, compared to diabetic normal rats (group G2). The results make it clear that oxidative stress plays a part in causing diabetes and suggest that adding barley to an animal's diet might help protect them.

Effect of 3-Amino-1,2,4-Triazole-5-Carboxylic Acid on Human Blood Erythrocyte Catalase

Catalase is an antioxidant enzyme with great therapeutic potential that scavenges hydrogen peroxide, a reactive oxygen species produced during cellular metabolism. Substances containing 1,2,4-triazole structures are biologically important heterocyclic compounds found in the structure of many pharmaceutical drugs used in drug discovery studies against various types of diseases in the human body. In this study, the effect of phosphate buffer prepared at different pHs and 3-amino-1,2,4-triazole-5-carboxylic acid (ATZc) on catalase enzyme activity in human blood erythrocytes was determined. It was determined that the catalase enzyme was inhibited by ATZc at different pH levels. The weakest inhibition was observed at pH 5.5 (IC50:49.01 µM), whereas the strongest inhibition was observed at pH 7.5 (IC50:23.21 µM).

Total Antioxidant Capacity, Lipid Peroxidation, and Erythrocyte Antioxidant Enzyme Activities in Subjects with Obesity: A Case-Control Study

Introduction: Considering that the prevalence of obesity has increased dramatically in recent years, one of the key targets of public health is obesity and its associated pathological conditions. Recent evidence suggests that oxidative stress (OS) may be the mechanistic link between obesity and the development of metabolic and vascular diseases related to obesity. In this study, it was hypothesized that obesity would be associated with lipid peroxidation (LP) and antioxidant enzyme activities in erythrocytes. Methods: In this case-control study, 80 subjects with obesity and 80 age- and gender-matched subjects with normal weight were selected from the health centers affiliated with Zabol University of Medical Sciences, Iran. General information was gathered from each participant using questionnaires. Serum malondialdehyde (MDA) and total antioxidant capacity (TAC), as well as, superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) activities underwent assessment. Results: The study sample consisted of 160 obese adults (42.5% males and 57.5% females, with a mean age of 41.0±7.6 years). Serum MDA levels (P=0.016) and erythrocyte SOD activity (P=0.013) were significantly higher in subjects with obesity compared to non-obese controls. Moreover, subjects with obesity had significantly lower serum TAC (P=0.008) in comparison to the controls. There were no significant differences in erythrocyte GPX and CAT activities between subjects with obesity and non-obese controls. Significant positive correlations were observed between body mass index (BMI) and serum MDA levels (r=-0.461, P&lt;0.001) and erythrocyte SOD activity (r=-0.442, P=0.002). Furthermore, a significant inverse correlation was found between BMI and serum TAC levels (r=-0.426, P=0.008). Conclusion: The present findings provide further evidence suggesting that obesity leads to substantial LP and OS, which, in turn, may contribute to the development of obesity-related diseases.

Evaluation of the relationship among gene expressions and enzyme activities with antioxidant role and presenilin 1 expression in Alzheimer's disease.

It is known that oxidative stress originating from reactive oxygen species plays a role in the pathogenesis of Alzheimer's disease. In this study, the role of antioxidant status associated with oxidative stress in Alzheimer's disease was investigated. Peripheral blood samples were obtained from 28 healthy individuals (as control) and 28 Alzheimer's patients who met the National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer's Disease and Related Disorders Association criteria. Catalase, glutathione S-transferase and paraoxonase 1 enzyme activities in blood plasma and glutathione S-transferase enzyme activities in erythrocytes were determined by spectrophotometer. Catalase, glutathione S-transferase and presenilin 1 gene expressions in leukocytes were determined using qRT-PCR. Data were analysed with SPSS one-way anova, a LSD post hoc test at p < 0.05. The activity of each enzyme was significantly reduced in Alzheimer's patients compared to control. The catalase gene expression level did not change compared to the control. Glutathione S-transferase and presenilin 1 gene expression levels were increased compared to the control.

Mechanisms of redox balance and inflammatory response after the use of methylprednisolone in children with multisystem inflammatory syndrome associated with COVID-19.

Multisystem inflammatory syndrome in children (MIS-C) associated with being infected with coronavirus-19 (COVID-19) is a life-threatening condition resulting from cytokine storm, increased synthesis of reactive oxygen species (ROSs), and hyperinflammation occurring in genetically predisposed children following an infection with SARS-CoV-2. The primary aims of our study were to identify changes in the activity of antioxidant enzymes in erythrocytes and total oxidative status in plasma after being treated with methylprednisolone (MP). A prospective cohort study of 67 children (56.7% male) under 18 with MIS-C being treated with MP was conducted at the Mother and Child Health Institute from January 2021 to April 2022. The impact of the therapy was assessed on the basis of the clinical condition, haematological and biochemical blood parameters, and echocardiographic findings. 59.7% of patients presented cardiovascular (CV) manifestations, while myocardial dysfunction was observed in half of all patients (50.7%). A severe clinical course was observed in 22/67 patients. Children with CV involvement had a significantly higher relative concentration of B lymphocytes and lower relative concentration of NK cells than patients without CV issues (p < 0.001 and p = 0.004, respectively). Patients with severe MIS-C had a lower relative count of NK cells than those with moderate MIS-C (p = 0.015). Patients with myocardial dysfunction had a higher total oxidative plasma status (TOPS) than children without (p = 0.05), which implicates pronounced oxidative stress in the former cohort. In patients with shock, lower erythrocytes superoxide dismutase (SOD) activity was observed on admission compared to patients without shock (p = 0.04). After MP was administered, TOPS was significantly reduced, while catalase (CAT) and SOD activity increased significantly. Treatment failure (TF) was observed in 6 patients, only females (p=0.005). These patients were younger (p=0.05) and had lower CAT activity on admission (p=0.04) than patients with favorable treatment responses. In the group of patients with TF, TOPS increased after treatment (before 176.2 ± 10.3 mV, after 199.0 ± 36.7 mV). MP leads to rapid modulation of TOPS and increases the activity of antioxidant enzymes in erythrocytes resulting in clinical and echocardiographic improvement. Based on the observed changes in the activity of the antioxidant enzymes, we can conclude that s hydrogen peroxide is the dominant ROS in patients with MIS-C. Patients with TF showed reduced CAT activity, whereas the treatment with MP led to pronounced oxidation. This implies that low CAT activity may be a contraindication for using MP.

Protective Effect of Melatonin Against Malathion Induced Alterations in Antioxidant Defense System and Morphology of Erythrocytes in Wistar Rats

Malathion intoxication has been shown to produce oxidative stress due to the generation of free radicals and alter the antioxidant defense system in erythrocytes. Previous studies have shown the ameliorative role melatonin against oxidative stress induced by generation of free radicals. Present study was designed to investigate the protective effect of melatonin against malathion induced oxidative stress. For this purpose, male Wistar rats were randomly divided into four groups: Control; Melatonin (10mg/Kg body weight) group; Malathion (250mg/Kg body weight) treated group; Malathion + Melatonin treated group. Animals were administered an acute dose of malathion orally. The result of this study shows that in vivo administration of malathion caused inhibition in AChE activity in erythrocytes. Malathion intoxication also significantly increased the oxidative damage as evidenced by increased level of LPO and GSH content. The Inhibition of GSH level and increased lipid peroxidation in erythrocytes was relieved in malathion + melatonin group. Enhanced activities of SOD, CAT, GR and GPx were observed in erythrocytes of malathion treated rats as compared to control group. Moreover, melatonin supplementation in malathion treated rats maintain normal level of antioxidant enzymes as compared to malathion treated rats which indicates that melatonin provide protection against malathion-induced oxidative stress in erythrocytes. No significant change in the membrane bound enzymes such as Na+/K+-ATPase, Mg2+-ATPase and Ca2+-ATPase was observed in malathion intoxicated rats. Findings of scanning electron micrographs of erythrocytes revealed that both the malathion treated and malathion+melatonin treated groups exhibited morphological changes in erythrocytes. However, concomitant melatonin supplementation normalized the morphological alterations in erythrocytes induced by malathion toxicity. In conclusion, melatonin supplementation may ameliorate malathion-induced oxidative imbalance by enhancing the glutathione level, reducing lipid peroxidation and normalizing antioxidant enzyme activities in erythrocytes.

Blood pro-oxidant/antioxidant balance in young men with class II obesity after 20 sessions of whole body cryostimulation: a preliminary study

ABSTRACT Objectives: In obesity, there is a shift in the pro-oxidative-antioxidant balance towards the oxidationreactions. However, it has been shown that in people with normal body composition, after a series of whole-body cryotherapy (WBC), the balance shifts in the opposite direction. Design: The aim of the study was to assess the impact of 20 WBC treatments on blood pro-oxidative-antioxidant balance. Interventions: Study included 14 obese (BMI > 35) and 10 non-obese volunteers. Methods: The total antioxidative (TAS/TAC) and pro-oxidative status (TOS/TOC) in serum and activity of antioxidant enzymes in erythrocytes were determined before the first and 2 hours after the last cryostimulation. Results: In the obese group, a significantly higher level of TOS/TOC, and its significant decrease after the WBC series, was observed. Cryotherapy had no influence on TAS/TAC level which was similar in both groups. Changes in activity of antioxidant enzymes were multidirectional. An increase in CAT activity in the obese group was observed. OSI, both before and after a series of treatments, was significantly higher in obese subjects. Conclusions: A beneficial effect on the level of TOS/TOC and CAT activity was indicated, but the proposed number of treatments for patients with class II obesity turned out to be insufficient. Trial registration: Australian New Zealand Clinical Trials Registry identifier: ACTRN12619000524190.

Clinical, metabolic, and molecular genetic characterization of hereditary methemoglobinemia caused by cytochrome b5 reductase deficiency in 30 dogs

Genotype–phenotype correlations of humans and dogs with hereditary methemoglobinemia are not yet well characterized. We determined total hemoglobin and methemoglobin (MetHb) concentrations, cytochrome b5 reductase (CYB5R) enzyme activities, genotypes, and clinical signs in 30 dogs with persistent cyanosis without cardiopulmonary disease. Erythrocytic CYB5R enzyme activities were low in all dogs assayed. Owner-reported quality of life ranged from subclinical to occasional exertional syncope. Two previously reported and two novel CYB5R3 missense variants were identified among the methemoglobinemic cohort and were predicted to impair enzyme function. Two variants were recurrent: a homozygous Ile194Leu substitution was found in Pomeranians and other small dogs, and a homozygous Arg219Pro change occurred predominately in pit bull terriers. The other two variants were Thr202Ala and Gly76Ser substitutions in single dogs. Of the two common CYB5R3 genotypes, Arg219Pro was associated with a more severe metabolic phenotype. We conclude that CYB5R3 deficiency is the predominate cause of canine hereditary methemoglobinemia. Although this finding is unlikely to alter the clinical approach to hereditary methemoglobinemia in dogs, it demonstrates the possibility of how genotype–phenotype cohort analysis might facilitate precision medicine in the future in veterinary medicine.

Hyperbaric oxygen preconditioning and the role of NADPH oxidase inhibition in postischemic acute kidney injury induced in spontaneously hypertensive rats.

Renal ischemia/reperfusion injury is a common cause of acute kidney injury (AKI) and hypertension might contribute to the increased incidence of AKI. The purpose of this study was to investigate the effects of single and combined hyperbaric oxygen (HBO) preconditioning and NADPH oxidase inhibition on oxidative stress, kidney function and structure in spontaneously hypertensive rats (SHR) after renal ischemia reperfusion injury. HBO preconditioning was performed by exposing to pure oxygen (2.026 bar) twice a day for two consecutive days for 60 minutes, and 24h before AKI induction. For AKI induction, the right kidney was removed and ischemia was performed by clamping the left renal artery for 45 minutes. NADPH oxidase inhibition was induced by apocynin (40 mg/kg b.m., intravenously) 5 minutes before reperfusion. AKI significantly increased renal vascular resistance and reduced renal blood flow, which were significantly improved after apocynin treatment. Also, HBO preconditioning, with or without apocynin treatment showed improvement on renal hemodynamics. AKI significantly increased plasma creatinine, urea, phosphate levels and lipid peroxidation in plasma. Remarkable improvement, with decrease in creatinine, urea and phosphate levels was observed in all treated groups. HBO preconditioning, solitary or with apocynin treatment decreased lipid peroxidation in plasma caused by AKI induction. Also, combined with apocynin, it increased catalase activity and solitary, glutathione reductase enzyme activity in erythrocytes. While AKI induction significantly increased plasma KIM– 1 levels, HBO preconditioning, solitary or with apocynin decreased its levels. Considering renal morphology, significant morphological alterations present after AKI induction were significantly improved in all treated groups with reduced tubular dilatation, tubular necrosis in the cortico-medullary zone and PAS positive cast formation. Our results reveal that NADPH oxidase inhibition and hyperbaric oxygen preconditioning, with or without NADPH oxidase inhibition may have beneficial effects, but their protective role should be evaluated in further studies.

Hyperbaric oxygenation protects the kidney against ischemia-reperfusion injury

Acute kidney injury (AKI) as a consequence of ischemia is a common clinical event that can lead to unacceptably high morbidity and mortality. Hyperbaric oxygen (HBO2) preconditioning has been shown to prevent ischemia-reperfusion injury (IRI) in different tissues. The aim of our study was to compare the effects of HBO2 preconditioning on renal hemodynamics, kidney function and oxidative stress in normotensive and spontaneously hypertensive rats that suffered kidney IRI. An experiment was performed on Wistar (normotensive) and spontaneously hypertensive rats (SHR). The animals were divided into the following experimental groups: sham-operated rats and rats with or without HBO2 preconditioning 24 hours before post-ischemic AKI induction. Treated rats were placed into experimental HBO2 chambers and exposed to pure oxygen twice a day for two consecutive days (2.026 bar of oxygen) for 60 minutes. AKI was performed the next morning. The right kidney was removed and the renal ischemia was performed by clamping the left renal artery for 45 minutes. In this study, HBO2 preconditioning significantly improved disturbed renal hemodynamics, major markers of kidney function in plasma (creatinine, urea and phosphate) as well as antioxidant enzymes (superoxide dismutase and catalase) activities in erythrocytes after AKI induction. Also, HBO2 preconditioning decreased lipid peroxidation in plasma after ischemic AKI. Positive effects were observed in both strains of rats. Our results suggest that HBO2 treatment improves renal hemodynamic and kidney function and decreases oxidative stress of Wistar and SHR rats with an AKI episode. Furthermore, it also implies that pre-existing hypertension does not affect the beneficial effects of HBO2 preconditioning.

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Galactosemia.

Olive cake reduces glycaemia and lipemia and increases antioxidant enzymes in STZ-induced diabetes in rat erythrocytes and tissues

PurposeThe purpose of this study is to determine the effect of olive cake (CO) on glycaemia and lipemia and lipid peroxidation and antioxidant enzymes activities in erythrocytes and tissues, in streptozotocin (STZ)-induced diabetic rats.Design/methodology/approachDiabetes was induced by a single intraperitoneal injection of STZ (55 mg/kg BW). In total, 12 diabetic D rats, weighing 260 ± 20 g, were divided into two groups fed a casein diet supplemented (D-OC) or not (D) with OC (7.5 per cent), for four weeks.FindingsIn D-OC compared with D, glycaemia, total cholesterol and triglycerides values (−40 per cent;p = 0.007, 27 per cent;p = 0.007 and −27 per cent;p = 0.0019). In erythrocyte, liver, kidney, heart, muscle and brain, thiobarbituric acid reactive substances contents were respectively, (−19 per cent;p = 0.03, −32 per cent;p = 0.002, −20 per cent;p = 0.04, −68 per cent;p = 0.003, −74 per cent;p = 0.0003 and −38 per cent;p = 0.04). In erythrocyte, SOD, GSH-Px and CAT activities were respectively, (+14 per cent;p = 0.01, +74 per cent;p = 0.012 and +34 per cent;p = 0.0009). In the liver, kidney, heart and muscle, SOD activity was respectively, (+31 per cent;p= 0.004, +12 per cent;p = 0.038, +43 per cent;p = 0.001 and +23 per cent;p = 0.18). GSH-Px activity was respectively, (+121 per cent;p = 0.0009, 89 per cent;p = 0.0006, + 95 per cent;p= 0.008, +71 per cent;p = 0.02 and +26 per cent;p = 0.01), in the liver, kidney, heart, muscle and brain. Catalase activity was (+21 per cent;p = 0.008) in the liver, (+88 per cent;p = 0.0002 in the kidney, +53 per cent;p = 0,002 in the heart and 83 per cent;p = 0.00004 in the muscle).Originality/valueIn diabetic rats, OC reduces hyperglycaemia induced by STZ and attenuates triglyceridemia and cholesterolemia. This residue is able to decrease the oxidative stress by increasing the antioxidant enzymes activity in erythrocytes and tissues. The high contents of phytoconstituents present in OC are considered to be responsible for this effect.

The changes of activity of separate carbohydrate metabolism enzymes in blood erythrocytes of pregnant rats under vanadium citrate

The aim of the work was to study the effect of vanadium citrate on the activity of glucose-6-phosphate dehydrogenase, lactate dehydrogenase, estradiol content and to establish correlations between the activity of the studied enzymes and the estradiol content in pregnant female rats under the effect of vanadium compound. The study was carried out on 25 female Wistar rats, divided into five groups: group I - non-pregnant, group II - pregnant consuming pure water without additives, groups III, IV, V - females which during the mating and pregnancy periods received the solution of vanadium citrate at the concentrations of 3.75, 15.63 and 62.5 μgV/kg of body weight, respectively. Glucose-6-phosphate dehydrogenase, lactate dehydrogenase and estradiol content increase in pregnant females of group II compared to group I of non-pregnant animals. In pregnant females, the effect of vanadium citrate resulted in the decrease in the activity of glucose-6-phosphate dehydrogenase and lactate dehydrogenase in the blood of animals in groups IV and V, and the content of estradiol in the animals of all three experimental groups (III, IV, V), compared to group II of pregnant females. The values of glucose-6-phosphate dehydrogenase activity in the animals of group IV, which received the solution of vanadium citrate at the concentration of 15.63 μgV/kg of body weight, was similar to that of the animals in group I. This may indicate the normalizing effect of vanadium citrate on the activity of glucose-6-phosphate dehydrogenase at the indicated concentration, which is probably due to the ability of the vanadium microelement to inhibit the activity of this enzyme. Vanadium citrate at the concentration of 15.63 μgV/kg of body weight caused the recovery of the enzyme activity to the values of the activity in group І.

Development and validation of a UPLC-UV method for the quantification of thiopurine methyltransferase enzyme activity in human erythrocytes

Thiopurines are drugs widely used for the treatment of autoimmune conditions, inflammatory bowel disease or acute lymphoblastic leukemia. Determination of thiopurine methyltransferase activity (TPMT), a major determinant of thiopurines toxicity, has been suggested before implementing thiopurine treatment. An ultraperformance liquid chromatography (UPLC) method was developed and validated for the quantification of TPMT enzyme activity based on the conversion of 6-mercaptopurine (6-MP) to 6-methylmercaptopurine (6-MMP) using S-adenosyl-L-methionine (SAM) as methyl donor in red blood cell lysates (RBC). This method was improved from a previous laborious high performance liquid chromatography (HPLC) method, using a lower volume of injection and with a shorter runtime.After incubation and protein precipitation 6-MMP was separated on a HSS-T3 (2.1 × 50 mm, 1.8 μm) column and monitored by UV detection (290 nm). A change on the organic solvent used to dissolve 6-MP resulted in a reduction of interference by endogenous or non-enzymatic methylated 6-MMP. A full validation of the 6-MMP assay was performed according to the FDA and EMA guidelines. The method was linear from 0.125 to 2 nmol/mL, with acceptable values of accuracy and precision.The method was applied in 106 patients treated with thiopurines whose TPMT activity was previously quantified by HPLC. Evaluation through Bland-Altman plot showed that TPMT activities were in agreement between both methods.

Correlation of lipid peroxidation and ATP enzyme on erythrocyte membrane with fetal distress in the uterus in patients with intrahepatic cholestasis of pregnancy.

This paper aims to investigate the correlation of lipid peroxide in erythrocytes and ATP (Adenosine Triphosphate) enzyme activity of erythrocyte membrane with fetal distress in patients with intrahepatic cholestasis of pregnancy (ICP). Forty-three patients with ICP treated at Jining No. 1 People's Hospital were enrolled as a study group, and another forty healthy parturient women in the same period were enrolled as a control group, to extract their elbow venous blood and fetal umbilical cord blood. Thiobarbituric acid (TBA) was used to detect superoxide dismutase (SOD) activity of erythrocytes, malondialdehyde (MDA) activity in plasma, Na+-K+-ATP enzyme activity and Ca2+-Mg2+-ATP enzyme activity of erythrocytes, which were compared between the study and control groups. The correlation of MDA, Na+-K+-ATP enzyme and Ca2+-Mg2+-ATP enzyme activities with fetal distress in the study group was analyzed, and the correlation of MDA with Na+-K+-ATP enzyme activity was investigated. SOD and MDA activities of erythrocytes in maternal blood of the study group were significantly higher than those in the control group (p<0.05, p<0.001, respectively), but MDA activity in umbilical cord blood of the study group was markedly higher than that in the control group (p<0.001). Na+-K+-ATP enzyme and Ca2+-Mg2+-ATP enzyme activities of maternal and fetal erythrocytes of the study group were remarkably lower than those of the control group (p<0.001). MDA in the fetal distress group was significantly higher than that in the no fetal distress group in the study group (p<0.001). Na+-K+-ATP enzyme activity was negatively correlated with MDA concentration in maternal and fetal erythrocytes of patients with ICP (both p<0.001). Lipid peroxidation in patients with ICP will affect ATP enzyme activity of erythrocyte membrane, and the down-regulation of ATP enzyme activity in umbilical cord blood of patients with ICP may cause fetal distress in the uterus.

Low dose exposure of patulin and protective effect of epicatechin on blood cells in vitro

In the present study, we aimed to assess antioxidant status in erythrocytes in vitro after patulin (PAT) and epicatechin exposure by measuring antioxidant enzymes (superoxide-dismutase – SOD, glutathione peroxidase – GPx and catalase – CAT) and parameters associated with oxidative stress (malondialdehyde – MDA and ROS). We also investigated the effect of PAT on viability and count of lymphocytes and lymphocyte subpopulations in rabbit blood in vitro. Whole blood of rabbits was used for analysis of antioxidant changes in rabbit erythrocytes after epicatechin and PAT treatment (separately or in combination, at concentrations of 0.2; 2; 20; 200 µg mL–1 of epicatechin and 0.5; 5; 10 µg mL–1 of PAT). Whole blood of rabbits was also used for analysis of count and viability of lymphocytes after PAT treatment at concentrations of 10; 25 and 50 µg mL–1. Results from our experiment confirmed the ability of epicatechin to protect cells against oxidative stress and lipoperoxidation. Our findings indicate that mycotoxin PAT in low concentrations did not affect the activity of antioxidant enzymes in erythrocytes of rabbits significantly. Only slight non-significant changes in lymphocytes count after treatment with low doses of PAT in rabbit blood were observed.

The Effects of Swimming Training in Cold Water on Antioxidant Enzyme Activity and Lipid Peroxidation in Erythrocytes of Male and Female Aged Rats.

The aim of this study was to verify whether eight-week-long swimming exercise training would evaluate the level of selected indicators of the pro-oxidant/antioxidant status in response to cold water in comparison with swimming under thermoneutral conditions in sedentary male and female elderly rats. The exercise-trained groups swam four min/day and five days a week during eight weeks of housing. Exercise was performed by swimming in glass tanks containing tap water maintained according to group at 5 °C and 36 °C. At the end of treatment (48 h after the last session), all rats were anaesthetized. The level of chosen biomarkers of oxidative stress and antioxidant enzyme activity was determined in the red blood cells and plasma. The results of study show that female rats seem to be better adapted to changing thermal conditions of the environment, developing not only morphological, but also antioxidant, defense mechanisms, mainly in the form of increased erythrocyte superoxide dismutase (SOD) activity and glutathione (GSH) concentration to restore the pro-oxidant/oxidant balance of the organism. Significantly higher concentrations of GSH were observed in the female rats of the group swimming in cold water (by 15.4% compared to the control group and by 20.5% in relation to the group of female rats swimming at 36 °C). In the group exposed to swimming training exercise in cold water, a significantly higher activity of SOD1 (by 13.4%) was found compared to the control group. On the other hand, the organs of ageing male rats show a reduced capacity to increase the metabolic response to low temperatures compared to female ones. In addition, it was demonstrated that cold exposure leads to an increase in lipid peroxidation in tissues. On the other hand, the repeated exposure to low levels of oxidative stress may result in some adaptive changes in organisms that help them to resist stress-induced damage.