Erythrocyte Membrane Damage Research Articles

Significant Increase in Oxidative Stress Indices in Erythrocyte Membranes of Obese Patients with Metabolically-Associated Fatty Liver Disease.

Metabolic dysfunction-associated hepatic steatosis (MAFLD) indicates the metabolic risk associated with hepatic steatosis, overweight and obesity, and clinical evidence of metabolic dysregulation. Since MAFLD is one of the diseases that show a high frequency of alterations in the lipid content of cell membranes, the aim of this study was to evaluate the indices of oxidative damage of erythrocyte membranes in overweight and obese MAFLD subjects. The study was conducted on serum samples and red blood cell membranes of overweight and obese MAFLD subjects. For each patient, biochemical measurements and lipidomic analyses of erythrocytes membranes were performed. Significant differences in fatty acid profiles of RBC membranes were found between overweight and obese patients. In particular, the Peroxidation Index (PI) was higher in the erythrocyte membranes of obese subjects than in overweight subjects. The same behavior was observed for Unsaturation Index (UI) and Free Radical Stress Index (Free RSI), supporting the fact that the systemic increase in oxidative stress was associated with obesity. The study shows that there is a different susceptibility to erythrocyte membrane peroxidation for overweight and obese subjects, and the increased values of oxidative stress indices observed in the erythrocyte membranes of obese patients with MAFLD may be a possible indicator of pro-oxidative events occurring in obesity-related diseases.

Bilirubin- and Blue-Green Light-Induced Damage of Human Erythrocytes

Phototherapy is widely used for neonatal hyperbilirubinemia treatment; however, the most important but not completely recognized issue is the determination of the optimal spectral range of light that provides an effective reduction of bilirubin level in the blood of a newborn with minimal adverse side effects. This study demonstrates that the exposure of radiation from LED sources of blue (emission wavelength λ max = 463 nm, FWHM 20 nm) and green (λ max = 517 nm, FWHM 38 nm) spectral regions to the erythrocyte suspension with the same energy dose (D = 14.4 J/cm 2 ) leads to approximately equally effective hemolysis of erythrocytes. It is concluded that the damage of erythrocyte membranes is caused by the excitation of endogenous porphyrin and flavin photosensitizers contained in the cells in low concentrations, but characterized by high efficiency of singlet oxygen generation. When bilirubin is added to the erythrocyte suspension, a spontaneous (dark) erythrocyte hemolysis intensifies, but the light-induced hemolysis slows down (compared to cells containing no bilirubin). Under the same conditions, the leakage of potassium ions from light-exposed erythrocytes is accelerating, with the light of green spectral region has a more pronounced effect, despite more intense absorption of blue light by bilirubin localized in cells.

Erythrocyte Membrane Resistance Of Actively Smoking Donors In Leukoreduced Packed Red Blood Cells During Storage: Focus On Oxidative Stress

Background — Leukoreduced (with removed white blood cells) packed red blood cells (PRC) are commonly for blood transfusions to reduce post-transfusion effects. The number of active smokers in Indonesia is relatively high; consequently, many of them could be blood donors since no regulations are set to rule them out. However, leukoreduced PRC in active smokers are highly risky as they may undergo erythrocyte membrane damage caused by oxidative stress, which hinders fighting the free radicals generated by smoking. Objective — Our study examined the impact of oxidative stress on membrane resistance of leukoreduced PRC, produced from actively smoking donors, during its storage. Material and Methods − The study was descriptive and cross-sectional in its design. It examined 12 nonsmoking (NS), 12 lightly smoking (LS), and 12 moderately smoking (MS) donors. Leukoreduced PRC produced from donors was separated into three groups: NS, LS, and MS. We performed assessments of malondialdehyde (MDA), superoxide dismutase enzyme (SOD) activity, and osmotic fragility test (OFT) on days 0 through day 35 of storage (D0-D35). We used nonparametric statistical tests (Kruskal-Wallis and Mann-Whitney). We assumed that p<0.05 implied statistically significant difference. Results — The Kruskal-Wallis test demonstrated differences on D0, D7, D14, D21, D28, and D35 between all three groups in MDA, SOD, and OFT, with p < 0.05. This study showed that leukoreduced PRC storage increased oxidative stress. The highest oxidative stress occurred in the MS group. Conclusion — Erythrocyte membrane fragility and resistance correlated with oxidative stress. Blood components of leukoreduced PRC produced from moderate smokers should be banned for repeated transfusions.

Antimalarial and Erythrocyte Membrane Stability Properties of Globimetula braunii (Engle Van Tiegh) Growing on Cocoa in Plasmodium berghei-Infected Mice

IntroductionResistant malaria is a fatal disease. Globimetula braunii (African Mistletoe) is traditionally used for malarial treatment but this fact has not been scientifically reported.MethodsPlasmodium berghei (NK65)-infected male Swiss mice (20±2 g) were treated orally and once daily with 100, 200, and 400 mg/kg BW of methanol extract and its respective hexane, dichloromethane and ethyl acetate fractions for 9 days. P-alaxin was used as control drug P. berghei (ANKA)-infected mice were then treated with the most potent fraction for 5 days. Parasitemia and parasite clearance were determined by microscopy, while hematological parameters, heme, hemozoin, and mouse erythrocyte membrane stabilisation were assayed. The phytochemicals in the most potent fraction were identified using gas chromatography-mass spectrometry.ResultsHexane fraction (HF)-treated mice (400 mg/kg BW) had the least mean parasite load (0.00 ± 0.00; 0.14 ± 0.05%) and highest clearance (100 ± 0.00; 75.50 ± 4.95%) compared with infected control (9.81 ± 0.09; 6.84 ± 0.09%) in susceptible and resistant models, respectively. Hexane fraction modulated hematological indices, minimised erythrocyte membrane damage in heat-induced (2.18 ± 0.94%) and hypotonic solution-induced (7.93 ± 0.93%) compared to artequin (5.05 ± 2.18; 6.38 ± 0.33%) and P-alaxin (67.45 ± 5.15; 56.78 ± 1.10%) in both models of membrane stabilisation, respectively. Hexane fraction (P<0.01) increased heme and decreased hemozoin contents. Friedelan-3-one was identified as the most abundant triterpene.ConclusionThe results indicated that G. braunii has anti-plasmodial properties and minimally dis-stabilised erythrocyte membrane. The major findings in this study are that n-hexane fraction of G. braunii possess excellent and moderate antiplasmodial activity against susceptible and resistant P. berghei, respectively. This was reflected via decreased parasite load, improved hematological parameters, increased heme and decreased hemozoin contents. Friedelan-3-one, a major constituent of the n-hexane fraction, may be responsible for this activity.

Protective effect of Terminalia arjuna against alcohol induced oxidative damage of rat erythrocyte membranes

BackgroundAlcohol is a widely abused drug with many health implications, mainly caused by the oxidative and nitrosative stress on different body parts. Ayurvedic herbalism authenticates the multiple therapeutic applications of Terminalia arjuna bark due to its rich phytochemical repertoire. ObjectiveTo observe the extent of oxidative damage caused to erythrocytes by alcohol and assess the protective ability of T. arjuna bark powder aqueous extract (AETA) against the damage. Materials and methodsWister albino rats were categorized into four groups of eight rats per group; first group (control) was fed with glucose, second group was given alcohol at a dose of 20% v/v; 5g alcohol/kg b. wt/day, third group was co-administered with AETA (0.5 g/kg b. wt/day) and alcohol and the fourth group was kept on bark extract alone. Blood samples were collected and evaluated for different biochemical parameters after the completion of the treatment period. ResultsAlcohol significantly increased the erythrocyte membrane protein carbonyl and malondialdehyde (MDA) contents, along with a concomitant decrease in the membrane antioxidant status, when compared to the control group. Chromatographic analysis of the alcohol-treated rat erythrocyte membranes revealed altered membrane individual phospholipid contents and fluidity properties. Alcohol-induced morphological changes in the erythrocytes and its effect on decreasing the resistance of hypotonic shock induced by NaCl are evident from the hemolysis curves. However, AETA administration to alcoholic rats beneficially modulated the membrane properties anvd protected erythrocytes from damage. ConclusionResults suggest that AETA protects erythrocytes from alcohol-induced oxidative stress, biophysical, and biochemical changes very effectively.

Loss of membrane asymmetry alters the interactions of erythrocytes with engineered silica nanoparticles.

Disruption of plasma membrane integrity is a primary mechanism of nanoparticle toxicity in cells. Mechanistic studies on nanoparticle-induced membrane damage have been commonly performed using model membranes with a focus on symmetric bilayers, overlooking the fact that the membrane has an asymmetric phospholipid composition. In this study, erythrocytes with normal and scrambled membrane asymmetry were utilized to examine how the loss of membrane asymmetry and the resulting alterations in the outer leaflet lipid composition affect nanoparticle-membrane interactions. Unmodified, amine-modified, and carboxyl-modified silica (30 nm) were used as nanoparticle models. Loss of membrane asymmetry was achieved by induction of eryptosis, using a calcium ionophore. Erythrocyte membrane disruption (hemolysis) by unmodified silica nanoparticles was significantly reduced in eryptotic compared to healthy cells. Amine- and carboxyl-modified particles did not cause hemolysis in either cell. In agreement, a significant reduction in the binding of unmodified silica nanoparticles to the membrane was observed upon loss of membrane asymmetry. Unmodified silica particles also caused significant cell deformation, changing healthy erythrocytes into a spheroid shape. In agreement with findings in the cells, unmodified particles disrupted vesicles mimicking the erythrocyte outer leaflet lipid composition. The degree of disruption and nanoparticle binding to the membrane was reduced in vesicles mimicking the composition of scrambled membranes. Cryo-electron microscopy revealed the presence of lipid layers on particle surfaces, pointing to lipid adsorption as the mechanism for vesicle damage. Together, findings indicate an important role for the lipid composition of the membrane outer leaflet in nanoparticle-induced membrane damage in both vesicles and erythrocytes.

Melatonin protects against membrane alterations affected by ‘Artificial Light at Night’ in a circadian-disrupted model of rat

ABSTRACT Artificial Light at Night (ALAN) causes alteration in the redox status and membrane-bound transporters. Melatonin has pleiotropic effects on normal physiology and acts as a potential antioxidant. This study was undertaken to evaluate the effects of ALAN-induced alterations in the membrane transporters, oxidative stress biomarkers and to evaluate the protective effects of melatonin supplementation prior to exposure of light in a circadian-disrupted model of rat. Young male Wistar rats 250 ± 20 g were randomly segregated into following groups; Group (I) control, Group (II) melatonin-treated group (10 mg/kg, orally), Group (III) ALAN (500 lux), Group (IV) ALAN with melatonin, for 10 days. Results show that melatonin is an effective mediator of membrane-bound transporters revealed by activation of Na+/K+-ATPase (NKA), plasma membrane Ca2+-ATPase (PMCA) and suppression of Na+/H+ exchanger (NHE) activity. Oxidative stress biomarkers such as total thiol (T-SH), sialic acid (SA), lipid hydroperoxides (LHs) and protein carbonylation (PC) are also restored to the normal level after supplementation of melatonin. These findings demonstrate the protective effect of melatonin on membrane-bound enzymes along with other oxidative stress biomarkers against light-mediated oxidative damage in erythrocyte membrane.

Chlorogenic acid improves lipid membrane peroxidation and morphological changes in nitrite-induced erythrocyte model of methemoglobinemia.

Nitrite salts are widely presented in food and their hazardous effects have been well documented. In this study, we evaluated the protective capacity of chlorogenic acid (CGA) against sodium nitrite (NaNO2) -induced damage to rat erythrocytes. Two dosing regimens of CGA were undertaken to alleviate the erythrocyte injury induced by NaNO2 . We examined the cell fragility, the level of methemoglobin and oxidative stress parameters of each treated group. In result, as compared to the CGA post-incubation, co-incubation of CGA with NaNO2 decreased the content of advanced oxidation protein products. The protective capacity of CGA was superior to its remedial effect. We infer that the reaction of CGA and NaNO2 may suppress the cytotoxicity of nitrite on erythrocytes and avoid the generation of oxidative stress induced by NaNO2 . Our results suggest a novel diet strategy for preventing the adverse effects of nitrite in those people with exposure to nitrite. PRACTICAL APPLICATIONS: Nitrite is ubiquitous in our environment and can also be formed from nitrogenous compounds by microorganisms which exist in the soil, water, and saliva. Several researches have been performed to explore the protection of natural products on the toxic effects of Nitrite. In this study, exogenous chlorogenic acid (CGA) is able to avert the membrane damage, lipid peroxidation, and morphology in nitrite-induced erythrocytes. The protective capacity of CGA shows superior to the remediate effect of CGA against NaNO2 caused damage to erythrocytes. These results suggest a novel diet strategy for preventing the adverse effects of NaNO2 in those people with acute exposure to nitrite.

Sickle cell disease and folate supplementation

Sickle Cell Disease is an important inherited blood disorder in which anemia occurs due to short life span of the deformed RBCs. Though SCD is predominantly present in Africa, it has been reported from other tropical regions including India. SCD may also manifest as vaso-occlusive crisis which occurs as a result of interplay among impaired blood rheology, increased adhesiveness of RBCs with inflammatory cells and vascular endothelium, and hemostatic activation. Damage of erythrocyte membranes also increases exposure of adhesion molecules and binding motifs viz. phosphatidyl serine, basal cell adhesion molecule-1/Lutheran, integrin-associated protein, and intercellular-adhesion-molecule-4. Release of immature RBCs or reticulocytes with adhesion molecules and increased cellular effect of selectins P- and E-, vascular-cell-adhesion-molecule-1, ICAM-1 and interleukin-8 on endothelial cells aggravates the crisis. Increased level of circulating homocysteine causes increased cytotoxic activity on endothelial cells, elevates hydrogen peroxide levels, decreases nitric oxide synthesis, induces cytokine production to stimulate the inflammatory state, activates procoagulant factors, and dysregulation of lipid metabolism. Positive role of folic acid supplementation in SCD is not well supported and there are possible side effects of folate supplementation. The final biologically active form of folic acid, L-Methylfolate or Levomefolic acid or 5-MTHF, is the best option which gets readily absorbed and exerts its action without requiring any bioconversion. Keywords: Sickle cell disease, Vaso-occlusive crisis, 5-MTHFR, Folate supplementation.

Copper(II) generates ROS and RNS, impairs antioxidant system and damages membrane and DNA in human blood cells.

Copper (Cu) is widely used in various industries, and human exposure to this metal results in severe multi-organ toxicity, which is thought to be due to the generation of free radicals by Fenton-like reaction. The generation of reactive oxygen as well as nitrogen species and free radicals results in induction of oxidative stress in the cell. We have studied the effect of different concentrations of Cu(II) on human erythrocytes and lymphocytes. Incubation of erythrocytes with copper chloride, a Cu(II) compound, enhanced the production of reactive oxygen and nitrogen species, decreased glutathione and total sulphydryl content and increased protein oxidation and lipid peroxidation. All changes were in a Cu(II) concentration-dependent manner. This strongly suggests that Cu(II) causes oxidative damage in erythrocytes. The activities of major antioxidant enzymes were altered, and antioxidant power was lowered. Cu(II) treatment also resulted in membrane damage in erythrocytes as seen by electron microscopy and lowered activities of plasma membrane-bound enzymes. Incubation of human lymphocytes with Cu(II) resulted in DNA damage when studied by the sensitive comet assay. These results show that Cu(II) exerts cytotoxic and genotoxic effects on human blood cells probably by enhancing the generation of reactive oxygen and nitrogen species.

Does Membrane Asymmetry Affect Nanoparticle-Membrane Interactions

Plasma membrane damage is one of the primary mechanisms through which engineered nanomaterials cause cytotoxicity. Despite a number of studies, the role of the structural features of the plasma membrane, in particular membrane phospholipid asymmetry in regulating nanoparticle-membrane interactions has remained obscure. In the current study, the role of membrane phospholipid asymmetry, differences in the lipid composition of exofacial and cytofacial leaflet of the plasma membrane in regulating nanoparticle-membrane interactions was investigated. Vesicles mimicking the exofacial (Vexo) and cytofacial leaflets (Vcyto) of the plasma membrane of erythrocytes were exposed to silica nanoparticles (50 nm), with different surface functional groups, plain, or carboxyl-, amine-, and polyethylene glycol (PEG)-modified and the effect of particles on vesicle integrity was examined. Symmetric and asymmetric vesicles with similar outer leaflet, but different inner leaflet lipid compositions, as well as live erythrocytes, were also used to elucidate the role of membrane asymmetry and individual leaflets in regulating nanoparticle-membrane interaction. Vexo and Vcyto vesicles showed significant difference in their interactions with nanoparticles. Vexo vesicles showed drastic leakage of intravesicular content after exposure to plain and amine-modified particles while none of the particles caused significant leakage in Vcyto vesicles. FRET experiments revealed that nanoparticle-induced disruption by plain and amine-modified particles occurs via pore formation. In agreement, FRET assay and GUV images revealed significant localization of plain and amine-modified particles at the surface of the Vexo vesicles. However, no localization was observed with the Vcyto vesicles. Interestingly, symmetric and asymmetric vesicles were disrupted similarly by plain and amine-modified particles. Importantly, hemolysis was observed after the incubation of erythrocytes with plain and amine-modified particles, consistent with leakage assays using Vexo vesicles. In conclusion, these results suggest that the exofacial leaflet of the plasma membrane is the primary regulator of nanoparticle-induced membrane damage in erythrocytes.

Decreased Na+/K+-ATPase Activity and Altered Susceptibility to Peroxidation and Lipid Composition in the Erythrocytes of Metabolic Syndrome Patients with Coronary Artery Disease

Background: The increased generation of reactive oxygen species that occurs in the case of a metabolic syndrome (MetS) may be responsible for the increased oxidative injury to erythrocyte membranes in coronary artery disease (CAD). Therefore, we studied the effects of MetS on both indexes of oxidative damage and biochemical properties of erythrocyte membranes in CAD patients. Methods: We analyzed the markers of oxidative stress, Na⁺/K⁺-ATPase activity, total cholesterol content of erythrocyte membranes (CEM), and fatty acid compositions of the erythrocyte membrane in 82 patients with stable CAD and 39 non-CAD subjects. Results: The CAD patients had higher levels of CEM, membrane lipid peroxidation, erythrocyte superoxide dismutase (SOD) activity, and Na⁺/K⁺-ATPase activity compared with non-CAD subjects. The Na⁺/K⁺-ATPase activity was correlated negatively with membrane lipid peroxidation, and positively with the CEM. In CAD patients with MetS compared with those without MetS, we found that the membrane lipid peroxidation and CEM were increased, whereas the n-3 fatty acids content, SOD activity, Na⁺/K⁺-ATPase activity were decreased. Conclusion: These findings suggest an impairment of erythrocyte membrane biochemical properties in stable CAD patients as a consequence of oxidative injury that may contribute to the development of CAD. In addition, MetS may be related to increased oxidative injury to erythrocyte membranes.

Determination of Sulfur Dioxide (SO2) Safe Duration in Residential Population Around the Fertilizer Industry X in Indonesia

People who have lived more than 22 years in settlements around the fertilizer industry X are at risk of being exposed to SO2 from the increase in exhaust emissions produced by the boilers and power generation equipment in the fertilizer industry. The purpose of this study was to determine the Risk Quotient (RQ) due to exposure to SO2 and to measure the duration of exposure to SO2 that is safe in the residential area around the fertilizer industry X. This research is a quantitative study with an environmental health risk analysis method, with a sample size of 297 adult population respondents in residential areas around the center of SO2 emissions in the fertilizer industry X area. Data analysis was done using manual data calculations to determine the intake of SO2 (non carcinogenic), risk level or risk quotient (RQ), and safe duration (Dt safe) exposure to SO2 in the population around the fertilizer industry X. The results showed that the average non-carcinogenic intake of SO2 in settlements around the fertilizer industry X was at 0.057427415mg/kg/day. While the average risk quotient is 1.788347507 (RQ> 1), from a total of 297 respondents as many as 197 respondents with RQ> 1 and 100 respondents with RQ 50 of the population in settlements around the fertilizer industry X have health risks resulting from exposure to SO2. The average safe duration of exposure to SO2 in the population in settlements around the fertilizer industry X is 23.47 years, depending on the food intake and body condition of the respondents. The recommendation that can be given is to increase the weight of respondents and the right diet pattern by consuming nutritional intake that can detoxify the main toxin to reduce sulfur dioxide levels in the body, one example is the provision of vitamins E and C which can reduce oxidative effects such as lipid peroxidation and membrane damage in erythrocytes due to exposure to sulfur dioxide2. Besides that, a related stakeholder policy is needed to periodically measure SO2 concentrations in community residential areas around the fertilizer industry X, so that the air quality of people exposed to SO2 can be monitored and is still within safe limits. The company holds a CSR program involving the surrounding community by conducting routine health checks, greening programs around the fertilizer industrial area6. © 2019, Indian Journal of Public Health Research and Development. All rights reserved.

Melatonin diminishes oxidative stress in plasma, retains erythrocyte resistance and restores white blood cell count after low dose lipopolysaccharide exposure in mice.

The aim of the study was to elucidate the effects of melatonin administration (10 mg/kg, 10 days) in a model of inflammation and oxidative stress induced by low-dose bacterial lipopolysaccharide (LPS, once 150 μg). Assays were carried out in quadruplicate in the control, melatonin (10 mg/kg, 10 days), acute LPS administration (once 150 μg) and LPS plus melatonin groups. Blood morphological examination was performed. Erythrocyte resistance to haemolytic agents, ceruloplasmin, diene conjugates, malondialdehyde, oxidatively modified protein concentrations, total antioxidant capacity and antioxidant enzyme activity in plasma were measured. LPS administration in mice resulted in white blood cell (WBC) depletion, erythrocyte cell membrane impairment and oxidative stress in plasma characterised by lipid and protein oxidative processes, decreased antioxidative defence and augmented ceruloplasmin concentrations. Melatonin treatment provided to LPS-exposed animals restored WBC counts, ameliorated erythrocyte membrane damage and decreased overall oxidative stress in plasma. Melatonin provides multilevel protection in animals exposed to low-dose LPS.

Kinetic characteristics of acetylcholinesterase and structural-functional state of rat erythrocyte membranes at moderate hypothermia

Artificial hypothermic state of homeothermic animals contributes to the stimulation of free radical processes in red blood cells. In order to understand what are the consequences of oxidative damage of erythrocyte membrane, we examined the dependence of the kinetic characteristics of integral membrane enzyme acetylcholinesterase (AChE) and structural and functional state of the membrane on the duration of mild hypothermia. For this purpose we reduced body temperature of adult Wistar rats by external cooling to 30°C (short-term moderate hypothermia) and then prolonged hypothermia up to 1.5 and 3 h. A short-term hypothermia was followed with an increase in V max and a decrease in K m, promoting an increase in the catalysis effectiveness.The optimum point on the graph of the concentration dependence was shifted to the area of lower concentrations, and the character of enzyme–substrate interactions at high concentrations of the enzyme changed. Upon prolongation of hypothermia, changes in the AChE kinetic characteristics favored normalization of the enzyme activity and concentration dependence. To test the hypothesis of a possible influence of the lipid matrix on the kinetic characteristics of AchE, we studied structural properties of the erythrocyte membranes using fluorescent probe pyrene. The observed changes in the structural and dynamic characteristics of erythrocyte membranes after a 1.5-h hypothermia suggested a reduction in microviscosity of both total and annular lipids. Prolongation of hypothermia up to 3 h favored normalization of this parameter. It was found that the indicators of the structural state of erythrocyte membranes at different durations of hypothermia correlate with certain kinetic characteristics of AChE. The data indicate that the prolongation of mild hypothermia up to 3 h triggers adaptive mechanisms directed to normalization of the erythrocytes membrane functioning.

The possibility of using cell test-systems for screening for anti-inflammatory activity of novel 5(S)-menthyloxy derivatives of 2(5H)-furanone

Aim. Study of the possibility of using cell experimental models (erythrocytes hemolysis and platelet aggregation) for screening for anti-inflammatory activity of novel synthesized 5(S)-menthyloxy derivatives of 2(5Н)-furanone (compounds R1-R6). &#x0D; Methods. Evaluation of membrane-stabilizing activity of the test compounds was performed by means of models of erythrocyte hemolysis induced by hypotonic environment (osmotic hemolysis) and free radicals. Antiplatelet effect of the compounds was studied by inducing platelet aggregation by 1 mM arachidonic acid. Study of anti-inflammatory activity of novel potential anti-inflammatory molecules was performed with the use of the model of carrageenan-induced paw edema in mice. &#x0D; Results. Compounds R1, R2, R3, and R4 increase the degree of osmotic hemolysis. Compounds R5, R6 decrease the intensity of hemolysis at different concentrations. Compounds R1, R2, R4 and R6 promote free-radical erythrocyte membrane damage at all tested concentrations. Compound R3 protects erythrocytes at low concentrations and promotes erythrocyte damage with increasing concentration. Compound R5 protects erythrocytes at concentrations 3×10-9 и 3×10-5 М. Compounds R1, R2, R4 enhance platelet aggregation at different concentrations. Compound R3 inhibits platelet aggregation at concentration 10-6 М, and at concentrations 10-8 and 10-5 М it induces platelet aggregation. Compound R5 does not affect platelet aggregation. Compound R6 inhibits platelet aggregation at all tested concentrations. On the basis of the results obtained from in vitro test systems compound R6 was selected for further studies of anti-inflammatory activity as it demonstrated maximum effect based on two out of three evaluation criteria. Compound R6 posseses anti-inflammatory activity in the model of inflammation. &#x0D; Conclusion. The novel derivative of 2(5Н)-furanone bearing l-menthol moiety (compound R6) protects erythrocyte membrane from damaging action of hypotonic environment, inhibits platelet aggregation and demonstrates anti-inflammatory activity; cell experimental models can be used for the first phase of screening of novel chemical compounds for anti-inflammatory activity.

Are Polyunsaturated Fatty Acid Metabolites, the Protective Effect of 4-hydroxytyrosol on Human Red Blood Cell Membranes and Oxidative Damage (4-hydroxyalkenals) Compatible in Hypertriglyceridemic Patients?

Background:Increased levels of malondialdehyde (MDA) and 4-hydroxynonenal (HNE) are demonstrated in plasma of uremic patients. A study showed that the comparison of erythrocytes of healthy and diseased patients (obese, hypertensive, and Type 2 diabetics) with age is associated to a disturbed oxidant/antioxidant balance when obesity is associated with hypertension. 4-hydroxytyrosol is shown to significantly protect red blood cells (RBCs) from oxidative damage (4-HNE). In literature, there are partial discussions on the role of lipids and their oxidation products. The products of degradation of membrane proteins are observed as self-consisting products without interrelations with membrane lipids.Objective:The aim of this study is to evaluate the role of polyunsaturated fatty acid (PUFA) metabolites on oxidative damage (4-hydroxy-alkenals) in RBCs of hypertriglyceridemic patients after membrane treatment with 4-hydroxytyrosol.Materials and Methods:The authors optimize the isolation of RBC ghosts and spectrophotometric method to measure free 4-hydroxyalkenals in human RBC membranes and investigated the effect on oxidative damage in human erythrocyte membranes and in vitro 4-hydroxytyrosol treatment to evaluate the membrane lipids reducible by this phenol.Results:Plasma triglyceride levels in patients are clearly higher than in controls. Moreover, total membrane proteins data are similar to previous described. The normalized alkenals levels are significantly enhanced in hyperlipemic patients in comparison to normoglyceridemic controls. After the 4-hydroxytyrosol action, lipid metabolites substantially decrease. The ratio of oxidized lipids (MDA + HNE) and membrane proteins data are similar to previously described ones.Conclusion:According to experimental data, the accumulation of the alkenals in RBC membrane could be produced either by partial PUFA oxidation contained in glycerides and plasma glycerides and by glycerides into plasma membrane recycled RBC.SUMMARY Hypertriglyceridemia induces oxidative stress in human red blood cell (RBC) membranesOxidative stress causes increased plasma membrane total protein concentration and hydroxynonenal and malondialdehyde levelsThe authors optimize the isolation of RBC ghosts and spectrophotometric method to measure free 4-hydroxyalkenals in human RBC membranesAfter the reduction with 4-hydroxytyrosol, oxidized lipid concentration significantly decrease. Abbreviations used: RBC: Red blood cell; MDA: Malondialdehyde; HNE\\HAE: 4-hydroxyalkenals; LPO: Lipid peroxidation; ROS: Reactive oxygen species; ORAC: Oxygen Radical Absorbance Capacity.

Effects of hypoxia and dietary vitamin E on growth performance and oxidative status of Cirrhinus mrigala (Ham., 1822)

Vitamin E is of importance for several physiological processes, some of which also apply to fish. Here, we conducted an experiment to assess the effect of environmental hypoxia and dietary vitamin E on oxidative status and tissue injury in a bottom dwelling carp,Cirrhinus mrigala(Ham., 1822). The four treatments combined oxygen availability (Normoxia/Hypoxua) and Vitamin E presence/absence. Lipid peroxidation parameters such as thiobarbituric acid reactive substances (TBAR), peroxide value (PV), polyunsaturated fatty acids/saturated fatty acid (PUFA/SFA) ratio, catalase (CAT), superoxide dismutase (SOD) and erythrocyte fragility were assessed. The results indicate that exposure to hypoxia elevates these parameters. However, the supplementation of vitamin E via the diet effectively reduced erythrocyte membrane damage (EF) and myeloperoxidase activity (MPO), which were enhanced by the exposure to hypoxia. Dietary vitamin E also improved antioxidant enzyme status in the hypoxia exposed fish, as indicated by the decreased catalase and superoxide dismutase activities. Vitamin E supplementation also compensated for increased levels of peroxide value, thiobarbituric acid reactive substances, and an increased polyunsaturated fatty acids/saturated fatty acid ratio resulting from the exposure to hypoxia. Overall, it can be concluded that fortification of vitamin E in the diet of this carp species, and possibly other fish that live under hypoxic conditions, can restore the antioxidant status and well-being to some extent.

PERUBAHAN BENTUK ERITROSIT DI GLOMERULONEFRITIS

In glomerulonephritis there are intraglomerular inflammation, cell proliferation, and hematuria. Hematuria is characterized by more than 3 (three) erythrocytes per high-power field in the urine, which indicates the pathological processes in kidney or urinary tract. The combination of mechanical damage of erythrocyte membrane through the damaged glomerular basement membrane followed by the osmotic damage when it passes through the tubular system in the hypotonic osmotic solutions causes dysmorphic morphology. Erythrocytes trapped in the Tamm-Horsfall protein will form erythrocyte casts. Dysmorphic erythrocytes and or erythrocyte casts in the urine indicate glomerular hematuria. Various forms of dysmorphic erythrocytes in the urine can be found. Acanthocytes (G1-cells) are specific for glomerular hematury. The examination of these urinary sediments can be done natively or by using automated urinalysis analyzers.

Redox-active biflavonoids from Garcinia brasiliensis as inhibitors of neutrophil oxidative burst and human erythrocyte membrane damage

Ethnopharmacological relevanceGarcinia brasiliensis, a plant native to the Brazilian Amazon Rainforest, is used in traditional medicine to treat inflammation of the urinary tract, peptic ulcers, arthritis and other conditions. Aim of the studyThe purposes of this study were to analyze the chemical constituents of G. brasiliensis branches and leaves and to evaluate the potential of isolated compounds to act as inhibitors of both the oxidative burst of stimulated neutrophils and oxidative damage in human erythrocyte membranes to verify the antioxidant and anti-inflammatory effects of this plant. Materials and methodsNeutrophils were isolated from the blood of healthy donors by Ficoll–Paque density gradient centrifugation. Superoxide anion and total reactive oxygen species (ROS) produced by stimulated neutrophils were measured by WST-1 reduction and luminol-enhanced chemiluminescence assays, respectively. Radical-induced lipoperoxidation and hemolysis were performed using erythrocytes from the blood of healthy donors. Compounds were isolated from G. brasiliensis branches and leaves by HPLC microfractionation, and structure elucidation of the isolated compounds was performed based on NMR and HR-MS analyses. ResultsThe biflavonoids procyanidin, fukugetin, amentoflavone and podocarpusflavone isolated from G. brasiliensis showed potent inhibitory effects on the oxidative burst of human neutrophils, inhibiting ROS production by 50% at 1μmolL−1. These biflavonoids also proved to be potent inhibitors of hemolysis (with 88±7% inhibition at 50µmolL−1 for procyanidin) and lipid peroxidation in human erythrocytes, with a malondialdehyde level (a biomarker of oxidative stress) of 8.5±0.3nmol/mg Hb at 50µmolL−1 for procyanidin. ConclusionsThese findings indicate that the biflavonoids extracted from G. brasiliensis branches and leaves modulate oxidative stress via inhibition of NADPH oxidase and ROS production by stimulated human neutrophils. Furthermore, the biflavonoids exhibited potent inhibition of oxidant hemolysis and lipid peroxidation induced by AAPH in human erythrocytes. Therefore, these studies suggest the use of G. brasiliensis extract as an antioxidant and anti-inflammatory agent.