Hemolysis Of Erythrocytes Research Articles

Sulfated polysaccharides from the viscera of Mustelus shark: Characterization and antioxidant, anticoagulant and anti-proliferative activities

In the present study, sulfated polysaccharides (SPs) from smooth hound shark were extracted using different precipitation agents, the cetylpyridinium chloride (CPC) or ethanol, named SHSP-I and SHSP-II, respectively. The UV–visible scan demonstrated the absence of nucleic acids or proteins in the extracted SHSPs. The antioxidant, anticoagulant and anti-proliferative activities were also investigated. Results showed that SHSPs displayed reducing and scavenging capacities, as shown by the oxygen radical absorbance capacity, the total antioxidant capacity and the hydroxyl radical-scavenging activities. Moreover, extracted SPs were able to prolong the activated partial thromboplastin time (aPTT), the prothrombin time (PT) and the thrombin time (TT) and they reduced the fibrinogen level (FL), without inducing erythrocytes hemolysis, which indicated that they inhibited the intrinsic and extrinsic coagulation pathways and the thrombin-mediated fibrin formation. The SHSP-I was more effective on prolonging the blood clotting time, by more than 120 s at 1 mg/ml in the aPTT and about 70 s and 60 s at 2.5 mg/ml in the PT and TT, respectively, compared to the SHSP-II. The anti-proliferative activity of SHSPs was tested against the growth of K562 human myelogenous leukemia cells and Caco-2 colon cancer cells. Data showed that both polysaccharides have a dose-dependent inhibitory effect, where SHSP-I exhibited the strongest activity against the tested cells and the K562 was more sensitive than Caco-2 line cells to the action of SHSPs. The overall data suggested that SPs from shark viscera could be useful as natural nutraceutical agents.

Assessment Hemolytic Effect of Lead, Cadmium and Copper on Erythrocytes of Pregnant Women

Background: Heavy metals are naturally occurring elements characterized by their elevated density and atomic weight. These elements are present in varying proportions within the Earth's soil and rock formations, their distribution contingent upon geographical location. Heavy metals, such as arsenic, lead, cadmium, copper, and mercury, have been identified as substances that can adversely affect the reproductive system. These heavy metals are particularly harmful to the developing fetus. Objective: to assess the hemolytic effect of lead cadmium copper on the erythrocytes of pregnant women and study reduced glutathione concentration in pregnant women with anemia compared with healthy pregnant. Material and method: Blood samples were collected from pregnant women around Kirkuk governorate, Iraq. In addition to 30 samples for glutathione estimation (15 from anemia pregnant women and 15 from control). The study concerns the effect of different concentrations of single metal (20, 40, 60, 80, and 100) mM from Pb, (20, 15,10,5, and 1 ) mM from Cd, and (10, 7, 5, 3 and 1) mM from Cu individually on the erythrocytes hemolysis. Also, this study concerns the effect of the combined metals on the hemolysis of erythrocytes, which represent double (Cd: Pb) ,(Pb: Cu) &(Cd: Cu), and triple (Pb:Cd: Cu) metals with different concentrations on erythrocytes hemolysis. Glutathione concentration estimated in three trimesters in pregnant with anemia compared to healthy pregnant Results: The results showed that the hemolysis achieved by accessing the concentration of the metals, with (100) mM pb the range of hemolysis is between (94-96)% of the three trimesters, with (20) mM Cd the range of hemolysis is between (89-99)% of the three trimesters and (10) mM Cu the range of hemolysis is between (65-76)% of 3 trimesters, effect of the metals in first trimester Cd(99%) Pb(94%) Cu(65%), second trimester Cd(97%) Pb( 96\%) Cu(76%) and third trimester Pb(96\%)$>>$Cd(89\%)$>>$Cu(72\%). The levels of GSH that there were indicated non-significant ( p 0.05) difference in all patients and subdivided trimesters compared to the control.

A Systematic Review on the Hemolytic Effect of Bisphenol-A on Human Erythrocytes (<em>In-vitro</em>)

Bisphenol A (BPA) is a high-production volume industrial chemical, and human exposure to BPA is essentially ubiquitous with the increased use of BPA-associated products. Though the ubiquitous nature of BPA exposure has resulted in circulating levels of BPA, as reported in numerous biomonitoring studies, a limited number of studies have been carried out to investigate the impact of BPA on human red blood cells. Yet the findings remain ambiguous. Thus, this study aimed to systematically review the published literature on the hemolytic activity of BPA on human erythrocytes. A systematic review of published literature was conducted following the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) approach. A comprehensive search of the literature was undertaken using Google Scholar, PubMed and Research Gate for studies published from 2015 to September 2023. The keywords "human erythrocytes", "Bisphenol-A", "in vitro", and "hemolysis" were included in the search. The search identified a total of 933 articles (PubMed = 3, research gate=99, and Google Scholar = 831). After following the exclusion and inclusion criteria, four full papers were entitled to review. In these four studies, they have incubated isolated human red blood cells with varying concentrations for different durations. BPA showed a dose-dependent and time-dependent hemolytic activity in-vitro on human erythrocytes. Reasons for BPA-induced hemolysis in erythrocytes involve the generation of reactive oxygen species. As there are contradictory observations, meta-analysis is recommended. However, no comprehensive investigations have been carried out to evaluate the impact of BPA on human red blood cells under physiological concentrations so far. Consequently, it is recommended that further research in this area be undertaken to provide a more robust understanding of the physiological implications of BPA exposure on red blood cell function.

Coumarins derived from natural methoxystilbene as oxidative stress-related disease alleviators: Synthesis and in vitro-in silico study

3,4,5-Trimethoxy-3′-hydroxy-4′-methoxystilbene (TMHMS) is an anticancer natural stilbene that targets tubulin polymerization. According to research, oxidative stress and inflammation are linked to cancer, and lowering both of these hazards may have a detrimental influence on tumor development. TMHMS was used as a building block in this investigation to generate 28 coumarins with increased medicinal value. TMHMS-COU-1, the first coumarin derivative, was activated by thionyl chloride and subsequently linked with different phenols, yielding 27 TMHMS-COU variants. This natural product was used as a reference for oxidative stress-alleviated activities such as anticancer activity against eight cancerous cellular lines, antioxidant activity on H2O2-treated human SH-SY5Y populations, and anti-inflammatory activity against three enzyme-based representatives of inflammation. TMHMS and its coumarins were tested for their impact on the normal development of three cell types as well as human erythrocyte hemolysis in biocompatibility tests. Finally, utilizing two web-based programs, the pharmacokinetic profiles of the building component and its variants were computed. The inclusion of an electron-donating group on the off-side aromatic ring directly boosted the oxidative stress-alleviated activities, according to the results. These activities were also boosted when this group occupied the para or meta position. When this aromatic ring was trisubstituted with this group type, the greatest activities were found, with the trimethoxy aromatic ring having preferential activities. In terms of biocompatibility, the synthesized coumarins showed a high level of compatibility with the tested normal cells as well as human erythrocytes. Furthermore, the in silico research confirmed the synthesized coumarins' ability to provide prospective therapeutic candidates. According to the author, the coumarin-structural change might open the way for the development of novel, powerful, and biosafe TMHMS derivatives. This work provided various insights into the structure-function connections that can direct subsequent studies on TMHMS-based derivatives.

Effect of Rhesus factor incompatibility on maternal outcome (fertility): A comprehensive review

Rh incompatibility, also known as Rh disease, is defined as a condition that occurs when a woman with Rh-negative blood type is exposed to Rh-positive blood cells, leading to the development of Rh antibodies. The incidence of occurrence is more frequently among those of Caucasian (North American and European) descent (15% to 17%) compared to those of African (4% to 8%) or Asian descent (0.1% to 0.3%). Worldwide, the prevalence of Rh disease is estimated to be 276 per 100,000 live births, which is significant considering that an estimated 50% of untreated cases of haemolytic disease of the neonate (HDN). HDN will either die or develop brain damage due to the disease. The condition is due to: If a Rhesus negative (Rh-) woman is impregnated by a man with Rhesus negative (Rh-) there wouldn’t be any problem. If a Rhesus negative woman (Rh-) is impregnated by a man with Rhesus positive (Rh+) and the baby inherited the rhesus positive (Rh+) from the father there will be a problem or when an Rh-negative mother is exposed to the Rh D antigen, the D antigen is perceived as a foreign threat leading to the haemolysis of the fetal erythrocytes, common signs and symptom include; Jaundice, a yellowing of the skin and whites of the eyes, lethargy, heart failure, enlarged organs. It can be prevented and treated by administering an injection of RhoGAM during the second trimester, and 28th week of pregnancy respectively, exchange transfusions either before birth or after delivery. Phototherapy is also another treatment modality which break down excess bilirubin into less toxic substance that the new borns liver can remove.

TISSUE ENGINEERING MATRIX BASED ON POLYURETHANE: IN VITRO RESEARCH

HighlightsThe article focuses on a new polyurethane-based material that has been developed and tested in vitro. This highly porous material with satisfactory physical and mechanical, hemocompatibility and matrix properties, obtained by using an electrospinning method, is suitable for the fabrication of cardiovascular products. AbstractAim. To manufacture a polyurethane-based tissue engineered matrix and study its physical and mechanical characteristics, hemocompatibility and matrix properties in comparison with decellularized xenopericardium and sheep carotid artery.Methods. Matrices based on polyurethane were produced by electrospinning. The surface structure was studied by scanning electron microscopy, the physical and mechanical characteristics were studied using a Zwick/Roell Universal testing machine, hemocompatibility was studied according to ISO 10993-4-2020, and the matrix properties of the material were studied in a cell experiment with Ea.hy 926.Results. The structure of the 12% polyurethane matrix was represented by a fibrous network with interpenetrating pores. The physical and mechanical characteristics of polyurethane matrices corresponded to the parameters of the carotid artery of sheep more than xenopericardium. Polyurethane had optimal hemocompatibility: hemolysis of erythrocytes did not exceed 0.52%, platelet aggregation corresponded to the aggregation of platelet-rich plasma – 80%. Platelet adhesion to the surface of the polyurethane matrix is statistically significantly lower than adhesion to the xenopericardium (p = 0.0041). Cell adhesion, viability and metabolic activity of Ea.hy 926 cultured on the surface of polyurethane matrices were higher relative to xenopericardium: cell density was 236.3 [198.5; 264.6] cells/mm2 (p = 0.458), viability 19.0 [16.0; 25.0] % (p = 0.0145).Conclusion. Physical and mechanical characteristics, hemocompatibility and matrix properties of polyurethane confirmed its suitability for potential use for the needs of cardiovascular surgery.

Жовчнокам'яна хвороба в дітей

The prevalence of gallstone disease among children is 0.13-1.9%. Cholelithiasis in children is a multifactorial disorder. Scientific data analysis indicates a diversity of pathogenetic mechanism of gallstone formation. The purpose of the review is to summarize the scientific data about risk factors, clinical features, diagnosis and treatment of gallstone disease in children. Based on the literature data, the main factors for the disease are genetic, metabolic, low-calorie diet, nutritional disorders, liver and small intestine diseases. The main pathogenetic mechanisms of gallstone formation are liver dyscholia, disorders of enterohepatic circulation of bile acids, increased erythrocyte hemolysis and erythrocyte enzyme system insufficiency, a decrease in hepatic enzyme activity, impairment of gallbladder motility due to decreased sensitivity to cholecystokinin. Most children undergo asymptomatic gallstone disease: clinical features are absent, concrements in the gallbladder or bile ducts appear as accidental findings during ultrasound examination. The first stage of diagnosing cholelithiasis is an abdominal ultrasound examination. In case of absence of concrements during ultrasound examination and presence of typical clinical picture of cholelithiasis, endoscopic ultrasound and magnetic resonance cholangiopancreatography are prescribed. To reduce biliary pain, non-steroidal anti-inflammatory drugs and analgesics are required. The only way to treat symptomatic form of gallstone disease is cholecystectomy. The asymptomatic form is subject to observation without treatment. For the treatment and prevention of cholelithiasis, it is not recommended to take bile acid preparations due to the low effectiveness and frequency of relapses in the formation of stones after their complete dissolution. Conclusions. The incidence of gallstone disease among children and adolescents increases and more than half of patients has asymptomatic form. During the treatment of patients with cholelithiasis, cholecystectomy or observation tactics are used, depending on the clinical form of the disease. Prevention of gallstone disease relies on healthy lifestyle, weight loss for the obese children, physical activity, diet high in fiber and calcium. The authors declare that they have no conflicts of interest.

Characterization of Nanoprecipitated PET Nanoplastics by 1H NMR and Impact of Residual Ionic Surfactant on Viability of Human Primary Mononuclear Cells and Hemolysis of Erythrocytes.

Manufactured nanoplastic particles (NPs) are indispensable for in vitro and in vivo testing and a health risk assessment of this emerging environmental contaminant is needed. The high surface area and inherent hydrophobicity of plastic materials makes the production of NPs devoid of any contaminants very challenging. In this study, we produced nanoprecipitated polyethylene terephthalate (PET) NPs (300 nm hydrodynamic diameter) with an overall yield of 0.76%. The presence of the ionic surfactant sodium dodecyl sulfate (SDS) was characterized by 1H NMR, where the relative ratio of NP/surfactant was monitored on the basis of the chemical shifts characteristic of PET and SDS. For a wide range of surfactant/NP ratios (17:100 to 1.2:100), the measured zeta potential changed from -42.10 to -34.93 mV, but with an NP concentration up to 100 μg/mL, no clear differences were observed in the cellular assays performed in protein-rich media on primary human cells. The remaining impurities contributed to the outcome of the biological assays applied in protein-free buffers, such as human red blood cell hemolysis. The presence of SDS increased the NP-induced hemolysis by 1.5% in protein-rich buffer and by 7.5% in protein-free buffer. As the size, shape, zeta potential, and contaminants of NPs may all be relevant parameters for the biological effects of NPs, the relative quantification of impurities exemplified in our work by the application of 1H NMR for PET NPs and the ionic surfactant SDS could be a valuable auxiliary method in the quality control of manufactured NPs.

SPECTROPHOTO AND DIGITAL COLORIMETRIC DETERMINATION INDICATOR OF BETA-ADRENOREACTIVITY OF ERYTHROCYTE MEMBRANES OF PATIENTS WITH BRONCHIAL ASTHMA

The change in the adrenoreactive properties of membrane and cellular structures under the influence of catecholamines makes it possible to consider the beta-adrenergic reactivity of the erythrocyte membrane (-ARM) as a systemic indicator of the organism's adrenoreactivity. To assess adrenoreactivity, a technique is used based on a quantitative assessment of the degree of inhibition of hypoosmotic hemolysis of erythrocytes in vitro in the presence of the beta-blocker propranolol. The article presents data on the comparison of spectrophoto- and colorimetric determination of erythrocyte membrane beta-adrenoreactivity based on the registration of erythrocyte hemolysis with digital signal processing. A smartphone was used to register the images of the analyzed samples. Photography was carried out in a special box under standard lighting conditions. The chromaticity of the obtained images was evaluated using the Photoshop program within the RGB color model intended for computer color rendering. The obtained RGB values were used for quantitative determinations. The study was performed on 20 blood samples of patients suffering from bronchial asthma. The discrepancy between the results of determining -ARM using the colorimetric and spetrophotometric methods was no more than 5.6%, which indicates the possibility of replacing the spectrophotometer with image registration in digital format using software.

Physiological Responses in Broiler Chickens Administered Lycopene During the Hot-Dry Season

Abstract This study evaluates the effects of lycopene administration on body weight, mortality, cloacal temperature, and haematological responses, in broiler chickens exposed to heat stress. 40 day-old broiler chicks were divided into control and lycopene groups, 20 chickens each. Each bird in the control group received olive oil (1 ml.kg−1), and lycopene at 10 mg.kg−1 mixed with olive oil was given to each bird in the lycopene group by oral gavage once daily for 28 days. The dry- and wet-bulb temperature of the broiler chickens’ pen was recorded three times daily from days 8 to 28. The body weights were measured weekly. The incidence of mortality was recorded. The cloacal temperatures were measured on days 14, 21 and 28. The blood samples were collected for haematological analyses, on day 28. The results indicated a high overall temperature-humidity index (31.24 ± 0.43 oC) of the thermal micro-environment of the broiler chickens. There was no significant difference (P > 0.05) in body weight. The percentage mortality in the control group was relatively higher compared to the lycopene group. Lycopene reduced the cloacal temperature responses and the daily fluctuations in broiler chickens. The decreased (P < 0.05) heterophil:lymphocyte ratio and percentage erythrocytes haemolysis were recorded in the lycopene group. In conclusion, lycopene administration reduced mortality and improved cloacal temperature and haematological responses without exerting any significant beneficial or negative effects on the body weight in broiler chickens exposed to heat stress.

Impaired Hemoglobin Clearance By Liver Sinusoidal Endothelium Promotes Liver Damage in Sickle Cell Disease

Sickle cell disease (SCD) is a monogenic disorder that affects 100,000 African Americans and millions of people worldwide. Intra-erythrocytic polymerization of sickle hemoglobin (HbS) promotes erythrocyte sickling, impaired rheology, ischemia and hemolysis, leading to the development of progressive liver injury in SCD. Liver resident macrophages and monocytes are known to enable the clearance of HbS, however, the role of liver sinusoidal endothelial cells (LSECs) in HbS clearance and liver injury in SCD remains unknown. Using real-time intravital ( in vivo) imaging of the liver as well as primary culture of human and mice LSECs, we show for the first time that liver injury is associated with accumulation of HbS and iron in the LSECs, leading to the development of senescence in LSECs. Hepatic monocytes were observed to attenuate LSEC-senescence by accelerating HbS clearance in the liver of SS mice, however, this protection was impaired in P-selectin-deficient SCD mice secondary to reduced monocyte recruitment in the liver. These findings are the first to suggest that LSECs contribute to HbS clearance and LSEC-senescence promotes progressive liver injury in SS mice. Our results reveal a novel insight into the pathogenesis of hemolysis induced chronic liver injury in SCD caused by LSEC senescence. Identifying the regulators of LSEC mediated HbS clearance may lead to new therapies to prevent the progression of liver and other organ injuries in SCD.

Influence of metabolic acidosis on erythrocyte addrenoreactivity in newborn

The aim of this work was to study the indicators of adrenoreactivity in the residual cord blood of full-term newborns, depending on the degree of acidosis. The study of the acid-base state and gases of the residual umbilical cord blood of newborns made it possible to evaluate the indicators of the diagnostic criteria for acidosis and highlight the degree of its severity in children at birth. Adrenoreactive properties of erythrocytes were assessed by the method of quantitative assessment of the degree of inhibition of hypoosmotic hemolysis of erythrocytes in the presence of beta-blockers and adrenoreactivity of the body was determined in 58 newborns. It was established that the violation of metabolic processes in the body of newborns was accompanied by activation of the sympathoadrenal system to varying degrees. The increase in metabolic acidosis in children is associated with a decrease in the body’s adrenoreactivity. The level of indicators of β-ARM of erythrocytes depends on the severity and duration of hypoxia.

Impaired hemoglobin clearance by sinusoidal endothelium promotes vaso-occlusion and liver injury in sickle cell disease.

Sickle cell disease (SCD) is a monogenic disorder that affects 100,000 African-Americans and millions of people worldwide. Intra-erythrocytic polymerization of sickle hemoglobin (HbS) promotes erythrocyte sickling, impaired rheology, ischemia and hemolysis, leading to the development of progressive liver injury in SCD. Liver-resident macrophages and monocytes are known to enable the clearance of HbS; however, the role of liver sinusoidal endothelial cells (LSEC) in HbS clearance and liver injury in SCD remains unknown. Using real-time intravital (in vivo) imaging in mice liver as well as flow cytometric analysis and confocal imaging of primary human LSEC, we show for the first time that liver injury in SCD is associated with accumulation of HbS and iron in the LSEC, leading to senescence of these cells. Hemoglobin uptake by LSEC was mediated by micropinocytosis. Hepatic monocytes were observed to attenuate LSEC senescence by accelerating HbS clearance in the liver of SCD mice; however, this protection was impaired in P-selectin-deficient SCD mice secondary to reduced monocyte recruitment in the liver. These findings are the first to suggest that LSEC contribute to HbS clearance and HbS-induced LSEC senescence promotes progressive liver injury in SCD mice. Our results provide a novel insight into the pathogenesis of hemolysis-induced chronic liver injury in SCD caused by LSEC senescence. Identifying the regulators of LSEC-mediated HbS clearance may lead to new therapies to prevent the progression of liver injury in SCD.

The Effect of Photoperiod Duration on Humoral Innate and Humoral Adaptive Immune Responsiveness in Campbell’s Dwarf Hamster

We studied the humoral innate immune responsiveness (HII), i.e. a hemolysis of rabbit erythrocytes by complement proteins, and adaptive humoral (antibody production) immune responsiveness (AHI) to SRBC, morphological and hormonal reproductive characteristics and stress level in male Campbell hamsters kept under long-day (LD; 16D: 8N) and short-day (SD; 8D: 16N) photoperiods. The results indicate lower HII, but not AHI in SD. In SD males we observed body mass, anogenital distance, midventral gland size and level of testosterone in the peripheral blood (but not the level of cortisol) decreased. Comparison of SD non-responders, SD responders and LD individuals demonstrated a statistically significant increase of HII in SD photosensitive hamsters, but not in non-responders compared to LD. There was no link between HII and AHI, which indicates an independent photoperiodic responsiveness of different branches of the immune system in Campbell’s hamster.

Antioxidant and Antiradical Properties of Rhabdosciadium anatolyi Flowers and Contents of Vitamin, Trace Element and Mineral

The aim of this study was to investigate the antioxidant and antiradical activity of the Rhabdosciadium anatolyi (R. anatolyi) flowers, an endemic plant grown in the Eastern Anatolia Region of Turkey, by determining the level of vitamins E and C, mineral (Ca, Na, Mg, P, K), and trace elements (Mn, Zn, Cu, Fe, V, Cr, Mo, Co, Sr, Pb, Ti, Tl, Sn, Cd, As). Within the scope of the study, mineral and trace element analyzes were carried out by ICP-OES and AAS, Vitamin E by HPLC, Vitamin C, total phenolic content, total flavonoid, antioxidant capacity, hydrogen peroxide, DPPH, ABTS, superoxide, hydroxyl and hemolysis of erythrocytes with phenylhydrazine, radical scavenging activity of the R. anatolyi flowers methanol extract were determined spectrophotometrically. According to the results, α-tocopherol, ascorbic acid, phenolic content, flavonoid content and total antioxidant activity of the R. anatolyi flowers were 3,99 ± 0,35 µmol kg-1, 346.27 ± 6.51 mg 100 g-1, 21.94 ± 0.37 mg gallic acid g-1, 5.60 ± 0.13 mg quercetin g-1 ve 29.65 ± 0.26 mM ascorbic acid g-1, respectively. Consequently, the mineral, trace element, vitamin E and vitamin C, total phenol and flavonoid levels in the R. anatolyi flowers were high, and the R. anatolyi flowers methanol extract effectively inhibited free radicals. From this point of view, it is thought that it can be used in the preventive treatment of many diseases that may be caused by free radical species and that these data will be a reference for other studies.

Prehemolytic impact of phenothiazine drugs on the attachment of spectrin network in red blood cells.

Chlorpromazine, thioridazine, and trifluoperazine are phenothiazine drugs that cause colloid-osmotic hemolysis of human erythrocytes by unknown mechanism. To clarify this mechanism, the impact of these drugs on the βsp (1.4 MHz) and γ1sp (9 MHz) dielectric relaxations was investigated. Each relaxation was shown to reduce its strength on the severing specific bridge that connects the spectrin network with the lipid membrane. For βsp relaxation, this is the spectrin-actin-glycophorin C bridge while for γ1sp relaxation this is the spectrin-ankyrin-band 3 bridge.

Therapeutic Dosage of Antipsychotic Drug Aripiprazole Induces Persistent Mitochondrial Hyperpolarisation, Moderate Oxidative Stress in Liver Cells, and Haemolysis.

Aripiprazole has fewer metabolic side effects than other antipsychotics; however, there are some severe ones in the liver, leading to drug-induced liver injury. Repeated treatment with aripiprazole affects cell division. Since this process requires a lot of energy, we decided to investigate the impact of aripiprazole on rat liver cells and mitochondria as the main source of cellular energy production by measuring the mitochondrial membrane potential, respiration, adenosine triphosphate (ATP) production, oxidative stress, antioxidative response, and human blood haemolysis. Here, we report that mitochondrial hyperpolarisation from aripiprazole treatment is accompanied by higher reactive oxygen species (ROS) production and increased antioxidative response. Lower mitochondrial and increased glycolytic ATP synthesis demand more glucose through glycolysis for equal ATP production and may change the partition between the glycolysis and pentose phosphate pathway in the liver. The uniform low amounts of the haemolysis of erythrocytes in the presence of aripiprazole in 25 individuals indicate lower quantities of the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH+H+), which is in accordance with a decreased activity of glucose 6-phosphate dehydrogenase and the lower dehydrogenase activity upon aripiprazole treatment. The lower activity of glucose 6-phosphate dehydrogenase supports a shift to glycolysis, thus rescuing the decreased mitochondrial ATP synthesis. The putative reduction in NADPH+H+ did not seem to affect the oxidised-to-reduced glutathione ratio, as it remained equal to that in the untreated cells. The effect of aripiprazole on glutathione reduction is likely through direct binding, thus reducing its total amount. As a consequence, the low haemolysis of human erythrocytes was observed. Aripiprazole causes moderate perturbations in metabolism, possibly with one defect rescuing the other. The result of the increased antioxidant enzyme activity upon treatment with aripiprazole is increased resilience to oxidative stress, which makes it an effective drug for schizophrenia in which oxidative stress is constantly present because of disease and treatment.

The monosialoganglioside GM1a protects against complement attack

The complement system is a part of the innate immune system in the fluid phase and efficiently eliminates pathogens. However, its activation requires tight regulation on the host cell surface in order not to compromise cellular viability. Previously, we showed that loss of placental cell surface sialylation in mice in vivo leads to a maternal complement attack at the fetal-maternal interface, ultimately resulting in loss of pregnancy. To gain insight into the regulatory function of sialylation in complement activation, we here generated trophoblast stem cells (TSC) devoid of sialylation, which also revealed complement sensitivity and cell death in vitro. Glycolipid-analysis by multiplexed capillary gel electrophoresis coupled to laser-induced fluorescence detection (xCGE-LIF) allowed us to identify the monosialoganglioside GM1a as a key element of cell surface complement regulation. Exogenously administered GM1a integrated into the plasma membrane of trophoblasts, substantially increased binding of complement factor H (FH) and was sufficient to protect the cells from complement attack and cell death. GM1a treatment also rescued human endothelial cells and erythrocytes from complement attack in a concentration dependent manner. Furthermore, GM1a significantly reduced complement mediated hemolysis of erythrocytes from a patient with Paroxysmal nocturnal hemoglobinuria (PNH). This study demonstrates the complement regulatory potential of exogenously administered gangliosides and paves the way for sialoglycotherapeutics as a novel substance class for membrane-targeted complement regulators.

Hemolysis by Saponin Is Accelerated at Hypertonic Conditions.

Saponins are a large group of organic amphiphilic substances (surfactants) mainly extracted from herbs with biological activity, considered as one of the main ingredients in numerous remedies used in traditional medicine since ancient times. Anti-inflammatory, antifungal, antibacterial, antiviral, antiparasitic, antitumor, antioxidant and many other properties have been confirmed for some. There is increasing interest in the elucidation of the mechanisms behind the effects of saponins on different cell types at the molecular level. In this regard, erythrocytes are a very welcome model, having very simple structures with no organelles. They react to changing external conditions and substances by changing shape or volume, with damage to their membrane ultimately leading to hemolysis. Hemolysis can be followed spectrophotometrically and provides valuable information about the type and extent of membrane damage. We investigated hemolysis of erythrocytes induced by various saponin concentrations in hypotonic, isotonic and hypertonic media using measurements of real time and end-point hemolysis. The osmotic pressure was adjusted by different concentrations of NaCl, manitol or a NaCl/manitol mixture. Unexpectedly, at a fixed saponin concentration, hemolysis was accelerated at hypertonic conditions, but was much faster in NaCl compared to mannitol solutions at the same osmotic pressure. These findings confirm the colloid-osmotic mechanism behind saponin hemolysis with pore formation with increasing size in the membrane.

Alpha hemolysin of E. coli induces hemolysis of human erythrocytes independently of toxin interaction with membrane proteins

Alpha hemolysin (HlyA) is a hemolytic and cytotoxic protein secreted by uropathogenic strains of E. coli. The role of glycophorins (GPs) as putative receptors for HlyA binding to red blood cells (RBCs) has been debated.Experiments using anti-GPA/GPB antibodies and a GPA-specific epitope nanobody to block HlyA-GP binding on hRBCs, showed no effect on hemolytic activity. Similarly, the hemolysis induced by HlyA remained unaffected when hRBCs from a GPAnull/GPBnull variant were used. Surface Plasmon Resonance experiments revealed similar values of the dissociation constant between GPA and either HlyA, ProHlyA (inactive protoxin), HlyAΔ914-936 (mutant of HlyA lacking the binding domain to GPA) or human serum albumin, indicating that the binding between the proteins and GPA is not specific.Although far Western blot followed by mass spectroscopy analyses suggested that HlyA interacts with Band 3 and spectrins, hemolytic experiments on spectrin-depleted hRBCs and spherocytes, indicated these proteins do not mediate the hemolytic process.Our results unequivocally demonstrate that neither glycophorins, nor Band 3 and spectrins mediate the cytotoxic activity of HlyA on hRBCs, thereby challenging the HlyA-receptor hypothesis. This finding holds significant relevance for the design of anti-toxin therapeutic strategies, particularly in light of the growing antibiotic resistance exhibited by bacteria.