Osmotic Fragility Research Articles

Reproducibility of Naked Eye Single Tube Red cell Osmotic Fragility Test (NESTROFT) as a screening test for the detection of b thalassemia and Hemoglobin E traits with the variation of reading time

Background: Though 0.36% NaCl buffered solution has been used as an effective reagent for carrying out Naked Eye Single Tube Red cell Osmotic Fragility Test (NESTROFT) as a screening test for the detection of b thalassemia and Hemoglobin E traits, reading time for its interpretation is yet to be settled. Methods: This cross -sectional analytic study was done at Department of Pediatric Hematology and Oncology, BSMMU from January 2006-June 2007. NESTROFT was performed in 3 separate tubes for each of the 100 subjects (with â thalassemia trait and HbE trait and normal hemoglobin) with 0.36% NaCl buffered solution and reading was taken at different time at 5-minute, 15-minuteand 30-minute. Results were recorded as positive and negative. Hb electrophoresis, Hemogram with RBC indices for each sample and iron profile of selected subjects were done. Results: Among the 100 study subjects, 48 were carriers (18 were â thalassemia traits, 30 were Hb E traits). Age range was 1 to 52 yrs. Mean Hemoglobin concentration, MCV, MCH of both b thalassemia and Hb E carrier were significantly lower than normal subjects (p values <. 001). At 5-minute observation, NESTROFT was positive in 17 out of 18 â thalassemia traits with a sensitivity of 94.4%, 24 out of 30 HbE traits gave positive result with a sensitivity of 80%. Among the 52 normal subjects 35 gave negative result with a specificity of 67%. Positive predictive value and negative predictive value for detection of b thalassemia traits and HbE traits were 50% & 97% and 58% and 85%respectively. Result of NESTROFT interpreted at 15-minute and 30-minute did not show any change. Conclusion: From this study it may be concluded that for interpretation of NESTROFT reading at 5-minute would be optimum. BANGLADESH J CHILD HEALTH 2022; VOL 46 (3) : 130-137

Evaluation of anti-sickling effects of two varieties of Cajanus cajan (L.) Huth on sickle cell beta thalassemia

Ethno-pharmacological relevance: Globally, the prevalence of sickle cell disease is on the rise, with developing countries experiencing particularly alarming mortality rate compared to developed nations. The World Health Organization (WHO) and United Nations (UN) have acknowledged sickle cell disease as a significant global public health concern. Unfortunately, a cure for this condition is yet to be discovered, and existing allopathic treatments, while offering relief, come with serious side effects. In recent times, there has been a growing interest in exploring the potential of medicinal plants for treating sickle cell disease due to their content of secondary metabolites that may impact the disease's mechanisms. Cajanus cajan, a crucial grain legume in rain-fed agriculture in semi-arid tropics, has been traditionally used in folk medicine to manage various illnesses and is suggested to possess anti-sickling properties.Aim of the study: The present study investigated two varieties of C. cajan for their effectiveness in treating sickle cell beta thalassemia, a variant of sickle cell disease. Materials and methodsThe study was divided into four groups consisting of the untreated group (group 1), group treated with standard drug (group 2), group treated with white C. cajan (group 3) and group treated with brown C. cajan (group 4). The effects of the two variety of C. cajan were measured by polymerization test, reversibility test, osmotic fragility test, deoxygenation and beta globin synthesis test. ResultThe results revealed that both varieties of C. cajan demonstrated a reduction in polymerization rates, reversed sickled red blood cells, increased the oxygen affinity of Hb-S/β, elevated the Fe2+/Fe3+ ratio, and maintained the membrane stability of red blood cells. Notably, the white variety exhibited superior anti-sickling properties compared to the brown variety. ConclusionThis suggests that this significant leguminous crop could be utilized for the treatment and management of sickling disorders, particularly in low-income countries where conventional treatments may be financially inaccessible to patients.

Membrane-Bound Ferric Hemoglobin in Nucleated Erythrocytes of the Black Scorpionfish Scorpaena porcus, Linnaeus 1758.

The content of membrane-bound methemoglobin (MtHb) in nucleated erythrocytes was studied in the black scorpionfish Scorpaena porcus (Linnaeus, 1758) in vitro. Spectral characteristics were determined for a whole hemolysate, a hemolysate obtained by stroma precipitation (a clarified hemolysate), and a resuspended stroma. The MtHb proportion in the erythrocyte stroma was found to exceed 80% (6.20 ± 0.59 µM). Clarified hemolysates were nearly free of MtHb (0.5 ± 0.2 µM). Membrane-bound ferric hemoglobin did not affect the erythrocyte resistance to osmotic shock. The osmotic fragility range was determined using a LaSca-TM laser microparticle analyzer (BioMedSystems, Russia) to be 102-136 mOsm/kg, much the same as in other bony fish species. A nitrite load (10 mg/L) significantly increased the MtHb content in the blood. However, the membrane-bound ferric hemoglobin content did not change significantly, amounting to 6.34 ± 1.09 µM (approximately 95%). The finding suggested a functional importance for MtHb present in the plasma membrane of nucleated erythrocytes. Membrane-bound MtHb was assumed to neutralize the external oxidative load and the toxic effect of hydrogen sulfide in bottom water layers, where the species lives.

Identifying toxic effects and metabolic perturbations of Duttaphrynus melanostictus skin extracts in human erythrocytes.

Skin secretions of toads are widely used in medicine all over the world for their antiviral, anti-infective, and cardiotonic properties. Because these secretions are mostly employed to combat blood parasite infection, it is important to understand their potential toxic effects on human erythrocytes. Therefore, the objective of the current investigation was to elucidate the effects of Duttaphrynus melanostictus (Schneider) skin extracts on the physiology of human erythrocytes. Toads captured from their natural habitat were separated into three groups according to their body size. Hydroalcoholic extracts of toad skin were prepared by reflux heating. These extracts were then evaluated for their hemolytic and hemoglobin denaturation potential. The effects of the extracts on cytosolic and membrane-bound enzymes of human erythrocytes were assessed. The hemolysis and hemoglobin denaturation caused by these extracts correlated positively with the respective toad sizes. Extracts from medium and large toads led to increased osmotic fragility even at near iso-osmotic concentrations. Biochemical analysis of hemolysate showed that the treatment induced a shift of metabolic flux toward the glutathione pathway. Analysis of membrane-bound enzymes revealed a significant decrease in the activity of Na+/K+ ATPase and acetylcholinesterase. SDS-PAGE analysis of the erythrocyte membrane did not show the band of tropomodulin for the cells treated with 1000 𝜇g/ml extract from large toads. In conclusion, the present study demonstrates that the toxicity of toad skin secretions aggravates with the size of the animal and interferes with the physiology of human erythrocytes, leading to their membrane disruption and rapid lysis.

Intelligent berberine-loaded erythrocytes attenuated inflammatory cytokine productions in macrophages

Erythrocytes are impressive tools for drug delivery, especially to macrophages. Therefore, berberine was loaded into erythrocytes using both hypotonic pre-swelling and endocytosis methods to target macrophages. Physicochemical and kinetic parameters of the resulting carrier cells, such as drug loading/release kinetics, osmotic fragility, and hematological indices, were determined. Drug loading was optimized for the study using Taguchi experimental design and lab experiments. Loaded erythrocytes were targeted to macrophages using ZnCl2 and bis-sulfosuccinimidyl-suberate, and targeting was evaluated using flow cytometry and Wright–Giemsa staining. Differentiated macrophages were stimulated with lipopolysaccharide, and the inflammatory profiles of macrophages were evaluated using ELISA, western blotting, and real-time PCR. Findings indicated that the endocytosis method is preferred due to its low impact on the erythrocyte’s structural integrity. Maximum loading achieved (1386.68 ± 22.43 μg/ml) at 1500 μg/ml berberine treatment at 37 °C for 2 h. Berberine successfully inhibited NF-κB translation in macrophages, and inflammatory response markers such as IL-1β, IL-8, IL-23, and TNF-α were decreased by approximately ninefold, sixfold, twofold, eightfold, and twofold, respectively, compared to the LPS-treated macrophages. It was concluded that berberine-loaded erythrocytes can effectively target macrophages and modulate the inflammatory response.

Hereditary spherocytosis due to a novel variant, p.Q1034X, in the beta subunit of the spectrin gene: A case report

BackgroundHeterozygous pathogenic variants of SPTB cause hereditary spherocytosis (HS) in a quarter of cases. Case reportA 14-day-old male presenting with persistent anemia and hyperbilirubinemia was diagnosed with HS by increased red blood cell osmotic fragility and decreased fluorescence on the eosin-5′-maleimide binding test. For his failure to thrive and hypotonia, genetic sequencing revealed a de novo variant of the SPTB gene (p.Q1034X) on exon 15. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. A variant of uncertain significance (p.R438W) in the chondroitin sulfate synthase 1 (CHSY1) gene was incidentally found. Loss of CHSY1 is associated with autosomal recessive Temtamy preaxial brachydactyly syndrome (TPBS). However, this patient's heterozygosity and lack of typical TPBS phenotype make this variant less likely the cause of his symptoms. ConclusionFurther investigation can evaluate a potential link between the patient's presentation and these gene variants.

The Effect of Chronic Levetiracetam Use on Erythrocyte Deformability

ABSTRACT Background: The inhibition of carbonic anhydrase (CA) isoenzymes is one of the targets in the development of new antiepileptics. Levetiracetam (LEV) is a new-generation antiepileptic drug frequently used in pediatric patients. It has a strong inhibitory effect on CA enzymes in many tissues, including erythrocytes. Objective: Due to CA enzymes have physical connection with the erythrocyte membrane and cytoskeleton, we aimed to evaluate the probable effect of LEV on the erythrocyte deformability. Materials and Methods: This study was conducted in the Experimental Animal Laboratory of Ankara Training and Research Hospital 24 prepubertal female Wistar albino rats were divided into four groups with six animals in each group. Group I: Control (distilled water), Group II: LEV50 (50 mg/kg/day), Group III: LEV150 (150 mg/kg/day), Group IV: LEV300 (300 mg/kg/day). The calculated dose for each animal was given by oral gavage once a day for 14 days, which is accepted as chronic use in experimental models. At the end of the treatment period, erythrocyte deformability was evaluated both with whole blood viscosity at high shear rates, and osmotic fragility test. Results: No statistically significant difference was found between the groups in terms of osmotic fragility. Whole blood and plasma viscosity values also did not show any statistically significant difference between the groups. Conclusion: In this study, it has been shown that LEV does not have a negative effect on erythrocyte deformability. Therefore, we thought that it may be a good choice when an antiepileptic is needed in pediatric patients with hematological disorders.

The effect of preanalytical phase on the stability of the osmotic fragility and morphological changes in erythrocytes in cattle (Bos taurus)

Hereditary spherocytosis in cattle is a disorder that results from a nonsense mutation in SLC4A1 gene that encodes band 3 membrane protein. This membranopathy leads to a production of spherically-shaped RBCs with reduced deformability and shorter lifespan in circulation. The laboratory diagnosis of hereditary spherocytosis commonly rely on erytrocyte osmotic fragility test (OFT), which is time and work consuming and can be influenced by the preanalytical factors. The aim of the study was to determine the effect of the preanalytical phase on the stability of the osmotic fragility and morphological changes of bovine erythrocytes. The blood was collected from the tail vein from Holstein-Friesian cows (n = 20) into tubes with EDTA or lithium heparin. The erythrocyte resistance to hemolysis was measured by osmotic fragility test immediately after blood collection and 24, 48 and 72 hours after storage at 4oC or room temperature. The thin blood smears were also prepared, stained and examined for cell morphology.The results showed that bovine erythrocyte osmotic fragility remains stable during 24 hours storage at 4oC regardless of the anticoagulant used. It suggests the possibility of performing OFT the day after blood collection when storing blood at 4oC. It was also found that bovine erythrocytes stored at room temperature have reduced osmotic resistance. However, heparin better preserves osmotic resistance of bovine erythrocytes at room temperature. Erythrocytes that are stored undergo changes during the storage period. The microscopic examination of cell morphology revealed the transformation of bovine discocytes into different stages of echinocytes, which rapidly occurs during the first three days of storage.

Effect of mangostin on the functional activity and integrity of the <i>Plasmodium falciparum</i> infected and Uninfected red blood cells membrane

Mangostin is a natural xanthanoid obtained from various parts of the mangosteen tree Garcinia mangostana with diverse medicinal effects, such as; antioxidant, antibacterial, anticancer and anti- inflammatory. This study aimed at exploring its impact on the integrity, and the physiological function of both Plasmodium falciparum-infected and uninfected red blood cells (RBCs). This was achieved by studying its impact on the RBCs morphology, integrity and osmotic fragility. On the one hand, its effect on the plasmodium-infected cells was achieved by screening its impact on the parasite-induced new permeation pathways (NPPs) and the plasmodial invasiveness to the RBCs and these were related to its growth inhibitory effect against the parasite. On the other hand, its molecular characteristics were determined using the In Silico Molispiration simulation software and its anti-oxidant activity was measured using conventional in vitro tests and the anti-lipid peroxidation assay. The results showed that mangostin had a good growth inhibitory effect against Plasmodium falciparum with a moderate selectivity as compared to its effect against RBCs. Furthermore, it showed a good inhibitory effect against merozoite invasion and the plasmodium-induced new permeation pathway at concentrations less than the cytotoxic dose against RBCs and the parasite. Besides it succeeded in hampering the oxidative stress- induced RBCs damage without affecting the RBC fragility when it was added at low doses. Overall, the results suggest that their anti-plasmodium effect is not related to their impact on the RBCs membrane. Further studies are recommended to explore their precise mechanism of action.

Environmental cadmium exposure perturbs systemic iron homeostasis via hemolysis and inflammation, leading to hepatic ferroptosis in common carp (Cyprinus carpio L.)

Cadmium (Cd) pollution is considered a pressing challenge to eco-environment and public health worldwide. Although it has been well-documented that Cd exhibits various adverse effects on aquatic animals, it is still largely unknown whether and how Cd at environmentally relevant concentrations affects iron metabolism. Here, we studied the effects of environmental Cd exposure (5 and 50 μg/L) on iron homeostasis and possible mechanisms in common carp. The data revealed that Cd elevated serum iron, transferrin saturation and iron deposition in livers and spleens, leading to the disruption of systemic iron homeostasis. Mechanistic investigations substantiated that Cd drove hemolysis by compromising the osmotic fragility and inducing defective morphology of erythrocytes. Cd concurrently exacerbated hepatic inflammatory responses, resulting in the activation of IL6-Stat3 signaling and subsequent hepcidin transcription. Notably, Cd elicited ferroptosis through increased iron burden and oxidative stress in livers. Taken together, our findings provide evidence and mechanistic insight that environmental Cd exposure could undermine iron homeostasis via erythrotoxicity and hepatotoxicity. Further investigation and ecological risk assessment of Cd and other pollutants on metabolism-related effects is warranted, especially under the realistic exposure scenarios.

Hypoxia leads to gill endoplasmic reticulum stress and disruption of mitochondrial homeostasis in grass carp (Ctenopharyngodon idella): Mitigation effect of thiamine

Hypoxia in water environment is one of the important problems faced by intensive aquaculture. Under hypoxia stress, the effects of dietary thiamine were investigated on grass carp gill tissue damage and their mechanisms. Six thiamine diets with different thiamine levels (0.22, 0.43, 0.73, 1.03, 1.33 and 1.63 mg/kg) were fed grass carp (Ctenopharyngodon idella) for 63 days. Then, 96-hour hypoxia stress test was conducted. This study described that thiamine enhanced the growth performance of adult grass carp and ameliorated nutritional status of thiamine (pyruvic acid, glucose, lactic acid and transketolase). Additionally, thiamine alleviated the deterioration of blood parameters [glutamic oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), glucose, cortisol, lactic dehydrogenase (LDH), erythrocyte fragility, and red blood cell count (RBC count)] caused by hypoxia stress, and reduced reactive oxygen species (ROS) content and oxidative damage to the gills. In addition, thiamine alleviated endoplasmic reticulum stress in the gills, which may be related to its inhibition of RNA-dependent protein kinase-like ER kinase (PERK)/eukaryotic translation initiation factor-2α (eIF2α)/activating transcription factor4 (ATF4), inositol-requiring enzyme 1 (IRE1)/X-Box binding protein 1 (XBP1) and activating transcription factor 6 (ATF6) pathways. Furthermore, thiamine maintaining mitochondrial dynamics balance was probably related to promoting mitochondrial fusion and inhibiting mitochondrial fission, and inhibiting mitophagy may involve PTEN induced putative kinase 1 (PINK1)/Parkin-dependent pathway and hypoxia-inducible factor (HIF)-Bcl-2 adenovirus E1B 19 kDa interacting protein 3 (BNIP3) pathway. In summary, thiamine alleviated hypoxia stress in fish gills, which may be related to reducing endoplasmic reticulum stress, regulating mitochondrial dynamics balance and reducing mitophagy. The thiamine requirement for optimum growth [percent weight gain (PWG)] of adult grass carp was estimated to be 0.81 mg/kg diet. Based on the index of anti-hypoxia stress (ROS content in gill), the thiamine requirement for adult grass carp was estimated to be 1.32 mg/kg diet.

Influence of lactation stages on erythrocyte osmotic fragility of indigenous Badri cattle of Uttarakhand

The aim of this study was to evaluate the influence of lactation stages on erythrocyte osmotic fragility. The study was carried out using forty healthy Badri cows divided into five groups with eight animals in each group during different stages of lactation, viz. 1 (0 to 60 days), 2 (61 to 120 days), 3 (121 to 180 days), 4 (181 to 240 days) and 5 (non-lactating animals) as control animals. The per cent haemolysis of erythrocytes among different lactation groups was found significant at 0.9% during mid and early late lactation i.e. 2 and 3 group and 0.5% saline concentration during all stages of lactation as well as non- lactating animals.

Complete Blood Count in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic disease that affects the central nervous system in primarily young adults. Although the exact etiology of MS is unknown, autoimmune mechanisms are thought to play a crucial role, especially with CD4+ T cells involved in the immune response. Inflammatory reactions involving T cells and macrophages are commonly observed in MS lesions. B lymphocytes, plasma cells, and antibodies also contribute to MS pathogenesis. Neutrophils, lymphocytes, monocytes, and platelets, key immune system components, play roles in inflammatory processes, but their association with MS prognosis remains inconclusive. Due to its heterogeneous nature, clinical manifestations of MS vary depending on the location of the affected central nervous system. While several potential biomarkers have been identified for MS diagnosis and monitoring, none have been universally accepted. Studies have examined complete blood count parameters in MS patients, including erythrocyte, platelet, and leukocyte populations. Changes in these parameters have been observed in MS patients compared to healthy controls and may be related to disease prognosis. For example, increased erythrocyte fragility and altered hemoglobin levels have been reported in MS patients. Leukocyte counts and ratios, such as the neutrophil/lymphocyte ratio, have shown associations with disease severity. Platelet activation and interaction with immune cells have also been implicated in MS pathophysiology. Nevertheless, further research is needed to fully understand the role of complete blood count parameters in MS. Identifying reliable biomarkers for early diagnosis and prognosis prediction would greatly enhance MS management. Moreover, these benefits could lead to substantial improvements in achieving complete recovery of patients, surpassing the focus on current symptomatic treatments.

Allicin (diallylthiosulfinate) Restores the Altered Lipid Profile, Erythrocyte Fragility and Permeability in 7,12-dimethylbenz(a)anthracene-induced Hamster Buccal Pouch Carcinogenesis

Allicin (diallylthiosulfinate) Restores the Altered Lipid Profile, Erythrocyte Fragility and Permeability in 7,12-dimethylbenz(a)anthracene-induced Hamster Buccal Pouch Carcinogenesis

Red cell concentrates from teen male donors contain poor-quality biologically older cells.

Donor factors influence the quality characteristics of red cell concentrates (RCCs) and the lesions that develop in these heterogeneous blood products during hypothermic storage. Teen male donors' RCCs contain elevated levels of biologically old red blood cells (RBCs). The aim of this study was to interrogate the quality of units of different donor ages and sexes to unravel the complex interplay between donor characteristics, long-term cold storage and, for the first time, RBC biological age. RCCs from teen males, teen females, senior males and senior females were density-separated into less-dense/young (Y-RBCs) and dense/old RBCs (O-RBCs) throughout hypothermic storage for testing. The unseparated and density-separated cells were tested for haematological parameters, stress (oxidative and osmotic) haemolysis and oxygen affinity (p50). The O-RBCs obtained from teen donor samples, particularly males, had smaller mean corpuscular volumes and higher mean corpuscular haemoglobin concentrations. While biological age did not significantly affect oxygen affinity, biologically aged O-RBCs from stored RCCs exhibited increased oxidative haemolysis and decreased osmotic fragility, with teenage male RCCs exhibiting the highest propensity to haemolyse. Previously, donor age and sex were shown to have an impact on the biological age distribution of RBCs within RCCs. Herein, we demonstrated that RBC biological age, particularly O-RBCs, which are found more prevalently in male teens, to be a driving factor of several aspects of poor blood product quality. This study emphasizes that donor factors should continue to be considered for their potential impacts on transfusion outcomes.

Functional effects of an African glucose-6-phosphate dehydrogenase (G6PD) polymorphism (Val68Met) on red blood cell hemolytic propensity and post-transfusion recovery.

Donor genetic variation is associated with red blood cell (RBC) storage integrity and post-transfusion recovery. Our previous large-scale genome-wide association study demonstrated that the African G6PD deficient A- variant (rs1050828, Val68Met) is associated with higher oxidative hemolysis after cold storage. Despite a high prevalence of X-linked G6PD mutation in African American population (>10%), blood donors are not routinely screened for G6PD status and its importance in transfusion medicine is relatively understudied. To further evaluate the functional effects of the G6PD A- mutation, we created a novel mouse model carrying this genetic variant using CRISPR-Cas9. We hypothesize that this humanized G6PD A- variant is associated with reduced G6PD activity with a consequent effect on RBC hemolytic propensity and post-transfusion recovery. G6PD A- RBCs had reduced G6PD protein with ~5% residual enzymatic activity. Significantly increased in vitro hemolysis induced by oxidative stressors was observed in fresh and stored G6PD A- RBCs, along with a lower GSH:GSSG ratio. However, no differences were observed in storage hemolysis, osmotic fragility, mechanical fragility, reticulocytes, and post-transfusion recovery. Interestingly, a 14% reduction of 24-h survival following irradiation was observed in G6PD A- RBCs compared to WT RBCs. Metabolomic assessment of stored G6PD A- RBCs revealed an impaired pentose phosphate pathway (PPP) with increased glycolytic flux, decreasing cellular antioxidant capacity. This novel mouse model of the common G6PD A- variant has impaired antioxidant capacity like humans and low G6PD activity may reduce survival of transfused RBCs when irradiation is performed.

Toward Translational Impact of Low-Glucose Strategies on Red Blood Cell Storage Optimization.

Transfusion of stored red blood cells (RBCs) to patients is a critical component of human healthcare. Following purification from whole blood, RBCs are stored in one of many media known as additive solutions for up to 42 days. However, during the storage period, the RBCs undergo adverse chemical and physical changes that are often collectively known as the RBC storage lesion. Storage of RBCs in additive solutions modified to contain physiological levels of glucose, as opposed to hyperglycemic levels currently used in most cases, reduces certain markers of the storage lesion, although intermittent doses of glucose are required to maintain normoglycemic conditions. Here, we describe an electrically actuated valving system to dispense small volumes of glucose into 100 mL PVC storage bags containing packed RBCs from human donors. The RBCs were stored in a conventional additive solution (AS-1) or a normoglycemic version of AS-1 (AS-1N) and common markers of stored RBC health were measured at multiple time points throughout storage. The automated feeding device delivered precise and predictable volumes of concentrated glucose to maintain physiological glucose levels for up to 37 days. Hemolysis, lactate accumulation, and pH values of RBCs stored in AS-1N were statistically equivalent to values measured in AS-1, while significant reductions in osmotic fragility and intracellular sorbitol levels were measured in AS-1N. The reduction of osmotic fragility and oxidative stress markers in a closed system may lead to improved transfusion outcomes for an important procedure affecting millions of people each year.

Evaluation of the biological safety of the extract of Senegalia bahiensis (Benth.) Seigler & Ebinger

The use of medicinal plants is recurrent for the treatment of various diseases, however, despite being a natural resource, they can cause adverse effects, depending on the way they are administered. Senegalia bahiensis is an angiosperm belonging to the Fabaceae family, with no records in the literature about its cytotoxic potential. The objective of this study was to evaluate the biological safety of S. bahiensis extract through cytotoxicity assays: hemolytic activity and osmotic fragility. At a concentration of 1000 ug/mL, the extract showed a high hemolytic rate for types A and O erythrocytes. The hemolytic activity was low at other concentrations, while the extract's concentrations of 10 and 100 ug/mL used for the anti-hemolytic assay did not protect erythrocytes against osmotic lysis. The results demonstrated that S. bahiensis extract is not safe at the highest concentrations tested in vitro, moreover, it did not show a cytoprotective effect. Therefore, further investigation regarding the cytotoxicity of this specimen is necessary, and its use must be cautious.

Alteration in the number, morphology, function, and metabolism of erythrocytes in high-altitude polycythemia.

Introduction: High-altitude polycythemia (HAPC) is a common chronic high-altitude disease characterized by significantly increased erythrocyte, hemoglobin (Hb), and hematocrit values and decreased arterial oxygen saturation. The mechanisms underlying HAPC development are unclear; we aimed to investigate this in an HAPC rat model. Methods: Twelve Sprague-Dawley rats were divided into control and HAPC groups. The HAPC group was exposed to hypobaric hypoxia. This HAPC model was assessed using routine blood tests and blood gas analyses. Bone marrow, peripheral blood reticulocytes (RETs), and peripheral blood erythrocyte apoptosis were measured using flow cytometry. Erythrocyte osmotic fragility (EOF) tests were conducted. Abnormal erythrocytes were counted using electron microscopy. Plasma-free hemoglobin, 5'-nucleotidase (CD73), adenosine, erythrocyte cytosolic adenosine, sphingosine-1-phosphate (S1P), and 2,3-bisphosphoglycerate (BPG) levels were measured using enzyme-linked immunosorbent assays. Erythrocyte metabolic pathway-related protein [adenosine A2B receptor (ADORA2B), erythrocyte equilibrative nucleoside transporter 1 (eENT1), sphingosine kinase 1 (SPHK1), phospho-SPHK1, bisphosphoglycerate mutase (BPGM), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH)] levels were assessed by Western blotting. Results: The HAPC rat model was successfully established (Hb > 210g/L). Indices of bone marrow and peripheral blood RET proportions were significantly higher in the HAPC than the control group (p = 0.04 and p < 0.001, respectively). The proportion of peripheral blood erythrocytes in early apoptosis was significantly lower in the HAPC than the control group (p < 0.001). Vesicular erythrocyte and acanthocyte proportions were significantly higher in the HAPC than the control group (p < 0.001 and p = 0.019, respectively). The EOF tests revealed that 50% erythrocyte hemolysis occurred at 4.0-4.5 and 4.5-5.0g/L NaCl in the control and HAPC groups, respectively. Plasma-free hemoglobin, CD73, adenosine, erythrocyte cytosolic adenosine, S1P, and 2,3-BPG levels and ADORA2B, eENT1, phospho-SPHK1, S1P, BPGM, and GAPDH erythrocyte expression levels (all p ≤ 0.02) were significantly higher in the HAPC than the control group. Conclusion: In model rats, an HAPC-related erythrocyte increase was associated with enhanced bone marrow hematopoietic function and reduced erythrocyte apoptosis, whereas numerous abnormal erythrocytes, increased EOF, and reduced hemolysis resistance were associated with erythrocyte metabolism. CD73/adenosine/S1P/2,3-BPG and eENT1/adenosine/BPGM/2,3-BPG metabolic pathways in erythrocytes were activated in HAPC rats, facilitating oxygen release. These findings further reveal the intrinsic HAPC mechanism and forms a basis for future development of preventive and therapeutic strategies for HAPC.

Preliminary monosodium glutamate-induced changes in mammary gland receptors and gene expression, water channel, oxidative stress, and some lactogenic biomarkers in lactating rats

BackgroundChanges induced by monosodium glutamate (MSG) can negatively impact milk production and secretion, among other adverse effects. This study aimed to investigate the effects of MSG consumption on receptor gene expression and quantification of hormones and receptors, as well as oxidative stress biomarkers and other lactogenic parameters in lactating animals. Twenty-four female Wistar rats, nine weeks of age, were randomly assigned to four groups, each containing six rats, at parturition. The rats in groups II, III, and IV were given varying doses of monosodium glutamate (MSG); while, group I was given distilled water and served as the control. The experimental period lasted two (2) weeks.ResultsThe groups administered with MSG showed a significant decrease in mammary PRLR gene expression (p < 0.05), as well as a marked reduction (p < 0.05) in mammary PRLR, OXT receptor, AQP-3, brain antioxidant enzymes (SOD, GPx, and CAT), and pituitary SOD compared to the control group (p < 0.05). Furthermore, there was a significant increase (p < 0.05) in reactive oxygen species levels in the serum and mammary gland homogenates, erythrocyte osmotic fragility, and elevated (p < 0.05) brain and pituitary MDA levels in the MSG-administered groups compared to the control group. Daily milk yields were significantly decreased (p < 0.05) in the MSG-administered groups between days 10 and 14 of lactation.ConclusionThe findings of this study suggest that prolonged consumption of MSG could interfere with lactation-associated functions via increased ROS production, reduced antioxidants, decreased AQP-3, mammary prolactin and oxytocin receptors, and prolactin receptor mRNA in lactating Wistar rats.Graphical