Mechanism of hypoxia-induced damage to the mechanical property in human erythrocytes-band 3 phosphorylation and sulfhydryl oxidation of membrane proteins.

Introduction: The integrity of the erythrocyte membrane cytoskeletal network controls the morphology, specific surface area, material exchange, and state of erythrocytes in the blood circulation. The antioxidant properties of resveratrol have been reported, but studies on the effect of resveratrol on the hypoxia-induced mechanical properties of erythrocytes are rare. Methods: In this study, the effects of different concentrations of resveratrol on the protection of red blood cell mor-phology and changes in intracellular redox levels were examined to select an appropriate concentration for further study. The Young's modulus and surface roughness of the red blood cells and blood viscosity were measured via atomic force microsco-py and a blood rheometer, respectively. Flow cytometry, free hemoglobin levels, and membrane lipid peroxidation levels were used to characterize cell membrane damage in the presence and absence of resveratrol after hypoxia. The effects of oxida-tive stress on the erythrocyte membrane proteins band 3 and spectrin were further investigated by immunofluorescent label-ing and Western blotting. Results and discussion: Resveratrol changed the surface roughness and Young's modulus of the erythrocyte mem-brane, reduced the rate of eryptosis in erythrocytes after hypoxia, and stabilized the intracellular redox level. Further data showed that resveratrol protected the erythrocyte membrane proteins band 3 and spectrin. Moreover, resistance to band 3 pro-tein tyrosine phosphorylation and sulfhydryl oxidation can protect the stability of the erythrocyte membrane skeleton net-work, thereby protecting erythrocyte deformability under hypoxia. The results of the present study may provide new insights into the roles of resveratrol in the prevention of hypoxia and as an antioxidant.

Hormonal Control of Blood Viscosity.

The hemodynamic milieu differs throughout the vascular tree because of varying vascular geometry and blood velocities. Accordingly, the risk of turbulence, which is dictated by the Reynolds and Dean numbers, also varies. Relatively high blood viscosity is needed to prevent turbulence in the left ventricle and aorta, where high-velocity blood changes direction several times. Low blood viscosity is needed in the capillaries, where erythrocytes pass through vessels with a diameter smaller than their own. In addition, higher blood viscosity is necessary when the cardiac output and peak blood velocity increase as a part of a sympathetic response or anemia, which occurs following significant hemorrhage. Blood viscosity, as reflected in systemic vascular resistance and vascular wall shear stress, is sensed, respectively, by cardiomyocyte stretching in the left ventricle and mechanoreceptors for wall shear stress in the carotid sinus. By controlling blood volume and red blood cell mass, the renin-aldosterone-angiotensin system and the systemic vascular resistance response control the hematocrit, the strongest intrinsic determinant of blood viscosity. These responses provide gross control of blood viscosity. Fine-tuning of blood viscosity in transient conditions is provided by hormonal control of erythrocyte deformability. The short half-life of some of these hormones limits their activity to specific vascular beds. Hormones that modulate blood viscosity include erythropoietin, angiotensin II, brain natriuretic factor, epinephrine, prostacyclin E2, antidiuretic hormone, and nitric oxide.

HIIT serves as an efficient training strategy for basketball players by improving blood fluidity and decreasing oxidative stress.

BACKGROUND: A challenge for coaches and athletes is to find the best combination of exercises during training. Considering its favorable effects, HIIT has been very popular recently. OBJECTIVE: The goal of this study was to investigate anthropometric features, performance, erythrocyte deformability, plasma viscosity (PV) and oxidative stress in response to acute and long-term (6 weeks) HIIT in adolescent basketball players. METHODS: 22 sportsmen between the ages of 14-16 were included. Tabata protocol was applied to the HIIT group in addition to their routine training program 3 days/week, for 6 weeks. Erythrocyte deformability was determined using an ectacytometer (LORCA), PV with a rotational viscometer. Total oxidant status (TOS), total antioxidant status (TAS) were measured by kits. RESULTS: HIIT for 6 weeks induced an improvement in performance tests and waist circumference. 6 weeks of HIIT resulted in a decrement, while the last exercise session yielded an increment in RBC deformability. PV and TOS of HIIT groups were decreased on the 6th week. CONCLUSIONS: Our results demonstrate that, HIIT in addition to the routine exercise program is beneficial for improving performance and blood fluidity as well as decreasing oxidative stress in basketball players. Therefore, HIIT seems as an efficient training strategy for highly-trained individuals.

Diseased Erythrocyte Enrichment Based on I-Shaped Pillar DLD Arrays.

Enrichment of erythrocytes is a necessary step in the diagnosis of blood diseases. Due to the high deformability and viscosity of erythrocytes, they cannot be regarded as stable point-like solids, so the influence of their deformability on fluid dynamics must be considered. Therefore, by using the special effect of an I-shaped pillar (I-pillar) on erythrocytes, erythrocytes with different deformability can be made to produce different provisional distances in the chip, so as to achieve the separation of the two kinds of erythrocytes. In this study, a microfluidic chip was designed to conduct a control test between erythrocytes stored for a long time and fresh erythrocytes. At a specific flow rate, the different deformable erythrocytes in the chip move in different paths. Then, the influence of erythrocyte deformability on its movement trajectory was analyzed by two-dimensional finite element flow simulation. DLD sorting technology provides a new method for the sorting and enrichment of diseased erythrocytes.

Investigation of hemorheological parameters in patients with major depressive disorder.

BACKGROUND: Hemorheological parameters have been reported to be altered in cardiovascular disease. Major depression has been associated with increased risk of cardiovascular disease. OBJECTIVE: Our hypothesis is that hemorheological parameters are disturbed in major depressive disorder. METHODS: Major depressive disorder and control groups consisted of 50 subjects. Plasma viscosity, erythrocyte aggregation, erythrocyte deformability, hematological parameters and hematological parameters were examined. RESULTS: Plasma viscosity was statistically significantly higher, erythrocyte elongation index at 0.53 Pa and 0.95 Pa was lower, and MCV, MCH, and MCHC values were also lower in the major depression group (P <  0.05). Elongation index and plasma viscosity were correlated with depressive symptomatology. CONCLUSIONS: The increased plasma viscosity and decreased elongation index of erythrocytes indicate an unfavorable hemorheological situation in patients with major depressive disorder compared with healthy controls. The results of this study confirm the findings of studies finding a potential threat to cardiovascular health from major depressive disorder. Increased plasma viscosity and decreased erythrocyte elongation index in depressed patients may be risk factors for cardiovascular events and provide data on the causality of the association between depression and cardiovascular disease.

New Onset Anemia, Worsened Plasma Creatinine Concentration, and Hyperviscosity in a Patient With a Monoclonal IgM Paraprotein.

A 76-year-old female followed closely for five years with IgM monoclonal gammopathy of uncertain significance developed anemia, worsened plasma creatinine concentration, and markedly elevated serum viscosity. This case illustrates the scope of pathology that can be caused by elevated blood viscosity. Our patient's anemia was a homeostatic response to normalize systemic vascular resistance and resulted from activation of the systemic vascular resistance response. The elevated plasma creatinine resulted from decreased renal perfusion because of elevated blood viscosity. Recent insights in hemorheology (the study of blood flow) are discussed, namely the recent identification of preferential blood flow patterns and erythrocyte autoregulation of deformability. These insights confirm that blood viscosity is part of the "milieu intérieur."

Aging in Normotensive and Spontaneously Hypertensive Rats: Focus on Erythrocyte Properties.

Erythrocyte deformability, crucial for oxygen delivery to tissues, plays an important role in the etiology of various diseases. As the factor maintaining the erythrocyte deformability, nitric oxide (NO) has been identified. Reduced NO bioavailability also plays a role in the pathogenesis of hypertension. Our aim was to determine whether aging and hypertension affect erythrocyte deformability and NO production by erythrocytes in experimental animals divided into six groups according to age (7, 20 and 52 weeks), labeled WKY-7, WKY-20 and WKY-52 for normotensive Wistar-Kyoto (WKY) rats, and SHR-7, SHR-20 and SHR-52 for spontaneously hypertensive rats (SHR). The filtration method for the determination of erythrocyte deformability and the fluorescent probe DAF-2 DA for NO production were applied. Deformability and NO production by erythrocytes increased at a younger age, while a decrease in both parameters was observed at an older age. Strain-related differences in deformability were observed at 7 and 52 weeks of age. SHR-7 had reduced deformability and SHR-52 had increased deformability compared with age-matched WKY. Changes in NO production under hypertensive conditions are an unlikely primary factor affecting erythrocyte deformability, whereas age-related changes in deformability are at least partially associated with changes in NO production. However, an interpretation of data obtained in erythrocyte parameters observed in SHRs of human hypertension requires precaution.

Red Cell Distribution Width and Elongation Index in a Cohort of Patients With Juvenile Acute Myocardial Infarction.

In a cohort of patients with juvenile myocardial infarction, we considered the red cell distribution width (RDW), hematocrit, hemoglobin, and elongation index values at the initial phase and at 3 and 12 months from the acute event. In the initial phase, only the elongation index values turn out reduced if compared with those of the control group, and that only turn out to discriminate the infarcted ST-segment elevation myocardial infarction (STEMI) from non-STEMI. Dividing the patients according to the traditional risk factors and the extent of coronary heart disease, there are no significant variations in the analyzed parameters. No major changes are observed after 12 months from the acute event. Both to 3 and to 12 months from the infarct episode, the negative statistical correlation between RDW and the value of elongation index remains. These data make us reflect on the role of the degree of anisocytosis of red blood cell expressed by the RDW on the determinism of erythrocyte deformability, which plays its role in the microcirculation district and that is essential in the transfer of tissue oxygen.

Microcirculatory and Rheological Adaptive Mechanisms at High Altitude in European Lowlander Hikers and Nepalese Highlanders.

BACKGROUND: Physical activity at high-altitudes is increasingly widespread, both for tourist trekking and for the growing tendency to carry out sports and training activities at high-altitudes. Acute exposure to this hypobaric-hypoxic condition induces several complex adaptive mechanisms involving the cardiovascular, respiratory and endocrine systems. A lack of these adaptive mechanisms in microcirculation may cause the onset of symptoms of acute mountain sickness, a frequent disturbance after acute exposure at high altitudes. The aim of our study was to evaluate the microcirculatory adaptive mechanisms at different altitudes, from 1350 to 5050 m a.s.l., during a scientific expedition in the Himalayas. METHODS: The main haematological parameters, blood viscosity and erythrocyte deformability were assessed at different altitudes on eight European lowlanders and on a group of eleven Nepalese highlanders. The microcirculation network was evaluated in vivo by conjunctival and periungual biomicroscopy. RESULTS: Europeans showed a progressive and significant reduction of blood filterability and an increase of whole blood viscosity which correlate with the increase of altitude (p < 0.02). In the Nepalese highlanders, haemorheological changes were already present at their residence altitude, 3400 m a.s.l. (p < 0.001 vs. Europeans). With the increase in altitude, a massive interstitial oedema appeared in all participants, associated with erythrocyte aggregation phenomena and slowing of the flow rate in the microcirculation. CONCLUSIONS: High altitude causes important and significant microcirculatory adaptations. These changes in microcirculation induced by hypobaric-hypoxic conditions should be considered when planning training and physical activity at altitude.

The unpredictable erythrocyte deformability alteration in some hematological disorders: How the classification of primary hyperviscosity syndromes could change.

According to Wells classification, it is possible to distinguish the primary hyperviscosity syndromes in polycythemic, sclerocythemic and sieric and/or plasmatic. In polycythemia vera, multiple myeloma, Waldenström's macroglobulinemia, and monoclonal gammopathy of undetermined significance, we have observed an unexpected behaviour of the erythrocyte deformability. This data highlights that the hemorheological alteration present in polycythemia vera has not been related to the increase of RBC mass only, as well as that present in plasmacellular dyscrasias has not been attributable to the increase of plasma viscosity only.The aim of this paper is to suggest some starting points for an accurate reflection, emphasizing the need of a revision of the current classification of primary hyperviscosity syndromes.

Erythrocyte deformability profile evaluated by laser diffractometry in patients with multiple myeloma: Re-examination of our cases.

BACKGROUND: Multiple myeloma is a complex pathology which represents about 10 % of all hematological neoplasms. It can often present changes in the hemorheological profile and, in relation to this last topic, our aim is to evaluate the hemorheological profile in a group of multiple myeloma patients, with reference to erythrocyte deformability. METHODS: We have examined the profile of the erythrocyte deformability in multiple myeloma enrolling 29 patients; this profile, expressed as elongation index at several shear stress, has been obtained using the diffractometric method. RESULTS: By comparing normal controls and MM patients, a significant decrease in erythrocyte deformability, especially at low shear stresses, but we did not observe any significant differences about this profile subdividing the whole group of MM patients according to the degree of bone marrow plasma cell infiltration, to the red blood cell distribution width and to the serum values of LDH. CONCLUSIONS: In this paper we have taken in consideration all the hypothesis for a possible explanation of the behaviour of this a reduced erythrocyte deformability in multiple myeloma. Erythrocyte deformability interferes with the physiological release of oxygen to tissues, with several clinical implications.

Red Blood Cell Distribution Width, Erythrocyte Indices, and Elongation Index at Baseline in a Group of Trained Subjects.

BACKGROUND: Regular exercise elicits adaptive changes in several organs and physiological processes, including erythrocyte properties. METHODS: In a group of 79 subjects (62 men and 17 women; mean age 31.37 ± 10.19 years) who trained several times a week as they practiced amateur sports, we evaluated the elongation index, markers of erythrocyte deformability, red blood cell distribution width (RDW), indicators of erythrocyte anisocytosis, hematocrit, hemoglobin, and the main erythrocyte indices (MCV, MCH, MCHC) in basal conditions. RESULTS: In comparison with a group of healthy, but not training, volunteers, the values of the elongation index, and not the RDW, are increased, and this datum is accompanied by an increase in MCV and MCHC, likely related to an increased presence of circulating young erythrocytes in training subjects. We also divided the same group according to the median of the VO2max, observing that the subgroup above the median shows both an increase in the elongation index values and a decrease in MCH and MCHC. CONCLUSIONS: In trained subjects, there is no correlation between the values of the elongation index and the RDW, while the interrelations among the elongation index, RDW, and main erythrocyte indices appear to be of particular interest and of a certain complexity.

Bovine erythrocytes are poor surrogates for human when exposed to sublethal shear stress.

Animal blood products are routinely used as surrogates for human tissue in haemocompatibility testing of rotary blood pumps. Bovine blood is particularly attractive due to the animal's large blood volume; however, bovine red blood cells (RBC) differ substantially from those of human, both in biophysical properties and molecular composition. We aimed to determine whether differences also exist in the sensitivity of bovine RBC to a standardised shear stress protocol. Fresh blood from healthy human and bovine donors was exposed to discrete combinations of shear stress using a Couette shearing system, prior to assessment of cellular deformability and mechanical sensitivity. Each sample was exposed to 25 sublethal shear stress combinations (ranging 60-100 Pa × 5-300 s). While bovine RBC exhibited decreased maximal elongation in the absence of conditioning shear, overall deformability at lower shears was ~1.8-fold greater than human. When exposed to any conditioning shear stresses >80 Pa (or 60-70 Pa beyond 5 s), human RBC were significantly rigidified, with greater magnitudes and prolonged exposure compounding this effect. Significantly larger shears were required to rigidify bovine RBC; the most extreme shear condition (100 Pa × 300 s) resulted in approximately three-times more rigidification of human RBC than bovine (137% and 47% respectively). Bovine RBC have superior resilience to mechanical stress when compared with human. Using bovine blood in ex vivo evaluation of rotary blood pumps may thus misrepresent and overestimate device-blood success, and may also have flow-on effects for eventual users. Fresh human blood during early-phase ex vivo testing is thus recommended, given shear-inducing blood pumps are designed for humans - not cattle.

Effects of Interval Training Under Hypoxia on the Autonomic Nervous System and Arterial and Hemorheological Function in Healthy Women.

PURPOSE: The present study verified the effects of interval training under hypoxia, a novel exercise modality for health promotion, on the autonomic nervous system (ANS) and arterial and hemorheological function in healthy women. METHODS: Twenty healthy Korean women (age: 19-29 [24.85 ± 3.84] years) were equally assigned to interval normoxic training (INT, n = 10; residing and training under normoxia) and interval hypoxic training (IHT, n = 10; residing under normoxia and training under 526 mmHg hypobaric hypoxia) groups. All participants performed 90-min of training sessions composed of 15-min of warm-up, 60-min of interval training, and 15-min of cool-down. The interval training sessions composed of 10 repetitions of interval exercise using a treadmill (5 min of exercise corresponding to 90-95% maximal heart rate [HR] and 1 min of rest). The training was performed 3 days per week for 6 weeks. All participants underwent body composition, HR variability, brachial-ankle pulse wave velocity, flow-mediated dilation (FMD), red blood cell (RBC) deformability and aggregation, and maximal oxygen uptake (VO2max) measurements before and after training. RESULTS: There were no significant differences in body composition between the groups. The IHT group showed a significant improvement in the ANS function (root mean square of successive differences, high frequency, and low frequency/high frequency ratio), arterial stiffness, arterial endothelial function (FMD), hemorheological function (RBC deformability and aggregation), and aerobic performance (VO2max) compared with the INT (all p < 0.05). CONCLUSION: In comparison with the interval training under normoxia, the interval training under hypoxia is a novel and effective exercise modality for promoting aerobic performance with the ANS and arterial and hemorheological function in healthy women.

Red Blood Cell Morphodynamics in Patients with Polycythemia Vera and Stroke.

Polycythemia vera (PV) is a Ph-negative myeloproliferative neoplasm (MPN) which is characterized by erythrocytosis and a high incidence of thrombotic complications, including stroke. The study aimed to evaluate red blood cell (RBC) morphodynamic properties in PV patients and their possible association with stroke. We enrolled 48 patients with PV in this cross-sectional study, 13 of which have a history of ischemic stroke. The control group consisted of 90 healthy subjects. RBC deformability and aggregation analysis were performed using a laser-assisted optical rotational red cell analyzer. The following parameters were calculated: aggregation amplitude (Amp), RBC rouleaux formation time constant (Tf), time of formation of three-dimensional aggregates (Ts), aggregation index (AI), rate of complete disaggregation (y-dis), and the maximal elongation of RBC (EImax). Statistical analysis was performed with the R programming language. There were significant differences in RBCs morphodynamics features between patients with PV and the control group. Lower EImax (0.47 (0.44; 0.51) vs. 0.51 (0.47; 0.54), p < 0.001) and γ-dis (100 (100; 140) vs. 140 (106; 188) s-1, p < 0.001) along with higher amplitude (10.1 (8.6; 12.2) vs. 7.7 (6.6; 9.2), p < 0.001) was seen in patients with PV compared with control. A statistically significant difference between PV patients with and without stroke in aggregation amplitude was found (p = 0.03). A logistic regression model for stroke was built based on RBC morphodynamics which performed reasonably well (p = 0.01). RBC alterations may be associated with overt cerebrovascular disease in PV, suggesting a possible link between erythrocyte morphodynamics and increased risk of stroke.

Effect of Paprika Xanthophyll Supplementation on Cognitive Improvement in a Multitasking Exercise: A Pilot Study for Middle-Aged and Older Adults.

Ingestion of paprika xanthophyll supplement (PX), which has antioxidant effects, has been recently reported to maintain red blood cell deformability and improve oxygen delivery efficiency. Therefore, we hypothesized that the brain activation induced by multitasking exercise in middle-aged and older participants along with the improved erythrocyte oxygen-carrying efficiency induced by PX supplementation would show a synergistic effect, increasing oxygen supply to the brain and improving cognitive function more effectively. In study 1, cerebral blood flow measurements were conducted during the multitasking exercise and cognitive function tests to verify their effect on cognitive function. The results confirmed that cerebral blood flow increased during the exercise and cognitive function improved after the exercise. In study 2, we compared the effects of the multitasking exercise on cognitive function before and after PX supplementation in middle-aged and older participants to evaluate the effects of PX supplementation. The results suggested that PX supplementation enhanced the effects of active multitasking exercise on cognitive function. We speculate that the improvement of oxygen transport efficiency by PX resulted in more effective oxygen supply, allowing the multitasking exercise to occur more effectively, which was reflected as an improvement in the cognitive function.

Microrheological disorders in patients with polycythemia vera suffered acute ischemic stroke.

The relevance of the study is determined by the fact that the combination of cerebrovascular disorders and myeloproliferative diseases requires the search for a predictive biomarker to improve outcomes. The aim of this article was to explore the meanings of microrheological disorders in patients with polycythemia vera (PV) who suffered an acute ischemic stroke (AIS). The study was carried out at the Research center of Neurology. We studied microrheological properties in 181 patients (aged 42-75 years). From the AIS developed in 68 (38%) patients with PV; 59 (32%) patients with AIS were without PV; 54 (30%) patients with PV did not suffer AIS. Microrheological disorders, first of all, the red blood cells (RBC) deformability correlated to AIS severity and its features in comorbid patients. The RBC deformability was dependent on the allelic load of the V617F mutation in the JAK2 gene. Additionally, it was found that RBC deformability perform diagnostic value in the acute phase of ischemic stroke as well as get predictive value for thrombotic complications development within 2 years after AIS in such patients. We suppose that in patients with PV an ischemic stroke and thrombosis would directly depend on the success of PV treatment. In turn, RBC deformability is applicable for some predictive models to late thrombosis development.

Mechanism of megaloblastic anemia combined with hemolysis.

Megaloblastic anemia (MA) patients often exhibit hemolysis, but it is not clear whether there are other hemolytic mechanisms in addition to intramedullary hemolysis. We retrospectively analyzed the clinical characteristics of 124 MA patients, measured erythrocyte physical parameters in two patients with hemolysis and one healthy volunteer by atomic force microscopy, and measured 18F-FDG uptake in one MA patient with hemolysis. In multivariate analysis, hemolysis was associated with mean corpuscular volume (MCV) and indirect bilirubin. A receiver operating characteristic curve analysis, with sensitivity of 83.1% and specificity of 68.7%, suggested that the MCV cutoff value that predicts hemolysis is 116.4 fL. Hb was negatively correlated with MCV in the hemolysis group (r = -0.317, P = 0.007) but not in the nonhemolysis group. The erythrocyte peak-valley value, average cell surface roughness and surface area in the MA patients with hemolysis were significantly lower than those in controls (P < 0.05). 18F-FDG uptake by the liver and spleen was diffuse and increased in MA patients undergoing hemolysis. MA combined with extramedullary hemolysis could be caused by macrophages removing mechanically damaged erythrocytes and the retention of erythrocytes with decreased deformability when blood circulates through narrow spaces in the liver and spleen.

Beneficial Effect of Quercetin on Erythrocyte Properties in Type 2 Diabetic Rats.

Diabetes mellitus is characterized by tissue oxidative damage and impaired microcirculation, as well as worsened erythrocyte properties. Measurements of erythrocyte deformability together with determination of nitric oxide (NO) production and osmotic resistance were used for the characterization of erythrocyte functionality in lean (control) and obese Zucker diabetic fatty (ZDF) rats of two age categories. Obese ZDF rats correspond to prediabetic (younger) and diabetic (older) animals. As antioxidants were suggested to protect erythrocytes, we also investigated the potential effect of quercetin (20 mg/kg/day for 6 weeks). Erythrocyte deformability was determined by the filtration method and NO production using DAF-2DA fluorescence. For erythrocyte osmotic resistance, we used hemolytic assay. Erythrocyte deformability and NO production deteriorated during aging-both were lower in older ZDF rats than in younger ones. Three-way ANOVA indicates improved erythrocyte deformability after quercetin treatment in older obese ZDF rats only, as it was not modified or deteriorated in both (lean and obese) younger and older lean animals. NO production by erythrocytes increased post treatment in all experimental groups. Our study indicates the potential benefit of quercetin treatment on erythrocyte properties in condition of diabetes mellitus. In addition, our results suggest potential age-dependency of quercetin effects in diabetes that deserve additional research.

Aqueous extract of chives (Allium schoenoprasum L.) plant impairs erythrocyte deformability in sickle cell patients.

Sickle cell anemia (SCA) is a genetic disorder characterized by chronic hemolysis and the presence of erythrocytes with low deformability, which may trigger vaso-occlusive crises. We tested the in-vitro effects of aqueous extract of chives (Allium schoenoprasum L.) on erythrocyte deformability of SCA patients. Blood samples from 6 apparently healthy volunteers and 5 SCA patients were collected into heparin coated tubes. Both apparently healthy and SCA patient blood samples were incubated with 80µg/mL chives plant aqueous extract at 37°C for 60 min and erythrocyte deformability was measured by ektacytometry (3 Pa and 30 Pa; 37°C). Results of incubation of apparently healthy blood samples with plant extract showed that incubation did not alter erythrocyte deformability significantly. However, for SCA blood samples, erythrocyte deformability decreased significantly with plant extract exposure at 3 Pa (p < 0.043) and 30 Pa (p < 0.043). In conclusion, although ex-vivo incubation with plant extract does not fully model gastrointestinal processing of onions, the decrease in SCA erythrocyte deformability following incubation with aqueous chives should stimulate further studies to test the in-vivo effects of this diet in sickle cell mice.