Oxidative Hemolysis Research Articles

Zawartość związków fenolowych w ekstrakcie z propolisu oraz ocena jego aktywności przeciwutleniającej i cytoochronnej względem erytrocytów ludzkich w warunkach stresu oksydacyjnego in vitro

Introduction. Propolis (bee glue) is a natural product collected by honeybees from buds of various trees, shrubs and other plant species. Extracts of propolis possess numerous biological activities, including antioxidant, antibacterial, antifungal and anticancer. For this reason, propolis is currently used in many applications, such as preparations for cold syndrome, dermatological preparations or as a constituent of nutritional supplements and health food. The chemical composition of this natural material is very complex and depending on many factors, including method of extraction and selection of the solvent for the extraction process. Aim. The aim of the study was to determine concentration of selected phenolic compounds (flavonoids and phenolic acids) in extract of Polish propolis and estimate its antioxidant activity and effect on human red blood cells. Material and methods. In the propolis extract was determined concentration of 14 flavonoids and 9 phenolic acids using ultra-performance liquid chromatography equipped with a photodiode detector and a triple quadrupole mass spectrometer. The antioxidant potential of propolis extract was evaluated applying DPPH˙ free radical scavenging activity assay and Fe3+ reducing power assay. Moreover, the cytotoxicity and cytoprotective potential of propolis extract was estimated using human erythrocytes in vitro. Results. The propolis extract contained high concentration of pinocembrin, galangin, chrysin, apigenin, kaempferol, coumaric acid and cinnamic acid. It exhibited also high antioxidant potential. The antiradical activity of examined propolis extract was equal to 75% approx. activity of both standard antioxidants used in the study, namely Trolox and BHT. The reducing power of extract was equal to 65% approx. of Trolox and 80% of BHT, respectively. The propolis extract had no hemolytic activity, moreover, effectively protected human erythrocytes against free radicals-induced damage in vitro. Conclusions. The results of this study indicate that the propolis extract of national origin is a rich source of flavonoids and phenolic acids. Therefore, the propolis extract possesses a high antioxidant potential and can protect erythrocytes against free radicals-induced oxidative hemolysis.

Novel Aminomethyl Derivatives of 4-Methyl-2-prenylphenol: Synthesis and Antioxidant Properties.

4-Methyl-2-prenylphenol (1) was synthesized from para-cresol and prenol, natural alcohol under the conditions of heterogeneous catalysis. A series of nine new aminomethyl derivatives with secondary and tertiary amino groups were obtained on the basis of compound 1. A comparative evaluation of their antioxidant properties was carried out using in vitro models. It was established that Mannich base with octylaminomethyl group has radical-scavenging activity, high Fe2+ -chelation ability as well as the ability to inhibit oxidative hemolysis of red blood cells.

In vitro and in vivo evaluation of enzymatic and antioxidant activity, cytotoxicity and genotoxicity of curcumin-loaded solid dispersions

Curcumin, the main bioactive polyphenolic compound in Curcuma longa L. rhizomes has a wide range of bioactive properties. Curcumin presents low solubility in water and thus limited bioavailability, which decreases its applicability. In this study, cytotoxic effects of curcumin solid dispersions (CurSD) were evaluated against tumor (breast adenocarcinoma and lung, cervical and hepatocellular carcinoma) and non-tumor (PLP2) cells, while cytotoxic and genotoxic effects were evaluated in Allium cepa. The effect of the CurSD on the acetylcholinesterase (AChE), butyrylcholinesterase (BChE), glutathione S-transferase (GST), and monoamine oxidase (MAO A-B) enzymes was determined, as well as its capacity to inhibit the oxidative hemolysis (OxHLIA) and the formation of thiobarbituric acid reactive substances (TBARS). CurSD are constituted by nanoparticles that are readily dispersible in water, and inhibited 24% and 64% of the AChE and BChE activity at 100 μM, respectively. GST activity was inhibited at 30 μM while MAO-A and B activity were inhibited at 100 μM. CurSD showed cytotoxicity against all the tested tumor cell lines without toxic effects for non-tumor cells. No cytotoxic and genotoxic potential was detected with the Allium cepa test. CurSD maintained the characteristics of free curcumin on the in vitro modulation of important enzymes without appreciable toxicity.

G3 sports supplement in short triathlon: improvements in training, performance, recovery and oxidative stress.

This registry study evaluated the effects of G3 Sports supplement drink (G3) on performance and endurance in triathlon in amateur athletes in a period of 2 weeks of training. G3 is composed of a proprietary fruit juice blend high in carotenoid compounds as well as 100 mg of standardized French oak (Quercus robur) wood extract, Robuvit®, per 50 mL bottle. The antioxidant and anti-inflammatory actions of the compounds in G3 may improve training efficiency (decreasing post-triathlon muscular pain, cramps and improve recovery time) and decrease post-training plasma free radicals (PFR). We selected 50 healthy subjects available to follow the registry plan (age 30-40). No clinical or risk condition were present; no medications were used. Subjects followed a free diet. None used sport supplements (aminoacids or anabolic products). The use of rehydrating drink (Polase) was suggested to all subjects. The only other admitted beverage was Gatorade for use by the control group only. Triathlon total time as well as objective markers of oxidative stress, measured as plasma concentration of free radicals (PFR), and intravascular hemolysis (hemoglobin, serum ferritin, unconjugated bilirubin (UBR) and lactate dehydrogenase (LDH) were measured. Fifty subjects were included: 25 using the supplement; 25 subjects did not use the supplement and acted as controls. Routine blood tests were normal at inclusion and after the final triathlon. The two groups were comparable considering men and women performances at inclusion and age distribution. Drinking and training regimens were comparable between the groups. No side effects or tolerance problems were reported; all G3 drinks were used as indicated. The final "measurement" run was not competitive but chronometric. All subjects completed the test. All subjects performances improved with training. The improvements were seen in parallel both in men and women. The improvement was significantly greater with G3 (P<0.05). The final variation in time was superior with G3 vs. controls (P<0.05). Oxidative stress (PFR), assessed 1 h after the final run, was higher in controls (P<0.05). The higher level of PFR may be associated to a slower recovery time after training and after the test run. After the final test run triathlon, there were no significant changes in hemoglobin or serum ferritin in both groups. Athletes using G3 had a lower variation in UBR and LDH; however, both were significantly increased in controls (P<0.05). G3 supplementation significantly improved exercise performance in two weeks training time and appeared to significantly decrease oxidative stress and hemolysis resulting from exercise.

Increased Methylation of Deamidated Asparagines and Aspartates in Stored Red Blood Cells from Glucose 6-Phosphate Dehydrogenase-Deficient Blood Donors

Blood transfusion is a life-saving intervention for millions of recipients worldwide every year. However, refrigerated storage of red blood cells (RBCs) for up to 42 days promotes impairments in energy and redox homeostasis, which impact RBC hemolytic propensity and post-transfusion performance of the storage-damaged RBC. Since mature RBCs are devoid of de novo protein synthesis - owing to the lack of organelles and nuclei - they evolved metabolic mechanisms to cope with oxidative stress. Two of these involve (i) activation of the pentose phosphate pathway (PPP), which generates reducing equivalents (NADPH) to preserve glutathione homeostasis and recharge NADPH-dependent antioxidant enzymes; and (ii) recycling of oxidatively damaged proteins via methylation of dehydrated and deamidated aspartate and asparagine residues, a process that consumes methionine as the main methyl group donor. Thus, we hypothesize that the latter mechanism is relevant to routine blood bank storage, especially in glucose-6-phosphate dehydrogenase (G6PD)-deficient donors. In this routinely accepted donor population (~10% of donors of African descent), mutations of G6PD, the rate-limiting enzyme of the PPP, result in instability and decreased enzymatic activity (e.g., <1% residual activity in the Mediterranean variant).Within the framework of the REDS-III RBC-Omics study, packed RBC units (n=599) were stored under blood bank conditions for 10, 23 and 42 days and profiled for oxidative hemolysis (following AAPH insult) and time-dependent metabolic dysregulation of the trans-sulfuration pathway. The rate of methionine consumption positively correlated with storage age and oxidative hemolysis. In a separate cohort, RBCs from G6PD-deficient and G6PD-normal donors were also collected and metabolically profiled during storage. The G6PD-deficient donors had higher pre-storage methionine levels as compared against G6PD-sufficient donors, although one week of storage was sufficient to significantly flip this ratio (p<0.01). To ensure that the phenomenon was driven by storage-induced oxidative insults, RBCs were also stored under normoxic, hyperoxic (SO2 >95%), or hypoxic conditions (SO2 = 20%, 10%, 5% of < 3%) for up to 42 days. Of note, hypoxia decreased methionine consumption rates and increased S-adenosylmethionine/S-adenosylhomocysteine ratios in comparison to normoxic control RBCs, while opposite trends were observed in response to oxidative stress. In parallel, RBCs were incubated under normoxic or hypoxic conditions for 16h, in presence or absence of a generic methyltransferase inhibitor, adenosine dialdehyde, or hydrogen peroxide (0.1 or 0.5%). 13C,15N-Methionine uptake and consumption rates were faster in response to pro-oxidant insults and were prevented by hypoxia or methyltransferase inhibition. Through a combination of proteomics approaches and 13C-methionine tracing, we observed oxidation-induced increases in both Asn deamidation to Asp and the formation of methyl-Asp on key structural proteins and enzymes, including band 3, hemoglobin, ankyrin, 4.1, spectrin beta, aldolase, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), biphosphoglycerate mutase, lactate dehydrogenase and catalase. Methylated regions tended to map proximal to the active site (e.g., N316 of GAPDH) and/or residues interacting with the N-terminal cytosolic domain of band 3. Hypoxic incubation with hydrogen peroxide phenocopied normoxic conditions in the presence of pro-oxidant insults, suggesting that the beneficial role of hypoxia in preventing methionine consumption and protein methylation is attributable to decreased oxidative stress. G6PD-deficient donor RBCs had significantly (p<0.0001) higher levels of methylated-deamidated Asn residues in hemoglobin, band 3, and GAPDH, as compared to stored G6PD-normal donor RBCs.Although methylation of basic amino acid residues is an epigenetic modification in nucleated cells, protein methylation at carboxylate side chains and deamidated Asn residues is a non-epigenetic post-translational sensor of oxidative stress and refrigerated storage in anucleate human RBCs. This damage repair mechanism is exacerbated in RBCs from G6PD-deficient donors, as a compensatory mechanism for the lack of normal PPP function. DisclosuresD'Alessandro:Hemanext inc: Membership on an entity's Board of Directors or advisory committees; Omix Technologies inc: Equity Ownership. Nemkov:Omix Technologies inc: Equity Ownership. Yoshida:Hemanext inc: Employment. Dunham:Hemanext inc: Employment. DuMont:Hemanext inc: Membership on an entity's Board of Directors or advisory committees. Hansen:Omix Technologies inc: Equity Ownership. Spitalnik:Hemanext inc: Membership on an entity's Board of Directors or advisory committees. Zimring:Rubius Therapeutics: Membership on an entity's Board of Directors or advisory committees.

Frequent blood donations alter susceptibility of red blood cells to storage- and stress-induced hemolysis.

Frequent whole blood donations increase the prevalence of iron depletion in blood donors, which may subsequently interfere with normal erythropoiesis. The purpose of this study was to evaluate the associations between donation frequency and red blood cell (RBC) storage stability in a racially/ethnically diverse population of blood donors. Leukoreduced RBC concentrate-derived samples from 13,403 donors were stored for 39 to 42 days (1-6°C) and then evaluated for storage, osmotic, and oxidative hemolysis. Iron status was evaluated by plasma ferritin measurement and self-reported intake of iron supplements. Donation history in the prior 2 years was obtained for each subject. Frequent blood donors enrolled in this study were likely to be white, male, and of older age (56.1 ± 5.0 years). Prior donation intensity was negatively associated with oxidative hemolysis (p < 0.0001) in multivariate analyses correcting for age, sex, and race/ethnicity. Increased plasma ferritin concentration was associated with increased RBC susceptibility to each of the three measures of hemolysis (p < 0.0001 for all), whereas self-reported iron intake was associated with reduced susceptibility to osmotic and oxidative hemolysis (p < 0.0001 for both). Frequent blood donations may alter the quality of blood components by modulating RBC predisposition to hemolysis. RBCs collected from frequent donors with low ferritin have altered susceptibility to hemolysis. Thus, frequent donation and associated iron loss may alter the quality of stored RBC components collected from iron-deficient donors. Further investigation is necessary to assess posttransfusion safety and efficacy in patients receiving these RBC products.

Intradonor reproducibility and changes in hemolytic variables during red blood cell storage: results of recall phase of the REDS-III RBC-Omics study.

Genetic determinants may underlie the susceptibility of red blood cells (RBCs) to hemolyze in vivo and during routine storage. This study characterized the reproducibility and dynamics of in vitro hemolysis variables from a subset of the 13,403 blood donors enrolled in the RBC-Omics study. RBC-Omics donors with either low or high hemolysis results on 4°C-stored leukoreduced (LR)-RBC samples from enrollment donations stored for 39 to 42 days were recalled 2 to 12 months later to donate LR-RBCs. Samples of stored LR-RBCs from the unit and from transfer bags were evaluated for spontaneous and stress-induced hemolysis at selected storage time points. Intradonor reproducibility of hemolysis variables was evaluated in transfer bags over two donations. Hemolysis data at serial storage time points were generated on LR-RBCs from parent bags and analyzed by site, sex, race/ethnicity, and donation frequency. A total of 664 donors were successfully recalled. Analysis of intradonor reproducibility revealed that osmotic and oxidative hemolysis demonstrated good and moderate reproducibility (Pearson's r = 0.85 and r = 0.53, respectively), while spontaneous hemolysis reproducibility was poor (r = 0.40). Longitudinal hemolysis in parent bags showed large increases over time in spontaneous (508.6%) and oxidative hemolysis (399.8%) and smaller increases in osmotic (9.4%) and mechanical fragility (3.4%; all p < 0.0001). Spontaneous hemolysis is poorly reproducible in donors over time and may depend on site processing methods, while oxidative and osmotic hemolysis were reproducible in donors and hence could reflect consistent heritable phenotypes attributable to genetic traits. Spontaneous and oxidative hemolysis increased over time of storage, whereas osmotic and mechanical hemolysis remained relatively stable.

132 - Antioxidant and anticancer activities from Stryphnodendron adstringens

Stryphnodendron adstringens is a tree species native to the Brazilian Cerrado commonly known as barbatimao or casca-da-mocidade. In traditional medicine, the stem bark of this plant are used in the treatment of several diseases. Scientifically, its antifungal, wound healing, anti-inflammatory and antidiabetic properties have already been shown. The objective of this study was assess their antioxidant activity, and anticancer effects, and chemical composition of the aqueous extract from stem bark of Stryphnodendron adstringens (SBSA). The antioxidant activity of the SBSA was assessed using two free radical scavenging methods, the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, oxidative hemolysis inhibition,and2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced lipid peroxidation inhibition in human erythrocytes. B16F10Nex-2 melanoma cells were used to assess the anticancer activity as well as the underlying mechanisms of SBSA-induced cell death. Phenolic compounds and flavonoids present in the SBSA were quantified using two colorimetric methods involving the Folin-Ciocalteu reagent and aluminum chloride complexation reaction, respectively. The concentration of phenolic compounds was 195.16 ± 0.94 mg GAE/g SBSA, and the concentration of flavonoids was 2.87 ± 0.08 mg QE/g. The SBSA showed the antioxidant activity through direct free radical scavenging as well as through oxidative hemolysis and lipid peroxidation inhibition in human erythrocytes incubated with an oxidizing agent. In addition, SBSA promoted apoptosis-induced cell death in B16F10Nex-2 by increasing the intracellular reactive oxygen species levels, inducing mitochondrial membrane potential dysfunction and activating caspase-3. Together, these data show the antioxidant and anticancer effects of the aqueous extract from stem bark of Stryphnodendron adstringens, which suggest its potential application for the treatment and/or prevention of diseases related to oxidative stress and tumor cell proliferation.

Dietary restrictions for people with glucose-6-phosphate dehydrogenase deficiency.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme deficiency in the world and renders those affected susceptible to potentially severe oxidative hemolysis. Although the resulting hemolysis is most often associated with drug exposure, it has also been reported after consumption of certain foods. With the exception of review articles that reiterated the historical knowledge that fava beans can provoke severe oxidative hemolysis in individuals with G6PD deficiency, very few articles have examined the safety of other food ingredients and food additives for people with G6PD deficiency. Some articles that associated specific foods with hemolysis appeared to be speculative and based on limited information. The objective of this review was to examine the association between foods, including food additives, and the triggering factors of acute hemolysis. The literature was searched for studies and case reports on food consumption and G6PD deficiency. In this review, fava beans were found to be the only food for which there is conclusive clinical evidence linking the risk of hemolytic anemia to individuals with G6PD deficiency. Food additives, at their permitted level of use in North America, can be consumed safely by most patients with G6PD deficiency.

Increased eryptosis in smokers is associated with the antioxidant status and C-reactive protein levels

Cigarette smoking has been linked with oxidative stress and inflammation. In turn, eryptosis, the suicidal erythrocyte death similar to apoptosis that can be triggered by oxidative stress, has been associated with chronic inflammatory diseases including atherosclerosis. However, the link between smoking and eryptosis has not been explored so far. The aim of the present study was to determine the level of eryptotic erythrocytes in healthy male smokers (n = 21) compared to non-smokers (n = 21) and assess its relationship with systemic inflammation (CRP) as well as with antioxidant defense (GSH) and their resistance to ex-vivo induced hemolysis. Smoking caused an increase in phosphatidylserine translocation outside the erythrocyte membrane (hallmark of eryptosis), significantly correlated to the plasma level of CRP (r = 0.546) and GSH concentration in erythrocytes (r=−0.475). With respect to non-smokers, smokers show a marginal increase of total leucocytes and erythrocyte volume, no modifications of the RBC resistance to oxidative stress-induced hemolysis and hematological and lipid parameters unvaried. We conclude that the inflammatory status (high CRP levels) and RBC oxidative stress (low GSH levels) caused by cigarette smoking are associated with an increase of eryptotic erythrocytes, a yet unknown relationship potentially involved with atherosclerosis and cardiovascular disease in smokers.

Methylation of protein aspartates and deamidated asparagines as a function of blood bank storage and oxidative stress in human red blood cells

Being devoid of de novo protein synthesis capacity, red blood cells (RBCs) have evolved to recycle oxidatively damaged proteins via mechanisms that involve methylation of dehydrated and deamidated aspartate and asparagine residues. Here we hypothesize that such mechanisms are relevant to routine storage in the blood bank. Within the framework of the REDS-III RBC-Omics (Recipient Epidemiology Donor Evaluation Study III Red Blood Cell-Omics) study, packed RBC units (n = 599) were stored under blood bank conditions for 10, 23, and 42 days and profiled for oxidative hemolysis and time-dependent metabolic dysregulation of the trans-sulfuration pathway. In these units, methionine consumption positively correlated with storage age and oxidative hemolysis. Mechanistic studies show that this phenomenon is favored by oxidative stress or hyperoxic storage (sulfur dioxide >95%), and prevented by hypoxia or methyltransferase inhibition. Through a combination of proteomics approaches and 13 C-methionine tracing, we observed oxidation-induced increases in both Asn deamidation to Asp and formation of methyl-Asp on key structural proteins and enzymes, including Band 3, hemoglobin, ankyrin, 4.1, spectrin beta, aldolase, glyceraldehyde 3-phosphate dehydrogenase, biphosphoglycerate mutase, lactate dehydrogenase and catalase. Methylated regions tended to map proximal to the active site (e.g., N316 of glyceraldehyde 3-phosphate dehydrogenase) and/or residues interacting with the N-terminal cytosolic domain of Band 3. While methylation of basic amino acid residues serves as an epigenetic modification in nucleated cells, protein methylation at carboxylate side chains and deamidated asparagines is a nonepigenetic posttranslational sensor of oxidative stress and refrigerated storage in anucleated human RBCs.

Does G6PD-Deficiency Related Oxidative Stress and Hemolysis Affect Erythroid Response to Erythropoietic Stimulating Agents (ESA) in Myelodysplastic Patients?

Background: Anemia is the most frequent cytopenia in Myelodysplastic Syndrome (MDS). Epoetin alfa, Epoetin beta and Darbepoetin alfa (ESA) have been investigated in several studies as useful to treat anemia in this category of patients. Available preclinical data support oxidative stress and hemolysis contributing to ESA resistance but not clinical data is today available. G6PD deficiency is an X-linked condition characterized by a markedly reduced capability to protect red blood cells from oxidative stresses. In the island of Sardinia the prevalence is reported to be as high as 12%. Patients and Methods: We retrospectively analyzed all MDS patients who had received ESA in our centre. Diagnosis of MDS was made according to WHO criteria. Patients were stratified based on International Prognostic Scoring System (IPSS). At diagnosis baseline EPO level and G6PD quantitative estimation were detected. G6PD deficiency was defined as an enzyme dosage of less than 0.96 UI/g of Hb in the peripheral blood. Red blood cell (RBC) transfusions requirement before starting treatment was evaluated. Erythroid hematologic improvement (HI-E) was evaluated according to the International Working Group (IWG) response criteria ( Cheson et al JCO 2006). Results: Thirty patients met the above specified criteria. Table 1 showed patients’ characteristics. Of them 7 were G6PD-defiecient and 23 had normal G6PD level values. Twenty four patients (80%) achieved an HI-E (14 major and 10 minor). In the G6PD-deficient group HI-E was observed in 7 over 7 patients ( major in 4 and minor in 3). In the control group HI-E was observed in 17 over 23 patients (major in 10 minor in 7). (P= 0.29). Conclusions: We evaluated 30 MDS lowrisk and Int I IPSS patients who received ESA in the last 20 years in our centre. Despite the common belief that oxidative stress and hemolysis may contribute to ESA resistance, no statistically significant difference to potentially resistance to ESA treatment in G6PD deficiency have been observed. We conclude that G6PD-deficiency does not contraindicate the use of ESA in this setting of patients.

Resveratrol supplementation reduces oxidative stress and modulates the immune response in free‐living animals during a viral infection

Abstract Diet quality may have an important effect on the regulation of oxidative status and the immune system during an infectious disease. However, the relationship among intake of specific dietary molecules, an individual’s oxidative status and the occurrence and progress of a viral disease remains almost unexplored in free‐living organisms. Here, we study a wild, long‐lived animal, the Magnificent frigatebird Fregata magnificens to investigate: (a) the differences in a number of physiological traits (biomarkers of blood oxidative status, corticosterone (CORT), immunity and inflammation) between sick and healthy nestlings; and (b) whether experimentally increased intake of resveratrol (a polyphenol with antioxidant and antiviral properties) affects these physiological markers during the progress of a severe viral disease. Birds with visible clinical signs showed higher oxidative damage, haemolysis and haemagglutination scores and lower antioxidant defences in comparison with birds without clinical signs. At the end of the experiment, supplemented birds showed the following: (a) increased plasma haptoglobin levels and circulating antioxidant defences; (b) reduced generation of lipid oxidative damage; and (c) negligible to no influence on immune markers, baseline CORT levels and activity of antioxidant enzymes. Our work illustrates how the availability of specific organic molecules in the diet may constrain the individuals’ capacity to cope with viral infections in free‐living animals. plain language summary is available for this article.

Protective Role of Selenium Against Hemolytic Anemia Is Mediated Through Redox Modulation

Selenium (Se), an essential trace element and potent nutritional antioxidant, exerts its biological effects through incorporation into selenoproteins like glutathione peroxidase (GPx). Modest decrement in the levels of GPx could be partly responsible for peroxidation of RBCs, which results into hemolytic anemia. Therefore, it is hypothesized that dietary Se, as selenoproteins (GPx), can maintain the homeostasis in RBCs and regulate the erythropoiesis by preventing oxidative stress-mediated hemolysis. Se-deficient (0.01ppm), Se-adequate (0.1ppm sodium selenite), and Se-supplemented (0.5ppm sodium selenite) status were created in Balb/c mice by feeding yeast-based diets for 8weeks and established by measuring Se levels in plasma and activities, expressions of Se-dependent selenoproteins. Fifty percent of mice from each differential Se group were treated with phenylhydrazine (PHZ, 20mg/kg, i.p.) to induce hemolytic anemia. Results indicated that PHZ-treated Se-deficient animals demonstrated increased hemolysis, abnormal RBC morphology, increase in Heinz bodies and reticulocytes, and denaturation of hemoglobin to globin precipitates and methemoglobin. Se supplementation protected against these hemolytic changes and makes RBCs less fragile. These findings were consistent with dietary Se concentration-dependent changes in activity and expression of GPx indicating that ROS-mediated oxidative stress is integral to hemolysis. Protective effects of Se supplementation against increased levels of ROS, protein carbonyls, and peroxide damage to membrane lipids and enzymatic antioxidants validated these observations. In conclusion, dietary Se supplementation protected the RBCs against hemolysis by mitigating ROS-mediated oxidative stress.

Evaluation of In Vitro Antioxidant and Anticancer Properties of the Aqueous Extract from the Stem Bark of Stryphnodendron adstringens.

Stryphnodendron adstringens (Mart.) Coville (Fabaceae) is a tree species native to the Brazilian Cerrado commonly known as barbatimão. In traditional medicine, decoctions or infusions of the stem bark of this plant are used in the treatment of several diseases. The objective of this study was to analyze the chemical composition of Stryphnodendron adstringens aqueous extracts (SAAE) prepared from the stem bark to assess their antioxidant activity and anticancer effects as well as characterize cell death mechanisms against murine B16F10Nex-2 melanoma cells. From the SAAE, gallic acid, gallocatechin, epigallocatechin, dimeric and trimeric proanthocyanidins mainly composed of prodelphinidin units and the isomeric chromones C-hexosyl- and O-pentosyl-5,7-dihydroxychromone were identified. The SAAE showed antioxidant activity through direct free-radical scavenging as well as through oxidative hemolysis and lipid peroxidation inhibition in human erythrocytes. Furthermore, SAAE promoted apoptosis-induced cell death in melanoma cells by increasing intracellular reactive oxygen species (ROS) levels, inducing mitochondrial membrane potential dysfunction and activating caspase-3. Together, these data show the antioxidant and anticancer effects of Stryphnodendron adstringens. These results open new perspectives for studies against other tumor cell lines and in vivo models as well as for the identification and isolation of the chemical constituents responsible for these effects.

Dapsone safety in hematology patients: Pathways to optimizing Pneumocystis jirovecii pneumonia prophylaxis in hematology malignancy and transplant recipients.

Dapsone may be used for Pneumocystis jirovecii pneumonia (PJP) prophylaxis in hematology patients receiving immunosuppressive therapy or after hematopoietic stem cell transplant (HSCT) in the setting of trimethoprim-sulfamethoxazole (TMP-SMX) adverse drug reaction (ADR) history. Dapsone-induced hematological toxicities such as oxidative hemolysis may limit use in these patients and modern assessments of dapsone allergy cross-reactivity in non-HIV patients with a sulfonamide allergy are largely absent. The aim of this single-centre, retrospective study was to describe dapsone usage in hematology patients requiring PJP prophylaxis, including HSCT recipients, over a 12-month period in terms of indications, incidence of dapsone-attributed oxidative hemolysis, and immune cross-reactivity in those previously labeled with a sulfonamide allergy, as well as describing potential opportunities for first-line TMP-SMX PJP prophylaxis reintroduction. Of 24 patients meeting the study inclusion criteria, 12 (50%) were receiving dapsone PJP prophylaxis post-HSCT. No cases of breakthrough PJP infection were noted. Sixteen patients (67%) were initiated on dapsone to avoid the perceived risk of further myelosuppression with TMP-SMX and five patients (21%) because of prior delayed immune-mediated allergy to TMP-SMX. None experienced rash with dapsone therapy. Six patients (25%) were successfully rechallenged on TMP-SMX, including one patient with prior TMP-SMX-associated rash. Four (17%) patients had confirmed oxidative hemolysis, all resulting in dapsone cessation. Dapsone PJP prophylaxis in hematology patients was effective and safe, with nonlife threatening dapsone-related hemolysis noted in a small number. An absence of sulfonamide allergy cross-reactivity was noted, suggesting greater TMP-SMX rechallenges or desensitization could be considered in those receiving dapsone.

Prognostic Values of Inflammation and Oxidative Stress Biomarkers on the Risk of Peripheral Arterial Disease in Type 2 Diabetes

Aim: We tested whether inflammation and oxidative stress biomarkers may predict the risk of peripheral arterial disease (PAD) in the SURDIAGENE (SURvie, DIAbete de type 2 et GENEtique) type 2 diabetes cohort. Methods: plasma concentrations of angiopoietin like 2 (ANGPTL2), TNF receptor 1 (TNFR1), fluorescent advanced glycation end products (F-AGE), advanced oxidation protein products (AOPP), protein carbonyl, ischemia-modified albumin (IMA), total reductive capacity of plasma (TRCP) and oxidative hemolysis inhibition assay (OxHLIA) were measured at baseline using ELISA, spectrofluorimetry, spectrophotometry and Folin-Ciocalteu methods. Cox model was fitted to assess the risk of severe PAD, requiring aortic or lower limb revascularization, by increasing tertiles of each biomarker at baseline adjusting for confounding variables. C-statistic was used to test PAD discrimination. Results: Among 1395 participants free for PAD at baseline (men 57%, mean±SD age 65±11 years, diabetes duration 14±10 years), aortic or lower limb revascularization was performed in 66 (4.7%) patients during 5.8±3.2 years of follow-up. The rate of revascularisation was higher in the upper tertiles (T2, T3) compared to the lower one (T1): TNFR1 (HR [95% CI] T2 vs. T1, 1.15 [1.01-1.32]; T3 vs. T1, 1.59 [1.34-1.88], trend p&amp;lt;0.0001), F-AGE (1.43 [1.25-1.64]; 2.[1.76-2.38], trend p&amp;lt;0.0001), and TRCP (1.00 [0.88-1.15]; 1.25 [1.09-1.44], trend p=0.002). Similar results were observed when the 3 markers were included together in the same model. TNFR1 (change in c-statistic 0.010 [0.004-0.015], p=0.001), F-AGE (0.026 [0.014-0.039], p&amp;lt;0.0001) and TRCP (0.017 [0.009-0.024], p&amp;lt;0.0001), considered individually or together (0.052 [0.038-0.065], &amp;lt;0.0001), improved PAD discrimination. Conclusion: Our results suggest that TNFR1, F-AGE, and TRCP can be used to screen severe PAD in type 2 diabetes, and support the role of inflammation and oxidative stress on the pathogenesis of PAD. Disclosure M. Nativel: None. F. Schneider: None. P. Saulnier: None. O. Meilhac: None. P. Rondeau: None. M. Cournot: None. L. Potier: Consultant; Self; Sanofi, Novo Nordisk A/S, Eli Lilly and Company. Board Member; Self; Merck Sharp &amp; Dohme Corp.. G. Velho: None. M. Marre: Board Member; Self; Abbott. Consultant; Self; AstraZeneca. Board Member; Self; Intarcia Therapeutics, Inc.. Consultant; Self; Eli Lilly and Company. Board Member; Self; Merck Sharp &amp; Dohme Corp., Novo Nordisk A/S. Research Support; Self; Sanofi. Board Member; Self; Servier. R. Roussel: Advisory Panel; Self; AbbVie Inc., Abbott, Eli Lilly and Company, Sanofi, Novo Nordisk A/S, AstraZeneca. Speaker's Bureau; Self; Servier. Consultant; Self; Bayer AG. Advisory Panel; Self; Merck Sharp &amp; Dohme Corp.. Research Support; Self; Amgen Inc., Sanofi, Novo Nordisk A/S, Danone Research. Stock/Shareholder; Self; Iriade. Advisory Panel; Self; Physiogenex S.A.S.. V. Rigalleau: None. K. Mohammedi: Speaker's Bureau; Self; Novo Nordisk Inc.. Other Relationship; Self; Novo Nordisk Inc.. Speaker's Bureau; Self; Sanofi. Other Relationship; Self; Sanofi, Takeda Development Centre Europe Ltd., Boehringer Ingelheim Pharmaceuticals, Inc. S. Hadjadj: Consultant; Self; Abbott, Novo Nordisk A/S, Servier, AstraZeneca, Merck Sharp &amp; Dohme Corp.. Board Member; Self; Valbiotis. Consultant; Self; Sanofi, Eli Lilly and Company.

Antioxidant, antihyperglycemic, and antidiabetic activity of Apis mellifera bee tea.

Diabetes has emerged as one of the largest global epidemics; it is estimated that by 2035, there will be 592 million diabetic people in the world. Brazilian biodiversity and the knowledge of traditional peoples have contributed to the treatment of several diseases, including diabetes. Apis mellifera bee tea is used by indigenous Brazilians to treat diabetes, and this traditional knowledge needs to be recorded and studied.The objective of this study was to record the use and to evaluate the antioxidant, antihyperglycemic, and antidiabetic activity of Apis mellifera bee tea, which is used by the Guarani and Kaiowá indigenous people for the treatment of diabetes. Semi-structured interviews were performed with Guarani and Kaiowá ethnic indigenous people from the State of Mato Grosso do Sul, Brazil, seeking to identify the animal species used for medicinal purposes. For the experimental procedures, tea prepared with macerated Apis mellifera bees was used. In vitro assays were performed to evaluate antioxidant activity; direct free radical scavenging, protection against oxidative hemolysis, lipid peroxidation were evaluated in human erythrocytes and potential in inhibiting the formation of advanced glycation end products (AGEs). In vivo, normoglycemic Swiss male mice treated with Apis mellifera tea (AmT) were subjected to the oral glucose tolerance test and compared with control and metformin-treated groups. Diet-induced diabetic mice were treated for 21 days with AmT and evaluated for glycemia and malondialdehyde levels in the blood, liver, nervous system, and eyes. During interviews, the indigenous people described the use of Apis mellifera bee tea for the treatment of diabetes. In in vitro assays, AmT showed direct antioxidant activity and reduced oxidative hemolysis and malondialdehyde generation in human erythrocytes. The AmT inhibited the formation of AGEs by albumin-fructose pathways and methylglyoxal products. In vivo, after oral glucose overload, normoglycemic mice treated with AmT had reduced hyperglycemia at all times evaluated up to 180 min. AmT also reduced hyperglycemia and malondialdehyde levels in the blood, liver, nervous system, and eyes of diabetic mice to similar levels as those in metformin-treated mice and normoglycemic controls. In summary, Apis mellifera bee tea showed antioxidant, antihyperglycemic, and antidiabetic activity, which provides support for the therapeutic application of Guarani and Kaiowá indigenous knowledge.

Glucose-6-Phosphate Dehydrogenase Deficiency is Associated with Cardiovascular Disease in U.S. Military Centers.

Glucose-6-phosphate dehydrogenase (G6PD) protects erythrocytes from oxidative stress and hemolysis; G6PD deficiency is the most prevalent enzymopathy. The United States military routinely performs tests to prevent exposing G6PD-deficient personnel to antimalarial drugs that might cause life-threatening hemolytic reactions. In addition, G6PD is a key determinant of vascular function, and its deficiency can lead to impaired nitric oxide production and greater vascular oxidant stress-precursors to atherosclerosis and cardiovascular disease. Using military medical records, we performed a retrospective, cross-sectional study to investigate whether deficient G6PD levels are associated with a higher prevalence of cardiovascular disease than are normal levels, and, if so, whether the relationship is independent of accepted cardiovascular risk factors. We analyzed the medical records of 737 individuals who had deficient G6PD levels and 16,601 who had normal levels. Everyone had been screened at U.S. military medical centers from August 2004 through December 2007. We evaluated our dependent variable (composite cardiovascular disease) at the individual level, and performed binary logistic regression of our independent variable (G6PD status) and control variables (modifiable cardiovascular risk factors). The adjusted odds ratio of 1.396 (95% CI, 1.044-1.867; P <0.05) indicated that G6PD-deficient individuals have 39.6% greater odds of developing cardiovascular disease than do those with normal levels. Early intervention may reduce the incidence of cardiovascular disease in military personnel and civilians who have deficient G6DP levels.

Structural characterization and antioxidant activities of a novel polysaccharide fraction from the fruiting bodies of Craterellus cornucopioides

A new polysaccharide fraction (CCPP-1) was obtained from Craterellus cornucopioides. CCPP-1 had an average molecular weight of 9.2 × 105 Da, which was mainly composed of mannose, glucose, xylose, arabinose, fructose in molar ratio of 0.7:0.05:0.18:1:0.05. Results of structural characterization revealed that the dominant linkage types of CCPP-1 were →3, 6)-Manp(1→, T-Araf, →4, 6)-Manp (1→, →5)-Araf (1→ and →3)-Araf (1→. Interesting, in vitro antioxidant activities assays showed that CCPP-1 possessed strong scavenging abilities on DPPH and ABTS radicals. The oxidative hemolysis induced by AAPH in mice erythrocytes was effectively reversed by incubation with CCPP-1. CCPP-1 significantly prevented AAPH-induced intracellular reactive oxygen species (ROS) generation. Moreover, CCPP-1 could significantly restore AAPH-induced increase of intracellular antioxidant enzyme glutathione peroxidase (GPx) and catalase (CAT) activities to normal level, as well as inhibit intracellular malondialdehyde (MDA) formation. Therefore, CCPP-1 could protect against AAPH-induced oxidative-stress in erythrocytes, which would be explored as naturally potential antioxidant agent applied in food and cosmetic fields.