The Effects of a Single Blood Donation on the Lipid Profile, Iron Storage and Enzymatic Antioxidants

Cardiovascular disease (CVD) is a global illness causing 31% of global mortality. Though many factors contribute to CVD, oxidative stress advances atherosclerosis through several complementary components, such as the initiation of lipid peroxidation by iron. Blood donation may decrease the risk of CVD due to reducing the iron level. Literature reported that blood donors have a lower risk of CVD, possibly due to the lower iron levels. Various effects of blood donation are involved in preventing type II diabetes. However, little is known of the exact mechanism of the benefits of blood donation. In this study, samples were collected from 33 healthy male participants pre- (1 day) and post-donation (1 day, 1, 2 and 3 weeks) and the effect of the blood donation on the iron, lipids and enzymatic antioxidants profiles were assessed. A repeated-measures ANOVA was used for comparing the quantitative variables between the visits. We found that the iron decreased significantly by week 1 (–25.3%). Ferritin decreased significantly at weeks 1, 2, and 3 (–26.3%, –40.3%, –36.7%, respectively). The superoxide dismutase increased significantly at post-donation day 1, weeks 1, 2, and 3 (17.9%,35.7%, 31.1%, 36.6%, respectively) and in correlation with time [r (165) = 0.50, P <0 .01]. Glutathione peroxide decreased significantly at week 1 (–25.0%). Glutathione reductase decreased significantly 1-day post donation (–5.7%) then increased over the next three weeks [r (165) = 0.3, P <0.01]. Finally, the lipids were significantly reduced 24 hours after the donation but not at week 1, 2 and 3. We conclude that blood donation, resulting in a lowered body iron concentration, is an effective way to increase superoxide dismutase and glutathione reductase, which prevent the initiation of lipid oxidation. Our results could be used to advocate for the benefits of blood donation. However, further studies are required to assess the role of blood donation in plaque formation and arteriosclerosis.

EFFECT OF OLIGOSACCHARIDES ON ENZYMES OF CARBOHYDRATE METABOLISM AND ANTIOXIDANT PROTECTION IN IN VITRO TREATED ERYTHROCYTES UNDER CONDITIONS OF HYPERGLYCEMIA

Introduction: The purpose of this experiment is to examine the effect of different oligosaccharides with proven prebiotic effects on enzymes of carbohydrate metabolism and the antioxidant protection of erythrocytes in vitro under conditions of hyperglycemia. Materials and methods: This experiment included 10 healthy men (27±3 years of age). The isolated erythrocytes were treated with 1% and 5% solutions of the following oligosaccharides: lactulose, inulin, galactooligosaccharide and fructooligosaccharide in the presence of 5mM, 50mM and 100mM glucose. After incubation, for 2 hours at 37 °C, the erythrocytes were lysed, and the supernatant was used for analyses of lactate dehydrogenase, hexokinase and glutathione reductase. FRAP (Ferric reducing antioxidant power) method was used for determining the total antioxidant activity of erythrocytes. Results: Lactate dehydrogenase was decreased in the presence of 5% lactulose in groups with 50mM and 100 mM Glc. An increase in the activity of glutathione reductase under severe hyperglycemia (100mM glucose) was observed after treatment with: 1% lactulose, 1% inulin, 1% galactooligosaccharide, 1% and 5% fructooligosaccharides (p<0.005). A significant difference in the enzymatic activity of hexokinase was found in all groups (p<0.05) and of glutathione reductase only in the control group as well as in the groups treated with 1% lactulose, 1% galactooligosaccharide, 1% and 5% fructooligosaccharides Conclusions: Galactooligosaccharides 1% and fructooligosaccharides 1% and 5% cause a statistically significant increase of the enzymatic activities of hexokinase and glutathione reductase in in vitro hyperglycemia induced by 100 mM glucose, as well as an increase in FRAP.

Metabolomic profiling reveals a differential role for hippocampal glutathione reductase in infantile memory formation

The metabolic mechanisms underlying the formation of early-life episodic memories remain poorly characterized. Here, we assessed the metabolomic profile of the rat hippocampus at different developmental ages both at baseline and following episodic learning. We report that the hippocampal metabolome significantly changes over developmental ages and that learning regulates differential arrays of metabolites according to age. The infant hippocampus had the largest number of significant changes following learning, with downregulation of 54 metabolites. Of those, a large proportion was associated with the glutathione-mediated cellular defenses against oxidative stress. Further biochemical, molecular, and behavioral assessments revealed that infantile learning evokes a rapid and persistent increase in the activity of neuronal glutathione reductase, the enzyme that regenerates reduced glutathione from its oxidized form. Inhibition of glutathione reductase selectively impaired long-term memory formation in infant but not in juvenile and adult rats, confirming its age-specific role. Thus, metabolomic profiling revealed that the hippocampal glutathione-mediated antioxidant pathway is differentially required for the formation of infantile memory.

MAIN INDICATORS OF THE OXIDANT-ANTIOXIDANT SYSTEM AND THEIR RELATIONSHIP WITH THE FORCE OF THE RESPIRATORY MUSCLES IN ADULT PATIENTS WITH COMMUNITY-ACQUIRED PNEUMONIA

Background. Currently, pneumonia ranks 4-5 rate in the world in the structure of death causes after cardiovascular and cancer diseases, cerebrovascular pathology, injuries and poisonings. Objective. The aim of the study was to evaluate the indicators of the oxidative-antioxidant system and their relationship with the strength of the respiratory muscles in adult patients with community-acquired pneumonia. Methods. The study was carried out in the period 2017-2020 on the basis of the therapeutic department of the Municipal non-profit enterprise "City Clinical Multidisciplinary Hospital № 25" of Kharkiv City Council. The study involved 52 adult patients with CAP aged 18 to 80 years. The control group consisted of 20 apparently healthy humans. It was determinated the activity of malondialdehyde, catalase and superoxide dismutase, level of reduced glutathione, glutathione reductase and glutathione peroxidase. The assessment of the RM strength was investigated by recording the maximum static pressures at the level of the mouth and nose with “closed” airways using a MicroRPM apparatus on the 1st and 10th days of illness. Results. Dysfunction of expiratory respiratory muscles prevailed in patients with non-severe CAP, and inspiratory respiratory muscles in patients with severe CAP. Were established significant negative correlations of malondialdehyde with indicators of respiratory muscles strength and positive correlations with glutathione reductase, glutathione peroxidase, catalase, and superoxide dismutase. Conclusions. The presence of relationships between pro- and antioxidant indicators and respiratory muscles strength complements the concept of the body's systemic response on pulmonary inflammation – one of the markers of respiratory muscles dysfunction. KEYWORDS: community-acquired pneumonia, respiratory muscles, oxidative-antioxidant system.

Glutathione Reductase Encoding Gene (gor) is Associated with Oxidative Stress and Antibiotic Susceptibility in Pseudomonas aeruginosa

Pseudomonas aeruginosa is a major causative agent of the hospital- and community-acquired infections. These infections are often antibiotic resistant and difficult to treat. Several intrinsic and acquired resistance mechanisms to antibiotics have reported in P. aeruginosa. Recently, oxidative- stress-scavenging-systems have suggested as a possible intrinsic resistance mechanism to antibiotics because oxidative stresses induced by bactericidal antibiotics contribute to bacterial killing effects. However, this remains controversial such that further clarification is required. Glutathione reductase is a key enzyme in the maintenance of the optimum level of intracellular glutathione-redox potential to ensure normal functioning of cellular processes including the detoxification of oxidative stress. In this study, the role of a glutathione-reductase-encoding gene (gor) in oxidative stress and antibiotic susceptibility was determined in P. aeruginosa. Results showed that a gor-mutant strain was more susceptible to hydrogen peroxide (but not superoxide) than the parental strain and 100% of cells were killed with 0.01% hydrogen peroxide while the parental strain survived at the same concentration of hydrogen peroxide. The gor-mutant strain was also more susceptible to carbenicillin, chloramphenicol, ciprofloxacin, and tetracycline than the parental strain, which was confirmed by bacterial killing-kinetics. These results suggest that the gor gene is associated with oxidative stress and susceptibility to bactericidal as well as bacteriostatic antibiotics and that the oxidative-stress-scavenging-systems may be a possible drug-target for multidrug resistant P. aeruginosa.