The effects of non-functionalized polystyrene nanoparticles with different diameters on human erythrocyte membrane and morphology.

In this study, the potential toxicity of non-functionalized polystyrene nanoparticles (PS-NPs) in human erythrocytes has been assessed. The effect of PS-NPs with different diameters (∼30 nm, ∼45 nm, ∼70 nm) on fluidity of erythrocytes membrane, red blood cells shape, as well as haemolysis of these cells has been investigated. Erythrocytes were incubated for 24 h with non-functionalized PS-NPs in concentrations ranging from 0.001 to 200 µg/mL in order to study haemolysis and from 0.001 to 10 µg/mL to determine other parameters. Fluidity was estimated by electron paramagnetic resonance (EPR) and the fluorimetric method. It has been shown that PS-NPs induced haemolysis, caused changes in the fluidity of red blood cells membrane, and altered their shape. Non-functionalized PS-NPs increased the membrane stiffness in the hydrophobic region of hydrocarbon chains of fatty acids. The observed changes in haemolysis and morphology were dependent on the size of the nanoparticles. The smallest PS-NPs of ∼30 nm (with the smallest absolute value of the negative zeta potential -29.68 mV) induced the greatest haemolysis, while the largest PS-NPs of ∼70 nm (with the highest absolute value of the negative zeta potential -42.00 mV) caused the greatest changes in erythrocyte shape and stomatocytes formation.

Molecular Mechanisms of Action of Selected Substances Involved in the Reduction of Benzo[a]pyrene-Induced Oxidative Stress.

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) primarily formed by burning of fossil fuels, wood and other organic materials. BaP as group I carcinogen shows mutagenic and carcinogenic effects. One of the important mechanisms of action of (BaP) is its free radical activity, the effect of which is the induction of oxidative stress in cells. BaP induces oxidative stress through the production of reactive oxygen species (ROS), disturbances of the activity of antioxidant enzymes, and the reduction of the level of non-enzymatic antioxidants as well as of cytokine production. Chemical compounds, such as vitamin E, curcumin, quercetin, catechin, cyanidin, kuromanin, berberine, resveratrol, baicalein, myricetin, catechin hydrate, hesperetin, rhaponticin, as well as taurine, atorvastatin, diallyl sulfide, and those contained in green and white tea, lower the oxidative stress induced by BaP. They regulate the expression of genes involved in oxidative stress and inflammation, and therefore can reduce the level of ROS. These substances remove ROS and reduce the level of lipid and protein peroxidation, reduce formation of adducts with DNA, increase the level of enzymatic and non-enzymatic antioxidants and reduce the level of pro-inflammatory cytokines. BaP can undergo chemical modification in the living cells, which results in more reactive metabolites formation. Some of protective substances have the ability to reduce BaP metabolism, and in particular reduce the induction of cytochrome (CYP P450), which reduces the formation of oxidative metabolites, and therefore decreases ROS production. The aim of this review is to discuss the oxidative properties of BaP, and describe protective activities of selected chemicals against BaP activity based on of the latest publications.

An In Vitro Comparative Study of the Effects of Tetrabromobisphenol A and Tetrabromobisphenol S on Human Erythrocyte Membranes-Changes in ATP Level, Perturbations in Membrane Fluidity, Alterations in Conformational State and Damage to Proteins.

Brominated flame retardants (BFRs) are substances used to reduce the flammability of plastics. Among this group, tetrabormobisphenol A (TBBPA) is currently produced and used on the greatest scale, but due to the emerging reports on its potential toxicity, tetrabromobisphenol S (TBBPS)-a compound with a very similar structure-is used as an alternative. Due to the fact that the compounds in question are found in the environment and in biological samples from living organisms, including humans, and due to the insufficient toxicological knowledge about them, it is necessary to assess their impacts on living organisms and verify the validity of TBBPA replacement by TBBPS. The RBC membrane was chosen as the research model. This is a widely accepted research model for assessing the toxicity of xenobiotics, and it is the first barrier to compounds entering circulation. It was found that TBBPA and TBBPS caused increases in the fluidity of the erythrocyte membrane in their hydrophilic layer, and conformational changes to membrane proteins. They also caused thiol group elevation, an increase in lipid peroxidation (TBBPS only) and decreases in the level of ATP in cells. They also caused changes in the size and shape of RBCs. TBBPA caused changes in the erythrocyte membrane at lower concentrations compared to TBBPS at an occupational exposure level.

Changes in Human Erythrocyte Membrane Exposed to Aqueous and Ethanolic Extracts from Uncaria tomentosa.

Uncaria tomentosa (Willd.) DC is a woody climber species originating from South and Central America that has been used in the therapy of asthma, rheumatism, hypertension, and blood purification. Our previous study showed that U. tomentosa extracts altered human erythrocyte shape, which could be due to incorporation of the compounds contained in extracts into the erythrocyte membrane. The aim of the present study was to determine how the compounds contained in U. tomentosa extracts incorporate into the human erythrocyte membrane. The study has assessed the effect of aqueous and ethanolic extracts from leaves and bark of U. tomentosa on the osmotic resistance of the human erythrocyte, the viscosity of erythrocyte interior, and the fluidity of erythrocyte plasma membrane. Human erythrocytes were incubated with the studied extracts in the concentrations of 100, 250, and 500 µg/mL for 2, 5, and 24 h. All extracts tested caused a decrease in erythrocyte membrane fluidity and increased erythrocyte osmotic sensitivity. The ethanolic extracts from the bark and leaves increased viscosity of the erythrocytes. The largest changes in the studied parameters were observed in the cells incubated with bark ethanolic extract. We consider that the compounds from U. tomentosa extracts mainly build into the outer, hydrophilic monolayer of the erythrocyte membrane, thus protecting the erythrocytes against the adverse effects of oxidative stress.

Changes in Cholinesterase Activity in Blood of Adolescent with Metabolic Syndrome after Supplementation with Extract from Aronia melanocarpa.

Obesity and metabolic syndrome (MetS) are growing problems among children and adolescents. There are no reports of changes in the activity of butyrylcholinesterase (BChE) in children and adolescents with metabolic syndrome especially after supplementation with extract from Aronia melanocarpa. Materials studied included plasma and erythrocytes isolated from peripheral blood of patients with MetS and healthy subjects. We have estimated the following parameters: acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity, lipid peroxidation and lipids levels in plasma, and erythrocytes membrane. In patients with MetS, a significant increase in AChE and BChE activity, higher LDL-cholesterol and triacylglycerol levels, and lower HDL-cholesterol level were observed. Supplementation with A. melanocarpa extract resulted in mild but statistically significant reduction of total cholesterol, LDL-cholesterol, and triacylglycerol levels and caused an increase in HDL-cholesterol level and a decrease in lipid peroxidation in plasma patients with MetS. Additionally, a decrease in lipid peroxidation and cholesterol level and a decrease in AChE activity in the erythrocyte membranes after supplementation with A. melanocarpa were noted. Summarizing, an increase in AChE and BChE activity and disruption of lipid metabolism in patients with MetS were observed. After supplementation of MetS patients with A. melanocarpa extract, a decrease in AChE activity and oxidative stress was noted.

The in vitro comparative study of the effect of BPA, BPS, BPF and BPAF on human erythrocyte membrane; perturbations in membrane fluidity, alterations in conformational state and damage to proteins, changes in ATP level and Na+/K+ ATPase and AChE activities.

Bisphenols are massively used in the industry, and thus the exposure of biota including humans to these substances has been noted. In this study we have assessed the effect of BPA and its selected analogs, i.e. BPS, BPF and BPAF on membrane of human red blood cells, which is the first barrier that must be overcome by xenobiotics penetrating the cell, and is commonly utilized as a model in the investigation of the effect of different xenobiotics on various cell types. Red blood cells were incubated with BPA and its analogs in the concentrations ranging from 0.1 to 250 µg/ml for 4 h and 24 h. We have noted that the compounds studied altered membrane fluidity at its hydrophobic region, increased internal viscosity and osmotic fragility of the erythrocytes and altered conformational state of membrane proteins. Moreover, bisphenols examined increased thiol groups level, caused oxidative damage to membrane proteins, decreased ATP level, depleted the activity of Na+/K + ATPase and changed the activity of AChE in human red blood cells. It has been shown that the strongest changes were noted in cells treated with BPAF, while BPS caused the weakest (or none) alterations in the parameters studied.

Evaluation of the effect of brominated flame retardants on hemoglobin oxidation and hemolysis in human erythrocytes.

Brominated flame retardants (BFRs) are widely used in many everyday products. Numerous studies have shown that BFRs can be released into the environment. Environmental pollution with these compounds raises concerns about their potentially adverse health effects. The aim of this study was to evaluate the effect of tetrabromobisphenol A (TBBPA), tetrabromobisphenol S (TBBPS), 2,4-dibromophenol (2,4-DBP), 2,4,6- tribromophenol (2,4,6-TBP) and pentabromophenol (PBP) on hemolysis induction and hemoglobin oxidation in human erythrocytes. The erythrocytes were incubated with selected BFRs in a wide concentrations ranging from 0.01 to 100 µg/ml for 24 h, 48 h and 72 h. All compounds studied, exhibited hemolytic potential and induced methemoglobin formation. Hemolytic and oxidative potential of BFRs increased along with the increasing concentrations of the compounds studied and elongation of the incubation time. Our study showed that both the number of aromatic rings and the number of bromine atoms in the molecule of the compounds examined influence hemoglobin oxidation and damage to the cellular membrane. Furthermore, we may conclude that 2,4-DBP is potentially most toxic compound because it causes statistically significant changes at the lowest concentration, while the highest toxicity at the highest concentrations was noted for TBBPA.

Tolerance of monocytes and macrophages in response to bacterial endotoxin.

Monocytes belong to myeloid effector cells, which constitute the first line of defense against pathogens, also called the nonspecific immune system and play an important role in the maintenance of tissue homeostasis. In response to stimulation, monocytes differentiate into macrophages capable of microorganism phagocytosis and secrete factors that play a key role in the regulation of immune responses. However excessive exposure of monocytes/macrophages to the lipopolysaccharide (LPS) of Gram negative bacteria leads to the acquisition of immune tolerance by these cells. Such state results from disruption of different biological processes, for example intracellular signaling pathways and is accompanied by a number of disease states (immune, inflammatory or neoplastic conditions). Regulation of monocytes/macrophages activity is controlled by miRNAs, which are involved in the modulation of immune tolerance acquired by these cells. Moreover, the tolerance to endotoxin is conditioned by the posttranscriptional processes and posttranslational epigenetic modifications leading to the impairment of normal immune response for example by alterations in the expression of many genes encoding immune signaling mediators. The aim of this paper is to provide an overview existing knowledge on the modulation of activity of monocytes/macrophages in response to bacterial endotoxin and impaired immune responses.

Influence of core and maltose surface modification of PEIs on their interaction with plasma proteins-Human serum albumin and lysozyme.

Regardless of the route of administration, some or all of a therapeutic agent will appear in the blood stream, where it can act on blood cells and other components of the plasma. Recently we have shown that poly(ethylene imines) (PEIs) which interact with plasma proteins are taken up into erythrocyte membranes. These observations led us to investigate the interactions between maltose functionalized hyperbranched PEIs (PEI-Mal) and plasma proteins. Two model proteins were chosen - human serum albumin (HSA) (albumins constitute ∼60% of all plasma proteins), and lysozyme. HSA is a negatively charged 66kDa protein at neutral pH, whereas lysozyme is a positively charged 14kDa protein. Fluorescence quenching and changes in the conformation of the amino acid tryptophan, diameter and zeta potential of proteins were investigated to evaluate the interaction of PEI-Mal with proteins. PEI-Mal interacts with both types of proteins. The strength of dendritic glycopolymer interactions was generally weak, especially with lysozyme. Greater changes were found with HSA, mainly triggered by hydrogen bonds and the electrostatic interaction properties of dendritic glycopolymers. Moreover, the structure and the size of PEI-Mal macromolecules affected these interactions; larger macromolecules with more sugar groups (95% maltose units) interacted more strongly with proteins than smaller ones with lower sugar modification (33% maltose units). Due to (i) the proven overall low toxicity of sugar-modified PEIs and, (ii) their ability to interact preferentially through hydrogen bonds with proteins of human plasma or possibly with other interesting protein targets, PEI-Mal is a good candidate for creating therapeutic nanoparticles in the fast developing field of nanomedicine.

[Increased level of lipid peroxidation products and disturbances in oxidation-reduction balance in erythrocytes from patients suffering from systemic sclerosis, who are chronically treated with vitamin E]. / Zwiekszone stezenie produktów peroksydacji lipidów oraz zaburzenia aktywnosci enzymów antyoksydacyjnych w erytrocytach u chorych na twardzine ukladowa, przewlekle leczonych witamina E.

UNLABELLED: Systemic sclerosis is a chronic connective tissue disease of unknown pathogenesis. In view of the reports of essential role of oxidative stress in development of disease, trials with supportive care with vitamin E are undertaken. The aim of the study was to estimate parameters of oxidation-reduction balance in erythrocytes from scleroderma patients, who were chronically treated with vitamin E compared with healthy controls. MATERIAL AND METHODS: In the study there were included 14 women with systemic sclerosis (limited form - ISSc - n = 10, diffuse form - dSsc - n = 4, age 53.8 lat +/- 11.5), who were treated with vitamin E in dose 400 mg/day not shorter than in 6 months period and 23 healthy women (age 52.7 +/- 11.2) as a control group. The following measurements were done: hs CRP (immunoturbidimetic method), glutathione peroxidase activity (Gpx--method of Rice-Evans, 1991), superoxide dismutase activity (SOD--method of Misra, 1972), catalase activity (CAT--method of Aebi H, 1984), free thiol group concentration (SH--method of ElIman, 1959), level of lipid peroxidation products (TBARs--method of Stocks and Dormandy, 1971), total antioxidant capacity (TAC) depended of slow (TAC "slow") and fast (TAC "fast") antioxidants. RESULTS: . In both forms of systemic sclerosis significantly higher TBARs in comparison of healthy controls (5.81 +/- 1.57 vs 4.28 +/- 0.89 nM TBARS/gHb; p < 0.01) was observed. Patients with limited systemic sclerosis have significantly higher activity of Gpx (59.9 +/- 26.11 vs 32.19 +/- 11.67 U/mg Hb; p < 0.01), and no differences in activity of CAT and SOD. In patients with diffuse systemic sclerosis significantly lower activity of CAT (173.06 +/- 60.3 vs 284.47 +/- 43.33 U/mg Hb; p < 0.01) and SOD (2334.95 +/- 193.97 vs 3231.47 +/- 840.21 U/mg Hb; p < 0.05) was observed. There are no differences in TAC and SH between investigated groups. CONCLUSIONS: In scleroderma patients despite chronical treatment with vitamin E, oxidation-reduction balance disturbances are observed in the form of increased level of lipid peroxidation products. Besides, a lower activity of catalase and superoxide dysmutase in patients who suffer from diffuse form of systemic sclerosis is noted. Patients with limited systemic sclerosis have higher glutathione peroxidase activity.

Effect of safeners on damage of human erythrocytes treated with chloroacetamide herbicides.

Chloroacetamides are used as pre-emergent substances for growth control of annual grasses and weeds. Since they can be harmful for crop plants, protective compounds (safeners) are used along with herbicides. So far, their effects on human blood cells have not been evaluated, and this study is the very first one devoted to this subject. We examined the harmful effects of chloroacetamides, their metabolites and safeners, used alone or in combination with herbicides, on human erythrocytes measuring the extent of hemolysis, lipid peroxidation and catalase activity. Higher impact of herbicides than their metabolites on all of the investigated parameters was found. Safeners alone did not produce any damage to erythrocytes and did not elicit any changes in oxidative stress parameters. Combination of safener with herbicide did not attenuate hemolysis of erythrocytes compared to the herbicide alone. Safeners reduced lipid peroxidation induced by herbicides, which suggest the role of safeners as antioxidants.

Effect of polyphenols extracts from Brassica vegetables on erythrocyte membranes (in vitro study).

The aim of this work was to estimate the in vitro effects of polyphenol extracts from Brassica vegetables (Brussels sprouts and red cabbage) on erythrocyte membranes with normal and high concentration of cholesterol. To determine the effect of phenolic compounds we prospectively studied cholesterol concentration, lipid peroxidation, membrane fluidity and ATPase activity. Polyphenol extracts from Brassica vegetables resulted in statistically significant reductions in cholesterol concentrations in hypercholesterolemic erythrocytes. For control erythrocytes, no significant reduction of cholesterol levels was observed for both extracts. Decreases in lipid peroxidation intensity were observed after incubation of hypercholesterolemic erythrocytes with the extracts. No changes in membrane fluidity for both extracts were noted for normal and hypercholesterolemic erythrocytes. The activity of ATPase decreased after incubation of normal and hypercholesterolemic erythrocytes with extract from Brassica vegetables. Our results indicate that polyphenols from red cabbage and Brussels sprout may directly influence erythrocyte membrane properties.

In vivo influence of extract from Aronia melanocarpa on the erythrocyte membranes in patients with hypercholesterolemia.

BACKGROUND: Hypercholesterolemia increases cholesterol concentration in erythrocyte membranes, which results in decrease of membrane fluidity and decreases the deformability of red blood cells. The fruits of Arona melanocarpa contains many of polyphenols and other compounds that have beneficial health effects. MATERIAL/METHODS: The aim of the study was to estimate the influence of 2-month supplementation of extract from Aronia melanocarpa (100 mg Aronox, three times per day) on cholesterol concentration, lipid peroxidation, membrane fluidity, level of thiol groups and activity of ATPase in erythrocytes from patients with hypercholesterolemia. The study involved 25 patients with hypercholesterolemia without pharmacological treatment and 20 healthy individuals as a control group. Blood samples were collected before, and after 1 and 2 months of Aronia administration. RESULTS: The 2-month Aronia supplementation resulted in a decrease of cholesterol concentration (by 22%) and a decrease of lipid peroxidation (by 40%), and an increase of membrane fluidity. No statistically significant increase of the concentration of thiol groups and of ATPase activity were observed. CONCLUSIONS: Our study shows that supplementation of extract from Aronia melanocarpa has a beneficial effect on rheological properties of erythrocytes.

Disorders of erythrocyte structure and function in hypertensive patients.

BACKGROUND: The prevalence of hypertension is growing at an alarming rate. Increasing attention is being focussed on the oxidative stress accompanying this disease. In this study we examined the impact of this disease on some parameters of erythrocytes and human blood plasma. MATERIAL/METHODS: We examined the impact of hypertension on some parameters of erythrocytes and human plasma. The study involved 13 patients with hypertension and 19 healthy subjects. We determined lipid peroxidation, SH groups concentration, antioxidants enzymes activity, ATPase activity, total antioxidant capacity, total cholesterol level and erythrocyte membrane fluidity. RESULTS: We found an increased level of lipid peroxidation and the concentration of SH groups in membrane proteins in patients with hypertension, and a decrease in the activity of catalase and superoxide dysmutase. No changes were observed in glutathione peroxidase and ATPase activity, level of total antioxidant capacity, total cholesterol level and fluidity of erythrocyte membranes. CONCLUSIONS: These results suggest the existence of an impaired oxidative balance in hypertensive human erythrocytes.

Hypolipidemic and antioxidant effects of hydroxycinnamic acids, quercetin, and cyanidin 3-glucoside in hypercholesterolemic erythrocytes (in vitro study).

OBJECTIVE: Four polyphenols: ferulic acid and p-coumaric acid (hydroxycinnamic acids), quercetin (flavonol) and cyanidin 3-glucoside (anthocyanin) were selected, and their antioxidant properties and their influence on cholesterol concentration in hypercholesterolemic and normal erythrocytes were investigated. METHODS: To determine the effect of phenolic compounds, we prospectively studied cholesterol concentration, lipid peroxidation and membranes fluidity. Whole-blood and isolated erythrocytes (2% hematocrit) were incubated for 24 h with selected compounds at concentration 1, 10 and 100 µmol/L. All investigated compounds decreased lipid peroxidation in whole blood. Cyanidin 3-glucoside and quercetin showed higher antioxidant properties than hydroxycinnamic acids (ferulic acid and p-coumaric acid). RESULTS: Incubation of whole blood of hypercholesterolemic patients with quercetin and cyanidin 3-glucoside resulted in statistically significant reduction of cholesterol concentration in erythrocytes down to 75% (at 10 µmol/L of polyphenols) and 69% (at 100 µmol/L of polyphenols) of initial values. The effect of both compounds on isolated erythrocytes was even more pronounced, reduction down to 70% (at 10 µmol/L of polyphenols) and 58% (at 100 µmol/L of polyphenols) of initial values. After incubation of isolated erythrocytes of hypercholesterolemic patients with quercetin and cyanidin 3-glucoside, increase of membrane fluidity was noticed. After incubation of isolated erythrocytes of healthy donors with investigated compounds, no changes in membrane fluidity were observed. CONCLUSION: Our results indicate that flavonols and anthocyanins have higher antioxidant properties and higher influence on cholesterol concentration in erythrocytes membranes than simple hydroxycinnamic acids.

Melatonin treatment improves blood pressure, lipid profile, and parameters of oxidative stress in patients with metabolic syndrome.

Experimental studies have proven that melatonin has many beneficial pleiotropic actions. The aim of this study was to assess melatonin efficacy in patients with metabolic syndrome (MS). The study included 33 healthy volunteers (who were not treated with melatonin) and 30 patients with MS, who did not respond to 3-month lifestyle modification. Patients with MS were treated with melatonin (5 mg/day, 2 hr before bedtime) for 2 months. The following parameters were studied: systolic and diastolic blood pressure (SBP, DBP), levels of glucose, serum lipids, C-reactive protein, fibrinogen, activities of antioxidative enzymes: catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), thiobarbituric acid reactive substrates (TBARS). After 2-month therapy in comparison with baseline, the following significant changes were measured: systolic blood pressure (132.8±9.8 versus 120.5±11.0 mmHg, P<0.001), DBP (81.7±8.8 versus 75±7.4 mmHg, P<0.01), low-density lipoprotein cholesterol (LDL-C) (149.7±26.4 versus 139.9±30.2 mg/dL, P<0.05), TBARS (0.5±0.2 versus 0.4±0.1 µm/gHb, P<0.01), and CAT (245.9±46.9 versus 276.8±39.4 U/gHb). Melatonin administered for 2 months significantly improved antioxidative defense (increase in CAT activity, decrease in TBARS level) and lipid profile (decrease in LDL-C), and lowered blood pressure. We conclude that melatonin therapy may be of benefit for patients with MS, particularly with arterial hypertension. Further studies with higher doses of melatonin or prolonged supplementation are awaited.

Aronia melanocarpa extract reduces blood pressure, serum endothelin, lipid, and oxidative stress marker levels in patients with metabolic syndrome.

BACKGROUND: Experimental studies have shown that anthocyanins may exert pleiotropic effects. The aim of the study was to determine the influence of Aronia melanocarpa extract on blood pressure and serum concentration of endothelin-1 (ET-1), lipids, glucose, uric acid, C-reactive protein (CRP), fibrinogen, the antioxidant enzymes catalase (CAT), superoxide dysmutase (SOD), and glutathione peroxidase (GSH-Px), and lipid peroxidation (thiobarbituric acid-reacting substrates, TBARS) in erythrocytes of patients with metabolic syndrome (MS). MATERIAL/METHODS: The study comprised 22 healthy volunteers and 25 patients with MS. Patients with MS were treated with aronia extract (3 x 100 mg/day) for two months. The above parameters were measured. RESULTS: After two months of therapy, statistically significant decreases were observed in SBP (143.40+/-7.87 vs. 131.83+/-12.24 mmHg, p<0.001), DBP (87.20+/-9.9 vs. 82.13+/-10.33 mmHg, p<0.05), ET-1 (2.44+/-0.51 vs. 1.74+/-0.42 pg/ml, p<0.001), TC (242.80+/-34.48 vs. 227.96+/-33.07 mg/dl, p<0.001), LDL-C (158.71+/-35.78 vs. 146.21+/-34.63 mg/dl, p<0.01), TG (215.92+/-63.61 vs. 187.58+/-90 mg/dl, p<0.05), TBARS (0.0712+/-0.0191 vs. 0.0362+/-0.0135 micromol/g-Hb, p<0.001), and CAT (261.30+/-59.78 vs. 213.34+/-47.36 U/mg-Hb) and significant increases in SOD (2380.63+/-419.91 vs. 3066.53+/-542.24 U/g-Hb, p<0.001), GSH-Px (12.60+/-5.97 vs. 19.18+/-9.09 U/g-Hb, p<0.01), and fibrinogen levels (249.20+/-27.17 vs. 276.67+/-57.41 mg/dl, p<0.05) compared with the baseline values. CONCLUSIONS: Aronia extract may be of benefit to patients with MS. This seems to result from the influence of anthocyanins and possibly other flavonoids on blood pressure, serum level of ET-1, lipids, and oxidative status (GSH-Px, SOD, TBARS).

Anti-inflammatory and hypolipemic effects in vitro of simvastatin comparing to epicatechin in patients with type-2 hypercholesterolemia.

OBJECTIVE: The study involved 25 patients with type-2 hypercholesterolemia (mean age 49.3+/-11.3). The control group consisted of 28 healthy individuals (mean age 50.7+/-7.2). METHODS: The cholesterol concentrations in plasma membranes of erythrocytes were measured by means of Liebermann-Burchard reagent. The membrane lipid peroxidation in whole erythrocytes was determined. The membrane fluidity was estimated by spin labelled method. RESULTS: The in vitro study shows that the cholesterol concentration in membranes incubated with simvastatin and epicatechin decreases; in healthy donors there are no changes. Simvastatin does not lead to changes in the lipid peroxidation in the in vitro data. Epicatechin decreases the level of membrane lipid peroxidation in patients with hypercholesterolemia and in healthy donors. Simvastatin and epicatechin cause an increase in the fluidity of plasma membranes of erythrocytes. CONCLUSIONS: Simvastatin causes the decrease in cholesterol concentration in erythrocytes membranes not only in the in vivo but also the in vitro experiments. Flavonoids have antioxidant properties in vitro. Simvastatin influences the lipid peroxidation only in vivo, not in vitro systems. This observation is an additional contribution to the statins' pleiotropic effect.

[Effect of anthocyanins from Aronia melanocarpa on blood pressure, concentration of endothelin-1 and lipids in patients with metabolic syndrome]. / Wplyw antocyjanin z aronii czarnoowocowej na cisnienie tetnicze oraz stezenie endoteliny-1 i lipidów u pacjentów z zespolem metabolicznym.

THE AIM OF THE STUDY: To estimate the influence of anthocyanins from Aronia melanocarpa on blood pressure, concentration of endothelin-1 (ET-1), serum lipids, fasting glucose, uric acid and membrane cholesterol in erythrocytes of patients (pts) with metabolic syndrome (MS). MATERIAL AND METHODS: The study comprised 22 healthy volunteers and 25 pts with MS treated with anthocyanins (3 x 100 mg/d) for 2 months. Waist circumference (> or = 80 cm for women and > or =94 cm for men), triglicerydes (TG) level >150 mg/dl (1.7 mmol/l), cholesterol-HDL (HDL-C) level < 40 mg/dl (1.0 mmol/l) for men and <50 mg/dl (1.3 mmol/l) for women, systolic blood pressure (SBP) >130 mmHg and/or diastolic blood pressure (DBP) >85 mmHg were inclusion criteria for patients with MS. Before and after 2 months of treatment the following parameters were determined: SBP, DBP, serum lipids (total cholesterol--TC, cholesterol LDL--LDL-C, cholesterol HDL--HDL-C, TG--by enzymatic method), membrane cholesterol in erythrocytes (method of IIcy), ET-1 (immunoenzymatic method), fasting glucose level was (colorimetric method), uric acid (enzymatic--colorimetric method). RESULTS: After two months therapy of anthocyanins from Aronia melanocarpa in comparison with baseline it was observed a significant decrease of: SBP (144.20 +/- 9.97 vs. 131.83 +/- 12.24 mmHg, p < 0.001) and DBP (87.20 +/- 9.9 vs. 82.13 +/- 10.33 mmHg, p < 0.05), TC (242.80 +/- 34.48 vs. 227.96 +/- 33.07 mg/dl, p < 0.001), LDL-C (158.71 +/- 35.78 vs. 146.21 +/- 34.63 mg/dl, p < 0.01), TG (215.92 +/- 63.61 vs. 187.58 +/- 90 mg/dl, p < 0.05), ET-1 (2.44 +/- 0.51 vs. 1.74 +/- 0.42 pg/ml, p < 0.001) and membrane cholesterol (4.85 +/- 0.65 vs. 2.81 +/- 0.54 mmol/Lpc, p < 0.001), uric acid and fasting blood glucose levels did not change significantly after study cessation. CONCLUSIONS: The results of our study show that anthocyanins from Aronia melanocarpa may be of benefit to patients with MS as for as atherosclerosis prevention is concerned. It seems to result from anthocyanins influence on blood pressure, serum lipid and endothelin-1 level.

[The erythrocyte membrane structure in patients with mixed hyperlipidemia]. / Struktura blon erytrocytów u pacjentów z mieszana hiperlipidemia.

In hypercholesterolemia the damage to the plasma membranes of erythrocytes is observed. This may result from higher concentration of cholesterol in plasma and membranes, lipids peroxidation and changes in protein conformation. The aim of the study was to estimate the membrane fluidity, concentration of cholesterol (Ch), phospholipids (PL), ratio of Ch/PL, thiobarbituric acid reaction substances (TBARS) in the isolated erythrocyte membrane of patients with mixed hyperlipidemia. The study comprised 50 patients in the age from 45 to 65 with the initial concentrations of total cholesterol (TC) > 200 mg/dl (5.2 mmol/l); cholesterol LDL (LDL-C) > 160 mg/dL (4.1 mmol/l); triglicerides (TG) > 150 mg/dL (4.5 mmol/L) and 22 healthy controls. The plasma lipids concentrations were determined by enzymatic method, the concentration of cholesterol membrane (by method of Ilcy), phospholipids (by method of Bartlett), lipids peroxidation (by method of Stocks and Dormandy) and the erythrocyte membrane fluidity (by a spin-label paramagnetic resonance method using 5-doxylstearic acid - 5-DSA, and 16-doxylstearic acid - 16-DSA). The order parameter S was determined using 5-DSA; 16-DSA was used to estimate the correlation taub and tauc. In group of patients with mixed hyperlipidemia in comparison to the control group it was noticed a significant increase of the mean values of order parameter S (0.74 +/- 0.01 vs. 0.72 +/- 0.005, p < 0.001), of membrane cholesterol concentration (3.39 +/-0.98 vs. 1.93 +/- 0.93 mmol/l pc, p < 0.001), ratio Ch/PL (2.32 +/- 1.22 vs. 1.22 +/- 0.44; p < 0,001) and TBARS (2.91 +/- 0.74 vs. 1.5 +/- 0.4 nmol/mg protein). The differences of the correlation times and phospholipids concentrations between the groups were not statistically significant. Significant correlation between the order parameter S and concentrations of TC, LDL-C in plasma and membrane cholesterol was observed. On the base of given results we conclude that mixed hyperlipidemia may have influence on the erythrocyte membrane structure caused significant decrease of membrane fluidity in the superficial layer without any significant changes in deeper layer and significant increase of membrane cholesterol and TBARS.