The polyphenol-rich extracts from black chokeberry and grape seeds impair changes in the platelet adhesion and aggregation induced by a model of hyperhomocysteinemia

Contribution of Physical Activity to the Oxidative and Antioxidant Potential in 60-65-Year-Old Seniors

Both acute exercise and regular physical activity (PA) are directly related to the redox system. However, at present, there are data suggesting both positive and negative relationships between the PA and oxidation. In addition, there is a limited number of publications differentiating the relationships between PA and numerous markers of plasma and platelets targets for the oxidative stress. In this study, in a population of 300 participants from central Poland (covering the age range between 60 and 65 years), PA was assessed as regards energy expenditure (PA-EE) and health-related behaviors (PA-HRB). Total antioxidant potential (TAS), total oxidative stress (TOS) and several other markers of an oxidative stress, monitored in platelet and plasma lipids and proteins, were then determined. The association of PA with oxidative stress was determined taking into the account basic confounders, such as age, sex and the set of the relevant cardiometabolic factors. In simple correlations, platelet lipid peroxides, free thiol and amino groups of platelet proteins, as well as the generation of superoxide anion radical, were inversely related with PA-EE. In multivariate analyses, apart from other cardiometabolic factors, a significant positive impact of PA-HRB was revealed for TOS (inverse relationship), while in the case of PA-EE, the effect was found to be positive (inverse association) for lipid peroxides and superoxide anion but negative (lower concentration) for free thiol and free amino groups in platelets proteins. Therefore, the impact of PA may be different on oxidative stress markers in platelets as compared to plasma proteins and also dissimilar on platelet lipids and proteins. These associations are more visible for platelets than plasma markers. For lipid oxidation, PA seems to have protective effect. In the case of platelets proteins, PA tends to act as pro-oxidative factor.

Dose-dependent effects of anthocyanin supplementation on platelet function in subjects with dyslipidemia: A randomized clinical trial

Background

Dyslipidemia induces platelet hyperactivation and hyper-aggregation, which are linked to thrombosis. Anthocyanins could inhibit platelet function in vitro and in mice fed high-fat diets with their effects on platelet function in subjects with dyslipidemia remained unknown. This study aimed to investigate the effects of different doses of anthocyanins on platelet function in individuals with dyslipidemia.

Methods

A double-blind, randomized, controlled trial was conducted. Ninety-three individuals who were initially diagnosed with dyslipidemia were randomly assigned to placebo or 40, 80, 160 or 320 mg/day anthocyanin groups. The supplementations were anthocyanin capsules (Medox, Norway). Platelet aggregation by light aggregometry of platelet-rich plasma, P-selectin, activated GPⅡbⅢa, reactive oxygen species (ROS), and mitochondrial membrane potential were tested at baseline, 6 weeks and 12 weeks.

Findings

Compared to placebo group, anthocyanins at 80 mg/day for 12 weeks reduced collagen-induced platelet aggregation (-3.39±2.36%) and activated GPⅡbⅢa (-8.25±2.45%) (P < 0.05). Moreover, compared to placebo group, anthocyanins at 320 mg/day inhibited collagen-induced platelet aggregation (-7.05±2.38%), ADP-induced platelet aggregation (-7.14±2.00%), platelet ROS levels (-14.55±1.86%), and mitochondrial membrane potential (7.40±1.56%) (P < 0.05). There were dose-response relationships between anthocyanins and the attenuation of platelet aggregation, mitochondrial membrane potential and ROS levels (P for trend <0.05). Furthermore, significantly positive correlations were observed between changes in collagen-induced (r = 0.473) or ADP-induced (r = 0.551) platelet aggregation and ROS levels in subjects with dyslipidemia after the 12-week intervention (P < 0.05).

Interpretation

Anthocyanin supplementation dose-dependently attenuates platelet function, and 12-week supplementation with 80 mg/day or more of anthocyanins can reduce platelet function in individuals with dyslipidemia.

Thermally driven formation of polyphenolic carbonized nanogels with high anticoagulant activity from polysaccharides

We have demonstrated that alginate with negligible anticoagulant activity can be converted into carbonized nanogels with potent anticoagulant activity through a solid-state heating process. The conversion of alginate into graphene-like nanosheet (GNS)-embedded polyphenolic-alginate nanogels (GNS/Alg-NGs) has been carried out through condensation and carbonization processes. The GNS/Alg-NGs exhibit much stronger anticoagulant activity (>520-fold) compared to untreated alginate, mainly because their polyphenolic structures have a high binding affinity [dissociation constant (K_d) = 2.1 × 10^-10 M] toward thrombin. In addition, the thrombin clotting time delay caused by the GNS/Alg-NGs is 10-fold longer than that of natural polyphenolic compounds, such as quercetin, catechin, naringenin, caffeic acid, and ferulic acid. The thrombin- or kaolin-activated thromboelastography of whole-blood coagulation reveals that the GNS/Alg-NGs display a much stronger anticoagulant ability than that of untreated alginate and naturally sulfated polysaccharides (fucoidan). The GNS/Alg-NGs exhibit superior biocompatibility and anticoagulant activity, as observed with an in vivo rat model, revealing their potential as a blood thinner for the treatment of thrombotic disorders.

The Efficacy of Black Chokeberry Fruits against Cardiovascular Diseases

Epidemiological studies have emphasized the association between a diet rich in fruits and vegetables and a lower frequency of occurrence of inflammatory-related disorders. Black chokeberry (Aronia melanocarpa L.) is a valuable source of biologically active compounds that have been widely investigated for their role in health promotion and cardiovascular disease prevention. Many in vitro and in vivo studies have demonstrated that consumption of these fruits is associated with significant improvements in hypertension, LDL oxidation, lipid peroxidation, total plasma antioxidant capacity and dyslipidemia. The mechanisms for these beneficial effects include upregulation of endothelial nitric oxide synthase, decreased oxidative stress, and inhibition of inflammatory gene expression. Collected findings support the recommendation of such berries as an essential fruit group in a heart-healthy diet. The aim of this review was to summarize the reports on the impact of black chokeberry fruits and extracts against several cardiovascular diseases, e.g., hyperlipidemia, hypercholesterolemia, hypertension, as well as to provide an analysis of the antioxidant and anti-inflammatory effect of these fruits in the abovementioned disorders.

Effects of antioxidant supplementation on oxidative stress balance in young footballers- a randomized double-blind trial

BACKGROUND

Intensive physical exercise that competitive sports athletes participate in can negatively affect their pro-oxidative-antioxidant balance. Compounds with high antioxidant potential, such as those present in chokeberry (Aronia melanocarpa), can prevent these adverse changes. We here investigated the effect of antioxidant supplementation on oxidative stress balance in young footballers.

METHODS

The study was designed as a double-blind randomized trial. Diet of a group of young football players (male; n = 20; mean age, 15.8 years-old) was supplemented with 200 ml of chokeberry juice per day, for 7 weeks. The players were randomly assigned to the experimental (supplemented, FP-S; n = 12) and control (placebo, FB-C; n = 8) groups. Before and after the supplementation period, the participants performed a beep test. Venous blood was sampled for serum analysis before, immediately after, 3 h, and 24 h after the beep test. Serum levels of thiobarbituric acid reactive products, 8-hydroxy-2'-deoxyguanosine, total antioxidant capacity, iron, hepcidin, ferritin, myoglobin, and albumin, and morphological blood parameters (red blood cells, (RBC), haemoglobin (HGB), haematocrit (HCT) mean corpuscular volume (MCV) mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), and lactic acid) were determined.

RESULTS

Chokeberry juice supplementation did not significantly affect the outcome of the beep test. The supplementation did not significantly affect any of the morphological, biochemical, or performance parameters analysed.

CONCLUSIONS

Chokeberry juice supplementation did not affect the measured parameters in the studied population, which may indicate insufficient antioxidant capacity of the juice.

Flavonoids as potential anti-platelet aggregation agents: from biochemistry to health promoting abilities

Cardiovascular ailments are the number one cause of mortalities throughout the globe with 17.9 million deaths per year. Platelet activation and aggregation play a crucial role in the pathogenesis of arterial diseases, including acute coronary syndrome, acute myocardial infarction, cerebrovascular transient ischemia, unstable angina, among others. Flavonoids-rich plant extracts are gaining interest for treating the heart-related problems due to safe nature of these herbal extracts. Consumption of plant-food-derived bioactives, particularly flavonoids, has shown antithrombotic, and cardiovascular protective effects due to its anti-platelet activity. Preclinical and clinical trials have proven that flavonoid-rich plant extracts are protective against the cardiac ailments through anti-platelet aggregation activity. This review aims to highlight the anti-platelet aggregation potential of flavonoids with a key emphasis on the therapeutic efficacy in humans. The mechanism of flavonoids in preventing and treating cardiovascular diseases is also highlighted based on preclinical and clinical experimental trials. Further studies are the need of time for exploring the exact molecular mechanism of flavonoids as anti-platelet aggregation agents for treating heart-related problems.

The Protective Effect of Anthocyanins Extracted from Aronia Melanocarpa Berry in Renal Ischemia-Reperfusion Injury in Mice

Background

Our previous research showed the antioxidant activity of anthocyanins extracted from Aronia melanocarpa of black chokeberry in vitro. Ischemia acute kidney injury is a significant risk in developing progressive and deterioration of renal function leading to clinic chronic kidney disease. There were many attempts to protect the kidney against this progression of renal damage. Current study was designed to examine the effect of pretreatment with three anthocyanins named cyanidin-3-arabinoside, cyanidin-3-glucodise, and cyaniding-3-galactoside against acute ischemia-reperfusion injury in mouse kidney.

Methods

Acute renal injury model was initiated by 30 min clamping bilateral renal pedicle and followed by 24-hour reperfusion in C57Bl/6J mice. Four groups of mice were orally pretreated in 50 mg/g/12 h for two weeks with cyanidin-3-arabinoside, cyanidin-3-glucodise, and cyaniding-3-galactoside and anthocyanins (three-cyanidin mixture), respectively, sham-control group and the renal injury-untreated groups only with saline.

Results

The model resulted in renal dysfunction with high serum creatinine, blood urea nitrogen, and changes in proinflammatory cytokines (TNF-ɑ, IL-1β, IL-6, and MCP-1), renal oxidative stress (SOD, GSH, and CAT), lipid peroxidation (TBARS and MDA), and apoptosis (caspase-9). Pretreatment of two weeks resulted in different extent amelioration of renal dysfunction and tubular damage and suppression of proinflammatory cytokines, oxidative stress, lipid peroxidation, and apoptosis, thus suggesting that cyanidins are potentially effective in acute renal ischemia by the decrease of inflammation, oxidative stress, and lipid peroxidation, as well as apoptosis.

Conclusion

the current study provided the first attempt to investigate the role of anthocyanins purified from Aronia melanocarpa berry in amelioration of acute renal failure via antioxidant and cytoprotective effects.

Ameliorative effect of tannic acid on hypermethioninemia-induced oxidative and nitrosative damage in rats: biochemical-based evidences in liver, kidney, brain, and serum

We investigated the ability of tannic acid (TA) to prevent oxidative and nitrosative damage in the brain, liver, kidney, and serum of a rat model of acute hypermethioninemia. Young Wistar rats were divided into four groups: I (control), II (TA 30 mg/kg), III (methionine (Met) 0.4 g/kg + methionine sulfoxide (MetO) 0.1 g/kg), and IV (TA/Met + MetO). Rats in groups II and IV received TA orally for seven days, and rats of groups I and III received an equal volume of water. After pretreatment with TA, rats from groups II and IV received a single subcutaneous injection of Met + MetO, and were euthanized 3 h afterwards. In specific brain structures and the kidneys, we observed that Met + MetO led to increased reactive oxygen species (ROS), nitrite, and lipid peroxidation levels, followed by a reduction in thiol content and antioxidant enzyme activity. On the other hand, pretreatment with TA prevented both oxidative and nitrosative damage. In the serum, Met + MetO caused a decrease in the activity of antioxidant enzymes, which was again prevented by TA pretreatment. In contrast, in the liver, there was a reduction in ROS levels and an increase in total thiol content, which was accompanied by a reduction in catalase and superoxide dismutase activities in the Met + MetO group, and pretreatment with TA was able to prevent only the reduction in catalase activity. Conclusively, pretreatment with TA has proven effective in preventing oxidative and nitrosative changes caused by the administration of Met + MetO, and may thus represent an adjunctive therapeutic approach for treatment of hypermethioninemia.

Molecular Mechanisms of Leonurus Cardiaca L. Extract Activity in Prevention of Staphylococcal Endocarditis-Study on in Vitro and ex Vivo Models

Better understanding the mechanisms of Leonurus cardiaca L. extract (LCE) activity is necessary to prepare recommendations for the use of LCE-based herbal products for preventive/supportive purposes in case of infective endocarditis (IE) and other staphylococcal invasive infections. The aim of the study was to analyze molecular mechanisms of LCE effect on Staphylococcus aureus and blood platelets in the context of their interactions playing a pivotal role in such disorders. Using atomic force microscopy, we demonstrated that adhesion forces of S. aureus were markedly reduced after exposure to LCE at subinhibitory concentrations. The effect resulted from the impact of LCE on S. aureus cell morphology and the composition of phospholipids and fatty acids in bacterial membranes (assessed by HPLC), which modulated their stabilization, hydrophobicity, and charge. Moreover, using FACS we showed also that LCE significantly reduced GP IIb/IIIa expression on blood platelets, thus the disruption of platelet-fibrinogen interactions seems to explain antiplatelet effect of LCE. The obtained results prove the usefulness of LCE in the prevention of S. aureus adhesion, platelet activation, and vegetations development, however, also pointed out the necessity of excluding the cationic antibiotics from the treatment of S. aureus-associated IE and other invasive diseases, when motherwort herb is used simultaneously as an addition to the daily diet.

Evaluation of anthocyanins in Aronia melanocarpa/BSA binding by spectroscopic studies

The interaction between Anthocyanins in Aronia melanocarpa (AMA) and bovine serum albumin (BSA) were studied in this paper by multispectral technology, such as fluorescence quenching titration, circular dichroism (CD) spectroscopy and Fourier transform infrared spectroscopy (FTIR). The results of the fluorescence titration revealed that AMA could strongly quench the intrinsic fluorescence of BSA by static quenching. The apparent binding constants K_SV and number of binding sites n of AMA with BSA were obtained by fluorescence quenching method. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS), were calculated to be 18.45 kJ mol⁻¹ > 0 and 149.72 J mol⁻¹ K⁻¹ > 0, respectively, which indicated that the interaction of AMA with BSA was driven mainly by hydrophobic forces. The binding process was a spontaneous process of Gibbs free energy change. Based on Förster’s non-radiative energy transfer theory, the distance r between the donor (BSA) and the receptor (AMA) was calculated to be 3.88 nm. Their conformations were analyzed using infrared spectroscopy and CD. The results of multispectral technology showed that the binding of AMA to BSA induced the conformational change of BSA.

Berry Phenolic Antioxidants - Implications for Human Health?

Antioxidants present in the diet may have a significant effect on the prophylaxis and progression of various diseases associated with oxidative stress. Berries contain a range of chemical compounds with antioxidant properties, including phenolic compounds. The aim of this review article is to provide an overview of the current knowledge of such phenolic antioxidants, and to discuss whether these compounds may always be natural gifts for human health, based on both in vitro and in vivo studies. It describes the antioxidant properties of fresh berries (including aronia berries, grapes, blueberries, sea buckthorn berries, strawberries and other berries) and their various products, especially juices and wines. Some papers report that these phenolic compounds may sometimes behave like prooxidants, and sometimes demonstrate both antioxidant and prooxidant activity, while others note they do not behave the same way in vitro and in vivo. However, no unwanted or toxic effects (i.e., chemical, hematological or urinary effect) have been associated with the consumption of berries or berry juices or other extracts, especially aronia berries and aronia products in vivo, and in vitro, which may suggest that the phenolic antioxidants found in berries are natural gifts for human health. However, the phenolic compound content of berries and berry products is not always well described, and further studies are required to determine the therapeutic doses of different berry products for use in future clinical studies. Moreover, further experiments are needed to understand the beneficial effects reported so far from the mechanistic point of view. Therefore, greater attention should be paid to the development of well-controlled and high-quality clinical studies in this area.

Dietary Supplements with Antiplatelet Activity: A Solution for Everyone?

Dietary supplements can have beneficial effects on a number of risk factors for cardiovascular diseases, and interest in the use of nonpharmacologic nutraceutical-based treatments for cardiovascular disorders is growing. The aim of this review is to present the role of dietary supplements with antiplatelet activity in the prophylaxis and treatment of cardiovascular disorders. In addition, this paper describes their effects on another very important element of hemostasis-blood coagulation. However, because controlled human clinical experiments are too limited to clearly identify the antiplatelet and anticoagulant properties of dietary supplements, used alone or in combination with classical antiplatelet therapy (e.g., with aspirin), most information in this article is based on in vitro studies. Therefore, it cannot be unequivocally stated whether dietary supplements are universally safe and bring benefits to all. Some authors suggest that blood platelet count and function should be monitored in patients taking such supplements, especially before and after surgery, as well as other hemostasis parameters such as coagulation times.

Plant-based Food Cyanidin-3-Glucoside Modulates Human Platelet Glycoprotein VI Signaling and Inhibits Platelet Activation and Thrombus Formation

Background: Platelets play an important role in hemostasis, thrombosis, and atherosclerosis. Glycoprotein VI (GPVI) is a major platelet receptor that interacts with exposed collagen on injured vessel walls. Our previous studies have shown that anthocyanins (a type of natural plant pigment) attenuate platelet function; however, whether anthocyanins affect collagen-induced GPVI signaling remains unknown.Objective: The objective of this study was to explore the effects of cyanidin-3-glucoside (Cy-3-g, one of the major bioactive compounds in anthocyanins) on platelet activation and thrombosis and the GPVI signaling pathway.Methods: Platelets from healthy men and women were isolated and incubated with different concentrations (0, 0.5, 5, and 50 μM) of Cy-3-g. The expression of activated integrin αIIbβ3, P-selectin, CD63, and CD40L, fibrinogen binding to platelets, and platelet aggregation were evaluated in vitro. Platelet adhesion and aggregation in whole blood under flow conditions were assessed in collagen-coated perfusion chambers. Thrombosis and hemostasis were assessed in 3-4-wk-old male C57BL/6J mice through FeCl₃-induced intravital microscopy and tail bleeding time. The effect of Cy-3-g on collagen-induced human platelet GPVI signaling was explored with Western blot.Results: Cy-3-g attenuated platelet function in a dose-dependent manner. The 0.5-μM dose of Cy-3-g inhibited (P < 0.05) human platelet adhesion and aggregation to collagen at both venous (-54.02%) and arterial (-22.90%) shear stresses. The 5-μM dose inhibited (P < 0.05) collagen-induced human platelet activation (PAC-1: -48.21%, P-selectin: -50.63%), secretion (CD63: -73.89%, CD40L: -43.70%), fibrinogen binding (-56.79%), and aggregation (-17.81%). The 5-μM dose attenuated (P < 0.01) thrombus growth (-66.67%) without prolonging bleeding time in mice. The 50-μM dose downregulated (P < 0.05) collagen-induced GPVI signaling in human platelets and significantly decreased phosphorylation of Syk-linker for activation of T cells (LAT)-SLP76 (Syk: -39.08%, LAT: -32.25%, SLP76: -40.00%) and the expression of Lyn (-31.89%), Fyn (-36.27%), and phospholipase C-γ2 (-39.08%).Conclusions: Cy-3-g inhibits human platelet activation, aggregation, secretion, and thrombus formation, and downregulates the collagen-GPVI signaling pathway. Supplementation of Cy-3-g may have protective effects against atherothrombosis.

Fruits for Prevention and Treatment of Cardiovascular Diseases

Cardiovascular diseases (CVDs) are leading global health problems. Accumulating epidemiological studies have indicated that consuming fruits was inversely related to the risk of CVDs. Moreover, substantial experimental studies have supported the protective role of fruits against CVDs, and several fruits (grape, blueberry, pomegranate, apple, hawthorn, and avocado) have been widely studied and have shown potent cardiovascular protective action. Fruits can prevent CVDs or facilitate the restoration of morphology and functions of heart and vessels after injury. The involved mechanisms included protecting vascular endothelial function, regulating lipids metabolism, modulating blood pressure, inhibiting platelets function, alleviating ischemia/reperfusion injury, suppressing thrombosis, reducing oxidative stress, and attenuating inflammation. The present review summarizes recent discoveries about the effects of fruits on CVDs and discusses potential mechanisms of actions based on evidence from epidemiological, experimental, and clinical studies.

The multifunctionality of berries toward blood platelets and the role of berry phenolics in cardiovascular disorders

Diet and nutrition have an important influence on the prophylaxis and progression of cardiovascular disease; one example is the inhibition of blood platelet functions by specific components of fruits and vegetables. Garlic, onion, ginger, dark chocolate and polyunsaturated fatty acids all reduce blood platelet aggregation. A number of fruits contain a range of cardioprotective antioxidants and vitamins, together with a large number of non-nutrient phytochemicals such as phenolic compounds, which may possess both antioxidant properties and anti-platelet activity. Fresh berries and berry extracts possess high concentrations of phenolic compounds, i.e. phenolic acid, stilbenoids, flavonoids and lignans. The aim of this review article is to provide an overview of current knowledge of the anti-platelet activity of berries, which form an integral part of the human diet. It describes the effects of phenolic compounds present in a number of berries, i.e. black chokeberries - aronia berries (Aronia melanocarpa), blueberries (Vaccinium myrtillus), cranberries (Vaccinium sect. Oxycoccus), sea buckthorn berries (Hippophae rhamnoides) and grapes (Vitis), as well as various commercial products from berries (i.e. juices), on platelets and underlying mechanisms. Studies show that the effects of berries on platelet activity are dependent on not only the concentrations of the phenolic compounds in the berries or the class of phenolic compounds, but also the types of berry and the form (fresh berry, juice or medicinal product). Different results indicate that berries may play a role in the prevention of cardiovascular disorders, but the development of well-controlled clinical studies with berries is encouraged.

Berberine activates peroxisome proliferator-activated receptor gamma to increase atherosclerotic plaque stability in Apoe-/- mice with hyperhomocysteinemia

AIMS/INTRODUCTION

An elevated level of plasma homocysteine has long been suspected as a metabolic risk factor for the development of atherosclerotic vascular diseases in diabetes. Berberine (BBR) has several preventive effects on cardiovascular diseases. The effects of BBR on atherosclerotic plaque stability increased by homocysteine thiolactone (HTL) remain unknown.

MATERIALS AND METHODS

The model of atherosclerotic vulnerable plaque was induced by placing a collar around the carotid artery in Apoe^-/- mice. Endothelium-dependent relaxation was assayed by organ chamber.

RESULTS

Homocysteine thiolactone (50 mg/kg/day, 8 weeks) reduced the atherosclerotic plaque stability in the carotid artery of Apoe^-/- mice, which was reversed by BBR administration (1.0 g/kg/day). In vivo and ex vivo experiments showed that HTL dramatically reduced acetylcholine-induced endothelium-dependent relaxation and superoxide dismutase activity, and increased malondialdehyde content, which were inhibited by BBR. Importantly, all effects induced by BBR were abolished by GW9662, an antagonist of peroxisome proliferator-activated receptor-γ. Incubation of cultured endothelial cells with HTL significantly reduced cell viabilities and enhanced production of reactive oxygen species. Pretreatment of cells with BBR dose-dependently reversed HTL-induced detrimental effects, which were GW9662-reversible.

CONCLUSIONS

Berberine increases atherosclerotic plaque stability in hyperhomocysteinemia mice, which is related to the activation of peroxisome proliferator-activated receptor-γ and subsequent suppression of oxidative stress in endothelial cells.

Resveratrol ameliorates low shear stress‑induced oxidative stress by suppressing ERK/eNOS‑Thr495 in endothelial cells

Fluid shear stress has been revealed to differentially regulate endothelial nitric oxide synthase (eNOS) distribution in vessels. eNOS, a key enzyme in controlling nitric oxide (NO) release, has a crucial role in mediating oxidative stress, and resveratrol (RSV)‑mediated eNOS also attenuates oxidative damage and suppresses endothelial dysfunction. To observe the protective effect of RSV on low shear stress (LSS)‑induced oxidative damage and the potential mechanisms involved, a parallel‑plate flow chamber, which imposed a low level of stress of 2 dynes/cm2 to cells, was employed. Reactive oxygen species (ROS), NO and apoptotic cells were examined in LSS‑treated endothelial cells (ECs) with or without RSV. Western blot analysis was used to examine LSS‑regulated eNOS‑Ser1177, Thr495 and Ser633, which were tightly associated with NO release. To further determine the underlying signaling pathways involved, extracellular signal‑regulated kinase (ERK), a possible upstream target of eNOS‑Thr495, was investigated, followed by examination of eNOS‑Thr495 in ERK‑inhibited cells. Additionally, eNOS mRNA expression levels were analyzed in cells challenged with LSS. The results revealed that RSV markedly decreased LSS‑induced oxidative damage in ECs. Furthermore, eNOS‑Ser1177 and Thr495 as well as phospho‑ERK were time‑dependently activated by LSS. The ERK inhibitor deactivated eNOS‑Thr495, which was accompanied by increased intracellular superoxide dismutase (SOD) levels. Of note, the activation effect of LSS on ERK/eNOS was markedly eliminated by RSV. In conclusion, RSV exerts antioxidant effects by suppressing LSS-activated ERK/eNOS and may provide a potential therapeutic target for atherosclerosis.

Extract of Aronia melanocarpa-modified hemostasis: in vitro studies

Purpose

Aronia melanocarpa has an extremely high content of procyanidins and anthocyanins. The multidirectional benefits of consumption of these berries are widely reported. Although numerous studies confirmed the influence of polyphenols on various stages of hemostasis, the exact mechanism of this phenomenon is not understood. The aim of our study was to evaluate the in vitro effect of A. melanocarpa extract on various parameters of hemostasis.

Methods

Adenosine 5′-diphosphate (ADP)-induced aggregation was measured with turbidimetric method. Spontaneous and ADP-activated platelet adhesion were investigated using a colorimetric method. The global assay of coagulation and fibrinolysis was performed with the use of optical clotting and lysis (CL) test. Thrombin (0.5 IU/mL) and tissue plasminogen activator (60 ng/mL) were used to obtain a CL curve. The activity of thrombin and plasmin was determined by means of chromogenic substrate (S-2238, S-2251)

Results

The aronia extract contributed to the reduction in spontaneous and ADP-activated platelet adhesion. A significant increase in overall potential of CL as well as significant changes in key parameters of these processes (T_t—thrombin time, F_vo—initial plasma clotting velocity, and L_max—maximum lysis) was reported. Chokeberry extract significantly inhibited the amidolytic activity of thrombin and plasmin.

Conclusion

Our in vitro findings indicate a complex mechanism of influence of chokeberry polyphenols on platelet activity and the overall potential of CL. We confirmed that chokeberry inhibits the amidolytic activity of thrombin. It was demonstrated for the first time that chokeberry polyphenols inhibit the amidolytic activity of another serine protease, i.e., plasmin, which is the main fibrinolytic enzyme. Furthermore, our research points out a significant contribution of other plasma components and fibrinogen in the modulation of hemostasis by polyphenols.

Comparative antiadhesive properties of crude extract and phenolic fraction isolated from aerial parts of Tribulus pterocarpus during severe hyperhomocysteinemia

The phenolic fraction and the crude extract from Tribulus pterocarpus have different biological activity, including antiplatelet-antiadhesive properties. Since it is demonstrated that hyperhomocysteinemia may act as stimulator of blood platelet activation (platelet adhesion, aggregation, and secretion), but various antiplatelet compounds are able to reduce hyperactivation of blood platelets induced by hyperhomocysteinemia. The aim of our present experiments was to investigate in vitro one of the step in platelet activation process - platelet adhesion to collagen induced by the model of severe hyperhomocyateinemia in the presence of the phenolic fraction and the crude extract from T. pterocarpus. Severe hyperhomocysteinemia was induced by reduced form of Hcy in the concentrations 0.1mM and 1mM, or using HTL in the concentrations 0.1, 0.5 and 1 μM. Adhesion of blood platelets to collagen was determined according to Tuszynski and Murphy. We observed that the phenolic fraction and the crude extract from T. pterocarpus have the inhibitory effect on platelet adhesion during severe hyperhomocysteinemia. The action of tested phenolic and crude extract was concentration-dependent, but the phenolic fraction was stronger antiadhesive action than the crude extract. We suggest that T. pterocarpus may be good source of antiplatelet compounds during hyperhomocysteinemia.