The Effects of Caffeine on Blood Platelets and the Cardiovascular System through Adenosine Receptors.

Caffeine is the most popular and widely consumed behaviourally active substance in the world. This review describes the influence of caffeine on the cardiovascular system, with a special focus on blood platelets. For many years, caffeine was thought to have a negative effect on the cardiovascular system mainly due to increasing blood pressure.

Potential for modulation of platelet function via adenosine receptors during inflammation.

Traditionally, platelets are known to play an important role in haemostasis and thrombosis; however, they serve also as important modulators of inflammation and immunity. Platelets secrete adhesion molecules and cytokines, interact with leukocytes and endothelium, and express toll-like receptors involved in a direct interaction with pathogens. Platelets express A and A subtypes of receptors for adenosine.

SARS-CoV-2 Spike Protein and Neutralizing Anti-Spike Protein Antibodies Modulate Blood Platelet Function.

Several studies report elevated blood platelet activation and altered platelet count in COVID-19 patients, but the role of the SARS-CoV-2 spike protein in this process remains intriguing. Additionally, there is no data that anti-SARS-CoV-2 neutralizing antibodies (nAb) may attenuate spike protein activity toward blood platelets. Our results indicate that under in vitro conditions, the spike protein increased the collagen-stimulated aggregation of isolated platelets and induced the binding of vWF to platelets in ristocetin-treated blood.

Platelet-Derived Procoagulant Microvesicles Are Elevated in Patients with Retinal Vein Occlusion (RVO).

The etiopathogenesis of retinal vein occlusion (RVO) is multifactorial, and the contribution of platelets to RVO development has not been fully elucidated. We aimed to analyze platelet function in RVO patients (n = 35) and controls (n = 35). We found a higher (p < 0.

Systemic immune-inflammation index (SII) and neutrophil to lymphocyte ratio (NLR) are useful markers for assessing effects of anti-inflammatory diet in patients before coronary artery bypass grafting.

Background: One of the risk factors responsible for coronary artery disease (CAD) is an inadequate diet that is frequently deficient in anti-inflammatory components, such as polyphenols and omega-3 fatty acids. The neutrophil to lymphocyte ratio (NLR) and the systemic immune-inflammation index (SII) are inflammatory markers that may reflect a diet's antiinflammatory potential.

Objective: The aim of this study was to evaluate the effects that CAD patients' nutrition patterns have on NLR and SII.

Platelet and Thrombophilia-Related Risk Factors of Retinal Vein Occlusion.

Retinal vein occlusion (RVO) is a heterogenous disorder in which the formation of a thrombus results in the retinal venous system narrowing and obstructing venous return from the retinal circulation. The pathogenesis of RVO remains uncertain, but it is believed to be multifactorial and to depend on both local and systemic factors, which can be divided into vascular, platelet, and hypercoagulable factors. The vascular factors include dyslipidaemia, high blood pressure, and diabetes mellitus.

Effects of Omega-3 Polyunsaturated Fatty Acids and Their Metabolites on Haemostasis-Current Perspectives in Cardiovascular Disease.

The beneficial effects of long-chain polyunsaturated omega-3 fatty acids (omega-3 PUFAs) in cardioprotection are widely known and generally accepted. In this literature review, we have focused on the known and postulated mechanisms of action of omega-3 PUFAs and their metabolites on various components of the haemostatic system, in particular on blood platelets and endothelium. We have also made an attempt to provide a comprehensive review of epidemiological studies with particular regard to clinical trials.

Adenosine Receptor Agonists Increase the Inhibition of Platelet Function by P2Y Antagonists in a cAMP- and Calcium-Dependent Manner.

We have shown previously that platelet activity can be lowered through the simultaneous inhibition of P2Y receptor and activation of adenosine receptors (AR). This work explores this concept by testing the antiplatelet potential of nine AR agonists in combination with P2Y receptor antagonists-cangrelor and prasugrel metabolite. A panel of in vitro methods was used to assess platelet viability, P-selectin expression, GPIIb-IIIa activation, fibrinogen binding, calcium ion mobilization, VASP-P level, and cAMP formation, utilizing whole blood or isolated platelets from healthy volunteers.

Adenosine Receptor Agonists Exhibit Anti-Platelet Effects and the Potential to Overcome Resistance to P2Y Receptor Antagonists.

Large inter-individual variation in platelet response to endogenous agonists and pharmacological agents, including resistance to antiplatelet therapy, prompts a search for novel platelet inhibitors and development new antithrombotic strategies. The present in vitro study evaluates the beneficial effects of three adenosine receptor (AR) agonists (regadenoson, LUF 5835 and NECA), different in terms of their selectivity for platelet adenosine receptors, when used alone and in combination with P2Y inhibitors, such as cangrelor or prasugrel metabolite. The anti-platelet effects of AR agonists were evaluated in healthy subjects (in the whole group and after stratification of individuals into high- and low-responders to P2Y inhibitors), using whole blood techniques, under flow (thrombus formation) and static conditions (study of platelet activation and aggregation).

Platelet reactivity expressed as a novel platelet reactivity score is associated with higher inflammatory state after coronary artery bypass grafting.

Introduction: Despite therapy, patients operated using a cardiopulmonary bypass demonstrate increased platelet aggregation, which rebounds to above preoperative levels. The aim of the study was to test the interaction between platelet reactivity/activation and selected inflammatory markers in the post-operative period.

Material And Methods: In total, 103 patients with non-ST elevation acute coronary syndrome (NSTE-ACS) who were not eligible for percutaneous coronary interventions (PCI), and required urgent revascularization, were included.

Dietary intake of omega fatty acids and polyphenols and its relationship with the levels of inflammatory markers in men with chronic coronary syndrome after percutaneous coronary intervention.

Background: The platelet‑to‑lymphocyte ratio (PLR), neutrophil‑to‑lymphocyte ratio (NLR), and C‑reactive protein (CRP) are useful in assessing inflammation in patients after percutaneous coronary intervention (PCI). The PLR and NLR are also independent predictors of cardiovascular mortality. Moreover, higher CRP levels increase the risk of long‑term mortality in patients undergoing PCI.

Blood Platelet Adenosine Receptors as Potential Targets for Anti-Platelet Therapy.

Adenosine receptors are a subfamily of highly-conserved G-protein coupled receptors. They are found in the membranes of various human cells and play many physiological functions. Blood platelets express two (A and A) of the four known adenosine receptor subtypes (A, A, A, and A).

Polyphenol-rich diet is associated with decreased level of inflammatory biomarkers in breast cancer patients.

Background: The study investigated the relationship between dietary intake of polyphenols and inflammatory markers: CRP, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), medium platelet volume/lymphocyte ratio (MPVRL), in newly-diagnosed breast cancer patients.

Objectives: The aim of this work was to verify whether diet rich in plant polyphenols affects inflammatory markers in breast cancer patients.

Materials And Methods: 78 patients (55.

Adenosine receptor agonists deepen the inhibition of platelet aggregation by P2Y antagonists.

Several adenosine receptor (AR) agonists have been shown in the past to possess anti-platelet potential; however, the adjunctive role of AR agonists in anti-platelet therapy with the use of P2Y receptor inhibitors has not been elucidated so far. This in vitro aggregation-based study investigates whether the inhibition of platelet function mediated by cangrelor or prasugrel metabolite can be potentiated by AR agonists. It evaluates the effect of non-selective (2-chloroadenosine), A-selective (UK 432097, MRE 0094, PSB 0777) and A-selective AR agonists (BAY 60-6583) on platelet function in relation to their toxicity, specificity towards adenosine receptor subtypes, structure and solubility.

The immunomodulatory potential of Leonurus cardiaca extract in relation to endothelial cells and platelets.

The immunomodulatory activity of Leonurus cardiaca L. polyphenol-rich extract (LCE) was tested in vitro on HUVECs to explore its potential therapeutic usefulness in the treatment of inflammatory lesions. The phytochemical composition of LCE, its antioxidant and cytotoxic activity, and the influence of LCE on NO and platelet-activating factor (PAF) secretion by HUVECs and platelet aggregation were all assessed.

Platelet activation patterns are different in mouse models of diabetes and chronic inhibition of nitric oxide synthesis.

Currently, there are several animal models of diabetes mellitus and hypertension, but relatively little is known about blood platelet function in these models. The aim of this work was to characterise and compare platelet reactivity and activation in db/db mice (mouse model of diabetes) and mice receiving L-NAME (model of chronic inhibition of NO synthesis), using various platelet function assays. We found higher platelet activation (circulating resting platelets) in db/db mice than in db/+heterozygotes, as evidenced by elevated expressions of CD62P and CD40L and a lower expression of CD42b.

Comparison of cytotoxic and anti-platelet activities of polyphenolic extracts from Arnica montana flowers and Juglans regia husks.

Polyphenolic compounds of plant origin are well known to be beneficial to human health: they exert protective effects on haemostasis and have a particular influence on blood platelets. However, the anti-platelet properties of polyphenolic compounds observed so far have not been weighed against their potential cytotoxic action against platelets. The aim of this study was to demonstrate that anti-platelet and cytotoxic effects on blood platelets may interfere and therefore, may often lead to confusion when evaluating the properties of plant extracts or other agents towards blood platelets.

Various laboratory protocols for measuring thromboxane A2 generation to detect the effectiveness of acetylsalicylic acid therapy: a comparative study.

A reliable and simple laboratory assay for predicting clinical effectiveness of antiplatelet acetylsalicylic acid (ASA) therapy is needed. We have compared various laboratory protocols for measuring blood thromboxane A2 (TXA2) generation used to detect the effects of ASA administration. Healthy volunteers (n = 15) were given 150 mg per day ASA for 10 days, followed by ASA at 75 mg per day for 10 days.

Antiadherent and antibiofilm activity of Humulus lupulus L. derived products: new pharmacological properties.

New antimicrobial properties of products derived from Humulus lupulus L. such as antiadherent and antibiofilm activities were evaluated. The growth of gram-positive but not gram-negative bacteria was inhibited to different extents by these compounds.

Antimicrobial/anti-biofilm activity of expired blood platelets and their released products.

Introduction: Although platelets are not part of the classical immune system, they have many features that indicate their role in the anti-infective host defense. They come into interactions with microorganisms, which results in co-aggregation and co-adhesion or destruction of the microbes due to the action of antimicrobial peptides released from platelets.The aim of this study was to evaluate the killing effect of platelets against planktonic and biofilm cultures of Staphylococcus aureus and to test their synergy with antibiotics.

Enhanced platelet-derived microparticle formation is associated with carotid atherosclerosis in convalescent stroke patients.

Platelets participate in the development and progression of atherosclerosis. During this process they interact with endothelial cells and leukocytes. Therefore, we investigated the associations between carotid atherosclerosis and platelet reactivity markers.

Calcium mobilization by the plant estrogen ferutinin does not induce blood platelet aggregation.

Platelet activation is closely associated with an increase in intracellular Ca(2+) concentration. Various compounds including Ca(2+) ionophores are able to trigger platelet aggregation by increasing intracellular Ca(2+) concentration in platelets. In the present study, we monitored the effect of the phytoestrogen ferutinin, which acts as a Ca(2+) ionophore in human blood platelets; its ionophore-like properties include upregulation of [Ca(2+)](in), activation of fibrinogen receptors and increased fibrinogen binding.

Platelet activation and reactivity in the convalescent phase of ischaemic stroke.

The study was aimed at the evaluation of blood platelet activation and reactivity in patients in the convalescent phase of stroke (n=58) and controls matched in respect to risk factors of vascular pathology (n=55). Both groups were treated daily with acetylsalicylic acid (ASA), 150 mg/day. Using flow cytometry, the expressions of P-selectin and the active GP IIb/IIIa receptor, as well as the fraction of platelet-derived microparticles (PMPs) and total platelet aggregates (Ag), were evaluated in non-stimulated platelets and in platelets stimulated in vitro by thrombin, thrombin receptor activating peptide (TRAP) or ADP.

Structure, stability, and antiplatelet activity of O-acyl derivatives of salicylic acid and lipophilic esters of acetylsalicylate.

The anti-thrombotic activity of acetylsalicylic acid (ASA) has been shown to be due to specific irreversible acetylation of blood platelet cyclooxygenase. The aim of our study was to investigate the associations between the antiplatelet activities of derivatives of both ASA and salicylic acid (SA), as well as the structure, stability, and molecular properties of these compounds. Homologous series of O-acyl derivatives of salicylic acid (propionyl-, butyrylsalicylic acids, PSA, BSA) and lipophilic dodecyl (C12)-, hexadecyl (C16)-, and cholesteryl acetylsalicylates were synthesized and tested for structure-activity relationships.

Can we use adenosine diphosphate (ADP) to study "aspirin resistance"? The Janus faces of ADP-triggered platelet aggregation.

There is a growing number of contradictory reports indicating that adenosine diphosphate (ADP) can be a useful agonist in monitoring of the antiplatelet action of acetylsalicylic acid (ASA) in humans and animals. In the current study, we aimed to determine the conditions for using ADP to trigger platelet aggregation in order to detect ASA-mediated inhibition of rat platelet reactivity. Initially, we examined the usefulness of different ADP concentrations (0.