Antiplatelet Activity Research Articles

New mechanisms of antiplatelet activity of nifedipine, an L-type calcium channel blocker

New mechanisms of antiplatelet activity of nifedipine, an L-type calcium channel blocker

Abstract 4134630: Focal Delivery of Antiplatelet Therapy to Prevent Post-Stent Bleeding in High-Risk Patients

Background: Over 3 million percutaneous coronary interventions (PCI) are performed yearly to treat coronary artery stenosis. Stent thrombosis is a catastrophic complication associated with high morbidity and mortality, and its prevention requires the use of prolonged dual antiplatelet therapy (DAPT), which increases bleeding risk. Within the first 30 days after PCI, the mortality of DAPT-associated major bleeding is on par with recurrent myocardial infarction. Research question: No stent system that provides focal antiplatelet activity to prevent stent thrombosis exists, eliminating the need for systemic DAPT and subsequent bleeding risk. Aim: To address this unmet need, we have developed such a stent, termed “the ticagrelor coated stent” (TCS). Methods: Self-assembled monolayers (SAMs) of 12-aminododecylphosphonic acid (ADPA) were formed on cobalt-chromium stents. The amine tail group of ADPA was used to link the ticagrelor molecule through a Mitsunobu reaction and confirmed via infrared spectroscopy. Coating uniformity was validated via atomic force microscopy. In an ex-vivo porcine arterio-venous fistula model, the ticagrelor-coated stents (TCS) were placed in alternating series adjacent to uncoated bare metal stents (BMS). Similarly, TCS and everolimus-eluting stents were placed in the porcine left circumflex arteries for acute (7 days) and chronic (35 days) studies. Results: ( Figure 1 ): Grossly, no thrombus was seen on the TCS compared to the BMS. Platelet and micro-thrombi adherence were significantly reduced on TCS. Notably, inflammation, measured by neutrophil and monocyte adherence, was also reduced by approximately 10-fold on the TCS vs the BMS. Angiography, optical coherence tomography (OCT), and histopathology results show the TCS widely patent without systemic DAPT. Conclusion: These findings show that TCS prevents stent thrombosis through focal anti-platelet action and may reduce the bleeding risk associated with prolonged use of systemic DAPT. Long-term safety and efficacy studies are underway.

Fabrication of an Antibacterial/Anticoagulant Dual-Functional Surface for Left Ventricular Assist Devices via Mussel-Inspired Polydopamine Chemistry.

Infections and thrombosis remain unsolved problems for implanted cardiovascular devices, such as left ventricular assist devices. Hence, the development of surfaces with improved blood compatibility and antimicrobial properties is imperative to reduce complications after artificial heart implantation. In this work, we report a novel approach to fabricate multifunctional surfaces for left ventricular transplanted ventricular assist devices (LVADs) by immobilizing nitric oxide (NO) generation catalysts and heparin and reducing silver nanoparticles in situ. The general view, structure, and chemical compositions of the pure/modified surfaces were characterized using digital imaging, scanning electron microscope (SEM), atomic force microscope (AFM), water contact angle (WCA), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma (ICP). All of the results demonstrated that the AgNPs and heparin were successfully immobilized on the surface. The Cu ions and NO release experimental results showed that the immobilized copper ions could catalyze the production of NO from S-nitrosothiols within the biological system. Meanwhile, due to the synergistic anticoagulant effect of NO and surface-immobilized heparin, the fabricated modified surfaces exhibited antiplatelet adhesion activities and good hemocompatibility. Finally, the antimicrobial activity of the samples was evaluated by Escherichia coli and Staphylococcus aureus, and cytocompatibility was measured using human umbilical vein endothelial cells (HUVECs). The results demonstrated that silver nanoparticles (AgNPs) immobilized by surface reduction reaction did not cause any significant inhibition of cell proliferation while providing stable and effective antimicrobial properties. We envision that this simple surface modification strategy with bifunctional activities of antimicrobial and anticoagulant will find widespread use in clinically used indwelling left ventricular assist devices.

Design, Synthesis, and Anti-Inflammatory Activity Evaluation of Novel Indanone Derivatives for the Treatment of Vascular Dementia.

Vascular dementia (VaD) is a neurodegenerative disease resulting from cerebral vascular obstruction, leading to cognitive impairment, and currently lacks effective treatment options.Due to its complex pathogenesis, multi-target drug design (MTDLs) strategies are considered among the most promising therapeutic approaches. In this study, we designed and synthesized a series of novel indanone derivatives targeting targets related to vascular health and dementia. The results indicated that compound C5exhibited excellent acetylcholinesterase inhibitory activity (IC50= 1.16 ± 0.41 μM) and anti-platelet aggregation activity (IC50= 4.92 ± 0.10 μM) within ranges of 0.1-1000 μM and 0.03-300 μM, respectively, possibly mediated by molecular docking interactions. Furthermore, compound C5demonstrated protective effects on cells at concentrations ≤50 μM, significantly reducing the release of nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) in a concentration-dependent manner, showcasing its potent neuroinflammatory inhibitory effects. Anti-inflammatory therapies are regarded as effective strategies for treating VaD. Therefore, compound C5holds promise as a novel candidate drug for further investigation into the treatment of vascular dementia.

Anticoagulant Effect of Snow mountain garlic: In Vitro Evaluation of Aqueous Extract.

Snow mountain garlic is traditionally eaten by Himalayan locals for its medicinal properties. Although different species of the genus Allium are known to have other biological effects, such as antiplatelet and antithrombotic activities, little is known about the anticoagulant effect of Snow mountain garlic, a member of the genus Allium. Therefore, the present study examined the in vitro anticoagulant effect of the aqueous extract, the lyophilized aqueous extract, and the isoflavone extract from the lyophilized aqueous extract of Snow mountain garlic in samples from 50 human blood donors. Compared to the control, concentrations of 25, 12.5, and 6.25 mg/100 µL lengthened the clotting times of prothrombin, and concentrations of 25 and 12.5 mg/100 µL lengthened the activated partial thromboplastin time (p ˂ 0.05). The isoflavone extract from the lyophilized aqueous extract containing isoflavones, organosulfur compounds, a polyphenol, and a steroid glycoside showed a significant effect (p ˂ 0.05) on the prothrombin time and the activated partial thromboplastin time at a dose of 20 µL (volume) compared to the control. The results regarding the use of Snow mountain garlic as a preventive measure and aid in treating thromboembolic disease are promising.

Synthesis, Docking Analysis, and Assessment of Chalcones for Antibacterial and Anthelmintic Activities

Background: Chalcones have been demonstrated to contain numerous therapeutic qualities in recent years, such as antibacterial, antiviral, anti-ulcerative, antioxidant, antiinflammatory, antihyperglycemic, antimalarial, antitubercular, analgesic, antiplatelet, and anticancer activities. Objective: To explorethe synthesis, docking, and characteristics of chalcones as antibacterial and anthelmintic compounds. Methods: The chalcone derivatives (3a-3k) and (6l-6v) were synthesized via two selective different reactions, based on the Claisen-Schmidt reaction. All synthesized compounds were evaluated for their antibacterial activity using an in vitro cup-plate method, and their anthelmintic activity was assessed using an in vitro earthworm paralysis and death assay. To validate these findings, conducted molecular docking experiments between the dihydrofolate reductase receptor (PDB ID: 4LAE) and the synthesised compounds (3a-3k) and (6l-6v) to determine catalytic interactions. Results: Compound 6(n) exhibited the greatest efficacy in biological in vitro activity against S. aureus compared to all other compounds examined. Compound 6(o) exhibited substantial efficacy against P. posthuma and E. coli. Emphasizing these findings, the compounds 3(a), 3(g), 3(i), 6(n), and 6(o) demonstrated hydrogen bond interactions with certain amino acid residues of the receptor, including THR 122, ASN 18, ASN19, GLN 96, SER 50, and ALA 8, during molecular docking. Conclusion: The study results showed that the synthesised derivative (E)-1-(napthalen-2-yl)-3-(4- (trifluoromethoxy)phenyl)prop-2-en-1-one 6(n) had beneficial antibacterial properties against S. aureus, while derivative (E)-1-(Napthalen-2-yl)-3-(4-trifluoromethyl)phenyl)prop-2-en-1-one 6(o) exhibited antibacterial activity against E. coli and anthlelmintic activity against P. posthuma.

Unbiased high-throughput screening of drug-repurposing libraries identifies small-molecule inhibitors of clot retraction

AbstractPlatelet clot retraction, the ultimate phase of platelet thrombus formation, is critical for clot stabilization. It requires functional αIIbβ3 receptors, fibrin, and the integrated actions of the actin-myosin contractile and cytoskeletal systems. Disturbances in clot retraction have been associated with both bleeding and thrombosis. We recently demonstrated that platelets treated with the αIIbβ3 antagonist peptide RGDW, which eliminates fibrinogen-mediated platelet aggregation, are still able to retract clots. We have exploited this observation to develop an unbiased, functional high-throughput assay to identify small-molecule inhibitors of fibrin-mediated clot retraction adapted for a 384-well plate format. We tested 9710 compounds from drug-repurposing libraries (DRLs). These libraries contain compounds that are either US Food and Drug Administration approved or have undergone preclinical/clinical development. We identified 27 compounds from the Library of Pharmacologically Active Compounds library as inhibitors of clot retraction, of which 14 are known inhibitors of platelet function. From the DRLs, we identified 135 compounds (1.6% hit rate). After extensive curation, these compounds were categorized based on the activity of their reported target. Multiple kinase and phosphodiesterase inhibitors with known antiplatelet effects were identified, along with multiple deubiquitination and receptor inhibitors, as well as compounds that have not previously been reported to have antiplatelet activity. Studies of 1 of the deubiquitination inhibitors (degrasyn) suggest that its effects are downstream of thrombin-induced platelet-fibrinogen interactions and thus may permit the separation of platelet thrombin-induced aggregation-mediated events from clot retraction. Additional studies of the identified compounds may lead to novel mechanisms of inhibiting thrombosis.

Antithrombotic activity of Punica granatum, L (Pomegranate): Experimental investigation and exploration of its mechanism of action on primary and secondary hemostasis in vitro and ex vivo

Hemostasis is the physiological process that stops bleeding by forming a thrombus (or blood clot). However, the inappropriate formation of a thrombus can constitute a pathophysiological event involving the same steps as those of hemostasis. Despite some adverse effects, antithrombotic therapy remains an effective means in the prevention and treatment of thrombotic diseases. In this regard, scientific research aimed at discovering new remedies of natural origin is particularly active.This study aims to evaluate the antithrombotic activity of the aqueous extract of Punica granatum peels in vivo. To understand the mechanism of action of this activity, we will investigate primary and secondary hemostasis in vitro and ex vivo. Furthermore, we will examine its antioxidant activity, toxicity, and phytochemical composition to identify the molecules responsible for the observed effects.The antithrombotic activity is assessed in vivo using the acute pulmonary thromboembolism model in mouse. Thrombosis is induced by injecting the thrombogenic solution (epinephrine + collagen) into the lateral caudal vein. Platelet aggregation, both in vitro and ex vivo, is performed on washed platelets isolated by centrifugation from rat blood. The platelet suspension is pre-incubated with the extract for 1 min. Aggregation is triggered by adding the following agonists: ADP, thrombin, collagen, and arachidonic acid. The bleeding time is measured in the absence and presence of the extract following an apical section of the mouse tail. This time corresponds to the duration of flow between the first and last drops of blood. To evaluate plasma coagulation, activated partial thromboplastin time (aPTT) and prothrombin time (PT) were measured under conditions both with and without the extract, using appropriate reagents. Acute toxicity is conducted by administering a single oral dose of the extract to mice (5 and 10 g kg-1). Possible changes in animal behavior are observed for fifteen days. The identification of polyphenols and flavonoids is performed by High Performance Liquid Chromatography (HPLC).The results obtained show that P. granatum exerted a significant preventive antithrombotic action (80 % protection) in mice. Furthermore, the extract inhibited platelet aggregation induced in vitro by all agonists in a dose-dependent manner, prolonged bleeding time, and coagulation times in rats. The results of the ex vivo study in rats confirmed these effects. We also noted that the extract did not exhibit toxicity following administration, and HPLC analysis revealed a richness of polyphenols and flavonoids in the extract.P. granatum exhibited an interesting antithrombotic activity, which could be attributed to its antiplatelet and anticoagulant actions. The phytochemical compounds identified in this extract could, at least in part, be responsible for these effects. Therefore, the demonstrated activities of this plant on hemostasis could lead to the development of more effective remedies and represent a means of prevention against thrombotic events.

Synthesis and pharmacological properties of novel guanidine derivatives of quinazoline-2,4(1H,3H)-dione

Introduction: Na+/H+ exchanger type 1 (NHE-1) is a validated drug target for the treatment of cardiovascular and ophthalmic diseases due to the cytoprotective, anti-ischemic and anti-inflammatory properties of NHE-1 inhibitors. This article presents data on the synthesis and pharmacological activity studies of novel guanidine derivatives of quinazoline-2,4(1H,3H)-dione 6-11 and reference drugs amiloride, rimeporide, zoniporide, dexamethasone, aminoguanidine, and acetylsalicylic acid. Materials and Methods: Pharmacological properties were assessed using pH-dependent platelets deformation assay, anti-inflammatory activity assay on LPS-stimulated peritoneal macrophages, antiglycation assay, analysis of platelet aggregation in vitro and measurement of intraocular pressure in vivo. Results: Several compounds combine NHE-1 inhibition with antiglaucomic and antiplatelet activity. Compound 11 significantly inhibits pro-inflammatory activation of murine macrophages (IC50 15.64 μM) and effectively suppresses the formation of glycated proteins (38.1±2.6% in C 1 mM). Conclusion: The investigated compounds represent a promising scaffold for development of agents for the treatment of cardiovascular pathologies, glaucoma, excessive inflammation, and late diabetic complications including retina diabetics and thrombosis.

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. However, more recent data suggest that habitual caffeine consumption may reduce the risk of cardiovascular disease and hypertension. This could be a significant finding as cardiovascular disease is the leading cause of death worldwide. Caffeine is known to inhibit A1 adenosine receptors, through which it is believed to modulate inter alia coronary blood flow, total peripheral resistance, diuresis, and heart rate. It has been shown that coffee possesses antiplatelet activity, but depending on the dose and the term of its use, caffeine may stimulate or inhibit platelet reactivity. Also, chronic exposure to caffeine may sensitize or upregulate the adenosine receptors in platelets causing increased cAMP accumulation and anti-aggregatory effects and decrease calcium levels elicited by AR agonists. The search for new, selective, and safe AR agonists is one of the new strategies for improving antiplatelet therapy involving targeting multiple pathways of platelet activation. Therefore, this review examines the AR-dependent impact of caffeine on blood platelets in the presence of adenosine receptor agonists.

Green-Synthesized Cobalt Ferrite Nanoparticle Alleviated Sodium Nitrite-Induced Oxidative Stress Through Its Anti-oxidant Property and Displayed Anti-inflammatory, Anti-diabetic and Anti-platelet Activities

Green-Synthesized Cobalt Ferrite Nanoparticle Alleviated Sodium Nitrite-Induced Oxidative Stress Through Its Anti-oxidant Property and Displayed Anti-inflammatory, Anti-diabetic and Anti-platelet Activities

Synthesis, characterization and thrombolytic activity evaluation of novel pyrazolo[3,4-b]pyridine-4-carbohydrazide derivatives

Thrombosis, a leading cause of numerous fatalities, particularly in developed nations, accounts for thousands of deaths. The contemporary lifestyle inevitably leads to occurrences of venous thrombosis, including deep vein thrombosis and thromboembolism. This article presents a groundbreaking study where a novel series of N′-(arylmethylidene)-6-(p-methoxyphenyl)-3-methyl-1-phenyl-1H-pyrazolo[3,4-b] pyridine-4-carbohydrazide derivatives were efficiently synthesized and screened for thrombolytic activities. Compounds 4a, 4c, 4d, and 4h demonstrated the best antiplatelet activities when using different agonists such as arachidonic acid and collagen. These compounds showed >50 % activity by using agonist collagen and inhibited >50 % platelet aggregation in whole human blood. Compounds 4c and 4d showed the greatest inhibitory effect of 97.98 % and 98.97 %, respectively as compared to other synthesized compounds and aspirin. For platelet aggregation using arachidonic acid, all the synthesized compounds 4a, 4c, 4d and 4h shown >93 % inhibition than that of aspirin. In computational studies, ligands 4c(ap) and 4d(ap) exhibited potent interaction with the COX-1 active site, suggesting inhibitory potential against thrombolytic activities. Ligand 4c(ap) scored 8896 and ACE of -418.31 kcal/mol, while 4d(ap) scored 8742 and ACE of -417.43 kcal/mol. Similarly, ligands 4c(ap) and 4h(ap) displayed outstanding docking scores at the COX-2 active site, with 4c(ap) scoring 8574 (ACE:301.49 kcal/mol) and 4h(ap) scoring 8424 (ACE:276.16 kcal/mol). Synthesized compounds particularly 4c and 4d have the potential to be used for clinical trials and could be beneficial for the designing and development of novel therapeutics for cardiovascular and thromboembolic ailments.

Eco-Friendly Synthesis, Characterization, and Biomedical Applications of Biosynthesized Bimetallic Silver-Gold Nanoparticles by Culture Supernatant of Aspergillus niger.

Green synthesis of bimetallic nanoparticles of noble metals is highly desirable in nanomedicine because of their potential use as anticoagulant, thrombolytic and anticancer agents. In this study, it was discovered that the filamentous fungus Aspergillus niger proved effective in producing bimetallic Ag-Au nanoparticles. A. niger culture supernatant was able to produce Ag-AuNPs by reducing the solution of chloroauric acid/silver nitrate (1.0:1.0 mM) within 2 min at 100 °C and pH 8. Experimental Ag-AuNP detection was performed by visually observing the color change to reddish brown. The produced nanoparticles displayed maximal absorbance at 530 nm in UV-vis spectroscopy. According to transmission electron microscopy, most of the nanoparticles were spherical, with a mean diameter of 8-10 nm. The biosynthesis of Ag-AuNPs by A. niger was confirmed by Fourier transform infrared spectroscopy, X-ray diffraction and energy dispersive X-ray analytical techniques. Its zeta potential was discovered to be -34.01 mV. The biosynthesized Ag-AuNPs exhibited effective thrombolytic and antiplatelet aggregation actions by totally preventing and dissolving the blood clot which was verified by microscopic examination, amelioration of blood coagulation assays, and carrageenan-induced tail thrombosis model. The findings verified the effectiveness of biosynthesized Ag-AuNPs as a powerful antitumor agent against HepG2 and A549 cell lines with IC50 values of 15.57 and 27.07 μg/mL, respectively. Crystal violet assay validated the cytopathic effects of Ag-AuNPs on A549 and HepG2 cell lines. Therefore, the produced Ag-AuNPs from A. niger are a promising candidate in the management of thrombosis.

Natural Phenolic Compounds with Antithrombotic and Antiplatelet Effects: A Drug-likeness Approach.

Thrombosis is one of the major causes of morbidity and mortality in a wide range of vessel diseases. Several studies have been conducted to identify antithrombotic agents from medicinal plants, and phenolic compounds (PCs) have been shown to effectively inhibit plasma coagulation and platelet aggregation. This study aimed to conduct a survey of the natural PCs with proven antithrombotic and antiplatelet activities, as well as to evaluate by computational modeling the physicochemical and toxicological properties of these compounds using drug-likeness approaches. The data were collected from the scientific database: 'Web of Science', 'Scifinder', 'Pubmed', 'ScienceDirect' and 'Google Scholar', the different classes of PCs with antithrombotic or antiplatelet effects were used as keywords. These molecules were also evaluated for their Drug-Likeness properties and toxicity to verify their profile for being candidates for new antithrombotic drugs. In this review, it was possible to register 85 lignans, 73 flavonoids, 28 coumarins, 21 quinones, 23 phenolic acids, 8 xanthones and 8 simple phenols. Activity records for tannins were not found in the researched databases. Of these 246 compounds, 213 did not violate any of Lipinski's rules of five, of which 125 (59%) showed non-toxicity, being promising candidates for new potential antithrombotic drugs. This review arouses interest in the isolation of phenolic compounds that may allow a new approach for the prevention of both arterial and venous thrombosis, with the potential to become alternatives in the prevention and treatment of cardiovascular diseases.

Anti-Platelet Activity of Sea Buckthorn Seeds and Its Relationship with Thermal Processing.

Sea buckthorn (Hippophae rhamnoides L.) is a tree or shrub with small, orange berries. Sea buckthorn seeds have shown many properties beneficial to human health, including antioxidant, anti-hypertensive, anti-hyperlipidemic, and retinoprotective activities. Seeds, as a component of food, are often exposed to high temperatures, which can increase or decrease their biological activity. In our previous study, we showed that both raw and roasted sea buckthorn seeds had significant antioxidant activity, which was measured in human plasma in vitro. In this paper, we evaluated the effect of extracts from raw and roasted sea buckthorn seeds on several parameters of hemostasis in vitro, including thrombus formation in full blood (measured by the Total Thrombus formation Analysis System-T-TAS), blood platelet activation (based on the exposition of P-selectin, the active form of GPIIb/IIIa on their surface and platelet-derived microparticles formation), aggregation (measured with impedance aggregometry), adhesion to fibrinogen and collagen, arachidonic acid metabolism in washed platelets stimulated by thrombin, and COX-1 activity. We also measured the levels of free 8-isoprostane in plasma and the total non-enzymatic antioxidant status of plasma. The extract from roasted seeds (50 µg/mL) significantly prolonged the time of occlusion measured by T-TAS-the AUC10 (area under the curve) value was decreased by approximately 18%. Both extracts decreased the exposition of the active form of GPIIb/IIIa on the surface of platelets activated with 10 μM ADP (by 38.4-62.2%) and 20 μM ADP (by 39.7-51.3%). Moreover, the extract from raw seeds decreased the exposition of P-selectin on the surface of platelets stimulated with 20 μM ADP (by 31.2-34.9%). The adhesion of thrombin-stimulated platelets to fibrinogen and collagen was inhibited only by the extract from roasted sea buckthorn seeds (by 20-30%). Moreover, the extract from raw seeds inhibited the level of TBARS (thiobarbituric acid-reactive substances, an indicator of enzymatic peroxidation of arachidonic acid) in washed platelets stimulated with thrombin; the activity of COX-1 was inhibited by both extracts, although the effect of the extract from raw seeds was stronger. These results indicate that sea buckthorn seeds have anti-platelet activity that is not decreased by thermal processing, but more research is needed to determine which exact chemical compounds and mechanisms are responsible for this phenomenon.

Fabrication of metal-organic frameworks containing Cu2+ coated medical PVC catheters with durable antiplatelet and antibacterial activities

Polyvinyl chloride (PVC) catheters are widely used in medical environments especially in blood-contacting devices. In this study, a copper containing MOF material was coated on a PVC catheter to endow it with antiplatelet adhesion and antibacterial activity for potential clinical applications. The immobilization of the coordination polymer containing Cu2+ (Cu-MOF) on the inner surface of PVC catheters was carried out using a bioinspired coating combined with a layer-by-layer self-assembly strategy. Characterization of the Cu-MOF modified surfaces was confirmed using micro-infrared spectroscopy (MIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and water contact angle measurements (WCA). The resultant modified surfaces significantly reduced non-specific adsorption to model proteins with excellent anti-biofouling activity, as well as significantly inhibited the platelet adhesion and activation with superior antiplatelet activity. In vitro whole blood circulation test using a peristaltic pump also showed good antithrombotic properties. Besides, the Cu-MOF modified surfaces exhibited good hemocompatibility (hemolysis ratio < 5 %) and excellent antibacterial activity (approximately 97 % against S. auerus and E. coli). This study develops a simple and effective method for the surface modification of medical PVC catheter as potential blood-contacting biomaterials.

Stilbene-pyridazinone hybrids: design, synthesis and in vitro antiplatelet activity screening

A series of stilbene analogues, in which a phenyl ring was replaced by the pyridazin-3(2H)-one nucleus, was designed and synthesized to be explored as platelet aggregation inhibitors. The proposed stilbene-pyridazinone hybrids were successfully obtained from simple starting materials and by Wittig’s reaction. Most of the target compounds displayed improved in vitro activity in comparison with the standard drug, resveratrol, highlighting as the most potent the analogues 10d and 10e, with inhibition percentages of 94.15 % at 100 µM and 100 % at 50 µM, respectively.The pharmacokinetic and toxicity (ADME/T) properties of the novel hybrids were also estimated with the SwissADME and ProTox-II web servers.

Antiplatelet Activity of Phenolic Compounds-Fortified Merlot Wine and Pure Phenolic Compounds

Red wines and their pomace are valuable sources of phenolic compounds (PCs), which have been proposed as potential contributors to their cardioprotective effect through the inhibition of platelet aggregation. The antiplatelet activity of an extract depends on its chemical composition, specifically the presence of certain phenolic compounds, as well as the interactions between them affecting biological activity. In order to assess the effect on platelet aggregation, we investigated the effect of the grape pomace PC enrichment of a Merlot wine, as well as the effect of the five major phenolic compounds present in wine extracts: caffeic acid, gallic acid, quercetin, epicatechin, and catechin. We analyzed how their combination influenced platelet aggregation. We found that the fortified wine sample with the highest PC content (W8) exhibited a potent antiplatelet effect in aggregation and platelet activation assays induced by the agonists TRAP-6, collagen, and ADP, with its activity being most potent against the latter agonist (78 ± 4%). Among the evaluated phenolic compounds, quercetin showed the highest antiplatelet potential against all three agonists studied, while gallic acid showed minimal antiplatelet effect. These findings suggest that the cardioprotective effect of wines is related to their chemical composition and the synergy among phenolic compounds. However, further research is required to fully understand the underlying mechanisms and clinical relevance of this activity.

Antithrombotic Effect of Oil from the Pulp of Bocaiúva-Acrocomia aculeata (Jacq.) Lodd. ex Mart. (Arecaceae).

The study aimed to evaluate the antithrombotic action of Acrocomia aculeata pulp oil (AAPO) in natura, in an in vitro experimental model. AAPO was obtained by solvent extraction, and its chemical characterization was performed by gas chromatography coupled to a mass spectrometer (GC-MS). In vitro toxicity was evaluated with the Trypan Blue exclusion test and in vivo by the Galleria mellonella model. ADP/epinephrine-induced platelet aggregation after treatment with AAPO (50, 100, 200, 400, and 800 μg/mL) was evaluated by turbidimetry, and coagulation was determined by prothrombin activity time (PT) and activated partial thromboplastin time (aPTT). Platelet activation was measured by expression of P-selectin on the platelet surface by flow cytometry and intraplatelet content of reactive oxygen species (ROS) by fluorimetry. The results showed that AAPO has as major components such as oleic acid, palmitic acid, lauric acid, caprylic acid, and squalene. AAPO showed no toxicity in vitro or in vivo. Platelet aggregation decreased against agonists using treatment with different concentrations of AAPO. Oil did not interfere in PT and aPTT. Moreover, it expressively decreased ROS-induced platelet activation and P-selectin expression. Therefore, AAPO showed antiplatelet action since it decreased platelet activation verified by the decrease in P-selectin expression as well as in ROS production.

New Findings Regarding the Effects of Selected Blue Food Colorants (Genipin, Patent Blue V, and Brilliant Blue FCF) on the Hemostatic Properties of Blood Components In Vitro.

Natural and synthetic colorants present in food can modulate hemostasis, which includes the coagulation process and blood platelet activation. Some colorants have cardioprotective activity as well. However, the effect of genipin (a natural blue colorant) and synthetic blue colorants (including patent blue V and brilliant blue FCF) on hemostasis is not clear. In this study, we aimed to investigate the effects of three blue colorants-genipin, patent blue V, and brilliant blue FCF-on selected parameters of hemostasis in vitro. The anti- or pro-coagulant potential was assessed in human plasma by measuring the following coagulation times: thrombin time (TT), prothrombin time (PT), and activated partial thromboplastin time (APTT). Moreover, we used the Total Thrombus formation Analysis System (T-TAS, PL-chip) to evaluate the anti-platelet potential of the colorants in whole blood. We also measured their effect on the adhesion of washed blood platelets to fibrinogen and collagen. Lastly, the cytotoxicity of the colorants against blood platelets was assessed based on the activity of extracellular lactate dehydrogenase (LDH). We observed that genipin (at all concentrations (1-200 µM)) did not have a significant effect on the coagulation times (PT, APTT, and TT). However, genipin at the highest concentration (200 µM) and patent blue V at the concentrations of 1 and 10 µM significantly prolonged the time of occlusion measured using the T-TAS, which demonstrated their anti-platelet activity. We also observed that genipin decreased the adhesion of platelets to fibrinogen and collagen. Only patent blue V and brilliant blue FCF significantly shortened the APTT (at the concentration of 10 µM) and TT (at concentrations of 1 and 10 µM), demonstrating pro-coagulant activity. These synthetic blue colorants also modulated the process of human blood platelet adhesion, stimulating the adhesion to fibrinogen and inhibiting the adhesion to collagen. The results demonstrate that genipin is not toxic. In addition, because of its ability to reduce blood platelet activation, genipin holds promise as a novel and valuable agent that improves the health of the cardiovascular system and reduces the risk of cardiovascular diseases. However, the mechanism of its anti-platelet activity remains unclear and requires further studies. Its in vivo activity and interaction with various anti-coagulant and anti-thrombotic drugs, including aspirin and its derivatives, should be examined as well.