Gintonin modulates platelet function and inhibits thrombus formation via impaired glycoprotein VI signaling

Antiplatelet and Antithrombotic Activities of Lespedeza cuneata via Pharmacological Inhibition of Integrin αIIbβ3, MAPK, and PI3K/AKT Pathways and FeCl3-Induced Murine Thrombosis

Cardiovascular diseases (CVDs) have been the major cause of mortality all around the globe. Lespedeza cuneata abbreviated as L. cuneata with the authority name of Dumont de Courset (G. Don) is a perennial flowering plant commonly grown in Asian countries such as Korea, Japan, China, and Taiwan. We aimed to investigate the L. cuneata extract's antiplatelet and antithrombotic properties as GC-MS analysis indicated that the extract contained short-chain fatty acids, which have been reported to possess beneficial cardiovascular effects. L. cuneata was extracted using water, 50% EtOH, 70% EtOH, and 100% EtOH. For in vitro antiplatelet analysis, washed platelets were prepared and incubated with L. cuneata with 200 μg/mL of 50% EtOH in the presence of 1 mM of CaCl2 for 1 minute followed by agonist (collagen 2.5 μg/mL or ADP 10 μM or thrombin 0.1 U/mL) stimulation for 5 minutes over light transmission aggregometer. Scanning electron microscopy was performed to assess platelet shape change. ATP release and intracellular calcium mobilization were quantified to assess the granular content. Fibrinogen-binding assay and clot retraction assay assessed integrin αIIbβ3-mediated inside-out and outside-in signaling. Protein phosphorylation expression was investigated by western blot analysis. Finally, the in vivo antithrombotic efficacy was investigated by oral dosage of L. cuneata 200 and 400 mg/kg and aspirin 100 mg/kg for 7 days, and tail bleeding and FeCl3-induced murine thrombus model were performed. In vitro platelet aggregation and platelet shape change were dose-dependently suppressed by L. cuneata. Calcium mobilization, dense granules secretion, integrin αIIbβ3-mediated inside-out and outside-in signaling, and protein phosphorylation of MAPK and PI3K/Akt pathways were significantly inhibited. In vivo assays revealed that L. cuneata prevents side effects of synthetic drugs via nonsignificantly increasing bleeding time and improving coronary artery blood flow and animal survival. Our results demonstrate that L. cuneata exhibited potent antiplatelet and antithrombotic effects and can be considered a potential herbal medicine with cardioprotective effects.

Antimicrobial, antioxidant, anticancer, and antithrombotic, competency of saponins from the root of Decalepis hamiltonii

The goal of this study was to extract saponins from the tuberous root of Decalepis hamiltonii and assess their potential clinical applications, which included antioxidant, antibacterial, antithrombotic, and anticancer properties. Surprisingly, the results of this study revealed that the extracted saponins have excellent antioxidant activities, as demonstrated by 2,2-diphenylpicrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), Hydrogen peroxide (H₂O₂), and Nitric oxide (NO) scavenging assays. Nonetheless, at a concentration of 100 g/mL, crude saponin had excellent antibacterial activity, particularly against gramme positive bacteria (Staphylococcus aureus, Bacillus subtilis, Staphylococcus epidermidis, and Micrococcus luteus), followed by gramme negative bacteria (Escherichia coli, Salmonella typhi, Proteus mirabilis, and Klebsiella pneumonia). Despite this, the crude saponin had no effect on Aspergillus niger and Candida albicans. The crude saponin also possesses outstanding in vitro antithrombotic activity on blood clot. Interestingly, the crude saponins have an outstanding anticancer activity of 89.26%, with an IC₅₀ value of 58.41 μg/mL. Overall, the findings conclude that crude saponin derived from D. hamiltonii tuberous root could be used in pharmaceutical formulations.

Spleen tyrosine kinase (SYK) signals are implicated in cardio-cerebrovascular diseases

Post-translational modifications regulate numerous biochemical reactions and functions through covalent attachment to proteins. Phosphorylation, acetylation and ubiquitination account for over 90% of all reported post-translational modifications. As one of the tyrosine protein kinases, spleen tyrosine kinase (SYK) plays crucial roles in many pathophysiological processes and affects the pathogenesis and progression of various diseases. SYK is expressed in tissues outside the hematopoietic system, especially the heart, and is involved in the progression of various cardio-cerebrovascular diseases, such as atherosclerosis, heart failure, diabetic cardiomyopathy, stroke and others. Knowledge on the role of SYK in the progress of cardio-cerebrovascular diseases is accumulating, and many related mechanisms have been discovered and validated. This review summarizes the role of SYK in the progression of various cardio-cerebrovascular diseases, and aims to provide a theoretical basis for future experimental and clinical research targeting SYK as a therapeutic option for these diseases.

Panax ginseng: Inflammation, platelet aggregation, thrombus formation, and atherosclerosis crosstalk

Ginseng has been widely studied due to its various therapeutic properties on various diseases such as cardiovascular disease (CVD). Cardiovascular disease has been canonically known to be caused by high levels of low-density lipoproteins (LDL) in the bloodstream, in addition to the impaired vasodilatory effects of cholesterol. However, current research on CVD has revealed a cascade of mechanisms involving a series of events that contribute to the progression of CVD. Although this has been elucidated and summarized in previous studies the detailed correlation between platelet aggregation and innate immunity that plays an important role in CVD progression has not been thoroughly summarized. Furthermore, immune cell subtypes also contribute to the progression of plaque formation in the subendothelial layer. Thrombus formation and the coagulation cascade also have a vital role in the progression of atherosclerosis. Hence, in this mini review we aim to elucidate, summarize, and propose the potent therapeutic effect of ginseng on CVD, mainly on platelet aggregation, plaque formation, and thrombus formation.

COVID-19 and Panax ginseng: Targeting platelet aggregation, thrombosis and the coagulation pathway

Coronavirus disease 2019 (COVID-19) not only targets the respiratory system but also triggers a cytokine storm and a series of complications, such as gastrointestinal problems, acute kidney injury, and myocardial ischemia. The use of natural products has been utilized to ease the symptoms of COVID-19, and in some cases, to strengthen the immune system against COVID-19. Natural products are readily available and have been regularly consumed for various health benefits. COVID-19 has been reported to be associated with the risk of thromboembolism and deep vein thrombosis. These thrombotic complications often affects mortality and morbidity. Panax ginseng, which has been widely consumed for its various health benefits has also been reported for its therapeutic effects against cardiovascular disease, thrombosis and platelet aggregation. In this review, we propose that P. ginseng can be consumed as a supplementation against the various associated complications of COVID-19, especially against thrombosis. We utilized the network pharmacology approach to validate the potential therapeutic properties of P. ginseng against COVID-19 mediated thrombosis, the coagulation pathway and platelet aggregation. Additionally, we aimed to investigate the roles of P. ginseng against COVID-19 with the involvement of platelet-leukocyte aggregates in relation to immunity-related responses in COVID-19.

Regulation of Key Antiplatelet Pathways by Bioactive Compounds with Minimal Bleeding Risk

Cardiovascular disease is strongly influenced by platelet activation. Platelet activation and thrombus formation at atherosclerotic plaque rupture sites is a dynamic process regulated by different signaling networks. Therefore, there are now focused efforts to search for novel bioactive compounds which target receptors and pathways in the platelet activation process while preserving normal hemostatic function. The antiplatelet activity of numerous fruits and vegetables and their multiple mechanisms of action have recently been highlighted. In this review, we review the antiplatelet actions of bioactive compounds via key pathways (protein disulfide isomerase, mitogen-activated protein kinases, mitochondrial function, cyclic adenosine monophosphate, Akt, and shear stress-induced platelet aggregation) with no effects on bleeding time. Therefore, targeting these pathways might lead to the development of effective antiplatelet strategies that do not increase the risk of bleeding.

Rumex acetosella Inhibits Platelet Function via Impaired MAPK and Phosphoinositide 3-Kinase Signaling

OBJECTIVE

To examine the antiplatelet and antithrombotic activity of Rumex acetosella extract.

METHODS

Standard light aggregometry was used for platelet aggregation, intracellular calcium mobilization assessed using Fura-2/AM, granule secretion (ATP release) by luminometer, and fibrinogen binding to integrin α_IIbβ₃ detected using flow cytometry. Western blotting is carried out to determine the phosphorylation of mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Akt signaling.

RESULTS

Rumex acetosella displayed the ability to inhibit platelet aggregation, calcium mobilization, granule secretion, and fibrinogen binding to integrin α_IIbβ₃. Rumex acetosella has also down-regulated MAPK and PI3K/Akt phosphorylation (all P<0.01).

CONCLUSION

Rumex acetosella extract exhibits antiplatelet activity via modulating GPVI signaling, and it may protect against the development of platelet-related cardiovascular diseases.

Antiplatelet and Antithrombotic Effects of Epimedium koreanum Nakai

Background and Objective. Epimedium koreanum Nakai is a medicinal plant known for its health beneficial effects on impotence, arrhythmia, oxidation, aging, osteoporosis, and cardiovascular diseases. However, there is no report available that shows its effects on platelet functions. Here, we elucidated antiplatelet and antithrombotic effects of ethyl acetate fraction of E. koreanum. Methodology. We analyzed the antiplatelet properties using standard in vitro and in vivo techniques, such as light transmission aggregometry, scanning electron microscopy, intracellular calcium mobilization measurement, dense granule secretion, and flow cytometry to assess integrin α_IIbβ₃ activation, clot retraction, and Western blot, on washed platelets. The antithrombotic effects of E. koreanum were assessed by arteriovenous- (AV-) shunt model in rats, and its effects on hemostasis were analyzed by tail bleeding assay in mice. Key Results. E. koreanum inhibited platelet aggregation in agonist-stimulated human and rat washed platelets, and it also reduced calcium mobilization, ATP secretion, and TXB2 formation. Fibrinogen binding, fibronectin adhesion, and clot retraction by attenuated integrin α_IIbβ₃-mediated inside-out and outside-in signaling were also decreased. Reduced phosphorylation of extracellular signal-regulated kinases (ERK), Akt, PLCγ2, and Src was observed. Moreover, the fraction inhibited thrombosis. HPLC results revealed that the fraction predominantly contained icariin. Conclusion and Implications. E. koreanum inhibited platelet aggregation and thrombus formation by attenuating calcium mobilization, ATP secretion, TXB2 formation, and integrin α_IIbβ₃ activation. Therefore, it may be considered as a potential candidate to treat and prevent platelet-related cardiovascular disorders.

Biological evidence of gintonin efficacy in memory disorders

Gintonin is a novel glycolipoprotein, which has been abundantly found in the root of Korean ginseng. It holds lysophosphatidic acids (LPAs), primarily identified LPA C18:2, and is an exogenous agonist of LPA receptors (LPARs). Gintonin maintains blood-brain barrier integrity, and it has recently been studied in several models of neurodegenerative diseases (NDDs) such as Alzheimer's disease (AD), Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis. Gintonin demonstrated neuroprotective activity by providing action against neuroinflammation-, apoptosis- and oxidative stress-mediated neurodegeneration. Gintonin showed an emerging role as a modulator of synaptic transmission and neurogenesis and also potentially regulated autophagy in primary cortical astrocytes. It also ameliorated the toxic agent-induced and genetic models of cognitive deficits in experimental NDDs. As a novel agonist of LPARs, gintonin regulated several G protein-coupled receptors (GPCRs) including GPR40 and GPR55. However, further study needs to be investigated to understand the underlying mechanism of action of gintonin in memory disorders.

Adaptogenic effects of Panax ginseng on modulation of cardiovascular functions

Cardiovascular diseases are a rapidly growing epidemic with high morbidity and mortality. There is an urgent need to develop nutraceutical-based therapy with minimum side effects to reduce cardiovascular risk. Panax ginseng occupies a prominent status in herbal medicine for its various therapeutic effects against inflammation, allergy, diabetes, cardiovascular diseases, and even cancer, with positive, beneficial, and restorative effects. The active components found in most P. ginseng varieties are known to include ginsenosides, polysaccharides, peptides, alkaloids, polyacetylene, and phenolic compounds, which are considered to be the main pharmacologically active constituents in ginseng. P. ginseng is an adaptogen. That is, it supports living organisms to maintain optimal homeostasis by exerting effects that counteract physiological changes caused by physical, chemical, or biological stressors. P. ginseng possesses immunomodulatory (including both immunostimulatory and immunosuppressive), neuromodulatory, and cardioprotective effects; suppresses anxiety; and balances vascular tone. P. ginseng has an antihypertensive effect that has been explained by its vasorelaxant action, and paradoxically, it is also known to increase blood pressure by vasoconstriction and help maintain cardiovascular health. Here, we discuss the potential adaptogenic effects of P. ginseng on the cardiovascular system and outline a future research perspective in this area.

Ulmus parvifolia Modulates Platelet Functions and Inhibits Thrombus Formation by Regulating Integrin αIIbβ3 and cAMP Signaling

Background

The prevalence of cardiovascular diseases (CVDs) is increasing at a high rate, and the available treatment options, sometimes, have complications which necessitates the need to develop safer and efficacious approaches. Ethnomedicinal applications reportedly reduce CVD risk. Ulmus parvifolia Jacq. (Ulmaceae) commonly known as Chinese Elm or Lacebark Elm, is native to China, Japan, and Korea. It exhibits anti-inflammatory, antiviral, and anticancer properties, but its anti-platelet properties have not yet been elucidated.

Purpose

To investigate the pharmacological anti-platelet and anti-thrombotic effects of U. parvifolia bark extract.

Study Design and Methods

Human and rat washed platelets were prepared; light transmission aggregometry and scanning electron microscopy was performed to assess platelet aggregation and the change in platelet shape, respectively. Intracellular calcium mobilization, ATP release, and thromboxane-B2 production were also measured. Integrin α_IIbβ₃ activation was analyzed in terms of fibrinogen binding, fibronectin adhesion, and clot retraction. The expression of MAPK, Src, and PI3K/Akt pathway proteins was examined. Cyclic nucleotide signaling pathway was evaluated via cAMP elevation and VASP phosphorylation. Anti-thrombotic activity of the extract was evaluated in vivo using an arteriovenous shunt rat model, whereas its effect on hemostasis in mice was assessed via bleeding time assay.

Results

U. parvifolia extract significantly inhibited human and rat platelet aggregation in a dose-dependent manner along with inhibition of calcium mobilization, dense granule secretion, and TxB2 production. Integrin α_IIbβ₃ mediated inside-out and outside-in signaling events, as evidenced by the inhibition of fibrinogen binding, fibronectin adhesion, and clot retraction. The extract significantly reduced phosphorylation of Src, MAPK (ERK, JNK, and p38^MAPK), and PI3K/Akt pathway proteins. Cyclic-AMP levels were elevated in U. parvifolia-treated platelets, while PKAαβγ and VASP^ser157 phosphorylation was enhanced. U. parvifolia reduced thrombus weight in rats and moderately increased bleeding time in mice.

Conclusion

U. parvifolia modulates platelet responses and inhibit thrombus formation by regulating integrin α_IIbβ₃ mediated inside-out and outside-in signaling events and cAMP signaling pathway.

Rumex acetosa modulates platelet function and inhibits thrombus formation in rats

Background

The Rumex acetosa has been used in medicinal treatment, food technology and phytotherapeutics in Eastern Asia and many other countries. However, its effect on cardiovascular system and antiplatelet activity remained to be known. In this study, we examined the antiplatelet activity of R. acetosa in detailed manner to understand underlying mechanism.

Methods

To study this, whole blood was obtained from male Sprague Dawley (SD) rats and aggregation of washed platelets measured using light transmission aggregometry. Intracellular calcium ion concentration ([Ca²⁺]_i) was measured using Fura-2/AM while ATP release evaluated by luminometer. Activation of integrin α_IIbβ₃ analyzed by flow cytometry and clot retraction. Furthermore, we studied the signaling pathways mediated by R. acetosa extract by western blot analysis.

Results

R. acetosa extract markedly inhibited collagen-induced platelet aggregation and ATP release in a dose-dependent manner. It also suppressed [Ca²⁺]_i mobilization, integrin α_IIbβ₃ activation and clot retraction. The extract significantly attenuated phosphorylation of the MAPK pathway (i.e., ERK1/2, JNK), MKK4, PI3K/Akt, and Src family kinase.

Conclusion

Taken together, this data suggests that R. acetosa extract exhibits anti-platelet activity via modulating MAPK, PI3K/Akt pathways, and integrin α_IIbβ₃-mediated inside-out and outside-in signaling, and it may protect against the development of platelet-related cardiovascular diseases.

First Report of Plant-Derived β-Sitosterol with Antithrombotic, in Vivo Anticoagulant, and Thrombus-Preventing Activities in a Mouse Model

Inhibitors of thrombin, a key enzyme in the blood coagulation cascade, are of great interest because of their selective specificity and effectiveness in anticoagulation therapy against cardiovascular disorders. The natural soybean phytosterol, β-sitosterol (BSS) demonstrated anticoagulant activity by dose-dependent inhibition of thrombin in an uncompetitive manner with a K_i value of 0.267 μM as well as by partial inhibition of thrombin-catalyzed platelet aggregation with a half-maximal inhibitory concentration (IC₅₀) value of 10.45 ± 2.88 μM against platelet-rich plasma and 9.2 ± 1.2 μM against washed platelets. An in silico study indicated binding of BSS to thrombin, which was experimentally verified by spectrofluorometric and isothermal calorimetric analyses. Under in vitro conditions, BSS demonstrated thrombolytic activity by activating plasminogen, albeit it is devoid of protease (fibrinogenolytic) activity. BSS was noncytotoxic to mammalian cells, nonhemolytic, demonstrated its in vivo anticoagulant activity when administered orally, and inhibited k-carrageen-induced thrombus formation in the tails of mice. Our results suggest that dietary supplementation of BSS may help to prevent thrombosis-associated cardiovascular disorders.

Astilbe chinensis Modulates Platelet Function via Impaired MAPK and PLCγ2 Expression

Background

Platelets play major role in maintaining hemostasis while hyperactivation of platelets may lead to arterial thrombosis. Natural products and ethnomedicine have been shown to reduce the risk of cardiovascular diseases (CVDs). Astilbe chinensis is a perennial herb found in China, Korea, Russia, and Japan, which is also known for its medicinal effects, and has been used in Korean traditional medicine to treat inflammation, cancer, chronic bronchitis, and headache. We hypothesized that given herbal plant exhibits pharmacological activities against CVDs, and we specifically explored their effects on platelet function.

Methodology

Platelet aggregation was evaluated using standard light-transmission aggregometry. Intracellular calcium mobilization was assessed using Fura-2/AM, and granule secretion (ATP release) was measured in a luminometer. Fibrinogen binding to integrin α_IIbβ₃ was assessed using flow cytometry. Phosphorylation of mitogen-activated protein kinase (MAPK) signaling molecules and activation of the phosphoinositide 3-kinase (PI3K)/Akt were assessed using western blots, and further, glycoprotein VI (GPVI) signaling components were studied using immunoprecipitation.

Key Results

A. chinensis extracts potently and significantly inhibited platelet aggregation, calcium mobilization, granule secretion, and fibrinogen binding to integrin α_IIbβ₃. Moreover, it significantly inhibited MAPK phosphorylation and expression of GPVI downstream signaling molecules.

Conclusion

A. chinensis extract inhibited platelet aggregation and granule secretion and attenuated GPVI downstream signaling, indicating the potential therapeutic effects of this plant extract on the cardiovascular system and platelet function. We suggest that given plant extract may be a potent candidate to treat platelet-related CVDs and to be used as antiplatelet agent.