[Fibrinolysis Enhancing Activity of Roasted Barley Extract (Mugicha) and Its Simulated Digestate].

Barley tea (Mugicha), commonly consumed in Japan and other East Asian countries, is prepared by decocting roasted barley (Hordeum vulgare) seed with hot or cold water. Although barley tea is commonly consumed, studies on its health benefits are limited, especially regarding its bioactivity against thrombosis. During the evaluation of functional foods and drinks, barley tea extract was found to exhibit potential fibrinolysis-enhancing activity induced by urokinase. Therefore, the aim of this study was to explore the application of barley tea as a functional food and conduct a preliminary investigation to reveal the effects of barley tea on thrombosis. Hot water extract of roasted barley was treated with pancreatin and separated via various techniques using macroporous resin and silica gel and tangential flow filtration with an ultra-filtration membrane. The low-molecular-weight fraction of the roasted barley tea extract was found to possess activity. We further purified the extract and found that the activity of each fraction decreased. Thus, the different fractions of the roasted barley extract may not exhibit the activity individually, instead additive or synergistic effects of multiple components may occur. The results suggest the potential use of barley extract as a functional food to prevent thrombosis.

Plant-Derived Compounds and Extracts as Modulators of Plasmin Activity-A Review.

Functionality of the fibrinolytic system is based on activity of its central enzyme, plasmin, responsible for the removal of fibrin clots. Besides the hemostasis, fibrinolytic proteins are also involved in many other physiological and pathological processes, including immune response, extracellular matrix degradation, cell migration, and tissue remodeling. Both the impaired and enhanced activity of fibrinolytic proteins may result in serious physiological consequences: prothrombotic state or excessive bleeding, respectively. However, current medicine offers very few options for treating fibrinolytic disorders, particularly in the case of plasmin inhibition. Although numerous attempts have been undertaken to identify natural or to develop engineered fibrinolytic system modulators, structural similarities within serine proteases of the hemostatic system and pleiotropic activity of fibrinolytic proteins constitute a serious problem in discovering anti- or profibrinolytic agents that could precisely affect the target molecules and reduce the risk of side effects. Therefore, this review aims to present a current knowledge of various classes of natural inhibitors and stimulators of the fibrinolytic system being well-defined low-molecular plant secondary metabolites or constituents of plant extracts as well as plant peptides. This work also discusses obstacles caused by low specificity of most of natural compounds and, hence, outlines recent trends in studies aimed at finding more efficient modulators of plasmin activity, including investigation of modifications of natural pharmacophore templates.

Beneficial Properties of Bromelain.

Bromelain is a major sulfhydryl proteolytic enzyme found in pineapple plants, having multiple activities in many areas of medicine. Due to its low toxicity, high efficiency, high availability, and relative simplicity of acquisition, it is the object of inexhaustible interest of scientists. This review summarizes scientific reports concerning the possible application of bromelain in treating cardiovascular diseases, blood coagulation and fibrinolysis disorders, infectious diseases, inflammation-associated diseases, and many types of cancer. However, for the proper application of such multi-action activities of bromelain, further exploration of the mechanism of its action is needed. It is supposed that the anti-viral, anti-inflammatory, cardioprotective and anti-coagulatory activity of bromelain may become a complementary therapy for COVID-19 and post-COVID-19 patients. During the irrepressible spread of novel variants of the SARS-CoV-2 virus, such beneficial properties of this biomolecule might help prevent escalation and the progression of the COVID-19 disease.

Docosahexaenoic Acid Suppresses Expression of Adipogenic Tetranectin through Sterol Regulatory Element-Binding Protein and Forkhead Box O Protein in Pigs.

Tetranectin (TN), a plasminogen-binding protein originally involved in fibrinolysis and bone formation, was later identified as a secreted adipokine from human and rat adipocytes and positively correlated with adipogenesis and lipid metabolism in adipocytes. To elucidate the nutritional regulation of adipogenic TN from diets containing different sources of fatty acids (saturated, n-6, n-3) in adipocytes, we cloned the coding region of porcine TN from a cDNA library and analyzed tissue expressions in weaned piglets fed with 2% soybean oil (SB, enriched in n-6 fatty acids), docosahexaenoic acid oil (DHA, an n-3 fatty acid) or beef tallow (BT, enriched in saturated and n-9 fatty acids) for 30 d. Compared with tissues in the BT- or SB-fed group, expression of TN was reduced in the adipose, liver and lung tissues from the DHA-fed group, accompanied with lowered plasma levels of triglycerides and cholesterols. This in vivo reduction was also confirmed in porcine primary differentiated adipocytes supplemented with DHA in vitro. Then, promoter analysis was performed. A 1956-bp putative porcine TN promoter was cloned and transcription binding sites for sterol regulatory-element binding protein (SREBP)-1c or forkhead box O proteins (FoxO) were predicted on the TN promoter. Mutating binding sites on porcine TN promoters showed that transcriptional suppression of TN by DHA on promoter activity was dependent on specific response elements for SREBP-1c or FoxO. The inhibited luciferase promoter activity by DHA on the TN promoter coincides with reduced gene expression of TN, SREBP-1c, and FoxO1 in human embryonic kidney HEK293T cells supplemented with DHA. To conclude, our current study demonstrated that the adipogenic TN was negatively regulated by nutritional modulation of DHA both in pigs in vivo and in humans/pigs in vitro. The transcriptional suppression by DHA on TN expression was partly through SREBP-1c or FoxO. Therefore, down-regulation of adipogenic tetranectin associated with fibrinolysis and adipogenesis may contribute to the beneficial effects of DHA on ameliorating obesity-induced metabolic syndromes such as atherosclerosis and adipose dysfunctions.

Fibrinolytic and Thrombolytic Effects of an Enzyme Purified from the Fruiting Bodies of Boletus pseudocalopus (Agaricomycetes) from Korea.

A fibrinolytic enzyme with thrombolytic, anticoagulant activities was purified from fruiting bodies of wild-growing mushroom Boletus pseudocalopus Hongo and homogenized with a two-step procedure with a 6.11-fold increase in specific activity and 3.2% recovery. The molecular weight of the enzyme was estimated to be 63.5 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. The enzyme was active at 40°C and pH 7, and activity was inhibited by zinc metal ion and by serine protease and trypsin inhibitors phenylmethylsulfonyl fluoride and N-α-tosyl-l-lysinyl-chloromethylketone. The enzyme displayed high specificity for Pyro-Glu-Gly-Arg-pNA. In vitro assays showed that the enzyme was able to degrade fibrin and blood clots, inhibit thrombin and activated factor X, and alter the density or structural change of fibrin clots. It could also delay activated partial thromboplastin time and prothrombin time. These results suggest that the enzyme may have characteristics of a trypsin or serine-like enzyme with fibrinolytic and thrombolytic activities and may have potential as an antithrombotic agent for blood clotting disorders.

Overview of the Therapeutic Potential of Aptamers Targeting Coagulation Factors.

Aptamers are single-stranded DNA or RNA sequences that bind target molecules with high specificity and affinity. Aptamers exhibit several notable advantages over protein-based therapeutics. Aptamers are non-immunogenic, easier to synthesize and modify, and can bind targets with greater affinity. Due to these benefits, aptamers are considered a promising therapeutic candidate to treat various conditions, including hematological disorders and cancer. An active area of research involves developing aptamers to target blood coagulation factors. These aptamers have the potential to treat cardiovascular diseases, blood disorders, and cancers. Although no aptamers targeting blood coagulation factors have been approved for clinical use, several aptamers have been evaluated in clinical trials and many more have demonstrated encouraging preclinical results. This review summarized our knowledge of the aptamers targeting proteins involved in coagulation, anticoagulation, fibrinolysis, their extensive applications as therapeutics and diagnostics tools, and the challenges they face for advancing to clinical use.

Curcumin Targets p53-Fibrinolytic System in TGF-ß1 Mediated Alveolar Epithelial Mesenchymal Transition in Alveolar Epithelial Cells.

AIMS: We aim to investigate curcumin interaction with p53-fibrinolytic system, smad dependent and independent pathways underlying their prime role during lung injury and fibrosis. BACKGROUND: Curcumin, an active component of Curcuma longa plant, substantially modulates respiratory conditions. TGF-ß1 plays a central role in lung remodeling by balancing extracellular matrix (ECM) production and degradation, which is a hallmark for alveolar EMT. However, the crosstalk of curcumin is not known yet with TGF- ß1 mediated p53-Fibrinolytic system regulating alveolar EMT leading to IPF. In the present study, the potential molecular mechanism of curcumin in TGF-ß1 mediated p53-fibrinolytic system in basal alveolar epithelial cells was explored. OBJECTIVES: To understand the potential molecular mechanism of curcumin in TGF-ß1 mediated p53-fibrinolytic system in basal alveolar epithelial cells. METHODS: Basal alveolar epithelial cells were treated with TGF- ß1 to induce alveolar EMT and after 24 hrs curcumin was administered to study its anti-fibrotic effects. Molecular techniques like immunoblot, RT-PCR and immunofluorescence were performed to assess the anti-fibrotic role of curcumin on EMT markers, IL-17A, p53-smad interaction to investigate the anti-fibrotic role of curcumin. RESULTS: The results indicated that TGF-ß1-induced EMT in A549 cells exhibited altered expression of the IL-17A, p53-fibrinolytic markers and EMT markers at the mRNA and protein level. Intervention with curcumin attenuated alveolar EMT and inactivated TGF-ß1 induced Smad/non Smad signaling pathways via blocking p53-fibrinolytic system. CONCLUSION: This study provides the first evidence of the dynamic response of curcumin on TGF- ß1 mediated p53-fibrinolytic system during alveolar injury in vitro.

Lagopsis supina extract and its fractions exert prophylactic effects against blood stasis in rats via anti-coagulation, anti-platelet activation and anti-fibrinolysis and chemical characterization by UHPLC-qTOF-MS/MS.

Lagopsis supina (Steph.) IK. -Gal. ex Knorr. has been used for centuries as an empiric treatment for blood stasis syndrome in China without scientific validation. The aim of this study was to evaluate for the first time the chemical profiling, efficacy and mechanism of L. supina ethanol extract (LS) and its four fractions (LSA∼D) in Dextran 500-induced acute blood stasis model rats. Oral administration of LS (229.0∼916.0 mg/kg) and LSC (17.6∼70.4 mg/kg) once daily for seven consecutive days significantly improved microcirculation hemodynamics function (blood flow, blood concentration and blood flow velocity), hemorheological parameters (whole blood viscosity, whole blood reduced viscosity, plasma viscosity, platelet aggregation rate, hematokrit, erythrocyte assembling index and erythrocyte deformation index), and coagulation parameters (thrombin time, prothrombin time, activated partial thromboplastin time, fibrinogen and antithrombin III). Furthermore, their markedly down-regulated thromboxane B2 and 6-keto-prostaglandin F1α levels. In addition, it significantly decreased tissue-type plasminogen activator (t-PA), urokinasetype plasminogen activator (u-PA) and plasminogen activator inhibitor-1 (PAI-1) levels, as well as PAI-1/t-PA and PAI-1/u-PA rations. In parallel, 51 chemical constituents were identified from LS based on ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UHPLC-qTOF-MS/MS), and quantitative analysis showed that the two major constituents of stachysoside A and acteoside were present in 0.90 ± 0.01 and 1.36 ± 0.01 mg/g of the L. supina whole plant, respectively. These findings suggest that LS and LSC possess prominent anti-blood stasis effect on rats by modulating the anti-coagulation, anti-platelet activation and anti-fibrinolysis, and supports the traditional folk use of this plant.

Prevailing Knowledge on the Bioavailability and Biological Activities of Sulphur Compounds from Alliums: A Potential Drug Candidate.

Allium sativum (garlic) is widely known and is consumed as a natural prophylactic worldwide. It produces more than 200 identified chemical compounds, with more than 20 different kinds of sulfide compounds. The sulfide compounds particularly are proven to contribute to its various biological roles and pharmacological properties such as antimicrobial, antithrombotic, hypoglycemic, antitumour, and hypolipidemic. Therefore, it is often referred as disease-preventive food. Sulphur-containing compounds from A. sativum are derivatives of S-alkenyl-l-cysteine sulfoxides, ajoene molecules, thiosulfinates, sulfides, and S-allylcysteine. This review presents an overview of the water-soluble and oil-soluble sulphur based phytochemical compounds present in garlic, highlighting their mechanism of action in treating various health conditions. However, its role as a therapeutic agent should be extensively studied as it depends on factors such as the effective dosage and the suitable method of preparation.

Effect of Tomato Pomace, Citrus and Beet Pulp on Productive Performance and Milk Quality of Egyptian Buffaloes.

BACKGROUND AND OBJECTIVES: Using agro-industrial waste in animal diet became a new strategy in the animal feeding system to decrease the cost of nutrition. This study aimed to investigate the effects of usage tomato pomace, citrus and beet pulp in dried form in diets on the performance of lactating buffaloes and milk quality. MATERIALS AND METHODS: Fifteen milking Egyptian buffaloes at the second and third seasons of lactation were divided into five groups (3 animals in each) to fed on five experimental rations. The experimental rations were: R1(control group) fed on Concentrate Feed Mixture (CFM1) contains 20% wheat bran+roughage, R2: CFM2 replacement wheat bran 10% Dried Tomato Pomace (DTP) and 10% Citrus Pulp Dried (CPD)+roughages, R3: fed CFM2 with 15 g fibrolytic enzyme/head/day+roughages, R4: Fed CFM3 replacement wheat bran 10% DTP and 10% Dried Beet Pulp (DBP)+roughages and R5: CFM3 with 15 g fibrolytic enzyme/head/day+roughages. RESULTS: Tested by-products observed different effects of nutrients digestibility and nutritive values comparing with control ration. There was no significant difference in fat corrected milk and milk fat among treatments. Polyunsaturated fatty acids especially C18:2c and C18:3n3 were recorded highly significant values with ration four. Rations 4 and 5 led to increased blood albumin, total protein. CONCLUSION: It could be concluded that tomato pomace, citrus and beet pulp could be used as alternative sources to replace wheat bran in buffalo's rations without adverse effects on milk yield with positive effects on milk quality and fatty acids profile.

N-acetylcysteine modulates effect of the iron isomaltoside on peritoneal mesothelial cells.

Intravenous (i.v.) iron supplementation is used in patients on chronic peritoneal dialysis (pd). Iron induced intraperitoneal inflammation observed in our previous studies with iron sucrose may deteriorate the function of the peritoneum as the dialysis membrane. We evaluated effect iron compound, iron-isomaltoside-100 (IIS) on the peritoneal mesothelial cells (MC). We studied the effect of iv treatment with IIS ± N-acetylcysteine (NAC) on the dialysate parameters and function of MC. In 7 uremic pd patients IIS 200 mg was infused i.v. ± NAC 600 mg. Afterward, a 4 hours exchange was performed with Dianeal 1.5%. As a control dialysate exchange preceding IIS treatment was used. Inflammatory parameters of the drained dialysates as well as the dialysates and IIS effects on MC were evaluated in ex vivo experiments. Intravenous infusion of IIS resulted in an increase of the dialysate Fe (+147%, P < 0.01). Concentrations of the dialysates inflammatory mediators were increased: interleukin-6 (IL-6) +39%, P < 0.02, monocyte chemoattractant protein-1(MCP1) +50%, P < 0.02, and hyaluronan (HA) +64%, P < 0.02. Simultaneous i.v. infusion of NAC prevented increase of the dialysate inflammatory mediators. Dialysates collected after IIS treatment induced oxidative stress in MC (+29%, P < 0.05) and stimulated IL-6 synthesis (+64%, P < 0.05) in MC; no such effect was seen in dialysates obtained after simultaneous IIS and NAC i.v. treatment. IIS used as the additive to culture medium stimulated synthesis in MC of IL6 (+76%, P < 0.001) and plasminogen activator inhibitor-1 (PAI-1) (28%, P < 0.001) whereas synthesis of tissue plasminogen activator (t-PA) was reduced (-16%, P < 0.001). These changes were prevented in the presence of NAC 1 mmol/L. Intravenous administration of IIS results in the mild stimulation of intraperitoneal inflammation. IIS changes MC phenotype to the inflammatory one with reduced fibrinolytic activity. These effects are prevented by NAC.

Unsaturated fatty acids enhance the fibrinolytic activity of subtilisin NAT (nattokinase).

Subtilisin NAT (STN), alternatively designated nattokinase, is a serine protease with potent fibrinolytic activity. In this study, we screened several foods to enhance the fibrinolytic potential of STN and identified unsaturated fatty acid-rich ones as candidates. We isolated linoleic acid as a major active compound from one of the most active foods, red pepper. Linoleic acid promoted the STN-mediated fibrin/fibrinogen degradation at >20 µg/ml. STN cleaved three of the fibrinogen polypeptide chains, among which linoleic acid accelerated Bß-chain and γ-chain degradations, but slightly suppressed the degradation of α-chain fragments. Linoleic acid failed to affect small synthetic peptide degradation, suggesting a conformational modulation of fibrin/fibrinogen for the linoleic acid promotion of STN activity. Of the various fatty acids tested, unsaturated ones were active but saturated ones were rather inhibitory to STN-mediated fibrinolysis. Thus, our data shed new light on the dietary promotion of STN activity. PRACTICAL APPLICATIONS: Subtilisin NAT (STN) is a serine protease abundantly contained in natto, a soybean food fermented with Bacillus subtilis var. natto. The use of STN as functional foods to improve blood circulation is getting attention because STN actively degrades fibrin. Our results demonstrate that widely occurring unsaturated fatty acids such as linoleic, eicosapentaenoic, and docosahexaenoic acids enhance the fibrinolytic activity of STN. Thus, the intake of natto or STN supplements in combination with unsaturated fatty acid-containing oil can be a novel way to gain cardiovascular benefits.

Evaluation of carbon tetrachloride fraction of Actinodaphne angustifolia Nees (Lauraceae) leaf extract for antioxidant, cytotoxic, thrombolytic and antidiarrheal properties.

Actinodaphne angustifolia Nees (Family: Lauraceae) is commonly used in folk medicine against urinary disorder and diabetes. The objective of the present study was to evaluate the antioxidant, cytotoxic, thrombolytic, and antidiarrheal activities of carbon tetrachloride (CCl4) fraction of leaves of A. angustifolia (CTFAA) in different experimental models. Antioxidant activity was evaluated by using qualitative and quantitative assays, while antidiarrheal effects assessed with castor oil-induced diarrheal models in mice. The clot lysis and brine shrimp lethality bioassay were used to investigate the thrombolytic and cytotoxic activities, respectively. CTFAA showed antioxidant effects in all qualitative and quantitative procedures. The fraction produced dose-dependent and significant (P<0.05 and P<0.01) activities in castor oil-induced diarrheal models. Moreover, CTFAA significantly (P<0.05) demonstrated a 15.29% clot lysis effect in the thrombolytic test, and the brine shrimp lethality assay LC50 value was 424.16 µg/ml bioassay. In conclusion, the current study showed CTFAA has significant antidiarrheal effects along with modest antioxidant and thrombolytic effects, and these data warrant further experiment to justify and include CTFAA as a supplement to mitigate the onset of diarrheal and cardiovascular disease.

Preparation of Peptide and Recombinant Tissue Plasminogen Activator Conjugated Poly(Lactic-Co-Glycolic Acid) (PLGA) Magnetic Nanoparticles for Dual Targeted Thrombolytic Therapy.

Recombinant tissue plasminogen activator (rtPA) is the only thrombolytic agent that has been approved by the FDA for treatment of ischemic stroke. However, a high dose intravenous infusion is required to maintain effective drug concentration, owing to the short half-life of the thrombolytic drug, whereas a momentous limitation is the risk of bleeding. We envision a dual targeted strategy for rtPA delivery will be feasible to minimize the required dose of rtPA for treatment. For this purpose, rtPA and fibrin-avid peptide were co-immobilized to poly(lactic-co-glycolic acid) (PLGA) magnetic nanoparticles (PMNP) to prepare peptide/rtPA conjugated PMNPs (pPMNP-rtPA). During preparation, PMNP was first surface modified with avidin, which could interact with biotin. This is followed by binding PMNP-avidin with biotin-PEG-rtPA (or biotin-PEG-peptide), which was prepared beforehand by binding rtPA (or peptide) to biotin-PEG-maleimide while using click chemistry between maleimide and the single -SH group in rtPA (or peptide). The physicochemical property characterization indicated the successful preparation of the magnetic nanoparticles with full retention of rtPA fibrinolysis activity, while biological response studies underlined the high biocompatibility of all magnetic nanoparticles from cytotoxicity and hemolysis assays in vitro. The magnetic guidance and fibrin binding effects were also confirmed, which led to a higher thrombolysis rate in vitro using PMNP-rtPA or pPMNP-rtPA when compared to free rtPA after static or dynamic incubation with blood clots. Using pressure-dependent clot lysis model in a flow system, dual targeted pPMNP-rtPA could reduce the clot lysis time for reperfusion by 40% when compared to free rtPA at the same drug dosage. From in vivo targeted thrombolysis in a rat embolic model, pPMNP-rtPA was used at 20% of free rtPA dosage to restore the iliac blood flow in vascular thrombus that was created by injecting a blood clot to the hind limb area.

Detoxifying Action of Aqueous Extracts of Mucuna pruriens Seed and Mimosa pudica Root Against Venoms of Naja nigricollis and Bitis arietans.

BACKGROUND: The World Health Organization included snakebite envenomation among Neglected Tropical Diseases in 2017. The importance of natural products from plants is enormous, given that most prescribed drugs originate from plants. Among this is Mucuna pruriens and Mimosa pudica, with many registered patents asserting their health benefits. OBJECTIVE: This study investigated the in vitro neutralizing effects of Mucuna pruriens seed and Mimosa pudica root extracts on venoms of Naja nigricollis and Bitis arietans. METHODS: In mice, the LD50 and phytochemical analysis of M. pruriens and M. pudica plant extracts were carried out prior to the evaluation of their haemolytic and fibrinolytic effect. Their effects on the activities of phospholipase A2 (PLA2) were also assessed. RESULTS: At a concentration of 50 mg/ml, both plant extracts were found to neutralize the fibrinolytic activity of N. nigricollis, but 400 mg/ml was required to neutralize the fibrinolytic activity of B. arietans. In haemolytic studies, 50 mg/ml concentration of M. pruriens extract suppressed haemolysis caused by N. nigricollis venom by 70% but at the same concentration, M. pudica extract reduced haemolysis by 49.4%. M. pruriens, at 50 mg/ml concentration, only inhibited phospholipase A2 activity by 7.7% but higher concentrations up to 400mg/ml had no effect against the venom of N. nigricollis; at 200 mg/ml. M. pudica extract inhibited PLA2 activity by 23%. CONCLUSION: The results suggest that M. pruriens and M. pudica may be considered as promising antivenom agents for people living in a snake-bite prone environment.

Randomised trial of chronic supplementation with a nutraceutical mixture in subjects with non-alcoholic fatty liver disease.

A mixture of natural ingredients, namely, DHA, phosphatidylcholine, silymarin, choline, curcumin and d-α-tocopherol, was studied in subjects with non-alcoholic fatty liver disease (NAFLD). Primary endpoints were serum levels of hepatic enzymes, and other parameters of liver function, the metabolic syndrome and inflammation were the secondary endpoints. The coagulation-fibrinolysis balance was also thoroughly investigated, as NAFLD is associated with haemostatic alterations, which might contribute to increased cardiovascular risk of this condition. The present study involved a double-blind, randomised, multicentre controlled trial of two parallel groups. Subjects with NAFLD (18-80 years, either sex) received the active or control treatment for 3 months. All assays were performed on a total of 113 subjects before and at the end of supplementation. The hepatic enzymes aspartate aminotransferase (AST), alanine aminotransferase and γ-glutamyl transpeptidase decreased from 23·2 to 3·7 % after treatment, only the AST levels reaching statistical significance. However, no differences were found between control and active groups. Metabolic and inflammatory variables were unchanged, except for a slight (less than 10 %) increase in cholesterol and glucose levels after the active treatment. Coagulation-fibrinolytic parameters were unaffected by either treatment. In conclusion, chronic supplementation with the mixture of dietary compounds was well tolerated and apparently safe in NAFLD subjects. The trial failed to demonstrate any efficacy on relevant physiopathological markers, but its protocol and results may be useful to design future studies with natural compounds.

Rationale and design of "Can Very Low Dose Rivaroxaban (VLDR) in addition to dual antiplatelet therapy improve thrombotic status in acute coronary syndrome (VaLiDate-R)" study : A randomised trial modulating endogenous fibrinolysis in patients with acute coronary syndrome.

Impaired endogenous fibrinolysis is novel biomarker that can identify patients with ACS at increased cardiovascular risk. The addition of Very Low Dose Rivaroxaban (VLDR) to dual antiplatelet therapy has been shown to reduce cardiovascular events but at a cost of increased bleeding and is therefore not suitable for all-comers. Targeted additional pharmacotherapy with VLDR to improve endogenous fibrinolysis may improve outcomes in high-risk patients, whilst avoiding unnecessary bleeding in low-risk individuals. The VaLiDate-R study (ClinicalTrials.gov Identifier: NCT03775746, EudraCT: 2018-003299-11) is an investigator-initiated, randomised, open-label, single centre trial comparing the effect of 3 antithrombotic regimens on endogenous fibrinolysis in 150 patients with ACS. Subjects whose screening blood test shows impaired fibrinolytic status (lysis time > 2000s), will be randomised to one of 3 treatment arms in a 1:1:1 ratio: clopidogrel 75 mg daily (Group 1); clopidogrel 75 mg daily plus rivaroxaban 2.5 mg twice daily (Group 2); ticagrelor 90 mg twice daily (Group 3), in addition to aspirin 75 mg daily. Rivaroxaban will be given for 30 days. Fibrinolytic status will be assessed during admission and at 2, 4 and 8 weeks. The primary outcome measure is the change in fibrinolysis time from admission to 4 weeks follow-up, using the Global Thrombosis Test. If VLDR can improve endogenous fibrinolysis in ACS, future large-scale studies would be required to assess whether targeted use of VLDR in patients with ACS and impaired fibrinolysis can translate into improved clinical outcomes, with reduction in major adverse cardiovascular events in this high-risk cohort.

Termination of bleeding by a specific, anticatalytic antibody against plasmin.

BACKGROUND: Excessive, plasmin-mediated fibrinolysis augments bleeding and contributes to death in some patients. Current therapies for fibrinolytic bleeding are limited by modest efficacy, low potency, and off-target effects. OBJECTIVES: To determine whether an antibody directed against unique loop structures of the plasmin protease domain may have enhanced specificity and potency for blocking plasmin activity, fibrinolysis, and experimental hemorrhage. METHODS: The binding specificity, affinity, protease cross-reactivity and antifibrinolytic properties of a monoclonal plasmin inhibitor antibody (Pi) were examined and compared with those of epsilon aminocaproic acid (EACA), which is a clinically used fibrinolysis inhibitor. RESULTS: Pi specifically recognized loop 5 of the protease domain, and did not bind to other serine proteases or nine other non-primate plasminogens. Pi was ~7 logs more potent in neutralizing plasmin cleavage of small-molecule substrates and >3 logs more potent in quenching fibrinolysis than EACA. Pi was similarly effective in blocking catalysis of a small-molecule substrate as α2 -antiplasmin, which is the most potent covalent inhibitor of plasmin, and was a more potent fibrinolysis inhibitor. Fab or chimerized Fab fragments of Pi were equivalently effective. In vivo, in a humanized model of fibrinolytic surgical bleeding, Pi significantly reduced bleeding to a greater extent than a clinical dose of EACA. CONCLUSIONS: A mAb directed against unique loop sequences in the protease domain is a highly specific, potent, competitive plasmin inhibitor that significantly reduces experimental surgical bleeding in vivo.

Transurethral resection versus holmium laser enucleation of the prostate: A prospective randomized trial comparing perioperative thrombin generation and fibrinolysis.

OBJECTIVES: The purpose of this study was to compare transurethral resection of the prostate (TURP) versus holmium laser enucleation of the prostate (HoLEP) in patients with benign prostatic hyperplasia (BPH) focusing on perioperative thrombin generation and fibrinolysis. METHODS: Sixty-five BPH patients were prospectively randomly assigned to undergo TURP (n = 32) or HoLEP (n = 33). The prothrombin fragment (PF) 1+2, thrombin-antithrombin complex (TAT), tissue plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) were measured preoperatively, at the 1st day and 3rd day after surgery. RESULTS: PF1+2, TAT, t-PA, and PAI-1 significantly elevated at day 1 and day 3 after surgery (P < .05) and remarkedly decreased from the 1st day to the 3rd day (P < .05). The levels of PF1+2 and TAT were higher in TURP group postoperatively than that in HoLEP group (P < .05). There is no significant difference between 2 groups in regard of t-PA and PAI-1 (P > .05). CONCLUSION: The activation of thrombin generation and fibrinolysis system were noticed in BPH patients after TURP or HoLEP. TURP may associate with a higher hypercoagulable thrombotic risk than HoLEP.