Antithrombotic Activity Research Articles

Ferric Chloride-Induced Arterial Thrombosis and Sample Collection for 3D Electron Microscopy Analysis.

Cardiovascular diseases are a leading cause of mortality and morbidity worldwide. Aberrant thrombosis is a common feature of systemic conditions like diabetes and obesity, and chronic inflammatory diseases like atherosclerosis, cancer, and autoimmune diseases. Upon vascular injury, usually the coagulation system, platelets, and endothelium act in an orchestrated manner to prevent bleeding by forming a clot at the site of the injury. Abnormalities in this process lead to either excessive bleeding or uncontrolled thrombosis/insufficient antithrombotic activity, which translates into vessel occlusion and its sequelae. The FeCl3-induced carotid injury model is a valuable tool in probing how thrombosis initiates and progresses in vivo. This model involves endothelial damage/denudation and subsequent clot formation at the injured site. It provides a highly sensitive, quantitative assay to monitor vascular damage and clot formation in response to different degrees of vascular damage. Once optimized, this standard technique can be used to study the molecular mechanisms underlying thrombosis, as well as the ultrastructural changes in platelets in a growing thrombus. This assay is also useful to study the efficacy of antithrombotic and antiplatelet agents. This article explains how to initiate and monitor FeCl3-induced arterial thrombosis and how to collect samples for analysis by electron microscopy.

Long-term thromboprophylaxis in metallic aortic valve prosthesis using oral nattokinase-A case report

Oral anticoagulation with a vitamin K antagonist like warfarin is the standard of care for thromboprophylaxis after cardiac valve replacement. However warfarin requires strict monitoring of INR to avoid bleeding.Bleeding is a major concern with warfarin, particularly in those at high risk. Nattokinase is an enzyme obtained from natto, a cheese-like food made of soybeans fermented with Bacillus subtilis, which has been consumed as a traditional food in certain Asian countries for more than 2000 years.Recent research has demonstrated that nattokinase has potent fibrinolytic activity and antithrombotic action. We present a case of a 37-year-old male who had undergone aortic valve replacement using a metallic prosthetic valve for rheumatic heart disease associated severe aortic regurgitation and has been maintained on oral nattokinase therapy for prophylaxis against thromboembolic complications post cardiac wall replacement since the last 12 years.This case highlights the role of oral nattokinase for thromboprophylaxis in valve prosthesis and other prothrombotic states. This case report presents the first documented case where oral nattokinase has been successfully used for long-term thromboprophylaxis in metallic aortic valve prosthesis.: We present a case of a 37-year-old male who had undergone aortic valve replacement using a metallic prosthetic valve for rheumatic heart disease associated severe aortic regurgitation and has been maintained on oral nattokinase therapy for prophylaxis against thromboembolic complications post cardiac wall replacement since the last 12 years.This case highlights the role of oral nattokinase for thromboprophylaxis in valve prosthesis and other prothrombotic states. This case report presents the first documented case where oral nattokinase has been successfully used for long-term thromboprophylaxis in metallic aortic valve prosthesis.

Bioactive phytoconstituents and hemostatic and angiogenetic activities of Chromolaena odorata L. leaf extract gel on an animal epistaxis model

Introduction: Epistaxis occurs in approximately 60% of the general population globally and herbal medicine for its treatment including Chromolaena odorata L. could be one of the alternatives. The aims of this study were: (a) to determine the putative compounds and the bioactivities of C. odorata leaf extract; and (b) to assess their hemostatic and angiogenesis properties in an animal epistaxis model. Methods: The putative compounds of C. odorata extract were determined using gas chromatography and mass spectroscopy (GC-MS) and the bioactivities were determined using the Molinspiration Cheminformatics 2018 software. The hemostatic and angiogenesis activities were assessed using an epistaxis model of male rabbits (Oryctolagus cuniculus), on which three concentrations of C. odorata were tested. The gel was applied twice a day until 21 days. The hemostatic activity was evaluated by measuring the clotting time and the angiogenesis activity was evaluated by measuring the serum blood electrolyte, serum CD34 and CD68 levels and the histopathology of fibroblast and new blood vessels. Results: Eight putative compounds with activities that increased immune responses and angiogenesis by having antithrombotic, antioxidant and anti-inflammatory effects were identified. Those compounds had a range of bioactivity to G-protein coupled receptor ligand, ion channel modulator, kinase inhibitor, nuclear receptor ligand, protease inhibitor and enzyme inhibitor. Our data suggested that C. odorata extract had an effect on the levels of sodium, potassium and chloride. There was no significant difference in the mean levels of CD34 and CD68 among treatment and control groups, p=0.443 and p>0.050, respectively. The extract had no significant effect in inducing the growth of fibroblasts. Our data indicated that C. odorata extract induced angiogenesis significantly (p=0.018). Conclusions: The C. odorata extract gel consisted of the compounds that contribute in antithrombotic, antioxidant and anti-inflammatory activities and these compounds increased the angiogenesis during wound healing in the epistaxis model.

Assessment of Effects of Rosemary Essential Oil on the Kidney Pathology of Diabetic Adult Male Albino Rats.

Background Diabetic nephropathy is a severe condition that causes persistent kidney problems and chronic renal failure. Rosemary (Rosmarinus officinalis L) is widely recognized for its antioxidant, antidiabetic, anti-inflammatory, antithrombotic, hepatoprotective, and anticancer activities. The current study evaluated rosemary essential oil (REO)effects on biochemical, histological, and immunohistochemical kidney alterations in streptozotocin (STZ)-induced diabetic rats and compared these effects with those of insulin and both combined. Methods We randomly distributed 36 adult albino rats into 6 groups: normal control (non-diabetic), diabetic (streptozotocin, 55 mg/kg, intraperitoneal), diabetic insulin-treated (Lantus insulin 2 units/day, SC), diabetic REO-treated (REO, 10 ml, nasogastric gavage), and diabetic insulin & REO-treated groups. Biochemical, histological, and immunohistochemical analyses were conducted. Results The diabetic group revealed a substantial increase in blood glucose, urea, creatinine, and uric acid, as well as malondialdehyde (MDA) and catalase (CAT) concentrations in kidney homogenates, high score of tubular injury, and increased glomerulosclerosis, along with marked reduction of total glutathione (GSH) and superoxide dismutase (SOD) when compared to control. Evident improvement was detected in rats treated with REO as it demonstrated antioxidant, anti-inflammatory, anti-apoptotic, pro-proliferative, and mild anti-hyperglycemic effects on diabetic rats, reducing the kidney damage caused by diabetes. Combined insulin and REO restored normal blood glucose, renal excretory function tests, antioxidant markers, and renal cortex histology. Conclusion The data presented in the current study's in vivo animal model suggests that REO supplementation has beneficial nephroprotective effects on the structural and, to a lesser extent, functional levels of diabetic rats. Furthermore, the detected nephroprotective effects of insulin and REO combined are superior to those of either administered alone. However, further studies are needed to evaluate these conclusions in humans further.

N1-Methylnicotinamide: The Mysterious Anti-aging Actor in Renal Transplantation.

The fast global aging of people worldwide is a crucial demographic trend. According to evidence, Americans aged 65 and above will compose 21.6% of the population by 2040. During the aging process, the kidney undergoes gradual functional decrease, which turned out to be a forthcoming problem in clinical practice. Age-related decrease in renal function, evaluated by total glomerular filtration rate (GFR), which has been shown to drop by approximately 5-10% per decade after the age of 35. The sustaining extended period renal homeostasis is the main purpose of any therapeutic options intended for delaying or even reversing the aging kidney. The renal transplant has been regarded as the common alternative for kidney replacement therapy for elderly patients with end-stage renal disease (ESRD). In the last few years, considerable progress has been made to find novel therapeutic options for alleviating renal aging, in particular, calorie restriction and pharmacologic therapy. Nicotinamide N-methyltransferase is an enzyme responsible for generating N1-Methylnicotinamide (MNAM), notorious for its anti-diabetic, anti-thrombotic, and anti-inflammatory activity. MNAM is one of the important factors regarded as in vivo probes for evaluating the activity of some renal drug transporters. Furthermore, it has been shown to have therapeutic potential in the pathogenesis of proximal tubular cell damage and tubulointerstitial fibrosis. In this article, in addition to addressing the role of MNAM in renal function, we also explained its anti-aging effects. We conducted an in-depth investigation of the urinary excretion of MNAM and its metabolites, especially N1-methyl-2-pyridone-5- carboxamide (2py) in RTR. The excretion of MNAM and its metabolite, 2py, was inversely correlated with the risk of all-cause mortality in renal transplant recipients (RTR), independent of possible confounders. Therefore, we have shown that the reason for the lower mortality rate in RTR who had higher urinary excretion of MNAM and 2py may be related to the anti- aging effects of MNAM through transiently generating low levels of reactive oxygen species, stress resistance and the activation of antioxidant defense pathways.

H2O2-triggered "off/on signal" nanoparticles target P-selectin for the non-invasive and contrast-enhanced theranostics for arterial thrombosis.

Pathological coagulation within an injured artery and the subsequent cardiovascular complications, such as stroke and heart attack, greatly threaten human life. Inspired by the biochemical features of acute arterial thrombosis, such as abundant activated platelets and hydrogen peroxide (H2O2), we constructed platelet-targeted theranostic nanoparticles (CyBA/PFM NPs) with H2O2-triggered photoacoustic contrast enhancement and antithrombotic capabilities. CyBA/PFM NPs were designed to target platelet-rich clots via fucoidan segment within the carrier, which could be activated by H2O2 to produce fluorescent "CyOH" molecules, thus turning on the photoacoustic signal. CyBA/PFM NPs showed obvious amplification of fluorescence following incubation with fresh clots, exhibiting efficient scavenging ability of intracellular reactive oxygen species (ROS). In a FeCl3-induced mouse model of carotid thrombosis, CyBA/PFM NPs significantly amplified the photoacoustic contrast in thrombogenic tissues, effectively eliminated ROS within the occlusion site, and suppressed the thrombus formation, accompanied by a normalization of the soluble CD40L level. Given their accurate imaging potential, potent antithrombotic activities and acceptable biosafety, CyBA/PFM NPs hold strong potential as nanoscale theranostics for H2O2-correlated cardiovascular diseases. STATEMENT OF SIGNIFICANCE: In this study, we developed a platelet-targeted and H2O2-triggered nanosystem self-assembled from phenylboronated fucoidan/maltodextrin polymers and responsive near-infrared probes. The fucoidan segment within the carrier could facilitate the specific delivery of the therapeutic polymers and probes to the platelet-rich arterial thrombus. In a mouse model of FeCl3-induced arterial thrombosis, the system could be activated by H2O2 to produce fluorescent "CyOH" molecules, thus turning on the photoacoustic signal and specifically imaging thrombosed tissues. Besides, CyBA/PFM NPs significantly effectively eliminated ROS within the occlusion site and suppressed the thrombus formation. Given their theranostic potential and acceptable biosafety, this system has great potential for H2O2-correlated cardiovascular diseases.

Secondary metabolites from marine derived fungus Penicillium chrysogenum Y19-1 with proangiogenic and antithrombotic activities

Investigation of the ethyl acetate extract from the marine derived fungus Penicillium chrysogenum Y19-1 led to the isolation and identification of nine compounds, including ethyl formyltyrosinate (1), ergosterol peroxide (2), ergosterol (3), cerebroside A (4), conidiogenone C (5), dihydroresorcylide (6), 7-hydroxydihydroresorcylide (7), N-(2-hydroxypropanoyl)-2-aminobenzoic acid amide (8), and 4-methyl-5,6-dihydro-2H-pyran-2-one (9). Their chemical structures were determined by NMR analysis, ESIMS experiment and comparison with the reported data in the literature. Among them, compound 1 was identified as a natural product for the first time. All compounds were evaluated for antithrombotic and proangiogenic activities. Compounds 1, 4 and 5 exhibited antithrombotic activities, while compounds 1, 2, 8 and 9 showed proangiogenic activities. Meanwhile, the chemotaxonomic significance of these isolated compounds was also discussed.

Sepsis-Induced Coagulopathy Phenotype Induced by Oxidized High-Density Lipoprotein Associated with Increased Mortality in Septic-Shock Patients

Sepsis syndrome is a highly lethal uncontrolled response to an infection, which is characterized by sepsis-induced coagulopathy (SIC). High-density lipoprotein (HDL) exhibits antithrombotic activity, regulating coagulation in vascular endothelial cells. Sepsis induces the release of several proinflammatory molecules, including reactive oxygen species, which lead to an increase in oxidative stress in blood vessels. Thus, circulating lipoproteins, such as HDL, are oxidized to oxHDL, which promotes hemostatic dysfunction, acquiring prothrombotic properties linked to the severity of organ failure in septic-shock patients (SSP). However, a rigorous and comprehensive investigation demonstrating that oxHDL is associated with a coagulopathy-associated deleterious outcome of SSP, has not been reported. Thus, we investigated the participation of plasma oxHDL in coagulopathy-associated sepsis pathogenesis and elucidated the underlying molecular mechanism. A prospective study was conducted on 42 patients admitted to intensive care units, (26 SSP and 16 non-SSP) and 39 healthy volunteers. We found that an increased plasma oxHDL level in SSP was associated with a prothrombotic phenotype, increased mortality and elevated risk of death, which predicts mortality in SSP. The underlying mechanism indicates that oxHDL triggers an endothelial protein expression reprogramming of coagulation factors and procoagulant adhesion proteins, to produce a prothrombotic environment, mainly mediated by the endothelial LOX-1 receptor. Our study demonstrates that an increased plasma oxHDL level is associated with coagulopathy in SSP through a mechanism involving the endothelial LOX-1 receptor and endothelial protein expression regulation. Therefore, the plasma oxHDL level plays a role in the molecular mechanism associated with increased mortality in SSP.

Pharmacological Inhibition of Glycoprotein VI- and Integrin α2β1-Induced Thrombus Formation Modulated by the Collagen Type.

In secondary cardiovascular disease prevention, treatments blocking platelet-derived secondary mediators pose a risk of bleeding. Pharmacological interference of the interaction of platelets with exposed vascular collagens is an attractive alternative, with clinical trials ongoing. Antagonists of the collagen receptors, glycoprotein VI (GPVI), and integrin α2β1, include recombinant GPVI-Fc dimer construct Revacept, 9O12 mAb based on the GPVI-blocking reagent Glenzocimab, Syk tyrosine-kinase inhibitor PRT-060318, and anti-α2β1 mAb 6F1. No direct comparison has been made of the antithrombic potential of these drugs. Using a multiparameter whole-blood microfluidic assay, we compared the effects of Revacept, 9O12-Fab, PRT-060318, or 6F1 mAb intervention with vascular collagens and collagen-related substrates with varying dependencies on GPVI and α2β1. To inform on Revacept binding to collagen, we used fluorescent-labelled anti-GPVI nanobody-28. In this first comparison of four inhibitors of platelet-collagen interactions with antithrombotic potential, we find that at arterial shear rate: (1) the thrombus-inhibiting effect of Revacept was restricted to highly GPVI-activating surfaces; (2) 9O12-Fab consistently but partly inhibited thrombus size on all surfaces; (3) effects of GPVI-directed interventions were surpassed by Syk inhibition; and (4) α2β1-directed intervention with 6F1 mAb was strongest for collagens where Revacept and 9O12-Fab were limitedly effective. Our data hence reveal a distinct pharmacological profile for GPVI-binding competition (Revacept), GPVI receptor blockage (9O12-Fab), GPVI signaling (PRT-060318), and α2β1 blockage (6F1 mAb) in flow-dependent thrombus formation, depending on the platelet-activating potential of the collagen substrate. This work thus points to additive antithrombotic action mechanisms of the investigated drugs.

Pharmacology of Heparin and Related Drugs: An Update.

Heparin has been used extensively as an antithrombotic and anticoagulant for close to 100 years. This anticoagulant activity is attributed mainly to the pentasaccharide sequence, which potentiates the inhibitory action of antithrombin, a major inhibitor of the coagulation cascade. More recently it has been elucidated that heparin exhibits anti-inflammatory effect via interference of the formation of neutrophil extracellular traps and this may also contribute to heparin's antithrombotic activity. This illustrates that heparin interacts with a broad range of biomolecules, exerting both anticoagulant and nonanticoagulant actions. Since our previous review, there has been an increased interest in these nonanticoagulant effects of heparin, with the beneficial role in patients infected with SARS2-coronavirus a highly topical example. This article provides an update on our previous review with more recent developments and observations made for these novel uses of heparin and an overview of the development status of heparin-based drugs. SIGNIFICANCE STATEMENT: This state-of-the-art review covers recent developments in the use of heparin and heparin-like materials as anticoagulant, now including immunothrombosis observations, and as nonanticoagulant including a role in the treatment of SARS-coronavirus and inflammatory conditions.

Immunopotentiating Activity of Fucoidans and Relevance to Cancer Immunotherapy.

Fucoidans, discovered in 1913, are fucose-rich sulfated polysaccharides extracted mainly from brown seaweed. These versatile and nontoxic marine-origin heteropolysaccharides have a wide range of favorable biological activities, including antitumor, immunomodulatory, antiviral, antithrombotic, anticoagulant, antithrombotic, antioxidant, and lipid-lowering activities. In the early 1980s, fucoidans were first recognized for their role in supporting the immune response and later, in the 1990s, their effects on immune potentiation began to emerge. In recent years, the understanding of the immunomodulatory effects of fucoidan has expanded significantly. The ability of fucoidan(s) to activate CTL-mediated cytotoxicity against cancer cells, strong antitumor property, and robust safety profile make fucoidans desirable for effective cancer immunotherapy. This review focusses on current progress and understanding of the immunopotentiation activity of various fucoidans, emphasizing their relevance to cancer immunotherapy. Here, we will discuss the action of fucoidans in different immune cells and review how fucoidans can be used as adjuvants in conjunction with immunotherapeutic products to improve cancer treatment and clinical outcome. Some key rationales for the possible combination of fucoidans with immunotherapy will be discussed. An update is provided on human clinical studies and available registered cancer clinical trials using fucoidans while highlighting future prospects and challenges.

The Regioselective Conjugation of the 15-nt Thrombin Aptamer with an Optimized Tripeptide Sequence Greatly Increases the Anticoagulant Activity of the Aptamer

Currently, oligonucleotide therapy has emerged as a new paradigm in the treatment of human diseases. In many cases, however, therapeutic oligonucleotides cannot be used directly without modification. Chemical modification or the conjugation of therapeutic oligonucleotides is required to increase their stability or specificity, improve their affinity or inhibitory characteristics, and address delivery issues. Recently, we proposed a conjugation strategy for a 15-nt G-quadruplex thrombin aptamer aimed at extending the recognition interface of the aptamer. In particular, we have prepared a series of designer peptide conjugates of the thrombin aptamer, showing improved anticoagulant activity. Herein, we report a new series of aptamer-peptide conjugates with optimized peptide sequences. The anti-thrombotic activity of aptamer conjugates was notably improved. The lead conjugate, TBA-GLE, was able to inhibit thrombin-induced coagulation approximately six-fold more efficiently than the unmodified aptamer. In terms of its anticoagulant activity, the TBA-GLE conjugate approaches NU172, one of the most potent G-quadruplex thrombin aptamers. Molecular dynamics studies have confirmed that the principles applied to the design of the peptide side chain are efficient instruments for improving aptamer characteristics for the proposed TBA conjugate model.

Shear Stress Markedly Alters the Proteomic Response to Hypoxia in Human Pulmonary Endothelial Cells.

Blood flow produces shear stress that homeostatically regulates the phenotype of pulmonary endothelial cells, exerting antiinflammatory and antithrombotic actions and maintaining normal barrier function. Hypoxia due to diseases, such as chronic obstructive pulmonary disease (COPD), causes vasoconstriction, increased vascular resistance, and pulmonary hypertension. Hypoxia-induced changes in endothelial function play a central role in the development of pulmonary hypertension. However, the interactive effects of hypoxia and shear stress on the pulmonary endothelial phenotype have not been studied. Human pulmonary microvascular endothelial cells were cultured in normoxia or hypoxia while subjected to physiological shear stress or in static conditions. Unbiased proteomics was used to identify hypoxia-induced changes in protein expression. Using publicly available single-cell RNA sequencing datasets, differences in gene expression between the alveolar endothelial cells from COPD and healthy lungs were identified. Sixty proteins were identified whose expression changed in response to hypoxia in conditions of physiological shear stress but not in static conditions. These included proteins that are crucial for endothelial homeostasis (e.g., JAM-A [junctional adhesion molecule A], ERG [ETS transcription factor ERG]) or implicated in pulmonary hypertension (e.g., thrombospondin-1). Fifty-five of these 60 have not been previously implicated in the development of hypoxic lung diseases. mRNA for 5 of the 60 (ERG, MCRIP1 [MAPK regulated corepressor interacting protein 1], EIF4A2 [eukaryotic translation initiation factor 4A2], HSP90AA1 [heat shock protein 90 alpha family class A member 1], and DNAJA1 [DnaJ Hsp40 (heat shock protein family) member A1]) showed similar changes in the alveolar endothelial cells of COPD compared with healthy lungs in females but not in males. These data show that the proteomic responses of the pulmonary microvascular endothelium to hypoxia are significantly altered by shear stress and suggest that these shear-hypoxia interactions are important in the development of hypoxic pulmonary vascular disease.

BJTJ-1837, a novel FXI activation-blocking antibody

BackgroundFactor (F)XI contributes to thrombosis development while it plays a limited role in normal hemostasis. FXI targeting has the potential for preventing and treating thrombosis with little bleeding risk. ObjectivesThe aim of this study was to develop novel antibody therapeutics against FXI for the treatment of thrombosis-related diseases. MethodsMouse hybridoma technology was applied to screen for anti-FXI antibodies. Surface plasma resonance, enzyme inhibition, activated partial thromboplastin time, and prothrombin time assays were conducted to characterize the binding affinity and activity of antibodies. A cynomolgus monkey arterial venous shunt model was applied to validate the antithrombotic activities. ResultsA humanized antibody, BJTJ-1837, reported here bound to the protease domain of FXI and activated FXI with high affinity. BJTJ-1837 fully inhibited the activation of FXI by activated FXII and thrombin. BJTJ-1837 also demonstrated strong anticoagulant activity in human and cynomolgus monkey plasma as measured by activated partial thromboplastin time. Moreover, BJTJ-1837 showed favorable antithrombotic activity with a dose-dependent protection in an arterial venous shunt thrombosis model in cynomolgus monkeys without the bleeding adverse effect. Furthermore, BJTJ-1837 displayed favorable pharmacokinetic and pharmacodynamic properties and good developability. ConclusionAs a potential antithrombotic therapeutic agent with a safe profile, BJTJ-1837 is a very promising FXI activation-blocking antibody candidate.

Ellagic acid alleviates motor, cognitive and hippocampal electrical activity deficits in the male rats with 2-vessel occlusion cerebral ischemia/reperfusion.

Cerebral ischemia/reperfusion (I/R) has been known as a major cause of inability and mortality worldwide. Ellagic acid (EA) has many pharmacological effects including antioxidant, antithrombotic and neurorestoration activities. The aim of this study was evaluation of the effects of EA on motor and cognitive behaviors, hippocampal local field potential (LFP), brain oxidative stress in male rats with cerebral 2-vessel occlusion ischemia/reperfusion (2VO I/R). Forty-eight male Wistar rats (250-300 g) were assigned into six groups. 1) The Sham: rats were treated with DMSO10%/normal saline as solvent of EA 3 times daily for 1 week; 2) I/R+Veh; I/R rats received vehicle; 3-5) EA-treated groups: I/R rats received 50, 75, or 100 mg/kg EA; and 6) Cont+EA100: intact rats received EA. The cerebral 2VO I/R was made by the bilateral common carotid arteries closing for 20 min followed by reperfusion. The behavioral tests and hippocampal LFP recording were performed after treatment with EA. The oxidative stress parameters were assayed by special ELISA kits. Cerebral 2VO I/R significantly decreased motor coordination, memory and hippocampal LFP and significantly increased oxidative stress. Treatment with EA improved all I/R complications. The current findings showed that treatment of I/R rats with EA could reverse cognitive and motor functions, and improve the LFP and oxidative stress markers. So, effects of EA on cognitive and motor function may at least in part, be due to its antioxidative actions.

Medically significant monotypic species Martynia annua L.: A review on ethnobotany, phytochemistry and pharmacology

Martynia annua commonly known as Thael kodukkai belonging to the Martyniaceae family is an herbaceous plant with many medicinal properties. It is a weedy peculiar species native to tropical and subtropical regions of Mexico. The entire herb is found to exhibit potential pharmacological activities. The various parts of this plant have been reported to show many therapeutic indications like anticancer, antibacterial, anticonvulsant, anti-inflammatory, wound healing, analgesic, antipyretic activity, antioxidant, anti-diabetic, anti-nociceptive, immunomodulatory, hepatoprotective, anti-hemolytic, anti-thrombotic, anti-arthritic, anti-haemorrhoidal, anti-alopecia, anti-muscular, anti-helminthic, gastroprotective and anti-fertility activities. This review aims to provide the compilation of existing knowledge on the phytochemistry and pharmacological properties of M. annua from the reported studies. The phytochemical screening results of various extracts of stem, root, leaves and fruits of M. annua were discussed in this review. A greater number of phytoconstituents were reported to be present in leaves. This review suggests that this plant contains various phytoconstituents like anthraquinones, terpenoids, flavonoids, tannins and phenolic compounds that are responsible for various pharmacological activities. In the future, this plant provides an immense scope for pharmacological investigations.

An undefined cystatin CsCPI1 from tea plant Camellia sinensis harbors antithrombotic activity

Tea consumption has been linked to a decreased risk of cardiovascular disease (CVD) mortality, which imposes a heavy burden on the healthcare system; however, which components in tea cause this beneficial effect is not fully understood. Here we uncovered a cystatin (namely CsCPI1), which is a cysteine proteinase inhibitor (CPI) of the tea plant (Camellia sinensis) that promotes antithrombotic activity. Since thrombosis is a common pathogenesis of fatal CVDs, we investigated the effects of CsCPI1, which showed good therapeutic effects in mouse models of thrombotic disease and ischemic stroke. CsCPI1 significantly increases endothelial cell production of nitric oxide (NO) and inhibits platelet aggregation. Notably, CsCPI1 exhibited no cytotoxicity or resistance to pH and temperature changes, which indicates that CsCPI1 might be a potent antithrombotic agent that contributes to the therapeutic effects of tea consumption against CVD. Specifically, the antithrombotic effects of CsCPI1 are distinct from the classical function of plant cystatins against herbivorous insects. Therefore, our study proposes a new potential role of cystatins in CVD prevention and treatment, which requires further study.

Saponins: Research Progress and Their Potential Role in the Post-COVID-19 Pandemic Era.

In the post-COVID-19 pandemic era, the new global situation and the limited therapeutic management of the disease make it necessary to take urgent measures in more effective therapies and drug development in order to counteract the negative global impacts caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its new infectious variants. In this context, plant-derived saponins-glycoside-type compounds constituted from a triterpene or steroidal aglycone and one or more sugar residues-may offer fewer side effects and promising beneficial pharmacological activities. This can then be used for the development of potential therapeutic agents against COVID-19, either as a therapy or as a complement to conventional pharmacological strategies for the treatment of the disease and its prevention. The main objective of this review was to examine the primary and current evidence in regard to the therapeutic potential of plant-derived saponins against the COVID-19 disease. Further, the aim was to also focus on those studies that highlight the potential use of saponins as a treatment against SARS-CoV-2. Saponins are antiviral agents that inhibit different pharmacological targets of the virus, as well as exhibit anti-inflammatory and antithrombotic activity in relieving symptoms and clinical complications related to the disease. In addition, saponins also possess immunostimulatory effects, which improve the efficacy and safety of vaccines for prolonging immunogenicity against SARS-CoV-2 and its infectious variants.

Euphorbia neriifolia (Indian Spurge Tree): A Plant of Multiple Biological and Pharmacological Activities

Although India has a well-established and growing economy surrounding synthetic drug chemistry with an antibiotic base, a large part of the population, especially in forested villages and tribal belts, is relying solely on plant-derived drugs. This is due to a lower number of side effects, low chances of resistance development against pathogenic microorganisms, as well as the diversity and affordability of such drugs. In the Indian subcontinents, Euphorbia neriifolia Linn. (EN) is one of the valuable plants from the big family of Euphorbiaceae, which is usually found in rocky and hilly areas. E. neriifolia was found to be useful in curing tumors, abdominal swelling, bronchial infection, hydrophobia, earache, cough and cold, asthma, leprosy, gonorrhea, spleen enlargement, leucoderma, snake bites, scorpion stings, and causing appetite improvement, etc. Different in vitro and in vivo experimental studies were performed to determine the antioxidant, anti-diabetic, immunomodulatory, anti-inflammatory, anti-arthritic, wound healing, anti-atherosclerosis, radioprotective, anti-anxiety, anti-convulsant, anti-psychotic, anti-thrombotic, dermal irritation, hemolytic, analgesic, anti-fertility, diuretic, anti-microbial, anti-diarrheal, and anti-carcinogenic activities of the various parts of EN. Several bioactive compounds, such as euphol, nerifoliol, taraxerol, euphonerins A–G, lectin, etc., were isolated from E. neriifolia and need to be investigated further for various biological activities (cardiovascular and neuronal diseases). In the pharmaceutical sector, E. neriifolia was selected for the development of new drugs due to its broad pharmacological activities. Therefore, in the present review, distribution, classification, morphological and microscopical description, phytochemical investigation, pharmacological activities, medicinal uses, harmful effects, and their treatment were evaluated, especially against different lifestyle-related diseases.

A snake venom-analog peptide that inhibits SARS-CoV-2 and papain-like protease displays antithrombotic activity in mice arterial thrombosis model, without interfering with bleeding time

Background(p-BthTX-I)2 K, a dimeric analog peptide derived from the C-terminal region of phospholipase A2-like bothropstoxin-I (p-BthTX-I), is resistant to plasma proteolysis and inhibits severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains with weak cytotoxic effects. Complications of SARS-CoV-2 infection include vascular problems and increased risk of thrombosis; therefore, studies to identify new drugs for treating SARS-CoV-2 infections that also inhibit thrombosis and minimize the risk of bleeding are required.ObjectivesTo determine whether (p-BthTX-I)2 K affects the hemostatic system.MethodsPlatelet aggregation was induced by collagen, arachidonic acid, and adenosine diphosphate (ADP) in the Chronolog Lumi-aggregometer. The coagulation activity was evaluated by determining activated partial thromboplastin clotting time (aPTT) and prothrombin time (PT) with (p-BthTX-I)2 K (5.0–434.5 µg) or 0.9% NaCl. Arterial thrombosis was induced with a 540 nm laser and 3.5–20 mg kg− 1 Rose Bengal in the carotid artery of male C57BL/6J mice using (p-BthTX-I)2 K. Bleeding time was determined in mouse tails immersed in saline at 37 °C after (p-BthTX-I)2 K (4.0 mg/kg and 8.0 mg/kg) or saline administration.Results(p-BthTX-I)2 K prolonged the aPTT and PT by blocking kallikrein and FXa-like activities. Moreover, (p-BthTX-I)2 K inhibited ADP-, collagen-, and arachidonic acid-induced platelet aggregation in a dose-dependent manner. Further, low concentrations of (p-BthTX-I)2 K extended the time to artery occlusion by the formed thrombus. However, (p-BthTX-I)2 K did not prolong the bleeding time in the mouse model of arterial thrombosis.ConclusionThese results demonstrate the antithrombotic activity of the peptide (p-BthTX-I)2 K possibly by kallikrein inhibition, suggesting its strong biotechnological potential.