Anticoagulant Activity Research Articles

Atrase A, a P-III class metalloproteinase purified from cobra venom, exhibits potent anticoagulant activity by inhibiting coagulation pathway and activating the fibrinolytic system

Snake venoms, comprising a complex array of protein-rich components, an important part of which are snake venom metalloproteinases (SVMPs). These SVMPs, which are predominantly isolated from viperid venoms, are integral to the pathology of snakebites. However, SVMPs derived from elapid venoms have not been extensively explored, and only a handful of SVMPs have been characterized to date. Atrase A, a nonhemorrhagic P-III class metalloproteinase from Naja atra venom, exhibits weak proteolytic activity against fibrinogen in vitro but has pronounced anticoagulant effects in vivo. This contrast spurred investigations into its anticoagulant mechanisms. Research findings indicate that atrase A notably extends the activated partial thromboplastin time, diminishes fibrinogen levels, and impedes platelet aggregation. The anticoagulant action of atrase A primarily involves inhibiting coagulation factor VIII and activating the endogenous fibrinolytic system, which in turn lowers fibrinogen levels. Additionally, its effect on platelet aggregation further contributes to its anticoagulant profile. This study unveils a novel anticoagulant mechanism of atrase A, significantly enriching the understanding of the roles of cobra venom metalloproteinases in snake venom. Furthermore, these findings underscore the potential of atrase A as a novel anticoagulant drug, offering insights into the functional evolutions of cobra venom metalloproteinases.

Xylans as a promising prebiotic agent: a brief review

Xylans are the most abundant hemicelluloses in nature, constituting components of the secondary cell wall of plant cells. They are polysaccharides with versatile properties, which can be used in various industrial sectors. Several biological activities have been identified in different xylans, such as antioxidant, antitumor, antimicrobial, emulsifying, anticoagulant, and immunomodulatory activities. Among these applications of xylans, its use as a prebiotic stands out, composing functional foods. Xylans form non-digestible dietary fibers that serve as a source of energy for beneficial microorganisms, modifying the intestinal microbiome and bringing a general improvement to the health status of those who consume them. The literature reports the use of xylooligosaccharides as promoters of the growth of probiotic microorganisms, such as species of Lactobacillus and Bifidobacterium, in addition to treating dysbiosis and reducing intestinal inflammation. Due to their structural diversity, abundance in nature, and a wide range of biological properties, xylans are valuable components that can be used to create various products aimed at enhancing human health.

Intermediate molecular weight–fucosylated chondroitin sulfate from sea cucumber Cucumaria frondosa is a promising anticoagulant targeting intrinsic factor IXa

Thromboembolic diseases pose a serious risk to human health worldwide. Fucosylated chondroitin sulfate (FCS) is reported to have good anticoagulant activity with a low bleeding risk. Molecular weight plays a significant role in the anticoagulant activity of FCS, and FCS smaller than octasaccharide in size has no anticoagulant activity. Therefore, identifying the best candidate for developing novel anticoagulant FCS drugs is crucial. Herein, native FCS was isolated from sea cucumber Cucumaria frondosa (FCScf) and depolymerized into a series of lower molecular weights (FCScfs). A comprehensive assessment of the in vitro anticoagulant activity and in vivo bleeding risk of FCScfs with different molecule weights demonstrated that 10 kDa FCScf (FCScf-10 K) had a greater intrinsic anticoagulant activity than low molecular weight heparin (LMWH) without any bleeding risk. Using molecular modeling combined with experimental validation, we revealed that FCScf-10 K can specifically inhibit the formation of the Xase complex by binding the negatively charged sulfate group of FCScf-10 K to the positively charged side chain of arginine residues on the specific surface of factor IXa. Thus, these data demonstrate that the intermediate molecular weight FCScf-10 K is a promising candidate for the development of novel anticoagulant drugs.

Cutaneous glands of the striped toad, Rhinella crucifer (Wied-Neuwied, 1821) (Amphibia: Bufonidae): Histological study and bioactivities of glandular secretions

This study investigated the morphology of Rhinella crucifer cutaneous glands, as well as the protein/peptide profiles and bioactivities of body gland secretions (BGS) and parotoid macrogland secretions (PS). The parotoid as well as dorsal and ventral skin fragments of male and female individuals were processed for histological analysis. The protein and peptide profiles of male and female gland secretions were evaluated. Male secretions were also assessed for proteolytic, trypsin inhibiting, hemagglutinating, hemolytic, antimicrobial, and anticoagulant activities. The R. crucifer skin structure presented protuberances that are clearly visible and formed by the integument, which has cutaneous glands throughout the body. An average of 438 and 333 glands were identified in males in females, respectively. No significant differences were observed in the distribution of glands across the body as well as for area and perimeter of glands. Differences were observed in protein composition between the PS and BGS from males and females, and secretions from animals collected from undisturbed and anthropogenically disturbed areas. Proteins with similarities to catalase and elongation factor 1-alpha were detected in the PS. Zymography revealed proteolytic activity in both male BGS and PS. Male BGS showed antibacterial activity against Enterococcus faecalis and Escherichia coli and anticoagulant activity, being able to prolong prothrombin time by 6.34-fold and activated partial thromboplastin time by 2.17-fold. Finally, male PS and BGS caused a maximum hemolysis degree of 1.4%. The data showed that the cutaneous secretions of R. crucifer are potentially promising for biotechnological prospecting.

Total Content and Composition of Phenolic Compounds from Filipendula Genus Plants and Their Potential Health-Promoting Properties.

This current article was dedicated to the determination of the composition of phenolic compounds in extracts of four species of the genus Filipendula in order to establish a connection between the composition of polyphenols and biological effects. A chemical analysis revealed that the composition of the extracts studied depended both on the plant species and its part (leaf or flower) and on the extractant used. All four species of Filipendula were rich sources of phenolic compounds and contained hydrolyzable tannins, condensed tannins, phenolic acids and their derivatives, and flavonoids. The activities included data on those that are most important for creating functional foods with Filipendula plant components: the influence on blood coagulation measured by prothrombin and activated partial thromboplastin time, and on the activity of the digestive enzymes (pancreatic amylase and lipase). It was established that plant species, their parts, and extraction methods contribute meaningfully to biological activity. The most prominent result is as follows: the plant organ determines the selective inhibition of either amylase or lipase; thus, the anticoagulant activities of F. camtschatica and F. stepposa hold promise for health-promoting food formulations associated with general metabolic disorders.

A small-molecule hemostatic agent for the reversal of direct oral anticoagulant–induced bleeding

BackgroundThe bleeding risk associated with direct oral anticoagulants (DOACs) remains a major concern, and rapid reversal of anticoagulant activity may be required. Although specific and nonspecific hemostatic biotherapies are available, there is a need for small-molecule DOAC reversal agents that are simple and cost-effective to produce, store, and administer. ObjectivesTo identify and characterize a small molecule with procoagulant activity as a DOAC reversal agent. MethodsWe sought to identify a small procoagulant molecule by screening a chemical library with a plasma clotting assay. The selected molecule was assessed for its procoagulant properties and its ability to reverse the effects of the DOACs in a thrombin generation assay. Its activity as a DOAC reversal agent was also evaluated in a tail-clip bleeding assay in mice. ResultsThe hemostatic molecule (HeMo) dose-dependently promoted thrombin generation in plasma, with dose values effective in producing half-maximum response ranging between 3 and 5 μM, depending on the thrombin generation assay parameter considered. HeMo also restored impaired thrombin generation in DOAC-spiked plasma and reversed DOAC activity in the mouse bleeding model. HeMo significantly reduced apixaban-induced bleeding from 709 to 65 μL (vs 43 μL in controls; P < .01) and dabigatran-induced bleeding from 989 to 155 μL (vs 126 μL in controls; P < .01). ConclusionHeMo is a small-molecule procoagulant that can counterbalance hemostatic disruption by a thrombin inhibitor (dabigatran) or factor Xa inhibitors (apixaban and rivaroxaban). The compound’s effective clot formation and versatility make it a possible option for managing the inherent hemorrhagic risk during DOAC therapy.

Role of CES1 and ABCB1 Genetic Polymorphisms on Functional Response to Dabigatran in Patients with Atrial Fibrillation.

Background: Dabigatran etexilate is a pro-drug hydrolyzed into dabigatran by carboxylesterases (CES) and is a substrate of the P-Glycoprotein encoded by the adenosine-triphosphate-binding cassette sub-family B member (ABCB)1 genes. We evaluated the functional response to dabigatran according to different CES1 and ABCB1 single-nucleotide polymorphisms (SNPs) in patients with atrial fibrillation (AF). Methods: A total of 100 consecutive patients with AF taking dabigatran were enrolled by two Italian centers. A venous blood sample was drawn for genetic determinations, as well as a measurement of the diluted thrombin time (dTT) and drug plasma concentrations, at the trough and peak. The main objective was the relationship between the dTT values and CES1 rs2244613, CES1 rs8192935 and ABCB1 rs4148738 SNP while on two different dabigatran doses (110 and 150 mg BID). Results: A total of 43 patients were on a 110 mg dabigatran dose and 57 on 150 mg. The DTT values at the trough and at peak were not different among patients with different CES1 rs2244613 and CES1 rs8192935 genotypes, regardless of the dabigatran dose. In patients on 150 mg dabigatran, the dTT values at the trough were 77 (44-111) ng/mL in patients with the ABCB1 rs4148738 heterozygous CT genotype vs. 127 (85-147) ng/mL in the wild-type CC genotype vs. 110 (47-159) ng/mL in the mutant trait TT genotype (p = 0.048). In patients with the ABCB1 rs4148738 CT genotype, OR for having dTT values at a trough below the median was 3.21, 95% CI 1.04-9.88 (p = 0.042). Conclusions: ABCB1 rs4148738 CT heterozygous is associated with the reduced anticoagulant activity of dabigatran at the trough in patients receiving the higher dose regimen.

Exploring a Hirudin variant from nonhematophagous leeches: Unraveling full-length sequence, alternative splicing, function, and potential as a novel anticoagulant polypeptide

Ethnopharmacological relevanceLeeches exhibit robust anticoagulant activity, making them useful for treating cardiovascular diseases in traditional Chinese medicine. Whitmania pigra, the primary source species of leech-derived medicinal compounds in China, has been demonstrated to possess formidable anticoagulant properties. Hirudin-like peptides, recognized as potent thrombin inhibitors, are prevalent in hematophagous leeches. Considering that W. pigra is a nonhematophagic leech, the following question arises: does a hirudin variant exist in this species? Aim of the studyIn this study we identified the hirudin-encoding gene (WP_HV1) in the W. pigra genome. The goal of this study was to assess its anticoagulant activity and analyze the related mechanisms. Materials and methodsIn this study, a hirudin-encoding gene, WP_HV1, was identified from the W. pigra genome, and its accurate coding sequence (CDS) was validated through cloning from cDNA extracted from fresh W. pigra specimens. The structure of WP_HV1 and the amino acids associated with its anticoagulant activity were determined by sequence and structural analysis and prediction of its binding energy to thrombin. E. coli was used for the expression of WP_HV1 and recombinant proteins with various structures and mutants. The anticoagulant activity of the synthesized recombinant proteins was then confirmed using thrombin time (TT). ResultsValidation of the WP_HV1 gene was accomplished, and three alternative splices were discovered. The TT of the blank sample exceeded that of the recombinant WP_HV1 sample by 1.74 times (0.05 mg/ml), indicating positive anticoagulant activity. The anticoagulant activity of WP_HV1 was found to be associated with its C-terminal tyrosine, along with the presence of 9 acidic amino acids on both the left and right sides. A significant reduction in the corresponding TT was observed for the mutated amino acids compared to those of the wild type, with decreases of 4.8, 6.6, and 3.9 s, respectively. In addition, the anticoagulant activity of WP_HV1 was enhanced and prolonged for 2.7 s when the lysine-67 residue was mutated to tryptophan. ConclusionOnly one hirudin-encoding variant was identified in W. pigra. The active amino acids associated with anticoagulation in WP_HV1 were resolved and validated, revealing a novel source for screening and developing new anticoagulant drugs.

An orthosteric/allosteric bivalent peptide agonist comprising covalently linked protease-activated receptor-derived peptides mimics in vitro and in vivo activities of activated protein C

BackgroundActivated protein C (APC) has anticoagulant and cytoprotective cell-signaling activities, which often require protease-activated receptor (PAR) 1 and PAR3 and PAR cleavages at noncanonical sites (R46-N47 and R41-G42, respectively). Some PAR1-derived (P1) peptides and PAR3-derived (P3) peptides, eg, P1-47-66 and P3-42-65, mimic APC’s cell signaling. In anti-inflammatory assays, these 2 peptides at low concentrations synergistically attenuate cellular inflammation. ObjectivesTo determine whether a P1 peptide covalently linked to a P3 peptide mimics APC’s anti-inflammatory and endothelial barrier stabilization activities. MethodsAnti-inflammatory assays employed stimulated THP-1 cells and caspase-1 measurements. Cultured human EA.hy926 or murine aortic endothelial cells (ECs) exposed to thrombin were monitored for transendothelial electrical resistance. Bivalent covalently linked P1:P3 peptides were studied for APC-like activities. ResultsIn anti-inflammatory assays, P1-47-55 was as active as P1-47-66 and some P3 peptides (eg, P3-44-54 and P3-51-65) were as active as P3-42-65. The bivalent P1:P3 peptide comprising P1-47-55-(Gly[10 residues])-P3-51-65 (designated “G10 peptide”) was more potently anti-inflammatory than the P1 or P3 peptide alone. In transendothelial electrical resistance studies of thrombin-challenged ECs, P1-47-55 and the G10 peptide mimicked APC’s protective actions. In dose-response studies, the G10 peptide was more potent than the P1-47-55 peptide. In murine EC studies, the murine PAR-sequence–derived G10 peptide mimicked murine APC’s activity. Anti-PAR1 and anti-PAR3 antibodies, but not anti–endothelial protein C receptor antibodies, abated G10’s cytoprotection, showing that G10’s actions involve PAR1:PAR3. G10 significantly increased survival in murine endotoxemia. ConclusionThe PAR-sequence–derived G10 peptide is a bivalent agonist that mimics APC’s cytoprotective, anti-inflammatory, and endothelial barrier–stabilizing actions and APC’s protection against endotoxemic mortality.

Systemic inflammation and delirium during critical illness.

The purpose of this study was to determine associations between markers of inflammation and endogenous anticoagulant activity with delirium and coma during critical illness. In this prospective cohort study, we enrolled adults with respiratory failure and/or shock treated in medical or surgical intensive care units (ICUs) at 5 centers. Twice per day in the ICU, and daily thereafter, we assessed mental status using the Richmond Agitation Sedation Scale (RASS) and the Confusion Assessment Method-Intensive Care Unit (CAM-ICU). We collected blood samples on study days 1, 3, and 5, measuring levels of C-reactive protein (CRP), interferon gamma (IFN-γ), interleukin (IL)-1 beta (IL-1β), IL-6, IL-8, IL-10, IL-12, matrix metalloproteinase-9 (MMP-9), tumor necrosis factor-alpha (TNF-α), tumor necrosis factor receptor 1 (TNFR1), and protein C using validated protocols. We used multinomial logistic regression to analyze associations between biomarkers and the odds of delirium or coma versus normal mental status the following day, adjusting for age, sepsis, Sequential Organ Failure Assessment (SOFA), study day, corticosteroids, and sedatives. Among 991 participants with a median age (interquartile range, IQR) of 62 [53-72] years and enrollment SOFA of 9 [7-11], higher concentrations of IL-6 (odds ratio [OR] [95% CI]: 1.8 [1.4-2.3]), IL-8 (1.3 [1.1-1.5]), IL-10 (1.5 [1.2-1.8]), TNF-α (1.2 [1.0-1.4]), and TNFR1 (1.3 [1.1-1.6]) and lower concentrations of protein C (0.7 [0.6-0.8])) were associated with delirium the following day. Higher concentrations of CRP (1.4 [1.1-1.7]), IFN-γ (1.3 [1.1-1.5]), IL-6 (2.3 [1.8-3.0]), IL-8 (1.8 [1.4-2.3]), and IL-10 (1.5 [1.2-2.0]) and lower concentrations of protein C (0.6 [0.5-0.8]) were associated with coma the following day. IL-1β, IL-12, and MMP-9 were not associated with mental status. Markers of inflammation and possibly endogenous anticoagulant activity are associated with delirium and coma during critical illness.

Chemical Synthesis of Fucosylated Chondroitin Sulfate Tetrasaccharide with Fucosyl Branch at the 6-OH of GalNAc Residue.

Fucosylated chondroitin sulfate is a unique glycosaminoglycan isolated from sea cucumbers, with excellent anticoagulant activity. The fucosyl branch in FCS is generally located at the 3-OH of D-glucuronic acid but, recently, a novel structure with α-L-fucose linked to the 6-OH of N-acetyl-galactosamine has been found. Here, using functionalized monosaccharide building blocks, we prepared novel FCS tetrasaccharides with fucosyl branches both at the 6-OH of GalNAc and 3-OH of GlcA. In the synthesis, the protective group strategy of selective O-sulfation, as well as stereoselective glycosylation, was established, which enabled the efficient synthesis of the specific tetrasaccharide compounds. This research enriches knowledge on the structural types of FCS oligosaccharides and facilitates the exploration of the structure-activity relationship in the future.

Protein disulfide isomerase cleaves allosteric disulfides in histidine-rich glycoprotein to regulate thrombosis

The essence of difference between hemostasis and thrombosis is that the clotting reaction is a highly fine-tuned process. Vascular protein disulfide isomerase (PDI) represents a critical mechanism regulating the functions of hemostatic proteins. Herein we show that histidine-rich glycoprotein (HRG) is a substrate of PDI. Reduction of HRG by PDI enhances the procoagulant and anticoagulant activities of HRG by neutralization of endothelial heparan sulfate (HS) and inhibition of factor XII (FXIIa) activity, respectively. Murine HRG deficiency (Hrg−/−) leads to delayed onset but enhanced formation of thrombus compared to WT. However, in the combined FXII deficiency (F12−/−) and HRG deficiency (by siRNA or Hrg−/−), there is further thrombosis reduction compared to F12−/− alone, confirming HRG’s procoagulant activity independent of FXIIa. Mutation of target disulfides of PDI leads to a gain-of-function mutant of HRG that promotes its activities during coagulation. Thus, PDI-HRG pathway fine-tunes thrombosis by promoting its rapid initiation via neutralization of HS and preventing excessive propagation via inhibition of FXIIa.

Semisynthesis of new sulfated heterorhamnan derivatives obtained from green seaweed Gayralia brasiliensis and evaluation of their anticoagulant activity

Marine green algae produce sulfated polysaccharides with diverse structures and a wide range of biological activities. This study aimed to enhance the biotechnological potential of sulfated heterorhamnan (Gb1) from Gayralia brasiliensis by chemically modifying it for improved or new biological functions. Using controlled Smith Degradation (GBS) and O-alkylation with 3-chloropropylamine, we synthesized partially water-soluble amine derivatives. GBS modification increase sulfate groups (29.3 to 37.5 %) and α-l-rhamnose units (69.9 to 81.2 mol%), reducing xylose and glucose, compared to Gb1. The backbone featured predominantly 3- and 2-linked α-l-rhamnosyl and 2,3- linked α-l-rhamnosyl units as branching points. Infrared and NMR analyses confirmed the substitution of hydroxyl groups with aminoalkyl groups. The modified compounds, GBS-AHCs and GBS-AHK, exhibited altered anticoagulant properties. GBS-AHCs showed reduced effectiveness in the APTT assay, while GBS-AHK maintained a similar anticoagulant activity level to Gb1 and GBS. Increased nitrogen content and N-alkylation in GBS-AHCs compared to GBS-AHK may explain their structural differences. The chemical modification proposed did not enhance its anticoagulant activity, possibly due to the introduction of amino groups and a positive charge to the polymer. This characteristic presents new opportunities for investigating the potential of these polysaccharides in various biological applications, such as antimicrobial and antitumoral activities.

Biosynthesis, characterization and antivenom activities of &lt;i&gt;Moringa oleifera&lt;/i&gt; silver nanoparticles: an experimental approach

Moringa oleifera has been previously established to possess neutralizing potentials against Echis ocellatus venom. This study however, investigated the bioefficacy of silver nanoparticles biosynthesized from M. oleifera leaf extract aimed at improving its bioactivity against E. ocellatus venom-induced toxicities using in vivo and in vitro methods. The intrinsic characteristics of the produced M. oleifera-Silver nanoparticles (MO-AgNPs) were carried out using energy dispersive X-ray, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier-transform infrared spectroscopy. Twenty-five male Wistar rats divided randomly into five groups (n=5) were used for the antivenom study. Group 1 received saline while groups 2 to 5 were envenomed intraperitoneally with 0.22mg/kg (LD50) of E. ocellatus venom. Group 2 was left untreated while groups 3 to 5 were treated with 0.2ml of antivenom, 5 and 10mg/kg MO-AgNPs post-envenomation, respectively. Blood and tissue of treated rats were analyzed for heamatological parameters and histopathology, respectively. The MO-AgNPs formation was confirmed with a colour change from light brown to yellowish-brown with maximum SPR band at 420nm from UV-Vis analysis, indicating a reflection of the bio-reduction of Ag+ to Ag0. The Transmission electron micrographs showed well dispersed spherical AgNPs with average particle size of 15.7nm. Treatment with MO-AgNPs caused a significant improvement of acute anemia, leucopenia and thrombocytopenia induced by the venom in the envenomed treated rats. Also, MO-AgNPs inhibited the haemorrhagic, haemolytic and anticoagulant activities of the venom. Tissue lesions observed in heart of envenomed untreated rats were attenuated after treatment with MO-AgNPs. The biosynthesized MO-AgNPs exhibited potent neutralizing potentials than M. oleifera crude extract against E. ocellatus venom toxicities.

Biochemical and biological characterization of the venoms of Naja kaouthia and Naja mandalayensis from Myanmar and neutralization effects of BPI cobra antivenom

Snakebite is a neglected public health issue, with many scientific and medical issues to be solved. Cobras are among the most common venomous snakes in Myanmar and are responsible for a considerable number of severe snakebite envenoming. There are three species of cobra (Naja kaouthia, Naja mandalayensis and Ophiophagus hannah) in Myanmar. The study aims to characterize the N. kaouthia and N. mandalayensis venoms and to investigate the efficacy of anti-cobra antivenom (BPI) against the two venoms. Protein components and fibrinogenolytic activity were determined by SDS-PAGE. Enzymatic activities for PLA2, protease and acetylcholinesterase were determined by spectrophotometric method. Anticoagulant activity was determined by recalcification time of citrated human plasma. Myotoxicity, necrotizing activity, median lethal dose (LD50) and median effective dose (ED50) were determined by WHO recommended methods. The SDS-PAGE displayed the proteins and enzymes containing in two venoms were different. N. kaouthia venom exhibited more in PLA2, acetylcholinesterase, anticoagulant, fibrinogenolytic and necrotizing activities than N. mandalayensis venom. N. mandalayensis venom had more protease activity and myotoxicity than N. kaouthia venom. The median lethal dose (LD50) of N. kaouthia and N. mandalayensis venom was 4.33 μg/mouse and 5.04 μg/mouse respectively. Both venoms induced fibrinogen Aα chain degradation in 30 min (N. kaouthia) and in 6 h (N. mandalayensis). The same median effective dose (ED50) (19.56 μg/mouse) showed that anti-NK antivenom can neutralize against lethal effect of N. mandalayensis venom. It can also neutralize the protease activity, anticoagulant activity and fibrinogenolytic activity of both venoms. Immunodiffusion and immunoblotting studies showed that the antivenom recognized its homologous venom (N. kaouthia) and cross-reacted against the heterologous venom (N. mandalayensis). The anti-NK antivenom is suitable to use for N. mandalayensis bite if monospecific antivenom is not available.

Anticoagulant properties and therapeutic potentials of wasp venom

AbstractWasp venom is rich in bioactive substances, such as proteins, peptides, and small molecules. The venom significantly affects the mammalian cardiovascular, nervous, and immune systems, causing mild to severe symptoms following stings. It exhibits both procoagulant and anticoagulant activities, and significant research has identified its ability to modulate the mammalian coagulation system. Active substances that inhibit clotting have been identified and purified through patient case reports and experimental studies. This study reviewed the findings on how wasp venom interacts with platelets and coagulation factors, such as fibrinogen and prothrombin, and demonstrated its dual influence on the coagulation cascade. This highlights the potential of the venom in therapeutic applications, especially as an anticoagulant, as evidenced by the inhibition of coagulation factors and prolonged clotting times after envenomation, suggesting its utility in developing novel anticoagulant therapies. This review focuses on the anticoagulant effects of social wasp venom, which is prevalent in sting incidents, summarizing the research and observations on its therapeutic potential. This emphasizes the significance of further studies to identify and utilize venom components as innovative anticoagulant treatments.

Polymers as candidates for broad‐spectrum antivirals—in vitro inhibition of Zika virus with sodium polyanethole sulfonate

AbstractZika virus (ZIKV), belonging to the family of flaviviruses, is an emerging mosquito‐borne pathogen causing microcephaly and other congenital abnormalities in newborns as well as various neurologic pathologies in adults. The climate change and the lifestyle of current societies, involving global mobility, result in a rapid broadening of ZIKV geographic distribution. There are no vaccines or drugs available to protect against or cure the diseases caused by that virus. Our in vitro studies have demonstrated that sodium polyanethole sulfonate (PASNa), a degradable polymer used in various biomedical applications, acts as an efficient ZIKV inhibitor, both in animal and human cells. The mechanistic studies indicated that PASNa bound to the ZIKV particles thus hindering their attachment to the host cells and also interfered in the late steps of viral replication. PASNa is characterized by very low cytotoxicity and its antiviral activity can be achieved at a concentration much lower than that at which its anticoagulant activity has to be considered. Isothermal titration calorimetry (ITC) studies have shown that the interaction of PASNa with human serum albumin (HSA), the most abundant blood protein, is the endothermic, entropy‐driven process resulting in the formation of stoichiometric (1:1) PASNa‐HSA complexes with a hydrodynamic diameter of 8.8 ± 0.8 nm and zeta potential (ζ) equal to −21.3 mV. The analysis of CD spectra indicated that PASNa did not significantly affect the HSA secondary structure on binding to that protein.

A Deep Overview of Anticoagulant Drugs: Recent Synthesis and Their Activity Assay

During the unprecedented COVID-19 pandemic, anticoagulant drugs have emerged as a crucial component of treatment alongside antivirus medications. Patients with severe COVID-19 frequently have critical conditions marked by blood clot development, necessitating the administration of anticoagulants. This review aims to provide a comprehensive overview of various anticoagulant drugs, their synthesis methods, and assays employed to predict their anticoagulant activity. Notable anticoagulant categories frequently utilized include oral anticoagulants heparin, non-vitamin K antagonists, and vitamin K antagonists. In recent years, the development of new anticoagulants has seen a shift towards a multifaceted approach that combines in silico prediction with in vitro and in vivo assays. In silico prediction techniques play a pivotal role in the initial screening process. This integrated approach has yielded promising results, paving the way for the synthesis of novel anticoagulant candidates, as substantiated by a battery of in vitro, in vivo, and ex-vivo tests.

Interference of oral anti-Xa anticoagulants during monitoring of unfractionated heparin treatments: practical and future attitudes

Contrary to direct oral anticoagulants (DOAC), unfractionated heparin (UFH) requires daily monitoring when administered at therapeutic dose. At present, UFH monitoring is preferably carried out by measuring plasma anti-Xa activity, however, in patients previously treated with an anti-Xa DOAC and switched to UFH, there is a high risk of DOAC interfering with the measurement of UFH anti-Xa activity. Residual anti-Xa DOAC in the sample can lead to an overestimation of the anticoagulant activity attributed to heparin and thus to incorrect anticoagulation. This risk of interference should not be overlooked because interference may occur even at concentration of DOAC below the hemostatic safety threshold and can last several days. To overcome this issue, several alternatives are being studied. This note provides an update on anti-Xa DOAC interference and different strategies available in current practice. It also underlines the importance of communication between biologists and clinicians on anticoagulant treatments received by patients.

Design and Development of Fast-dissolving Tablets of Apixaban using Single Coprocessed Excipient

Background: Apixaban is administered orally as an anticoagulant action and minimizes the chances of strokes and systemic embolism. The conventional film-coated tablet showed less bioavailability due to its minimal solubility in the gastrointestinal tract. Rationale: The goal of designing the current analysis is to prepare a prompt release tablet using a single Coprocessed excipient which minimizes multistep processing, time, and cost effectiveness. Methods: The prompt release tablets of Apixaban were developed by direct compression technique using multifunctional material like Prosolve ODT G2 and Prosolve Easytab. Drug excipients inertness was confirmed with FTIR and DSC. Flowing characteristics of Apixaban and co-processed excipients were evaluated in terms of Carr’s index, Angle of repose, and Hausner’s ratio. These co-processed excipients indicated exceptional flowing and compression characteristics. The ready tablets were assessed for weight variation, hardness, friability, dispersion time, disintegration, and dissolution studies. Results: Among 12 batches, the least disintegration time was shown with C6 with a cumulative drug release of 99.06 % within 25 min. The optimized batch C6 was highly stable when tested under stability guidelines at 40 0 C and at 75 % relative humidity. Conclusion: Among these co-processed excipients, Prosolve Easytab SP was found the best one for direct compression intended for the immediate or fast dissolving tablets.