The Antithrombotic Effect of Recombinant Neorudin on Thrombi.

Introduction: Recombinant neorudin (EPR-hirudin, EH) was developed through the addition of an EPR (Glu-Pro-Arg) peptide to the amino terminus of hirudin, which can be recognized and cut by coagulation factors XIa (FXIa) and/or Xa (FXa). In this study, the low-bleeding antithrombotic effects of EH were evaluated utilizing experimental models of thrombosis in rabbits and rats to provide a test basis for clinical trials. Methods: The bleeding risks of EH and hirudin were first compared in mice by the tail-clipping method, and then the antithrombotic activity of EH was investigated in a rabbit model of arteriovenous bypass thrombosis and a rat model of thrombotic cerebral infarction. Results: In mice, intravenous administration of EH at 1.5 mg/kg and 3 mg/kg did not affect the bleeding time compared with normal saline, while the administration of hirudin at 1.5 mg/kg prolonged the bleeding time by over 3 times the administration of normal saline. Furthermore, intravenous administration of EH had a significant dose-dependent inhibitory effect on the formation and development of arteriovenous bypass thrombosis and thrombotic cerebral infarction. Compared with an equimolar dose of hirudin, the antithrombotic effect of EH was similar, while the bleeding side effects were significantly attenuated. Moreover, when the antithrombotic effects were similar, EH had a shorter bleeding time and was associated with less bleeding than low molecular weight heparin (LMWH). EH had a therapeutic effect on thrombotic cerebral infarction without increasing the occurrence of cerebral hemorrhage. Conclusion: The findings from the preclinical animal models used in this study showed that EH could not only effectively inhibit thrombus formation but also reduce the risk of bleeding.

Inhibitory role of recombinant neorudin on canine coronary artery thrombosis.

The anticoagulant application is an effective treatment modality for cardiovascular diseases such as coronary heart disease, unstable angina pectoris, and myocardial infarction. In this study, the antithrombotic effect of recombinant neorudin (EPR-hirudin, EH) was evaluated using a canine model of coronary artery thrombosis. A canine model with platelet thrombosis in the left circumferent branch of the coronary artery was designed using Folt's method, and the anti-thrombus activity of EH was investigated. Femoral administration of EH intravenously had a significant dose-dependent inhibitory effect on canine coronary artery thrombosis and the effective rates were 66.7% (p < .05), 83.3% (p < .05), and 100% (p < .01) after injection of 0.3, 1.0, and 3.0 mg/kg EH, respectively. Furthermore, EH demonstrated lower bleeding, with shorter bleeding time and less bleeding loss than low molecular weight heparin (LMWH). Under the similar effect intensity of EH and LMWH (85 IU/kg), the bleeding time of the EH group at 30 min was shorter, and the blood loss at 30-120 min was less than that of LMWH (p < .05 and p < .05-.001, respectively). EH had a significant dose-dependent inhibitory effect in the dose range of 0.3-3.0 mg/kg on the coronary artery thrombosis and lower bleeding side effects than LMWH with a similar antithrombosis effect.

Corrigendum to "Effects of total iridoid glycosides of Picrorhiza scrophulariiflora against non-alcoholic steatohepatitis rats induced by high-fat and high-sugar diet through regulation of lipid metabolism" [Chin Herb Med 12 (2019) 67-72].

[This corrects the article DOI: 10.1016/j.chmed.2019.12.005.].

Corrigendum to "Neuroprotective effect of Sanqi Tongshuan Tablets on sequelae post-stroke in rats" [Chinese Herbal Medicines 11 (2019) 45-51].

[This corrects the article DOI: 10.1016/j.chmed.2018.12.002.].

Effects of total iridoid glycosides of Picrorhiza scrophulariiflora against non-alcoholic steatohepatitis rats induced by high-fat and high-sugar diet through regulation of lipid metabolism.

Objective: To investigate the therapeutic effect of total iridoid glycosides of Picrorhiza scrophulariiflora (TIGP) on non-alcoholic steatohepatitis (NASH). Methods: SD rats were fed with high-fat and high-sugar diet for 8 weeks to establish NASH. TIGP were given orally at doses of 20, 40 and 80 mg/kg/d for 4 weeks. Triglycerides assay (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), aspartate aminotransferase (AST), alanine aminotransferase (ALT), fasting plasma glucose (FPG), fasting insulin (FINS), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), chemokine-1 (MCP-1), leptin (LEP) in serum were tested. TG, TC, superoxide dismutase (SOD), malondialdehyde (MDA), and free fatty acid (FFA) in liver tissue were determined by colorimetric methods. Steatosis of hepatocytes and inflammation was performed by pathological examination. Results: The results showed that TIGP significantly decreased TC, TG and FFA in liver tissue, increased SOD activity, decreased MDA content, decreased serum levels of TG, TC, HDL-C/LDL-C, ALT, AST, GLU, HOMA-IR, TNF-α and LEP, and in addition, improved steatosis of liver cells compared to NASH. Conclusion: TIGP had anti-fatty liver effect against NASH rats induced by high-fat and high-sugar diet. Its mechanism was related to the regulation of lipid metabolism and reduction of insulin resistance, through inhibition of oxidative stress and inflammation.

Thrombolysis with rhPro-UK 3 to 6 hours after embolic stroke in rat.

Objectives: To investigate the thrombolysis with recombinant human prourokinase (rhPro-UK) on thromboembolic stroke in rats at different therapeutic time windows (TTW). Methods: Rats were subjected to embolic middle cerebral artery occlusion. RhPro-UK and positive control drugs rt-PA,UK were administered 3 h, 4.5 h, 6 h after inducing thromboem-bolic stroke. Neurological deficit scoring (NDS) was evaluated at 6 h and 24 h after the treatment. The lesion volume in cerebral hemispheres was measured by MRI scanning machine after 6 h of thrombolysis, and the infarct volume was measured by TTC stain, together with hemorrhagic volume quantified by a spectrophotometric assay after 24 h of thrombolysis. Results: RhPro-UK 10, 20 × 104 U/kg significantly improved the NDS after cerebral thromboembolism in rats at 3 h, 4.5 h TTW, and at the 6 h TTW, the NDS was improved by 28.0% (P = 0.0690) and 29.2% (P = 0.0927) at 6 h and 24 h after rhPro-UK 20 ×104 U/kg administration, respectively. RhPro-UK 10, 20 × 104 U/kg significantly reduced the brain lesions measured by MRI at 3 h and 4.5 h TTW. RhPro-UK 10, 20 × 104 U/kg significantly reduced the cerebral infarction measured by TTC at 3 h, 4.5 h TTW. There was no increase in cerebral hemorrhage compared with untreated group after rhPro-UK administration. Conclusions: RhPro-UK had an obvious therapeutic effect on ischemic stroke caused by thrombosis, and could be started within 4.5 h TTW with less side effects of cerebral hemorrhage than that of UK.

Effect of a new inhibitor of factor Xa zifaxaban, on thrombosis in the inferior vena cava in rabbits.

In recent years, oral factor Xa inhibitors have become a research focus as anticoagulant drugs. Zifaxaban is the first oral FXa inhibitor to enter clinical trials in China. The aim of this study was to determine the inhibitory effect of zifaxaban on thrombosisthrough a model ofinferior vena cava (IVC) thrombosis in rabbits. IVC thrombosis model was established by electrical injury and stenosis, and zifaxaban was administered (p.o.) for 5 consecutive days, then coagulation indicators and bleeding were observed. The results showed that zifaxaban had obvious inhibitory effects on FXa, and had a significant inhibitory effect on IVC thrombosis induced by electrical damage and stenosis. The effect of zifaxaban was similar to that of rivaroxaban, but the bleeding side-effects of zifaxaban were less severe than those of rivaroxaban. Zifaxaban could prolong the prothrombin time and activated partial thromboplastin time of plasma similar to that of other oral FXa inhibitors. Zifaxaban had a significant inhibitory effect on FXa, but it had no obvious effect on other coagulation factors, major anticoagulant factors or fibrinolytic indices. Our results suggest that zifaxaban had specific inhibitory effects on FXa and inhibited IVC thrombosis in rabbits with its hemorrhagic effect was less than that of rivaroxaban. Zifaxaban is ecpected to be developed as a new drug for the prevention of deep venous thrombosis, providing more medication options for patients with such disease, more research is required to support it in the future.

Pre-clinical pharmacodynamic study of a novel oral factor Xa inhibitor zifaxaban.

Zifaxaban is an orally active, direct Factor Xa (FXa) inhibitor that is in development for the prevention and treatment of arterial and venous thrombosis. This study was conducted to investigate the biochemical and pharmacological activity of zifaxaban. In vitro activity was evaluated by enzyme, platelet aggregation, and clotting assays. In vivo effects were examined in venous thrombosis, arteriovenous-shunt thrombosis, carotid thrombosis, and bleeding models in rats. Zifaxaban competitively inhibits human FXa (IC50 = 11.1 nM) with > 10,000-fold greater selectivity than other serine proteases. It did not impair platelet aggregation induced by collagen, adenosine diphosphate (ADP) or arachidonic acid. It significantly prolonged clotting time, prothrombin time (PT), and activated partial thromboplastin time (APTT) in the plasma of humans, rabbits, and rats, with a relatively weak effect on thrombin time (TT). In venous thrombosis models in rats, zifaxaban strongly suppressed thrombus formation with ED50 values of 3.09 mg/kg, and its best efficacy time occurred at 2 h after administration. In arteriovenous-shunt thrombosis and carotid thrombosis models in rats, it inhibited thrombus formation in a dose-dependent manner. And in the rat tail bleeding assay, it showed a trend of less bleeding than rivaroxaban at doses that achieved the same antithrombotic effect. In conclusion, zifaxaban is a selective and direct FXa inhibitor and a promising oral anticoagulant for the prophylaxis and treatment of thromboembolic diseases.

Transcriptomic Study Reveals Recovery of Impaired Astrocytes Contribute to Neuroprotective Effects of Danhong Injection Against Cerebral Ischemia/Reperfusion-Induced Injury.

Danhong Injection (DHI) is widely used in clinics for treating cardiovascular and cerebrovascular diseases in China. However, the mode of action of DHI for neuroprotection remains unclear. In the present study, we deemed to investigate the effects of DHI on a rat model of cerebral ischemia/reperfusion injury (IRI) with an emphasis on its regulated gene profile obtained from microarray assays. Firstly, we showed that a 14-day DHI treatment effectively ameliorated severity of neurological deficits, reduced size of ischemic damage, improved status of oxidation stress, as well as systemic inflammation for IRI rats, along with which was a pronounced reduced cell infiltration in the area of periaqueductal gray matter. Secondly, bioinformatic analyses for the 429 differentially expressed genes (DEGs) regulated by DHI treatment pointed out ECM-receptor interaction, neuroactive ligand-receptor interaction, and endocytosis as the top three biological processes, while Toll-like recptor 4 (TLR4) as the most relavant singaling molecule. Lastly, we provided evidences showing that DHI might directly protect primary astrocytes from oxygen and glucose deprivation/re-oxygenation (OGD/Re) injury, the effects of which was associated with LAMC2 and ADRB3, two DEGs related to the top three biological processes according to transcriptomic analysis. In conlusion, we reported that DHI might work through maintaining the integrity for brain-blood barrier and to regulate TLR4-related signaling pathway to diminish the inflammation, therefore, effectively improved the outcomes of IRI. Our findings suggested that the attenuated astrocytic dysfunction could be a novel mechanism contributing to the neuroprotective effects of DHI against cerebral ischemia/reperfusion-induced damage.

Effect of recombinant human prourokinase on thrombolysis in a rabbit model of thromboembolic stroke.

The aim of the present study was to investigate the efficacy of recombinant human prourokinase (rhPro-UK) on thromboembolic stroke in rabbits. A total of 210 rabbits were used in experiments. The 180 thromboembolic stroke rabbits were divided into three therapeutic time windows with six groups in each time window (n=10). The model group was administered saline, the reagent groups were administered rhPro-UK (2.5×, 5× and 10×104 U/kg), and the positive control groups were administered 5×104 urokinase (UK) U/kg and 4.5 mg/kg recombinant human tissue plasminogen activator via intravenous infusion at 3, 4.5 and 6 h after embolism. The remaining 30 rats (that had not undergone occlusion by autologous blood clots) served as a sham group and were administered saline. The radioactive intensity was detected using a medical gamma counter before and after the administration of the drug for 15, 30, 45, 60, 75, 90, 105 and 120 min. At 24 h after treatment, the brain samples were coronally sliced into 5 mm sections and hemorrhage was estimated used a semiquantitative method by counting the number of section faces with hemorrhaging. The plasma was collected for prothrombin time, activated partial thromboplastin time, fibrinogen and thrombin time tests using a solidification method with a blood coagulation factor analyzer. In addition, α2-antiplasmin (α2-AP) was evaluated using ELISA methods using a RT-6100 microplate reader. At the 3 h time point, the thrombolysis rate of rhPro-UK(2.5×, 5× and 10×104 U/kg) was 21.5% (P<0.05), 36.8% (P<0.001) and 55.0% (P<0.001), respectively together with patency rates of 10% (P>0.05), 40% (P<0.05) and 70% (P<0.001). Furthermore, α2-AP levels were reduced by 5.3% (P>0.05), 5.3% (P>0.05) and 18.1% (P<0.05). At the 4.5 h time point, the thrombolysis rate was 18.8% (P<0.05), 29.9% (P<0.01) and 49.0% (P<0.001) together with patency rates of 10% (P>0.05), 30% (P<0.05) and 50% (P<0.01), and α2-AP levels were reduced by 2.4% (P>0.05), 6.5% (P>0.05) and 17.8% (P<0.05). At the 6 h time point, the thrombolysis rate was 14.7% (P<0.05), 24.1%(P<0.01) and 35.7% (P<0.001) together with patency rates of 20% (P>0.05), 30% (P<0.05) and 40% (P<0.01), and α2-AP levels were reduced by 5.7% (P>0.05), 12.7% (P>0.05) and 22.2% (P<0.01). No significant differences (P>0.05) were identified between rhPro-UK (2.5×, 5× and 10×104 U/kg) and the model group regarding hemorrhage type, size and blood coagulation factors at the different time points. Thus, rhPro-UK promoted thrombolysis and recanalization (patency rate), with reduced risk of cerebral hemorrhage, and thus exerted protective effects on cerebral ischemia rabbits.

Effect of human recombinant prourokinase(rhpro-UK) on thromboembolic stroke in rats.

We evaluated the efficacy and safety of human recombinant prourokinase ( rhpro-UK) on thromboembolic stroke in rats. 60 rats with thromboembolic stroke were divided into 6 groups (n = 10). The model group was given saline, the reagent groups were given rhpro-UK (5, 10, 20 × 104U/kg), and positive control groups were given urokinase (UK) 10 × 104U/kg and recombinant tissue plasminogen activator (rt-PA) 9mg/kg through intravenous infusion at 1.5h after embolism. And other 10 rats without occluded by autologous blood clots as the sham group were given saline. At 6h after treatment, neurological deficit score and Magnetic Resonance Imaging(MRI) including T1WI and T2WI sequence scanning were measured. At 24h after treatment, the brain was cut for 2,3,5-triphenyltetrazolium chloride (TTC) staining and aspectrophotometric assay to measure the infarct area and intracerebral hemorrhage after neurological deficit detection. rhpro-UK (5, 10, 20 × 104 U/kg) improved neurological disorder by 39.1 ± 19.7% (n = 10, P > 0.05), 65.2 ± 14.2% (n = 10, P < 0.01) and 65.2 ± 14.2% (n = 10, P < 0.01) maximally; decreased brain lesion volume by 36.7 ± 34.8% (n = 10, P < 0.05), 77.6 ± 7.7% (n = 10, P < 0.01) and 80.5 ± 6.9% (n = 10, P < 0.01); decreased infarction area by 38.2 ± 24.0% (n = 10, P < 0.01), 73.9 ± 5.2% (n = 10, P < 0.001) and 79.7 ± 4.0% (n = 10, P < 0.001) respectively, and there were no statistics difference between rhpro-UK (5, 10, 20 × 104 U/kg) and each positive groups at intracerebral hemorrhage (P > 0.05). Rhpro-UK improved the damaged neural function, decreased the extent of the disease and did not raise bleeding, had protective effects for cerebral ischemia in rats.

[Network pharmacology study of mechanism on xuesaitong injection against retinal vein occlusion].

Retinal vein occlusion (RVO) is a common clinical disease causing vision loss. Risk factors such as diabetes, atherosclerosis are closely associated with RVO. Xuesaitong injection is used extensively in clinical treatment of RVO, however the mechanism is still unclear. In this study, we investigated the protective effect of Xuesaitong injection on RVO rat model. Using a compound-target network of Xuesaitong on anti-RVO constructed by literature mining, we aim to elucidate the multi-compound, multi-target effect of Xuesaitong injection. Fifteen potential targets of Xuesaitong injection associated with inflammation, angiogenesis, apoptosis, and coagulation were identified in this study. VEGF, IL-1beta and IL-6, three important targets in the compound-target network were further experimentally validated. This study provided experimental evidence for Xuesaitong injection being effective in treating RVO and a network view on its anti-RVO mode of action through a multi-compound and multiple-target mechanism.

Protective effects of mutant of acidic fibroblast growth factor against cerebral ischaemia-reperfusion injury in rats.

OBJECTIVE: To investigate the protective effect of a mutant of acidic fibroblast growth factor (MaFGF) against cerebral ischaemia-reperfusion injury in rats. METHODS: Sixty male Sprague-Dawley rats were randomly divided into six groups as follows: sham-operated group, untreated group, 20microg/kg, 40microg/kg and 80microg/kg MaFGF-treated groups and also the positive control group. Cerebral ischaemia-reperfusion injury was induced by middle cerebral artery occlusion (MCAO) for 2h followed by reperfusion for 24h. Different dose of MaFGF were infused intravenously at 1h after middle cerebral artery (MCA) occlusion. Nimodipine was used as positive control. The behaviour deficit score, brain-infarcted area, brain oedema degree, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were detected at 24h after reperfusion. RESULTS: The results showed that MaFGF at the dose of 20microg/kg, 40microg/kg and 80microg/kg significantly alleviated brain injury. Compared to untreated group, the behaviour deficits were much less severe, the brain oedema alleviated obviously, the MDA contents decreased and SOD activity increased dramatically in MaFGF-treated groups respectively. The efficacy of MaFGF was similar to that of nimodipine. CONCLUSION: The results demonstrate that MaFGF has neuroprotective effect against brain injury resulting from focal ischaemia-reperfusion in Sprague-Dawley rats.

Effects of Astragaloside IV on heart failure in rats.

BACKGROUND: Astragaloside IV (ASI) in Radix Astragali is believed to be the active component in treating heart failure. The present study aims to examine the effects of ASI on cardiovascular parameters in long-term heart failure in rats. METHODS: Using echocardiographic and haemodynamic measurements, we studied the effects of ASI on congestive heart failure (CHF) induced by ligation of the left coronary artery in rats. RESULTS: ASI (0.1, 0.3 and 1.0 mg/kg/day) attenuated the decline of fractional shortening (FS). The peak derivatives of the left ventricle (LV) pressure (dp/dt) in ASI-treated groups significantly increased. Both LV internal diameters in diastole (LVIDd) and in systole (LVIDs) decreased significantly after ASI treatment (0.3 and 1.0 mg/kg/day). ASI (1.0 mg/kg/day) attenuated the decrease of LV systolic pressure (LVSP). ASI treatment inhibited compensatory hypertrophy of myocardial cells and lowered the number of apoptotic myocytes. CONCLUSION: ASI improved cardiac functions as measured by cardiovascular parameters.

Cloning, purification and biochemical characterization of a thrombus-ditargeting thrombolytic agent, comprised of annexin B1, ScuPA-32K and fibrin-adherent peptide.

The development of thrombolytic agent could provide invaluable progress for antithrombotic therapy. In this paper, we reported the cloning, purification and biochemical characterization of AnxB1ScuPAFap, a thrombus-ditargeting chimera composed of annexin B1, low molecular single-chain urokinase (ScuPA-32K) and fibrin-adherent peptide (dodecapeptide, Fap). In vitro test showed that, the chimera was a thrombolytic agent with anticoagulant activity and thrombus-ditargeting with the activated-platelet membrane binding and fibrin clot binding activity. Compared to urokinase, the chimera had less reperfusion time, higher reperfusion ratio, and less bleeding effects on coronary thrombolysis by clot lysis assay in dogs. Thus, the chimera appeared to be suitable for thrombolytic therapy of thrombus diseases.

[A component of earthworm fibrinolytic enzyme having higher thrombolytic activity than total components in vivo].

AIM: To select higher thrombolytic and lower toxic single component of earthworm fibrinolytic enzymes (EFE). METHODS: EFE containing total components were obtained by affinity chromatography from Eisenia fetida. Using ion-exchange chromatography to separate three main components EfP-0-2, EfP-I-1 and EfP-I-2 from EFE, their thrombolytic activity and toxicity were compared with EFE. RESULTS: Among these components, EfP-I-1 had higher thrombolytic activity in vitro. When 4.5 mg x kg(-1) of these components were injected, the contents of fibrinogen in rat serum were not affected, but only EfP-I-1 exhibited distinct thrombolytic activity. When 6.0 mg x kg(-1) of them were injected intravenously, the bleeding time was not evidently delayed only by EfP-I-1. The acute toxicity test showed that the LD50 of EfP-I-1 was higher than EFE by 2. 17 times. CONCLUSION: Because of distinct thrombolytic activity, lower toxicity in vivo, higher content in EFE and easy to purify, EfP-I-1 was adapted to be developed as a single component medicine for treating thrombus.

Construction, expression, and characterization of a recombinant annexin B1-low molecular weight urokinase chimera in Escherichia coli.

To produce a thrombi-targeting plasminogen activator, low molecular weight single-chain urokinase gene (scuPA32k) was spliced with the full-length cDNA of annexin B1 gene (anxB1) by overlap extension method. The fused gene anxB1scuPA was ligated into pET28a vector, transformed into E. coli BL21-RIL, and then induced to express under the control of T7 promoter. The AnxB1ScuPA protein expressed amounted to 22% of the total bacterial proteins. The product was refolded, and then purified by using DEAE Sepharose fast flow ion-exchange column and Superdex S-200 gel-filtration column. HPLC analysis revealed that the final purity is about 95%. The specific activity of AnxB1ScuPA, measured as amidolytic activity, reached 100,000 IU/mg. It had a similar S2444 catalytic efficiency (kcat/Km) to ScuPA32k, and also showed high activated-platelet membrane-binding activity and anticoagulant activity, indicating that the chimera fully retained the components of enzymatic and membrane-binding activities of the parent molecules. In vivo test revealed that, the dogs administered with AnxB1ScuPA had less reperfusion time, higher reperfusion ratio, and less bleeding effects than those with urokinase. These findings indicated that AnxB1ScuPA might have advantages over current available thrombolytic agents.

[Effects of recombinant human brain natriuretic peptide and milrinone on cardiac hemodynamics and renal function in anesthetized dog].

AIM: To study the effects of rhBNP and milrinone on the cardiac hemodynamics and renal function in anesthetized dogs. METHODS: The actions of rhBNP given cumulatively i.v. 10, 30 and 100 ng.kg-1 for 30 min and milrinone of single dose (100 micrograms.kg-1, i.v.) on cardiac hemodynamics and renal function were studied in anesthetized open-chest dogs. RESULTS: In anesthetized dogs (n = 7) intravenous infusion of rhBNP at 10-100 ng.kg-1, caused decreases in mean arterial pressure (MAP), left ventricular systolic pressure (LVSP), LVdp/dtmax, pulmonary arterial pressure (PAP), left ventricular end diastolic pressure (LVEDP), total peripheral resistance (TPR) and renal vascular resistance (RVR) dose-dependently, without significant changes in cardiac output (CO), LV(dp/dt)/P, renal blood flow (RBF) and heart rate (HR), increases in urinary volume and sodium excretion. In anesthetized dogs (n = 6), there were remarkable decreases in MAP, LVEDP, PAP, TPR, RBF, RVR and urinary volume following the MIL (100 micrograms.kg-1, i.v.), with significant increases of LVSP, +/- LVdp/dtmax, HR and CO, but no marked changes in urinary volume and sodium excretion. CONCLUSION: rhBNP reduces the pre-load and after-load in the anaesthetized dogs but showed no distinct effect on the contractility of the heart. Positive inotropic and chronotropic actions have been demonstrated after intravenous injection of milrinone 100 micrograms.kg-1 in anesthetized dogs.