Exploring hemostatic and thrombolytic potential of heynein - A cysteine protease from Ervatamia heyneana latex

ETHNOPHARMACOLOGICAL RELEVANCE

The latex of Ervatamia heyneana (Wall.) T. Cooke plant has been used for wound healing and various skin diseases by Indian tribes and folklore.

AIM OF THE STUDY

To validate the scientific basis of heynein - a key protease of Ervatamia heyneana, in hemostasis and wound healing process.

MATERIALS AND METHODS

The latex from E. heyneana was processed and subjected to two step purification. The purified heynein was assayed for proteolytic activity using casein as substrate and also attested by zymography. The inhibition studies confirmed the nature of heynein. Pure fibrinogen was used for fibrinogenolytic activity and citrated plasma was used for coagulant and fibrinolytic activities. The edema inducing action and hemorrhagic activity of heynein were assessed on mice model.

RESULTS

The purified heynein exhibited proteolytic activity, which was confirmed by caseinolytic assay and zymography. The inhibition studies confirmed heynein to be a cysteine protease. Heynein showed complete hydrolysis of all the three subunits of human fibrinogen (Aα, Bβ, γ). It exhibited strong pro-coagulant activity by reducing plasma clotting time from 248 to 39s at 40µg concentration. Heynein cleaved α polymer subunit in fibrin clot and did not induce edema and hemorrhage in mice models. The non-hemorrhagic nature was supported with histopathological studies of skin samples.

CONCLUSION

Heynein displays strong pro-coagulant action associated with fibrin(ogen)olytic activity. This provides basis for the observed pharmacological action of Ervatamia heyneana and thereby justifies its use in folk medicine.

Evaluation of analgesic, anti-inflammatory, thrombolytic and hepatoprotective activities of roots of Premna esculenta (Roxb)

BACKGROUND

The objective of this study was to investigate the antinociceptive, anti-inflammatory, thrombolytic and hepatoprotective activities of root extracts of Premna esculenta (family: Verbenaceae).

METHODS

The analgesic activity was evaluated using the acetic-acid-induced writhing test in mice and radiant heat tail-flick method in rats. The anti-inflammatory activity was investigated by carrageenan-induced rat's paw edema, while the thrombolytic activity was evaluated by in vitro clot lysis model. The hepatoprotective activity was investigated against carbon-tetrachloride-induced liver damage in rats.

RESULTS

In acetic-acid-induced writhing test, chloroform and ethyl acetate fraction of ethanolic extract at a dose of 200 mg/kg showed a significant (p<0.001) reduction in the number of writhes with 85.96% and 61.98% of inhibition, respectively. In radiant heat tail-flick method, the ethanolic extract produced 88.49% (p<0.001) elongation of tail-flicking time at 90 min after oral administration at same dose level. In the carrageenan-induced edema test, the ethanolic extract at a dose of 200 mg/kg showed a significant inhibition of paw edema with 22.68% and 17.24% inhibition after the first and third hours of the study period, respectively. In clot lysis model, the ethanolic extract at 5 mg/mL induced a significant clot lysis activity (37.69%, p<0.001). Oral administration of ethanolic extract at the dose of 400 mg/kg/day for 7 days significantly (p<0.001) reduced the elevated levels of serum glutamic pyruvic transaminase, serum glutamyl oxaloacetate transaminase and alkaline phosphatase compared to the CCl4-treated control group.

CONCLUSIONS

The results of the study demonstrated the antinociceptive, anti-inflammatory, thrombolytic and hepatoprotective activities of roots of P. esculenta.

Stimulatory effect of an algal fucoidan on the release of vascular endothelial tissue-type plasminogen activator as a mechanism of fucoidan-mediated thrombolysis

Identifying a pharmacological means for increasing the production of tissue-type plasminogen activator (t-PA) is always desirable to cure impaired production of this enzyme. An algal fucoidan has been shown to exhibit both novel thrombolytic and synergistic stimulatory effects in a mouse thrombosis model. The plasma levels of active t-PA were measured in mouse arterial thrombus models that were treated with various fucoidans to investigate the mechanism of thrombolysis. The mean plasma level of active t-PA after the infusion of fucoidan was 2.136 ± 0.231 ng/ml for nonthrombolytic Fucus fucoidan and 3.917 ± 0.0.529 ng/ml for thrombolytic Undaria fucoidan, which resulted in a 1.56-2.29-fold increase compared with the healthy control group (1.706 ± 0.194 ng/ml) and the untreated thrombus group (2.506 ± 0.301 ng/ml) (P < 0.01). An algal fucoidan has demonstrated to exert a thrombolytic and stimulatory effect via the induction of t-PA release in a dose-dependent manner in an arterial thrombosis model.

Destabilase-lysozyme-2 - original recombinant thrombolytic preparation of medicinal leech inhibits horse platelets aggregation

The purpose. Identifying the capacity of the medicinal leech novel original recombinant thrombolytic preparation Destabilase-Lysozyme-2 to inhibit the blood platelet aggregation.

METHODS

Gene of destabilase-lysozyme. ds2 (mlDL-Ds2 ), was cloned in E.coli cells. Recombinant protein was isolated in denaturing conditions using metal-chelate chromatography followed by denaturation of the polypeptide by rapid dilution in exact accordance with the procedure described by Kurdyumov A.S. et al. ( 2016, Russian Journal of Bioorganic Chemistry, v.42, s. 42-52). Blood was collected from the jugular vein of 18 horses. The functional status of platelets in the presence of different destabilase-lysozyme concentrations were evaluated for their aggregation in Platelet Rich Plasma ( PRP) and in Washed Platelet suspension (WP) using aggregometers Chrono-Log-700 and Сhrono-Log-560, USA560, США. As used aggregation inducers of ADP, collagen type III and human thrombin.

RESULTS

First demonstrated the ability of newly synthesized (Kurdyumov A.S. et al. 2016, Russian Journal of Bioorganic Chemistry, v42, s. 42-52) thrombolytic recombinant enzyme destabilase-lyzosyme to inhibit more than 40% of ADP-stimulated PRP aggregation and ADP- stimulated aggregation of horse blood washed platelets.

CONCLUSION

The ability of destabilase-lyzosyme -2 to inhibit platelets aggregation extends biological properties of recombinant thrombolytic enzyme, pre-clinical trials which resulted in the end of 2015.

Alternative Sources of Fibrinolytic, Anticoagulative, Antimicrobial and Anticancer Molecules

The medicinal properties of earthworms in various remedies date back to 1340 A.D. and have been extended to other countries and cultures. Assays of tissue homogenates of earthworm (Eisenia foetida) have revealed a glycolipoprotein mixture referred to as G-90 that is composed of macromolecules with medical and pharmaceutical applications. There are several functions attributed to G-90: possession of several growth factors that: stimulate proliferation in cell cultures, contain an insulin like growth factor (IGF like), an immunoglobulin like growth factor (IgFG-like), possess two serine peptidases with a tyrosine code and epidermal growth factor (EGF). In contrast, G-90 exerts strong fibrinolytic and anticoagulative activity capable of lysing fibrin clots. Actions of these two properties are dependent upon concentration. Anticoagulative activity also depends upon the kind of anticoagulants (G-90, PI, PII). G-90 can also act as antioxidant, exert antimicrobial activities in vitro and in vivo. The bacteriostatic effect is significantly greater for non-pathogenic species. Finally G-90 also participates in tissue regeneration and wound healing. Taken together, components of earthworms could be tested in certain clinical trials.

Antithrombotic and Antioxidant Activity of Amaranth Hydrolysate Obtained by Activation of an Endogenous Protease

Ingestion of diets with antithrombotic and antioxidant components offer a convenient and effective way to prevent and reduce the incidence of cardiovascular diseases. The aim of the present work was to obtain an amaranth hydrolysate by the activation of an endogenous aspartic protease, to establish adequate experimental conditions, and to evaluate its antithrombotic and antioxidant activity in order to assess its potential application as an ingredient in functional foods. The results obtained not only confirmed the presence of an endogenous protease in the amaranth isolate, but also allowed us to select an adequate incubation conditions (pH 2, 40 °C, 16 h). The hydrolysate obtained (degree of hydrolysis 5.3 ± 0.4 %) showed potential antithrombotic activity (IC50 = 5.9 ± 0.1 mg soluble protein/mL) and had more antioxidant activity than the isolate, indicating that the activation of the protease released bioactive peptides from amaranth proteins. Decreasing the pH is a simple and cheap process and is another way to obtain potential functional ingredients with bioactive compounds.

Antithrombotic Effects of Amaranthus hypochondriacus Proteins in Rats

Cardiovascular disease (CVD) is a major cause of disability and premature death throughout the world. Diets with antithrombotic components offer a convenient and effective way of preventing and reducing CVD incidence. The aim of the present work was to assess in vivo and ex vivo effects of Amaranthus hypochondriacus proteins on platelet plug formation and coagulation cascade. Amaranth proteins were orally administrated to rats (AG, 8 animals) and bleeding time was determined showing no significant difference compared with control rats (CG, 7 animals). However, results show a strong tendency, suggesting that amaranth proteins are involved in the inhibition of thrombus formation. Non-anticoagulated blood extracted from animals was analyzed with the hemostatometer, where AG parameters obtained were twice the values showed by CG. The clotting tests, thrombin time (TT) and activated partial thromboplastin time (APTT), presented a 17 and 14% clotting formation increase respectively when comparing AG with CG. The ex-vivo assays confirm the hypothesis inferring that amaranth proteins are a potential antithrombotic agent.

In Vitro Mode of Action and Anti-thrombotic Activity of Boophilin, a Multifunctional Kunitz Protease Inhibitor from the Midgut of a Tick Vector of Babesiosis, Rhipicephalus microplus

Background

Hematophagous mosquitos and ticks avoid host hemostatic system through expression of enzyme inhibitors targeting proteolytic reactions of the coagulation and complement cascades. While most inhibitors characterized to date were found in the salivary glands, relatively few others have been identified in the midgut. Among those, Boophilin is a 2-Kunitz multifunctional inhibitor targeting thrombin, elastase, and kallikrein. However, the kinetics of Boophilin interaction with these enzymes, how it modulates platelet function, and whether it inhibits thrombosis in vivo have not been determined.

Methodology/Principal Findings

Boophilin was expressed in HEK293 cells and purified to homogeneity. Using amidolytic assays and surface plasmon resonance experiments, we have demonstrated that Boophilin behaves as a classical, non-competitive inhibitor of thrombin with respect to small chromogenic substrates by a mechanism dependent on both exosite-1 and catalytic site. Inhibition is accompanied by blockade of platelet aggregation, fibrin formation, and clot-bound thrombin in vitro. Notably, we also identified Boophilin as a non-competitive inhibitor of FXIa, preventing FIX activation. In addition, Boophilin inhibits kallikrein activity and the reciprocal activation, indicating that it targets the contact pathway. Furthermore, Boophilin abrogates cathepsin G- and plasmin-induced platelet aggregation and partially affects elastase-mediated cleavage of Tissue Factor Pathway Inhibitor (TFPI). Finally, Boophilin inhibits carotid artery occlusion in vivo triggered by FeCl₃, and promotes bleeding according to the mice tail transection method.

Conclusion/Significance

Through inhibition of several enzymes involved in proteolytic cascades and cell activation, Boophilin plays a major role in keeping the midgut microenvironment at low hemostatic and inflammatory tonus. This response allows ticks to successfully digest a blood meal which is critical for metabolism and egg development. Boophilin is the first tick midgut FXIa anticoagulant also found to inhibit thrombosis.

Hematophagous animals express a repertoire of anti-hemostatics which target enzymes involved in proteolytic reactions. These molecules are present in the salivary glands or midguts and target components of both coagulation and complement cascades, in addition to cells involved in hemostasis and immune system. These inhibitors are critical for development and survival of mosquitoes and ticks, and might also contribute to parasite transmission and completion of their life cycle. While much is known regarding sialomics and functional genomics of the salivary glands components, comparatively less information has been gained over the years with respect to midgut anti-hemostatics and their mechanisms of action. The vector of Babesiosis and Q fever, Rhipicephalus microplus, expresses Boophilin, a midgut thrombin inhibitor with low specificity, which contributes to tick development. Notably, we reported that Boophilin targets FXIa, kallikrein, and neutrophil enzymes elastase and cathepsin G, which play a direct or indirect role in the contact pathway of the coagulation cascade. Boophilin also abrogates platelet aggregation by cathepsin G and plasmin, and attenuates Tissue Factor Pathway Inhibitor cleavage by elastase. In vivo, Boophilin inhibits thrombosis and promotes bleeding in mice. It is concluded that Boophilin redundantly down-modulates host biochemical reactions involved in mounting and sustaining pro-inflammatory events which are detrimental to tick development.

A fibrinolytic protease AfeE from Streptomyces sp. CC5, with potent thrombolytic activity in a mouse model

Fibrinolytic proteases have potential applications in cardiovascular disease therapy. A novel fibrinolytic protease, AfeE, with strong thrombolytic activity was purified from Streptomyces sp. CC5. AfeE displayed maximum activity at 40°C in the pH range of 7.0-12.0. It was strongly inhibited by serine protease inhibitor phenylmethanesulfonylfluoride, soybean trypsin inhibitor, tosyl-l-lysine chloromethyl ketone and tosyl-l-phenylalanine chloromethyl ketone. The activity of the enzyme was partially inhibited by Cu(2+), Co(2+) and Zn(2+). AfeE exhibited higher substrate specificity for fibrin than fibrinogen, which has rarely been reported in fibrinolytic enzymes. AfeE also showed high thrombolytic activity in a carrageenan-induced mouse tail thrombosis model. AfeE prolonged prothrombin time, activated partial thromboplastin time, and thrombin time in rat blood. A bleeding time assay revealed that AfeE did not prolong bleeding time in mice at a dose of 1mg/kg. No acute cytotoxicity was observed for AfeE at 320μg/well in human umbilical vein endothelial cells. The afeE gene was cloned from the genome of Streptomyces sp. CC5. Full-length AFE-CC5E contained 434 amino acids and was processed into a mature form consisting 284 amino acids by posttranslational modification, as revealed by high-resolution mass spectrometry analysis. These results indicate that AfeE is a prospective candidate for antithrombotic drug development.

Mature coconut water exhibits antidiabetic and antithrombotic potential via L-arginine-nitric oxide pathway in alloxan induced diabetic rats

BACKGROUND

The aims of the present study were to assess whether the antidiabetic activity of mature coconut water (MCW) is mediated through L-arginine-nitric oxide pathway in diabetic rats, and to study the effects of MCW on blood coagulation.

METHODS

Diabetes was induced in male Sprague-Dawley rats by injecting them with alloxan (150 mg/kg body weight). MCW (4 mL/100 g body weight) and L-arginine (7.5 mg/100 g body weight) was given orally for 45 days. L-NAME was given at a dose of 0.5 mg/kg body weight. Concentrations of blood glucose, plasma insulin, glycosylated hemoglobin (HbA1c), L-arginine, urine volume and urinary creatinine levels, activity of nitric oxide synthase (NOS), and arginase as well as the abnormalities in hemostasis and thrombosis were measured in all the experimental groups.

RESULTS

Treatment with MCW and L-arginine reduced the concentration of blood glucose and HbA1c in diabetic rats. MCW and L-arginine treatment exhibited significant antithrombotic activity in diabetic rats, which was evident from the reduced levels of WBC, platelets, fibrin, and fibrinogen. MCW and L-arginine treatment prolonged the prothrombin time in diabetic rats and reduced the activity of Factor V. In addition to this, the activity of nitric oxide synthase, liver and plasma arginine content, and urinary nitrite were higher in MCW-treated diabetic rats whereas L-NAME treatment inhibited the beneficial effects induced by MCW and arginine.

CONCLUSIONS

The results clearly indicate that L-arginine is a major factor responsible for the antidiabetic and antithrombotic potential of coconut water, and is mediated through the L-arginine-nitric oxide pathway.

Biochemical characterization of a new glycosylated protease from Euphorbia cf. lactea latex

A dimeric protease designated as EuP-82 was purified from Euphorbia cf. lactea latex. Since its proteolytic activity was inhibited by a serine protease specific inhibitor (PMSF), EuP-82 was classified as a serine protease. N-glycan deglycosylation tests revealed that EuP-82 was a glycosylated protein. MALDI-TOF MS showed that EuP-82 was a homodimer, which was its active form. The optimal conditions for fibrinogenolytic activity were at pH 11 and 35 °C. EuP-82 enzyme had broad range of pH stability from 4 to 12. Moreover, the enzyme was still active in the presence of reducing agent (β-mercaptoethanol). EuP-82 was a proline-rich enzyme (about 20.69 mol%). Increased proline production can be found in higher plants in response to both biotic and abiotic stresses, high proline in the molecule of EuP-82 might stabilize its activity, structure and folding. Based on the N-terminal amino acid sequences and peptide mass fingerprint (PMF) of EuP-82, the enzyme was identified as a new serine protease. The digested products from EuP-82 cleavage of human fibrinogen were analyzed by SDS-PAGE and PMF. The results confirmed that EuP-82 could digest all subunits of human fibrinogen. EuP-82 cleaved fibrinogen with a Michaelis constant (Km) of 3.30 ± 0.26 μM; a maximal velocity (Vmax) of 400.9 ± 0.85 ng min(-1); and a catalytic efficiency (Vmax/Km) of 121.5 ± 9.25 ng μM(-1) min(-1). EuP-82 has potential for use in medicinal treatment, for example thrombosis, since the enzyme had fibrinogenolytic activity and high stability.

Purification and biochemical characterization of a novel fibrinolytic enzyme, PSLTro01, from a medicinal animal Porcellio scaber Latreille

A novel protease, named PSLTro01, with fibrinolytic and anticoagulant activity was isolated from Porcellio scaber Latreille and was purified by a combination of hollow fibre membrane molecular weight cut-off (MWCO), ammonium sulfate fractionation, gel filtration and ion-exchange chromatography. PSLTro01 is a single-chain protein with a molecular mass of 38,497 Da as estimated by non-reduced SDS-PAGE and MALDI-TOF MS spectrometry, and its N-terminal 15 amino acid sequence was determined as DINGGGATLPQPLYQ. PSLTro01 is stable in the range of 20-40 °C and pH 6.0-10.0, with a maximum fibrinolytic activity at 40 °C and pH 7.0. The PSLTro01-induced fibrinolytic activity was not influenced by K(+) or Na(+) but was slightly increased by Mg(2+) and completely inhibited by aprotinin and pepstatin A. Fibrin plate assays revealed that PSLTro01 could not directly degrade fibrin but was a plasminogen activator. PSLTro01 exhibited high specificity for the substrate S-2251 for plasmin, followed by S-2238 for thrombin and S-2444 for urokinase. Moreover, the fibrinogenolysis pattern of PSLTro01 was Aα-chains>Bβ-chains>γ-chain. Tail-thrombus of the enzyme treated group was significantly shorter than the physiological saline treated group and the thrombus decrement was correlated with the enzyme dose. PSLTro01 prolongs both thrombin time (TT) and activated partial thromboplastin time (APTT). These results indicate that PSLTro01 may have potential applications in the prevention and treatment of thrombosis.

Lignans and aromatic glycosides from Piper wallichii and their antithrombotic activities

ETHNOPHARMACOLOGICAL RELEVANCE

Piper wallichii (Miq.) Hand.-Mazz. is a medicinal plant used widely for the treatment of rheumatoid arthritis, inflammatory diseases, cerebral infarction and angina in China. Previous study showed that lignans and neolignans from Piper spp. had potential inhibitory activities on platelet aggregation. In the present study, we investigated the chemical constituents of Piper wallichii and their antithrombotic activities, to support its traditional uses.

MATERIALS AND METHODS

The methanolic extract of the air-dried stems of Piper wallichii was separated and purified using various chromatographic methods, including semi-preparative HPLC. The chemical structures of the isolates were determined by detailed spectroscopic analysis, and acidic hydrolysis in case of the new glycoside 2. Determination of absolute configurations of the new compound 1 was facilitated by calculated electronic circular dichroism using time-dependent density-functional theory. All compounds were tested for their inhibitory effects on platelet aggregation induced by platelet activating factor (PAF) in rabbits׳ blood model, from which the active ones were further evaluated the in vivo antithrombotic activity in zebrafish model.

RESULTS

A new neolignan, piperwalliol A (1), and four new aromatic glycosides, piperwalliosides A-D (2-5) were isolated from the stems of Piper wallichii, along with 25 known compounds, including 13 lignans, six aromatic glycosides, two phenylpropyl aldehydes, and four biphenyls. Five known compounds (6-10) showed in vitro antiplatelet aggregation activities. Among them, (-)-syringaresinol (6) was the most active compound with an IC50 value of 0.52 mM. It is noted that in zebrafish model, the known lignan 6 showed good in vivo antithrombotic effect with a value of 37% at a concentration of 30 μM, compared with the positive control aspirin with the inhibitory value of 74% at a concentration of 125μM.

CONCLUSION

This study demonstrated that lignans, phenylpropanoid and biphenyl found in Piper wallichii may be responsible for antithrombotic effect of the titled plant.

Purification and biochemical characterization of a novel fibrinolytic enzyme from culture supernatant of Cordyceps militaris

A novel fibrinolytic enzyme from Cordyceps militaris was produced by submerged culture fermentation, purified, and biochemically characterized. The enzyme was purified to homogeneity, with an overall yield of 4.0% and a specific activity of 1682 U/mg. The molecular weight and pI of the enzyme were 32 kDa and 9.3 ± 0.2, respectively. The optimal pH and temperature of the enzyme were 7.4 and 37 °C, respectively. The enzyme activity was inhibited by Fe(2+), phenylmethane sulfonyl fluoride (PMSF), aprotinin, and pepstatin but not by N-tosyl-L-phenylalanine chloromethyl ketone (TPCK) and ethylenediamine tetracetic acid (EDTA). Three internal peptides of the enzyme, APQALTVAAVGATWAR, EKNVGSTVNLLSYDGNK, and TDATSVLLDGYNVSAVNDLVAK, were obtained. The enzyme could hydrolyze fibrin(ogen) directly and cleave the α-chains more efficiently than β- and γ-chains, suggesting that it is a plasmin like protein. It degraded thrombin, which indicated that it can act as an anticoagulant and prevent thrombosis. Intravascular thrombosis is one of the major reasons of cardiovascular diseases. On the basis of these results, the purified enzyme can be developed as a natural agent for oral fibrinolytic therapy or prevention of thrombosis.

Evaluation of the antithrombotic effects of Crataegus monogyna and Crataegus davisii in the carrageenan-induced tail thrombosis model

CONTEXT

Crataegus species are widely used as herbal medicines for preventing cardiovascular diseases (CVDs). However, there are no studies on the effects of Crataegus monogyna Jacq. (Rosaceae) and C. davisii Browicz on thrombosis, which is an important mechanism in CVDs.

OBJECTIVE

The purpose of this study was to investigate the antithrombotic effects of ethanol extracts of Crataegus monogyna (CMEx) and C. davisii (CDEx) leaves by using the carrageenan-induced tail thrombosis model.

MATERIALS AND METHODS

The hind paw of each mouse was injected with 1% Type I carrageenan to induce thrombosis. CMEx was tested at the doses of 100, 200, and 300 mg/kg and CDEx at the dose of 50, 100, 200, and 300 mg/kg in comparison with heparin. The lengths of tail thrombosis were measured at the 24, 48, and 72 h.

RESULTS

Does of 200 and 300 mg/kg CMEx showed significant effects (p < 0.01; p < 0.001) at 24 h when compared with the control group. The antithrombotic activity of 200 and 300 mg/kg CMEx showed a decrease at 48 and 72 h but the activity of 300 mg/kg dose of CMEx was still significant (p < 0.01). The activities of 50 and 100 mg/kg doses of CDEx were significant (p < 0.001; p < 0.01) between 24 and 72 h whereas 200 and 300 mg/kg CDEx did not show any significance.

DISCUSSION AND CONCLUSIONS

CMEx and CDEx significantly inhibited the carrageenan-induced mouse tail thrombosis. Based on these results, it was concluded that CDEx and CMEx may potentially be used as therapeutic agents or complementary treatments against thrombosis.

[Chemical constituents from safflower injection and their bioactivity]

The chemical constituents of Safflower injection were isolated and purified by polyamide, silica gel, Sephadex LH-20, ODS column chromatographies and preparative HPLC. As a result, sixteen compounds have been isolated. Based on the spectral data analysis, their structures were elucidated as scutellarin (1), kaempferol-3-O-β-rutinoside(2), hydroxysafflor yellow A(3), rutin (4), coumalic acid(5), adenosine(6), syringoside(7), (3E)-4-(4'-hydroxyphenyl)-3-buten-2-one(8), (8Z)-decaene-4, 6-diyne-1-Oβ-D-glucopyranoside(9), 4-hydroxybenzaldehyde (10), (2E, 8E) -tetradecadiene-4, 6-diyne-1, 12, 14-triol-1-O-β-D-glucopyranoside (11), kaem-pferol-3-O-β-sophorose (12), uridine (13), roseoside (14), cinnamic acid (15), and kaempferol (16). Compounds 1,2,7,9,11 and 12 were isolated from the Safflower injection for the first time. The anti-platelet aggregation activities of the isolated compounds were assayed. The results indicated all tested compounds exhibited potent activity except for 5, while 2, 3, 9 and 12 showed strong activity against platelet aggregation.

Fibrin(ogen)olytic and platelet modulating activity of a novel protease from the Echis multisquamatis snake venom

The variety of enzymes including serine proteases that possess fibrin(ogen)olytic and platelet modulating activity have been discovered in different snake venoms. In our work the fibrin(ogen)olytic and platelet modulating activity of a new protease from Echis multisquamatis snake venom was studied. It was shown that purified enzyme cleaved the ВβR42-A43 bond of fibrinogen during first contact with the substrate following much slower hydrolysis of C-terminus of fibrinogen Aα-chain. Protease hydrolysed fibrin clot too, but at much slower rate and cleaved both C-terminus of Aα-chain and ВβR42-A43 bond of Bβ-chain simultaneously. Preincubation of fibrinogen with protease dramatically elongated thrombin clotting time and the clot formed from a mixture of native fibrinogen and fibrinogen desВβ(1-42)2 digested by plasmin much faster than a native fibrin clot. The protease did not activate platelets nor cause changes in their shape and granularity, but it reduced platelets aggregation induced by ADP.

Network pharmacology analyses of the antithrombotic pharmacological mechanism of Fufang Xueshuantong Capsule with experimental support using disseminated intravascular coagulation rats

ETHNOPHARMACOLOGICAL RELEVANCE

Fufang Xueshuantong (FXST) Capsule is developed on a traditional Chinese medicine remedy, with a four-herb formula of Panax notoginseng, Radix astragali, Salvia miltiorrhizae and Radix scrophulariaceae. It has been used for treatment of the clinic cardiovascular disease for many years.

MATERIALS AND METHODS

Due to its complexity of compositions and polypharmacological effects, it often complicates understanding of the mechanisms of action. In the present work, we have constructed an integrated model of system pharmacology to investigate the polypharmacological mechanisms of FXST formulation for treatment of thrombosis disease.

RESULTS

The predicted results showed that 22 ingredients in FXST were closely associated with 41 protein targets related to blood coagulation, fibrinolysis and platelet aggregation. Through analysis of the compound-protein target association, significant cross-targets between each herb indicated the multiple active chemical ingredients might interact with the same target simultaneously and thus explained the synergistic mechanisms of the principle of Traditional Chinese medicines (TCMs) as ''Jun (emperor) - Chen (minister) - Zuo (adjuvant) - Shi (courier)''. To validate the polypharmacological effects predicted by our network pharmacology (NetPharm) analysis, we have carried out experimental investigation the effects of FXST on the disorders of the blood coagulation system in a lipopolysaccharide-induced disseminated intravascular coagulation (DIC) rat model. The results showed that FXST could significantly ameliorate the activation of coagulation system, which is congruent with the cross-target prediction by NetPharm approach.

CONCLUSIONS

The combined investigations provide more insight into better understanding of the pharmacological mechanisms of FXST, and may also offer an alternative avenue to further explore the chemical and pharmacological basis of TCMs.

Structure elucidation of ACE-inhibitory and antithrombotic peptides isolated from mackerel skin gelatine hydrolysates

BACKGROUND

The fish-processing industry generates significant amounts of waste and by-products that are usually discarded. This study investigated the preparation of bioactive gelatine peptides from fish skin. Gelatine was extracted from mackerel (Scomber scombrus) skin and hydrolysed by pepsin for 1, 2, 6 and 24 h. All hydrolysates were screened for antioxidant, ACE-inhibitory and antithrombotic activities.

RESULTS

Gelatine peptides obtained after 24 h of hydrolysis exhibited the highest antioxidant activity (DPPH reduction ∼80%, FRAP ∼130 µmol Trolox equivalent L(-1) ). These hydrolysates had high ACE-inhibitory activity (>70%) and were able to significantly (P < 0.05) inhibit platelet aggregation by about 30%, corresponding to moderate antithrombotic activity.

CONCLUSION

The bioactive properties were mainly due to the presence of low-molecular-weight peptides of 337 and 423 Da.

[Highly active fractions of the medicinal leech recombinant destabilase-lysozyme]

From the highly purified but lowly active recombinant protein Destabilas-Lysozyme (Dest-Lys) by use cation-exchange column TSK CM 3-SW chromatography, it was separated non-active fraction IV, contained 90% of protein. Fractions I, II and III, represented proteins with lysozyme and isopeptidase activities. Their lysozyme activity correlates with the activity of natural Des-Lys. The ratio of the activities in fractions I - III is such, that maximal lysozyme activity is concentrated in fraction III, isopeptidase - in fraction I. It is discussed the possibility of Dest-Lys different functions regulation is depended on the formation of protein complex forms.

[Complexes of cobalt (II, III) with derivatives of dithiocarbamic acid--effectors of peptidases of Bacillus thuringiensis and alpha-L-rhamnozidase of Eupenicillium erubescens and Cryptococcus albidus]

The influence of cobalt (II, III) coordinative compounds with derivatives of dithiocarbamic acid on Bacillus thuringiensis IMV B-7324 peptidases with elastase and fibrinolytic activity and Eupenicillium erubescens and Cryptococcus albidus alpha-L-rhamnosidases have been studied. Tested coordinative compounds of cobalt (II, III) on the basis of their composition and structure are presented by 6 groups: 1) tetrachlorocobaltates (II) of 3,6-di(R,R')-iminio-1,2,4,5-tetratiane--(RR')2Ditt[CoCl4]; 2) tetrabromocobaltates (II) of 3,6-di(R,R')-iminio-1,2,4,5-tetratiane--(RR')2Ditt[CoBr4]; 3) isothiocyanates of tetra((R,R')-dithiocarbamatoisothiocyanate)cobalt (II)--[Co(RR'Ditc)4](NCS)2]; 4) dithiocarbamates of cobalt (II)--[Co(S2CNRR')2]; 5) dithiocarbamates of cobalt (III)--[Co(S2CNRR')3]; 6) molecular complexes of dithiocarbamates of cobalt (III) with iodine--[Co(S2CNRR')3] x 2I(2). These groups (1-6) are combined by the presence of the same complexing agent (cobalt) and a fragment S2CNRR' in their molecules. Investigated complexes differ by a charge of intrinsic coordination sphere: anionic (1-2), cationic (3) and neutral (4-6). The nature of substituents at nitrogen atoms varies in each group of complexes. It is stated that the studied coordination compounds render both activating and inhibiting effect on enzyme activity, depending on composition, structure, charge of complex, coordination number of complex former and also on the enzyme and strain producer. Maximum effect is achieved by activating of peptidases B. thuringiensis IMV B-7324 with elastase and fibrinolytic activity. So, in order to improve the catalytic properties of peptidase 1, depending on the type of exhibited activity, it is possible to recommend the following compounds: for elastase--coordinately nonsaturated complexes of cobalt (II) (1-4) containing short aliphatic or alicyclic substituents at atoms of nitrogen and increasing activity by 17-100% at an average; for fibrinolytic--neutral dithiocarbamates of cobalt (II, III) (4-5) (by 29-199%). For increasing the fibrinolytic activity of peptidase it is better to use dibenzyl- or ethylphenyldithiocarbamates of cobalt (III), which increase activity by 15-40% at an average. The same complexes, and also compound {(CH2)6}2Ditt[CoCl4] make an activating impact on alpha-L-rhamnosidase C. albidus (by 10-20%).

Production, optimization and characterization of fibrinolytic enzyme by Bacillus subtilis RJAS19

The present study aimed at the production, purification and characterization of fibrinolytic nattokinase enzyme from the bacteria isolated from natto food. For the purpose, a fibrinolytic bacterium was isolated and identified as Bacillus subtilis based on 16S rDNA sequence analysis. The strain was employed for the production and optimization of fibrinolytic enzyme. The strain showed better enzyme production during 72nd h of incubation time with 50 degrees C at the pH 9. The lactose and peptone were found to be increasing the enzyme production rate. The enzyme produced was purified and also characterized with the help of SDS-PAGE analysis. The activity and stability profile of the purified enzyme was tested against different temperature and pH. The observations suggesting that the potential of fibrinolytic enzyme produced by Bacillus subtilis RJAS 19 for its applications in preventive medicines.

Purification and characterization of a novel C-type hemolytic lectin for clot lysis from the fresh water clam Villorita cyprinoides: a possible natural thrombolytic agent against myocardial infarction

Villorita cyprinoides (black clam) is a fresh water clam that belongs as a bivalve to the group of mollusc. The saline extracts from the muscle reveal high titers of agglutination potency on trypsin-treated rabbit erythrocytes. With the help of affinity chromatography a hemolytic protein with lectin activity which could all be inhibited by D-galactose were isolated. The lectins were separated on DEAE-cellulose and the main component was purified after an additional step of gel filtration on sephadex G-75. The main component is a non-glycosylated protein with a molecular weight of 96,560 Da determined by MALDI-ToF, consisting of a single protein chain and characterized by the lack of polymers and intermediate disulfide bonds. The pure main lectin with clot lytic feature shows two bands at molecular weights 36,360 and 26, 520 Da. Optimal inhibition of the pure lectin is achieved by D-galactose containing oligo- and polysaccharides. The lectin activity decreased above 40 °C and was lost at 62 °C, the stability over the pH range between 7.0 and 8.0 and requires divalent cations for their activity. The novel C-type hemolytic lectin for clot lysis from the clam Villorita cyprinoides was identified and evaluated, the purified hemolytic lectin (0.35 mg/ml and 0.175 mg/ml) enhanced clot lysis activity when compared to the different concentration (5 mg/ml and 1 mg/ml) of commercial streptokinase. In the present study identified hemolytic lectin was a rapid and effective clot lytic molecule and could be developed as new drug molecule in future.

Thrombolytic effects of the snake venom disintegrin saxatilin determined by novel assessment methods: a FeCl3-induced thrombosis model in mice

Saxatilin, a novel disintegrin purified and cloned from the venom of the Korean snake Gloydius saxatilis, strongly inhibits activation and aggregation of platelets. Glycoprotein (GP) IIb/IIIa receptor antagonists can resolve thrombus, so saxatilin might also have thrombolytic effects. We investigated the thrombolytic effects of saxatilin in mice using a ferric chloride-induced carotid arterial thrombosis model. Thrombotic occlusion and thrombus resolution were evaluated quantitatively by measuring blood flow in the carotid artery with an ultrasonic flow meter and calculating the degree of flow restoration on a minute-by-minute basis; results were confirmed by histological examination. Saxatilin dissolved thrombi in a dose-dependent manner. Saxatilin at 5 mg/kg restored blood flow to baseline levels. As saxatilin dose increased, time to recanalization decreased. A bolus injection of 10% of a complete dose with continuous infusion of the remaining dose for 60 minutes resulted in effective recanalization without reocclusion. The thrombolytic effect of saxatilin was also demonstrated in vitro using platelet aggregometry by administering saxatilin in preformed thrombi. Bleeding complications were observed in 2 of 71 mice that received saxatilin. Fibrin/fibrinogen zymography and platelet aggregometry studies indicated that saxatilin does not have fibrinolytic activity, but exerted its action on platelets. Integrin-binding assays showed that saxatilin inhibited multiple integrins, specifically α2bβ3 (GP IIb/IIIa), α5β1, αvβ3, αvβ1, and αvβ5, which act on platelet adhesion/aggregation. Saxatilin inhibited multiple integrins by acting on platelets, and was safe and effective in resolving thrombi in mice.

Two new compounds from Crataegus pinnatifida and their antithrombotic activities

One new sesquiterpene, (1α,4aβ,8aα)-1-isopropanol-4a-methyl-8-methylenedecahydronaphthalene (1), with one new phenylpropanoid, threo-2-(4-hydroxy-3,5-dimethoxyphenyl)-3-(4-hydroxy-3-methoxyphenyl)-3-ethoxypropan-1-ol (2), along with four known phenylpropanoids were isolated from Crataegus pinnatifida. The structures of compounds 1 and 2 were elucidated on the basis of 1D, 2D NMR analyses, and HR-ESI-MS. The antithrombotic activity in vitro of all isolates was assayed, and only compound 1 exhibited potent antithrombotic activity by inhibiting platelet aggregation in rat plasma by 81.4% at 1 mg/ml.