[Influence of intravenous injection of fucoidan from brown seaweed Fucus evanescens by plasma rabbits anticoagulant activity and neutralisation by sulphate protamin of fucoidans antithrombin activity in vitro].

With fucoidan from Fucus evanescens dose increase from 1 to 5 mg/kg plasma coagulation time in test A(see symbol)TB increases. Sulphate protamin in final concentration 0.67-1.35 mkg/ml will neutralise antithrombin activity of fucoidans from brown seaweed Fucus evanescens and Laminaria cichorioides. The gravimetrichesky relation for the investigated samples makes an antidot/anticoagulant 1.

[Effects of intravenous injection of sulphated galactomannan on anticoagulant activity of rat plasma].

We studied anticoagulant activity in vitro and in vivo of sulfate depolymerisation galactomannan guar with the following characteristics: Man:Gal 1.64, molecular mass 127 kDa, sulfation degree 1.46. We found the ability of galactomannan-HSO3Na (GM) to increase the time of blood coagulation in the test aPTT with an increase of its concentration and to decrease velocity of chromogenic substrate on the factor Xa hydrolysis. Specific antithrombin and anti-factor Xa activities of GM were 35.8 +/- 1.8 IU/mg and 6.6 +/- 0.5 IU/mg, respectively. In biospecific electrophoresis complexes arise between GM and protamine sulfate. Intravenous injection of GM to rats prolonged plasma coagulation time in the aPTT test with dose reduction from 1 to 3 mg/kg. In rat thrombosis model a dose of 3 Mg/kg produced a 100% inhibition of blood clot.

[Anticoagulant activity of arabinogalactane sulfate and cedar bark extract studied in vitro].

We have studied in vitro the ability of the Siberian cedar crust (SCC) extract (Pinus sibirica Du Tour) and arabinogalactan sulphate (AGS) extracted from wood of Siberiam pine-tree (Larix sibirica Ledeb.) to increase the human blood plasma coagulation time and also to inhibit the amydolytic activity of thrombin (aIIa) and the coagulation factor Xa (aXa). A method has been developed by means of which SCC increases the aXa activity by a factor of 3.7 and the aIIà activity by a factor of 2.5. The AGS preparation increased the blood plasma coagulation time in the test for activated partial thromboplastin time. An effective concentration, at which the time of plasma coagulation was increased by a factor of 2 (in comparison to the control) was 2.94 +/- 0.33 mg/ml. AGS did not exhibit the ability to inhibit the Xa activity.

Inhibition of thrombin and factor Xa by Fucus evanescens fucoidan and its modified analogs.

Specimens of fucoidan extracted from Fucus evanescens were purified from protein and polyphenols, deacetylated and depolymerized by fucoidanase for evaluation of their biological activity. Deacetylation did not modify the capacity of fucoidan to inhibit thrombin and factor Xa, while purification from protein and polyphenols reduced this capacity. Depolymerization of fucoidan increased its capacity to inhibit thrombin mainly through heparin cofactor II. All the studied specimens formed complexes with protamine sulfate.

[Anticoagulant activity of low-molecular-weight heparins obtained using a hydrolase complex].

The anticoagulant activity of low-molecular weight heparins (LMWH-PC) with average distribution of molecular weights within 3.4-5.8 kD was investigated. The samples of LMWH-PC were obtained from unfractionated heparin using immobilized enzyme complex of protease C. The LMWH-PC derivatives inhibited the activity of blood coagulation factors IIa (thrombin) and Xa. The LMWH-PC derivatives had an anti-factor-Xa activity up to 131-208 IU/mg and anti-factor-IIa activity up to 81-175 IU/mg. All LMWH-PC derivatives form complexes with protamine sulfate during electrophoresis in agarose gel. The anticoagulant activity of rabbit plasma exhibits a doze-dependent increase upon the intravenous or subcutaneous injection of LMWH-PC with a molecular weight of 5.4 kD.