ObjectiveTo compare the contents and relative molecular weight distributions of proteins and polypeptides in Naoxuekang dropping pills， Huoxue Tongmai capsules and Maixuekang capsules of Hirudo single medicinal preparations， to evaluate the in vitro anticoagulant， antiplatelet and fibrinolytic activities of the three preparations， and to investigate the effects of temperature， pH and digestive enzymes on the anticoagulant activities of the three preparations.MethodsThe contents of soluble proteins and polypeptides in the three preparations were determined by bicinchoninic acid assay（BCA） and Bradford method， and the relative molecular weight distributions of the three preparations were determined by electrophoresis combined with gel chromatography. The antithrombin activity of the three preparations was evaluated by fibrinogen-thrombin time（Fibg-TT） method， and their anticoagulant activities were further assessed by the elongations of activated partial thromboplastin time（APTT）， prothrombin time（PT） and thrombin time（TT）. The antiplatelet aggregation activities of the three preparations were measured by turbidimetry and the fibrinolytic activities were measured by fibrin plate method. Relative TT was used as index to investigate the effects of temperature， pH and digestive enzyme buffer on anticoagulant activities of the three preparations.ResultsAt the lowest single dosage， the contents of proteins and polypeptides were in the order of Maixuekang capsules>Huoxue Tongmai capsules>Naoxuekang dropping pills. Both Huoxue Tongmai capsules and Maixuekang capsules had 11 electrophoretic bands between 4.0 kDa and 90 kDa， the bands of Maixuekang capsules were more clear in the range of >25 kDa， and there was 1 obvious band at 14 kDa for the two capsules. Huoxue Tongmai capsules had one specific band at 9.0 kDa and Maixuekang capsules had one specific band at 48.0 kDa. Naoxuekang dropping pills only had 2 electrophoretic bands at 6.5 kDa and 8.5 kDa， primarily containing peptides below 2 kDa， most of which were oligopeptides. The anticoagulant activity concentrations of the three preparations exhibited a certain dose-dependent effect. At the lowest single dosage， The anticoagulant activity concentrations were ranked as Naoxuekang dropping pills>Huoxue Tongmai capsules>Maixuekang capsules. The prolongation effect of the three preparations on coagulation time was dose-dependent. At the same concentration， the prolongation effect of Naoxuekang dropping pills and Huoxue Tongmai capsules was APTT prolongation rate>TT prolongation rate>PT prolongation rate， whereas for Maixuekang capsules， the sequence was TT prolongation rate>APTT prolongation rate>PT lengthening rate. At the single minimum dosage， the order of APTT prolongation rate was Maixuekang capsules>Huoxue Tongmai capsules≈Naoxuekang dropping pills， the order of PT prolongation rate was Naoxuekang dropping pills≈Maixuekang capsules>Huoxue Tongmai capsules， and the order of TT prolongation rate was Maixuekang capsules>Huoxue Tongmai capsules>Naoxuekang dropping pills. The three preparations showed dose-dependent effects on platelet aggregation induced by adenosine diphosphate（ADP） and arachidonic acid（AA）， and the effect induced by ADP was stronger than that induced by AA. The anti-platelet aggregation effect of Naoxuekang dropping pills was significantly stronger than that of Maixuekang capsules（P<0.01）， whereas Huoxue Tongmai capsules had the effect of promoting platelet aggregation. None of the three preparations had the ability to dissolve fibrin. The anticoagulant activity of Naoxuekang dropping pills was least affected by heating， while the activities of the two capsules decreased significantly within 5 min above 80 ℃， and continued to decrease within 2 h. Compared with pure water， the anticoagulant activities of the three preparations could be increased by 1-3 times under strong acidity（pH 1-3）. In the pepsin buffer， the anticoagulant activity of Naoxuekang dropping pills could be increased by 1-3 times， while the anticoagulant activities of Huoxue Tongmai capsules and Maxuekang capsules were significantly decreased， the lowest levels were about 60% and 20%， respectively. In trypsin buffer， the anticoagulant activities of Naoxuekang dropping pills， Huoxue Tongmai capsules and Maixuekang capsules decreased significantly， and the lowest levels decreased to about 41%， 41% and 35%， respectively.ConclusionThe contents of proteins and polypeptides and relative molecular weights of the preparations derived from lyophilized fresh Hirudo powder， dried Hirudo powder and reflux extract of Hirudo decrease sequentially， and the anticoagulant activity decrease gradually， but the anticoagulant pathway is different. And the anti-platelet aggregation activity of the reflux extract is significantly enhanced. The heat resistance and gastrointestinal stability of the three preparations increase successively， and the first two are suitable for enteric-soluble preparations， while the latter is suitable for routine oral administration. The above results can provide data reference for the rationality of different preparation methods， active substances， pharmacodynamics and mechanism of Hirudo preparations.

Hirudo;anticoagulant activity;antiplatelet aggregation activity;bioactive peptides;Naoxuekang dropping pills;Huoxue Tongmai capsules;Maixuekang capsules