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

AimTo select higher thrombolytic and lower toxic single component of earthworm fibrinolytic enzymes (EFE). MethodsEFE 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. ResultsAmong these components, EfP-I-1 had higher thrombolytic activity in vitro. When 4.5 mg·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·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. ConclusionBecause 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.