American Society of Hirudotherapy

Leech Ecotin-like Factor

Trypsin and Factor Xa inhibitor with broad-spectrum serine protease activity.

Preclinical / mechanisticLast updated: 2026-05-26 · Reviewed by ASH Editorial Board
Molecular weight of Leech Ecotin-like Factor compared with other characterized leech-derived compoundsHementerin80 kDaHementin80 kDaHementin-Like Protein (HLP-1)80 kDaLeech Collagenase70 kDaHaemadipsa yanyuanensis Progr…70 kDaLeech Apyrase67 kDaCalin65 kDaHyaluronidase60 kDaAntithrombin III binding prot…58 kDaCollagenolytic Fibrinolysin55 kDaLeech Thrombospondin-Like Pro…50 kDaLeech Ecotin-like Factor16 kDa
Molecular weight (kilodaltons) of Leech Ecotin-like Factor (highlighted) alongside other characterized leech salivary compounds. Smaller proteins/peptides generally diffuse and act faster.

Mechanistic Evidence Box

Preclinical / mechanistic
Page type
Compound profile
Evidence type
Trypsin and Factor Xa inhibitor with broad-spectrum serine protease activity.
Evidence level
In vitro
Drug vs leech
Purified natural compound
Safety domains
Bleeding

Clinical translation limit

This factor's in vitro inhibition of trypsin and Factor Xa does not establish clinical efficacy. No FDA-approved derivative exists. Mechanism is preclinical/biochemical only.

Molecular Profile

Category
Proteinase Inhibitor
Evidence tier
Preclinical
Molecular weight
16,000 Da
Source species
Hirudo medicinalis
Leech Ecotin-like Factor molecular structure

Biological Targets

  • → trypsin family serine proteases
  • → Factor Xa

External Resources

    Related Proteinase Inhibitor Compounds

    Hirustasin

    Serine proteinase inhibitor targeting tissue kallikrein — anti-inflammatory pathway.

    Eglin C

    Potent inhibitor of human leukocyte elastase and cathepsin G — anti-inflammatory protein widely used as research tool.

    Bdellin B3

    Kazal-type proteinase inhibitor targeting trypsin and plasmin — modulates inflammatory cascade.

    LDTI (Leech-Derived Tryptase Inhibitor)

    Selective inhibitor of human mast cell tryptase — anti-inflammatory pathway.

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