American Society of Hirudotherapy

Bdellin B1

Plasmin inhibitor of Kazal-type family — anti-fibrinolytic.

Preclinical / mechanisticLast updated: 2026-05-26 · Reviewed by ASH Editorial Board
Molecular weight of Bdellin B1 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 kDaBdellin B15.5 kDa
Molecular weight (kilodaltons) of Bdellin B1 (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
Plasmin inhibitor of Kazal-type family — anti-fibrinolytic.
Evidence level
In vitro
Drug vs leech
Purified natural compound

Clinical translation limit

Bdellin B1's in vitro inhibition of plasmin 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
5,500 Da
Source species
Hirudo medicinalis
Bdellin B1 molecular structure

Biological Targets

  • → plasmin

Key Citations

  1. Fink E et al. (1986), Biol Chem Hoppe-Seyler

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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