American Society of Hirudotherapy

Leech Kallikrein Inhibitor

Plasma kallikrein-kinin system modulator — anti-inflammatory pathway distinct from cyclooxygenase.

Preclinical / mechanisticLast updated: 2026-05-26 · Reviewed by ASH Editorial Board
Molecular weight of Leech Kallikrein Inhibitor 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 Kallikrein Inhibitor7.5 kDa
Molecular weight (kilodaltons) of Leech Kallikrein Inhibitor (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
Plasma kallikrein-kinin system modulator — anti-inflammatory pathway distinct from cyclooxygenase.
Evidence level
Mechanistic discussion
Drug vs leech
Purified natural compound

Clinical translation limit

Leech kallikrein inhibitor's mechanism is preclinical only. No FDA-approved derivative exists; not to be confused with the FDA-approved synthetic kallikrein inhibitor ecallantide (Kalbitor), which is a separate pharmaceutical product.

Molecular Profile

Category
Proteinase Inhibitor
Evidence tier
Preclinical
Molecular weight
7,500 Da
Source species
Hirudo medicinalis
Leech Kallikrein Inhibitor molecular structure

Biological Targets

  • → plasma kallikrein

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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    This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.