American Society of Hirudotherapy

Lefaxin Family (Comparative)

Three lefaxin paralogs in H. nipponia + W. pigra genomes (Ye 2025) — H. nipponia variants exhibit stronger FXa binding and in vitro anticoagulant activity than W. pigra.

Preclinical / mechanisticLast updated: 2026-05-27 · Reviewed by ASH Editorial Board
Molecular weight of Lefaxin Family (Comparative) 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 kDaLefaxin Family (Comparative)30 kDa
Molecular weight (kilodaltons) of Lefaxin Family (Comparative) (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
Three lefaxin paralogs in H. nipponia + W. pigra genomes (Ye 2025) — H. nipponia variants exhibit stronger FXa binding and in vitro anticoagulant activity than W. pigra.
Evidence level
In vitro
Drug vs leech
Recombinant (genetically expressed)
Safety domains
Bleeding

Clinical translation limit

Comparative lefaxin family in vitro FXa inhibition does NOT establish clinical efficacy. No FDA-approved derivative exists; cross-species reanalysis challenges the assumption that only hematophagous leeches have therapeutic anticoagulant utility.

Molecular Profile

Category
Anticoagulant
Evidence tier
Preclinical
Molecular weight
30,000 Da
Source species
Hirudo nipponia, Whitmania pigra
Discovered
2025 · Ye T et al.
Lefaxin Family (Comparative) molecular structure

Biological Targets

  • Factor Xa (variable affinity by paralog and species)

Key Citations

  1. Ye T et al. (2025), Biology (Basel) · PMID 40906077

External Resources

    Related Anticoagulant Compounds

    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.