American Society of Hirudotherapy

Novel CRA Protein from Hirudo medicinalis — Complement Regulation

Discovery of a new complement-regulatory activity protein in leech salivary secretion

Last Updated: March 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Salivary PharmacologyDrug DevelopmentResearch team (2025) · Biomolecules, 2025

Summary

Identification and characterization of a novel complement-regulatory activity (CRA) protein from Hirudo medicinalis salivary gland secretion. The protein modulates complement cascade activation, adding a new immunomodulatory mechanism to the leech’s multi-compound therapeutic arsenal.

Why This Matters for Hirudotherapy

Complement dysregulation underlies numerous inflammatory and autoimmune conditions. A leech-derived complement regulator expands the known pharmacological repertoire of SGS beyond anticoagulation and represents a potential lead for anti-inflammatory drug development.

Citation

Novel Complement-Regulatory Activity Protein from Hirudo medicinalis

Research team (2025) · Biomolecules, 2025

Added to ASH library: March 18, 2026 · Site last updated: March 18, 2026

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.

Novel CRA Protein from Hirudo medicinalis — Complement Regulation | ASH