434 Salivary Proteins — Integrated Proteomics of Hirudo medicinalis
The most comprehensive catalog of leech salivary bioactive compounds
Why this matters for hirudotherapy
Investigational / Research Priority
Investigación en ciencia básica. Esta revisión cubre hallazgos de proteómica y transcriptómica sin aplicación clínica directa en esta etapa.
De 20 compuestos a 434 proteínas
For over a century, our understanding of leech SGSry composition was limited to approximately 20 compounds isolated through classical biochemistry — hirudin, calin, destabilase, hyaluronidase, bdellins, and eglins being the best characterized. Liu et al. (2019) transformed this picture using integrated proteomics and transcriptomics, revealing that the medicinal leech secretome is vastly more complex than previously understood.[R1]
Metodología
The study combined two complementary omics approaches:
Proteomics (protein-level)
Liquid chromatography–tandem mass spectrometry (LC-MS/MS) of salivary gland secretions identified 434 full-length protein sequences, of which 44 were confirmed as bioactive through functional annotation.
Transcriptomics (RNA-level)
RNA sequencing of salivary gland tissue identified 221 bioactive transcripts, providing evidence that the gland actively expresses a vast repertoire of functional molecules beyond what had been characterized.
Seis categorías funcionales
The 434 identified proteins were classified into six major functional groups, revealing the multi-target nature of leech SGS:
Anticoagulants
Thrombin inhibitors (hirudin variants), Factor Xa inhibitors, fibrinolytic enzymes. The primary functional group responsible for the sustained bleeding effect.
Anti-platelet
Platelet aggregation inhibitors (calin, saratin) and collagen adhesion blockers. Prevent primary hemostasis at the bite wound.
Vasodilators
Histamine-like compounds, acetylcholine, and vasodilatory peptides that increase local blood flow to the feeding site.
Anti-inflammatory
Proteinase inhibitors (bdellins, eglins), complement inhibitors, and immune modulators that suppress the host inflammatory response.
Analgesic
Anesthetic and analgesic compounds that reduce pain at the bite site — explaining why patients often do not feel the initial attachment.
Antimicrobial
Antimicrobial peptides (theromacin, destabilase-lysozyme, hirunipins) that protect the wound environment from secondary infection.
Impacto cuantitativo
434
Proteins identified
44
Confirmed bioactive
221
Bioactive transcripts
6
Functional categories
Por qué esto importa para la hirudoterapia
The Liu et al. study fundamentally changed our understanding of how leech therapy works. Instead of a simple anticoagulant effect (the hirudin-centric model), we now understand that the leech delivers a coordinated multi-target pharmacological cocktail — simultaneously acting on coagulation, platelets, vasculature, inflammation, pain, and infection. This multi-target mechanism may explain the broad therapeutic effects observed clinically, including the prolonged pain relief seen in osteoarthritis trials.[R1]
The dataset also provides a rich source for drug discovery: the vast majority of the 434 proteins remain uncharacterized for therapeutic potential, representing a largely untapped pharmacological resource.[R2][R3]
Complementary genomic data
References
- [R1]
Integrated Proteomics and Transcriptomics of Hirudo medicinalis Salivary Gland Secretion
Primary source. First integrated multi-omics study of leech salivary glands.
- [R2]
A Chromosome-Level Genome Assembly for the Medicinal Leech and Identification of Anticoagulant Genes
Kvist et al. genome assembly complementing the proteomics data.
- [R3]
Comparative Transcriptomics of Three Hirudo Species: Insights into Evolution of Salivary Proteins
Babenko et al. cross-species comparison of salivary transcriptomes.
Recursos relacionados
Added to ASH library: February 27, 2026 | Site last updated: March 14, 2026