American Society of Hirudotherapy

A novel protease-activated receptor 1 inhibitor from the leech Whitmania pigra

Pharmacology article published in Chinese Journal of Natural Medicines (2019)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Salivary PharmacologyDrug DevelopmentGenomics & ProteomicsRen SH, Liu ZJ, Cao Y et al. · Chinese journal of natural medicines, 2019

Abstract

Whitmania pigra has been used as a traditional Chinese medicine (TCM) for promoting blood circulation, alleviating blood coagulation, activating meridians and relieving stasis for several hundred years. However, the therapeutic components of this species, especially proteins and peptides were poorly exploited. Until now only a few of them were obtained by using chromatographic isolation and purification. In recent decade, transcriptome techniques were rapidly developed, and have been used to fully reveal the functional components of many animal venoms. In the present study, the cDNA of the salivary gland of Whitmania pigra was sequenced by illumina and the transcriptome was assembled by using Trinity. The proteome were analysed by LC-MS/MS. Based on the data of the transcriptome and the proteome, a potential antiplatelet protein named pigrin was found. Pigrin was cloned and expressed using P. pastoris GS115. The antiplatelet andantithrombotic bioactivities of pigrin were tested by using aggregometer and the rat arterio-venous shunt thrombosis model, respectively. Thebleeding time of pigrin was measured by a mice tail cutting method. The docking of pigrin and protease-activated receptor 1 (PAR1) or collagen were conducted using the ZDOCK Server. Pigrin was able to selectively inhibit platelet aggregation stimulated by PAR1 agonist and collagen. Pigrin attenuated thrombotic formation in vivo in rat, while did not prolong bleeding time at its effective dosage. There are significant differences in the key residues participating in binding of Pigrin-Collagen complex from Pigrin-PAR1 complex. In conclusion,a novel PAR1 inhibitor pigrin was found from the leech Whitmania pigra. This study helped to elucidate the mechanism of the leech for the treatment of cardiovascular disorder.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal Article
Indexed MeSH termsAmino Acid SequenceAnimalsDisease Models, AnimalFibrinolytic AgentsGene Expression ProfilingLeechesMice, Inbred ICRModels, MolecularPlatelet AggregationPlatelet Aggregation InhibitorsProteomicsRats, Sprague-DawleySalivary GlandsThrombosis

Summary

Transcriptomic and proteomic analysis of Whitmania pigra salivary glands identified pigrin, a novel antiplatelet protein that selectively inhibited PAR1-agonist- and collagen-stimulated platelet aggregation, attenuated thrombotic formation in a rat arterio-venous shunt model, and did not prolong bleeding time at its effective dose.

Why This Matters for Hirudotherapy

This study identified pigrin, a novel protease-activated receptor 1 (PAR1) inhibitor from the leech Whitmania pigra, through combined transcriptome and proteome analysis followed by recombinant expression in Pichia pastoris. Functional testing showed that pigrin selectively inhibited platelet aggregation stimulated by PAR1 agonist and collagen, attenuated thrombus formation in a rat arteriovenous shunt model, and did not prolong bleeding time in mice at its effective antithrombotic dosage. Pigrin represents a newly discovered leech-derived bioactive compound with antithrombotic properties, expanding the known pharmacological repertoire of the leech secretome. Caveat: this is a preclinical study using in vitro assays and rodent animal models; the findings have not been validated in human clinical trials, and the abstract does not address hirudotherapy practice with live leeches.

Citation

Reference (Vancouver style)

Ren SH, Liu ZJ, Cao Y, Hua Y, Chen C, Guo W, et al. A novel protease-activated receptor 1 inhibitor from the leech Whitmania pigra. Chin J Nat Med. 2019;17(8):591-599. doi:10.1016/S1875-5364(19)30061-5. PMID: 31472896

Bibliographic details (authors, volume, pages, DOI) are taken from the PubMed record.

Added to ASH library: May 26, 2026 · Site last updated: June 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.