American Society of Hirudotherapy

Leeches attenuate blood hyperviscosity and related metabolic disorders in rats differently than aspirin

Research article published in Journal of ethnopharmacology (2019)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Drug DevelopmentClinical TrialsWang X et al. · Journal of ethnopharmacology, 2019

Abstract

ETHNOPHARMACOLOGICAL RELEVANCE: Whitmania pigra Whitman (Whitmania pigra, WP), firstly recorded in the Shennong's Herbal Classic and officially listed in the Chinese Pharmacopoeia, is a well-used cardiovascular protective traditional Chinese medicine derived from leeches. Traditional Chinese physicians prefer to prescribe the dried whole body of leech processed under high temperatures. It has been reported that dried WP remains clinically effective. However, the therapeutic mechanism has yet not be clearly elucidated. AIM OF THE STUDY: This study was designed to investigate the protective activity of the extract of WP in a high-molecular-weight dextran-induced blood hyperviscosity rat model, and to explore the role of WP in improving blood hyperviscosity related metabolic disorders and to clarify the possible mechanism of metabolic regulation. MATERIALS AND METHODS: The hemorheological parameters were measured with an automated blood rheology analyzer. Hematoxylin-eosin staining was used to observe the pathological changes in aortic tissues samples. Further, a liquid chromatography-mass-spectrometry (LC-MS)-based untargeted metabolomics approach was applied to characterize the metabolic alterations. RESULTS: WP has evident attenuating effects on blood hyperviscosity and related metabolic disorders, and the influences are distinct from those of aspirin. The results showed that WP had good effects in reducing blood viscosity and ameliorating histopathological changes in the thoracic aorta in a high molecular weight dextran-induced blood hyperviscosity rat model. The middle dose (2.5 g raw material/kg body weight) of WP exhibited effects equivalent to aspirin (100 mg/kg) on hemorheological and histopathological parameters (P > 0.05). However, when using metabolomics profiling, we found that WP could significantly improve blood hyperviscosity-related metabolic disorders and restore metabolites to normal levels; while aspirin showed little effect. With principal component analysis and orthogonal partial least-squares discriminant analysis, WP regulated many more endogenous metabolites than aspirin. With pathway enrichment analysis, the differential endogenous metabolites were involved in cysteine and methionine metabolism, TCA cycle, arachidonic acid metabolism, etc., highlighting the metabolic reprogramming potential of WP against blood hyperviscosity-induced metabolic disorders. CONCLUSIONS: The study suggest that WP has a more potent effect, but a different mechanism, than aspirin in improving either blood hyperviscosity or related metabolic disorders associated with cardio- and cerebrovascular diseases.

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

Publication typeJournal Article
Indexed MeSH termsAnimalsBlood ViscosityComplex MixturesCyclooxygenase 2Cystathionine beta-SynthaseLeechesLiverMalePowdersRats, Sprague-Dawley

Summary

Whitmania pigra Whitman (Whitmania pigra, WP), firstly recorded in the Shennong's Herbal Classic and officially listed in the Chinese Pharmacopoeia, is a well-used cardiovascular protective traditional Chinese medicine derived from leeches.

Why This Matters for Hirudotherapy

This study investigated how an extract of dried whole-body Whitmania pigra, a leech used in traditional Chinese medicine, protects against high-molecular-weight dextran-induced blood hyperviscosity in a rat model. For hirudotherapy, this is highly relevant as it demonstrates that the leech extract reduces blood viscosity, improves histopathological changes in the aorta, and repairs related metabolic disorders more effectively and through different pathways than aspirin. These findings highlight the potential of leech-derived preparations in managing cardio- and cerebrovascular diseases. However, the research is entirely preclinical, relying on an animal model and high-temperature processed leech powder rather than live leech application or a clinical population.

Citation

Leeches attenuate blood hyperviscosity and related metabolic disorders in rats differently than aspirin

Wang X et al. · Journal of ethnopharmacology, 2019

Added to ASH library: May 27, 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.