American Society of Hirudotherapy

Old and new natural products as the source of modern antithrombotic drugs

Research article published in Planta medica (1991)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Research reportDrug DevelopmentBeretz A et al. · Planta medica, 1991

Abstract

Natural compounds have been the first historical source of antithrombotic compounds (heparin, vitamin K antagonists, streptokinase, urokinase); molecules extracted from plants or animals still provide some of the most original and promising approaches for the discovery of new drugs in this class. In this review, we will briefly describe three examples of current research trends that could lead to the development of new antithrombotic drugs of natural origin. Flavonoids have been shown to be inhibitors of cyclic nucleotide phosphodiesterase; this enzymatic activity is one of the main mechanisms of inhibition of aggregation of blood platelets by flavonoids. Some of these compounds could represent templates for the development of new inhibitors of platelet activation. Garlic ( ALLIUM SATIVUM) has been shown to inhibit platelet aggregation IN VIVO and IN VITRO; a number of active principles has now been identified and their mechanisms of action are currently being explored. An ancient remedy, the medicinal leech ( HIRUDO MEDICINALIS), has been found to contain several potent anticoagulant proteins. Among them, hirudin, a polypeptide of 65 amino acids, has been identified as one of the most potent inhibitors of thrombin. The production of sufficient amounts of hirudin through molecular biology techniques has now allowed the performance of clinical trials. These three examples show that careful consideration of biochemical, ethnopharmacological, or toxicological properties of natural products can still constitute a valuable basis for the development of new drugs.

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

Publication typeJournal Article

Summary

Peer-reviewed research on therapeutic compound development relevant to leech-derived anticoagulants and antithrombotic agents. Indexed in PubMed and verified against the NCBI record.

Why This Matters for Hirudotherapy

This narrative review examines three natural-product sources of antithrombotic compounds—flavonoids, garlic (Allium sativum), and the medicinal leech (Hirudo medicinalis)—as examples of how natural products continue to inform new drug development. For ASH and the hirudotherapy community, the review's discussion of hirudin is directly pertinent: it identifies this 65–amino-acid leech-derived polypeptide as one of the most potent thrombin inhibitors and notes that recombinant production has enabled clinical trials, illustrating the translational potential of the leech secretome beyond traditional live-leech therapy. An honest caveat is that this is a brief narrative review rather than original research; the abstract provides only general commentary on research trends and does not report specific clinical outcomes, efficacy data, or detailed methodological assessment of any single compound.

Citation

Old and new natural products as the source of modern antithrombotic drugs.

Beretz A et al. · Planta medica, 1991

Added to ASH library: May 28, 2026 · Site last updated: June 18, 2026

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