Snake venom-based antiplatelet drug could cut bleeding risk

National Taiwan University scientists based their antiplatelet drug on a protein in snake venom that latches onto a platelet surface protein to promote clotting. (Guido Bohne/CC BY-SA 2.0)(G. Bohne CC BY-SA 2.0)

A team from the National Taiwan University has created an antiplatelet drug based on snake venom, which could be free of the bleeding risks associated with currently available drugs.

Some antiplatelet drugs, such as aspirin, work by blocking platelets’ production of thromboxane, a chemical that causes them to stick together, forming a clot. Another type of antiplatelet drug targets glycoproteins IIb/IIIa and is based on a different protein present in snake venom. While these drugs can be lifesaving for patients at risk of heart attack or stroke, they also have side effects, including excessive bleeding.

From earlier work, the researchers knew that trowaglerix, a protein found in the venom of the Wagler’s pit viper, bound to glycoprotein VI (GPVI), found on the surface of platelets, and that spurred clot formation. Furthermore, previous research had shown that platelets lacking GPVI do not form clots and do not cause severe bleeding in patients.

So they designed a GPVI-blocking molecule based on the structure of trowaglerix. When mixed with blood, the drug stopped platelets from clotting. Mice given the drug showed slower clot formation and did not bleed longer than untreated mice, according to the statement.

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The researchers plan to improve the molecule’s design to make it last longer in the body and to ensure it does not cause unintended side effects. Their work is published in Arteriosclerosis, Thrombosis and Vascular Biology.

"In general, this type of molecule design does not last long in the body, so techniques like formulation or delivery system are likely needed to extend the exposure time in the human body," said co-author Jane Tseng, director and professor at Graduate Institute of Biomedical Electronics and Bioinformatics and Drug Research Center at the National Taiwan University, in the statement. "The design must also be optimized to ensure that the molecule only interacts with GPVI and not other proteins which can cause unintended reactions."