Ученые Малайзии изучают антикоагулянты из слюны водяных пиявок для медицины

A three-year study by Universiti Malaysia Kelantan has been examining proteins produced by the local buffalo leech, “Hirudinaria manillensis”, for their potential as anticoagulants – substances that help delay or prevent blood clotting. UMK Faculty of Agro-Based Industry senior lecturer Dr Zulhisyam Abdul Kari said laboratory tests showed that protein extracted from the leeches could slow clot formation. “Laboratory tests prove that leech protein extract is capable of delaying blood clotting, comparable to other anticoagulants,” he told Bernama recently. Among the substances of interest is hirudin, a naturally occurring anticoagulant found in leech saliva. It acts on thrombin, an enzyme involved in the blood-clotting process, which is why such compounds have long attracted medical and pharmaceutical interest. Zulhisyam said buffalo leeches were chosen for the study because they produce a greater quantity of saliva and useful proteins than the terrestrial leeches commonly known in Malaysia as “pacat”. For researchers, that makes them a particularly interesting candidate for further study and potential biotechnology applications. Leeches themselves are not strangers to medicine. Medicinal leech therapy is still used in certain specialised clinical settings, particularly where doctors need to improve blood flow in tissue following some reconstructive procedures. Strict clinical procedures are required, Zulhisyam noted, with each leech used for only one patient to minimise the risk of cross-infection. The greater scientific interest, however, lies in the biologically active compounds contained in the animals’ saliva and how they might eventually be isolated, studied and developed. Buffalo leeches were once a more familiar sight in Malaysian paddy fields, but Zulhisyam said their numbers in natural habitats have declined significantly. He attributes the drop partly to agricultural practices, including uncontrolled use of pesticides and chemical fertilisers, which can affect freshwater ecosystems where the animals live. Malaysia also once had a more active leech-farming industry, although Zulhisyam said confidence in the sector was damaged by problems involving fraudulent contract-farming schemes. Management of leeches in Malaysia has come under the fisheries department since 2011, after responsibility was transferred from the wildlife and national parks department. Zulhisyam believes conservation is important not simply for biodiversity, but because local species may contain compounds with scientific or commercial potential that have yet to be fully understood. For now, the work remains at the research stage: Zulhisyam said further funding would allow the team to conduct more detailed studies, including molecular biology research to identify and better understand the proteins involved. Such work would be necessary before any extract or compound could eventually be considered for wider medical or commercial use. Overall, buffalo leeches may not inspire much affection when encountered in the wild – but under a microscope, they offer researchers a surprisingly useful avenue of investigation.