© 2011 Victoria Bowmann, PhD
A simple healing principle lies at the heart of all hirudo-miracles. Hirudin is the naturally occurring peptide of the Hirudo medicinalis (medicinal leech). This is a four-inch long carnivorous, hermaphroditic segmented worm. It has a sucker on each end, five pairs of eyes, and 32 nerve bundles (or brains) in the middle. This buccal secretion from the salivary glands is best known for its anticoagulant property. This is fundamental for the alimentary habit of hematophagy since it keeps the blood flowing through the leech after the initial phlebotomy on the host’s skin. During the feeding process, leeches secrete a complete mixture of pharmacologically active substances, with hirudin being the best-known component of the saliva.
It is difficult to extract large amounts of hirudin from the natural sources, however in June 2004, the FDA lent its seal of approval on the centuries old medical device of leeches. The traditional medical use of leeches is for skin grafts on burn patients and reattachment surgery; and the natural medical uses are more far reaching.
While there are roughly 600 leech species only about 15 are classified as “medicinal leeches.” Today, the medicinal leeches are farmed in pristine conditions, shipped and stored for a one-time use as they are disposed of after the treatment. There is no risk of indirect transfer of infectious diseases from one patient to anther, nor has the transmission of other pathogens (bacterial or viral) within this context of leech therapy been observed.
While they are raised in sterile conditions, Aeromonas hydrophila, a bacterium that prevents putrefaction of the leech’s blood meal and supplies enzymes crucial to its digestion, 20% of patients can become infected by this bacterium, especially those with weakened immune systems. Aeromonas also kills other bacteria; and for some reason, staph cannot grow inside a leech. Perhaps it is the inhospitable condition within the leech or something the Aeromonas produces that inhibits the growth of staph.
The action of the hirudin is the ability to inhibit the procoagulant activity of thrombin. In fact, hirudin is the most potent natural inhibitor of thrombin as it dissolves the formation of clots and thrombi; thus having a therapeutic value in blood coagulation disorders, superficial varicose veins, and skin hematomas. An advantage over commonly used prescription anticoagulants is that hirudin does not interfere with the biological activity of other serum proteins and can act on complexed thrombin.
However, the salivary glands contain more than 100 bioactive substances with more benefits than anticoagulation. These include: anti-edematous, analgesic, bacteriostatic, eliminates microcirculation disorders, detoxifies the organism thereby reducing complications such as infarct or stroke, restores damaged vascular permeability (organs and tissues), reduces blood pressure, increases immune system activity and eliminates oxygen starvation.