“The colour should be greenish (like duckweed), and there should be two longitudinal lines having the colour of orpiment and ruddy; they should be rounded and liver-coloured. One may accept leeches which look like little locusts, or like mousetails, with very small heads. But do not accept those with red bellies and green backs, especially if they were collected from running waters.” ~ Avicenna on Leeches, from “The Canon of Medicine”
Leeches have been used for therapeutic purposes for millennia. The earliest traces of the use of leeches appear to date back to 1600-1300 BC to a Greek named Nicander of Colophon. The medical use of leeches is discussed by Avicenna ( Ibn Sina) in The Canon of Medicine (follow this link for the Online Edition of The Canon of Medicine and the section on leeches), as well as by Abd-el-latif al-Baghdadi in the 12th century.
Leech therapy became a popular practice in medieval Europe, due to the influence of Avicenna’s Canon. A more modern use for the medicinal leech was introduced by Abd el-latif al-Baghdadi in the twelfth century, who documented the use of leeches for cleaning tissue after surgical operations. Like al-Baghdadi and Avicenna, Abu al-Qasim al-Zahrawi (Albucasis) who is considered the patron of modern surgery, recommended the use of leeches post surgery.
“Since the 1970s hirudo-therapy has been used increasingly by doctors and surgeons throughout the world, in particular also for tissue restoration, trauma surgery, and micro-surgery.”
After a peek in the mid 1800s, the use of leeches became less popular in Europe towards the end of the 19th century, but they are making a steady resurgence in popularity since the 20th century. Since the 1970s hirudo-therapy has been used increasingly by doctors and surgeons throughout the world, in particular also for tissue restoration, trauma surgery, and micro-surgery.
“Hirudo Medicinalis is now the most widely used leech species for medicinal purposes, although other species of leeches suitable for medicinal purposes are also known, in particular in Iran that has a lively culture around leech therapy,”
One specific species of leeches used for medicinal purposes was studied and classified in Europe by Carl Linnaeus (1707 – 1778) and declared as “Hirudo Medicinalis”, Medicinal Leech. Hirudo Medicinalis is now the most widely used leech species for medicinal purposes, although other species of leeches suitable for medicinal purposes are also known, in particular in Iran that has a lively culture around leech therapy, research, the breeding of leeches and their use in popular and specialist human and veterinary medicine. Leeches intended for medicinal use are always bred under strict conditions to prevent illnesses spread via leeches to humans or animals and vice versa.
“Of the suspected 30 to 100 leech saliva secretions, only very few are isolated and named.”
Avicenna considered the use of leech therapy to be more effective than Hijama in “letting off the blood from deeper parts of the body”. In 1903 the German Biologist Friedrich Franz first isolated Hirudin as the responsible agent in the leech’s salvia that prevents the blood from clotting. The saliva of the leech is a mystery. When attaching, sucking and releasing, the leech injects saliva into the wound. In this saliva, there are substances that enter the wound and the patient. Of the suspected 30 to 100 leech saliva secretions, only very few are isolated and named. The known substances act as anticoagulants (anti-clotting) and anti-inflammatories. They also include anti-bacterial, antibiotic and pain reducing substances. Leech salvia and the secretions of the leech skin are also used for the production of a variety of medicinal ointments.
In some esoteric-medicinal schools of thought the leech is seen also as a healing agent against deep seated depressions and other psychological ailments. I will talk further about this in my follow up posts on this series on leeching/Taleeq.