History of Leech in Medicine
Leech might play a special role in certain kinds of surgery by helping promote blood flow to damaged tissue. The first recorded use of medicinal leeches was about 2500 years ago, although there is some evidence that the ancient Egyptians and Aztecs may have used these little blood-sucking creatures to help people that were having medical problems. Back then, leeches were used to remove the “bad blood” from patients that were suffering from things as basic as headaches. Egyptian medics believed that letting a leech sip a sick patient's blood could help cure everything from fever to flatulence. Roughly 600 leech species have been identified to date, but only about 15 are used in medicine and classified as “medicinal leeches”.
The first recorded use of leeches in medicine was in 200 BC by the Greek physician Nicander in Colophon. Hirudotheraphy, the use of medical leech for the medical purposes, was later popularized by Avicenna in The Canon of Medicine (1020s). He considered the application of leech to be more useful than cupping in “letting off the blood from deeper parts of body”. He also introduced the use of leech as treatment for skin disease.
Leech Biology
A common misconception among the public is that there is only one type of leech. In fact, there are between 700 and 1000 species of leeches worldwide and they can be found in a variety of different habitats including moist terrestrial and marine, estuarine, freshwater ecosystems. Within these habitats, leeches can be found attached to various substrates and animals including fish and other marine organisms, underneath rocks or clinging to vegetation, or living on submerged wood, stones and aquatic vegetation in ponds, streams and rivers. Leeches are hermaphroditic, bloodsucking worms that are grouped in the class of Hirudinea in the phylum Annelida. The class includes two orders: the Gnathobdellidae, which draw blood by biting through the skin of the host with toothed, rasping jaws, and the Rhynchobdellidae, which do so by inserting the proboscis under the skin of the host. Contrary to popular belief, not all leeches are bloodsuckers. In fact, many are sit and wait predators and feed on a variety of different invertebrates such as insects (mosquito larvae, and water bugs), oligochaetes (terrestrial earthworms), amphipods and lots of different kinds of mollusks including pond snails and freshwater clams. Leeches are predators, vectors of parasites, as well as prey of other aquatic animals too (Saywer, 1986; Keim, 1993). Recently, some leech populations have declined dramatically due to over exploitation for fishing bait and medicinal purposes and also due to pollution in several parts of the world particularly in European and Asian countries. For example, the medicinal leech (Hirudo medicinalis) has been included in the IUCN Invertebrate Red Data Book (Wells et al., 1983) and Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) in 1987 (Wells and Coombes, 1987). To maintain leech populations as well as conservation and rehabilitation point of view, development of a suitable technology for breeding, rearing larvae of leeches is essential. Further, the medicinal leech, Hirudo medicinalis, has been used increasingly for relief of venal congestion, especially for salvage of compromised pedicled flaps and microvascular free-tissue transfer, digital re-implantation and breast reconstruction (Voge and Lehnherr, 1999). ^ Back to Top
Malaysian Leech Industry
Leeches farming is blooming in Malaysia with the increase in demand locally and worldwide together with the simplicity in breeding operation. The activities are concentrated in rural areas and operated by low income farmers. The specific demand for leeches extracts in form of leeches oil, cream and gel are currently due to folks claim that it can boost intimacy and sexual pleasure besides the cream for rejuvenating. The processing of leeches in Malaysia is still vague and claimed to be trade secret among the leech traders. Some traders claimed to have produced crude water extracts, oil extract and some making powder form using various methods (boiling, drying etc). ^ Back to Top
Leech Potential
For thousands of years, leeches have been worming their way in and out of medicine as a questionable cure for anything from headaches to gangrene, reaching their height of medicinal use in the mid-1800s. Today, the slimy aquatic creatures are making a comeback as a legitimate treatment that can help heal skin grafts and restore blood circulation. Their primary function is to drain blood.
In June 2004, the Food and Drug Administration cleared the first application for leeches (Hirudo medicinalis) to be used in modern medicine as medical devices. Surgeons who performed plastic and reconstructive surgery find leeches especially valuable when regrafting amputated appendages, such as fingers or toes. The cost for a leech used for treatment is around US$7 to US$10 a piece.
Interestingly, the extensive scientific studies on the medicinal leech such as Hirudo medicinalis produces various types of proteinase inhibitors: bdellins (inhibitors of trypsin, plasmin, and acrosin), hirustasin (inhibitor of tissue kallikrein, trypsin, a-chymotrypsin, subtilisin, and chymasin and the granulocyte proteinase elastase and cathepsin G), inhibitor of factor Xa, hirudin (thrombin inhibitor), inhibitor of carboxypeptidase, and inhibitor of complement complement C1s. These important components have great potential for medical and esthetic applications and may be applied to affect a function or structure of the body through a chemical action and metabolic pathways. No biochemical data is available for the local leech.
No certified is available now in Malaysia to validate the quality and leech extract content analysis. Heat treatment to deform many compounds in organic body so as the leech. Since leeches important components are of protein based, heat treatment could reduced the medicinal and efficacy of leech products.
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