Hirudo medicinalis

Last updated

Hirudo medicinalis
Svommende blodigle.JPG
CITES Appendix II (CITES) [2]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Annelida
Clade: Pleistoannelida
Clade: Sedentaria
Class: Clitellata
Subclass: Hirudinea
Order: Arhynchobdellida
Family: Hirudinidae
Genus: Hirudo
Species:
H. medicinalis
Binomial name
Hirudo medicinalis

Hirudo medicinalis, or the European medicinal leech, is one of several species of leeches used as medicinal leeches.

Contents

Other species of Hirudo sometimes also used as medicinal leeches include H. orientalis , H. troctina, and H. verbana . The Asian medicinal leech includes Hirudinaria manillensis, and the North American medicinal leech is Macrobdella decora.

Medicinal leech populations were reduced significantly in many countries during the 19th century due to the high demand in medical contexts, and remain endangered in many countries today. [3]

Morphology

The general morphology of medicinal leeches follows that of most other leeches. Fully mature adults can be up to 20 centimeters in length, and are green, brown, or greenish-brown with a darker tone on the dorsal side and a lighter ventral side. The dorsal side also has a thin red stripe. These organisms have two suckers, one at each end, called the anterior and posterior suckers. The posterior is used mainly for leverage, whereas the anterior sucker, consisting of the jaw and teeth, is where the feeding takes place. Medicinal leeches have three jaws (tripartite) that resemble saws, on which are approximately 100 sharp edges used to incise the host. The incision leaves a mark that is an inverted Y inside of a circle. After piercing the skin, they suck out blood while injecting anticoagulants (hirudin). [4] Large adults can consume up to ten times their body weight in a single meal, with 5–15 mL being the average volume taken. [5] These leeches can live for up to a year between feedings. [6]

Medicinal leeches are hermaphrodites that reproduce by sexual mating, laying eggs in clutches of up to 50 near (but not under) water, and in shaded, humid places. A study done in Poland found that medicinal leeches sometimes breed inside the nests of large aquatic birds, noting that conservation efforts directed at bird habitats may also indirectly help preserve dwindling leech populations. [7]

Range and ecology

Typical habitat with a large population, Germany HirudoMedicinalisHabitat.jpg
Typical habitat with a large population, Germany

Their range extends over almost the whole of Europe and into Asia as far as Kazakhstan and Uzbekistan. The preferred habitat for this species is muddy freshwater pools and ditches with plentiful weed growth in temperate climates.

Over-exploitation by leech collectors in the 19th century has left only scattered populations, [3] and reduction in natural habitat through drainage has also contributed to their decline. Another factors include the replacement of horses - medicinal leeches' preferred host species - by motor vehicles and mechanical farming equipment, and the provision of artificial water supplies for cattle. As a result, this species is now considered near threatened by the IUCN, and European medicinal leeches are legally protected through nearly all of their natural range. They are particularly sparsely distributed in France and Belgium, and in the UK there may be as few as 20 remaining isolated populations (all widely scattered). The largest, located at Lydd, England, is estimated to contain several thousand individuals; 12 of these areas have been designated Sites of Special Scientific Interest. There are small, transplanted populations in several countries outside their natural range, including the USA. The species is protected under Appendix II of CITES meaning international trade (including in parts and derivatives) is regulated by the CITES permitting system. [2]

Medical use

Beneficial secretions

Medicinal leeches have been found to secrete saliva containing about 60 different proteins. [8] These achieve a wide variety of goals useful to the leech as it feeds, helping to keep the blood in liquid form and increasing blood flow in the affected area. Several of these secreted proteins serve as anticoagulants (such as hirudin), platelet aggregation inhibitors (most notably apyrase, collagenase, and calin), vasodilators, and proteinase inhibitors. [9] It is also thought that the saliva contains an anesthetic, [10] as leech bites are generally not painful.

Treating mastitis of a cattle with leech Leach on cow teat.jpg
Treating mastitis of a cattle with leech

Historically

A caricature of a physician prescribing leeches for a weak, bedbound woman A corpulent physician diagnoses more leeches for a young woman Wellcome V0011771.jpg
A caricature of a physician prescribing leeches for a weak, bedbound woman

The first recorded use of leech therapy was 3,500 years ago in Ancient Egypt. [11] The next recorded uses of leeches in medicine come in the last few centuries BCE, by the Greek physician Nicander in Colophon [5] and in the ancient Sanskrit text Sushruta Samhita. [12] Leech therapy is mentioned a few hundred years later in Shennong Ben Cao Jing, a 3rd-century CE book of traditional Chinese medicine. [13]

Medical use of leeches was discussed by Avicenna in The Canon of Medicine (1020s), and by Abd al-Latif al-Baghdadi in the 12th century.[ citation needed ]

These sources indicated leech therapy for a wide variety of ailments, including edema,. [12] "blood stasis", [13] and skin diseases. [14]

Earthenware jar for holding medicinal leeches LeechJarBedfordMuseum.JPG
Earthenware jar for holding medicinal leeches

In medieval and early modern European medicine, the medicinal leech (Hirudo medicinalis and its congeners H. verbana, H. troctina, and H. orientalis) was used to remove blood from a patient as part of a process to balance the humors that, according to Galen, must be kept in balance for the human body to function properly. (The four humors of ancient medical philosophy were blood, phlegm, black bile, and yellow bile.) Any sickness that caused the subject's skin to become red (e.g. fever and inflammation), so the theory went, must have arisen from too much blood in the body. Similarly, any person whose behavior was strident and sanguine was thought to be suffering from an excess of blood. Leeches, by removing blood, were thought to help with these kinds of conditions — a wide range which included illnesses like polio and laryngitis. [5] Leeches were often gathered by leech collectors and were eventually farmed in large numbers. A unique 19th-century "Leech House" survives in Bedale, North Yorkshire on the bank of the Bedale Beck, used to store medicinal leeches until the early 20th century.

Manchester Royal Infirmary used 50,000 leeches a year in 1831. The price of leeches varied between one penny and threepence halfpenny each. In 1832 leeches accounted for 4.4% of the total hospital expenditure. The hospital maintained an aquarium for leeches until the 1930s. [15] The use of leeches began to become less widespread towards the end of the 19th century. [5]

Current

Medicinal leech therapy (also referred to as Hirudotherapy or Hirudin therapy) made an international comeback in the 1970s in microsurgery, [16] [17] [18] used to stimulate circulation in tissues threatened by postoperative venous congestion, [16] [19] particularly in finger reattachment and reconstructive surgery of the ear, nose, lip, and eyelid. [17] [20] Other clinical applications of medicinal leech therapy include varicose veins, muscle cramps, thrombophlebitis, and osteoarthritis, among many varied conditions. [21] The therapeutic effect is not from the small amount of blood taken in the meal, but from the continued and steady bleeding from the wound left after the leech has detached, as well as the anesthetizing, anti-inflammatory, and vasodilating properties of the secreted leech saliva. [5] The most common complication from leech treatment is prolonged bleeding, which can easily be treated, but more serious allergic reactions and bacterial infections may also occur. [5] Leech therapy was classified by the US Food and Drug Administration as a medical device in 2004. [22]

Because of the minuscule amounts of hirudin present in leeches, it is impractical to harvest the substance for widespread medical use. Hirudin (and related substances) are synthesized using recombinant techniques. Devices called "mechanical leeches" that dispense heparin and perform the same function as medicinal leeches have been developed, but they are not yet commercially available. [23] [24] [25]

See also

Related Research Articles

<span class="mw-page-title-main">Hirudin</span> Chemical compound in leeches

Hirudin is a naturally occurring peptide in the salivary glands of blood-sucking leeches that has a blood anticoagulant property. This is essential for the leeches' habit of feeding on blood, since it keeps a host's blood flowing after the worm's initial puncture of the skin.

<i>Aeromonas</i> Genus of bacteria

Aeromonas is a genus of Gram-negative, facultative anaerobic, rod-shaped, bacteria that morphologically resemble members of the family Enterobacteriaceae. Most of the 14 described species have been associated with human diseases. The most important pathogens are A. hydrophila, A. caviae, and A. veronii biovar sobria. The organisms are ubiquitous in fresh and brackish water.

Lepirudin is an anticoagulant that functions as a direct thrombin inhibitor.

Aeromonas veronii is a Gram-negative, rod-shaped bacterium found in fresh water and in association with animals. In humans A. veronii can cause diseases ranging from wound infections and diarrhea to sepsis in immunocompromised patients. In leeches, this bacterium is thought to function as a symbiote aiding in the digestion of blood, provision of nutrients, or preventing other bacteria from growing. Humans treated with medicinal leeches after vascular surgery can be at risk for infection from A. veronii and are commonly placed on prophylactic antibiotics. Most commonly ciprofloxacin is used but there have been reports of resistant strains leading to infection.

Direct thrombin inhibitors (DTIs) are a class of medication that act as anticoagulants by directly inhibiting the enzyme thrombin. Some are in clinical use, while others are undergoing clinical development. Several members of the class are expected to replace heparin and warfarin in various clinical scenarios.

<span class="mw-page-title-main">Hirudiniformes</span> Suborder of annelid worms

The Hirudiniformes are one of the currently-accepted suborders of the proboscisless leeches (Arhynchobdellida). Their best-known member is the European medical leech, Hirudo medicinalis, and indeed most of the blood-sucking "worms" as which leeches are generally perceived belong to this group. In general, though some leeches suck blood, many are predators which hunt small invertebrates.

<span class="mw-page-title-main">Leech</span> Parasitic or predatory annelid worms

Leeches are segmented parasitic or predatory worms that comprise the subclass Hirudinea within the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, and like them have soft, muscular segmented bodies that can lengthen and contract. Both groups are hermaphrodites and have a clitellum, but leeches typically differ from the oligochaetes in having suckers at both ends and in having ring markings that do not correspond with their internal segmentation. The body is muscular and relatively solid, and the coelom, the spacious body cavity found in other annelids, is reduced to small channels.

<span class="mw-page-title-main">Hematophagy</span> Ecological niche involving feeding on blood

Hematophagy is the practice by certain animals of feeding on blood. Since blood is a fluid tissue rich in nutritious proteins and lipids that can be taken without great effort, hematophagy is a preferred form of feeding for many small animals, such as worms and arthropods. Some intestinal nematodes, such as Ancylostomatids, feed on blood extracted from the capillaries of the gut, and about 75 percent of all species of leeches are hematophagous. The spider Evarcha culicivora feeds indirectly on vertebrate blood by specializing on blood-filled female mosquitoes as their preferred prey. Some fish, such as lampreys and candirus; mammals, especially vampire bats; and birds, including the vampire finch, Hood mockingbird, Tristan thrush, and oxpeckers, also practise hematophagy.

<span class="mw-page-title-main">Sucker (zoology)</span> Specialised attachment organ of an animal

A sucker in zoology is a specialised attachment organ of an animal. It acts as an adhesion device in parasitic worms, several flatworms, cephalopods, certain fishes, amphibians, and bats. It is a muscular structure for suction on a host or substrate. In parasitic annelids, flatworms and roundworms, suckers are the organs of attachment to the host tissues. In tapeworms and flukes, they are a parasitic adaptation for attachment on the internal tissues of the host, such as intestines and blood vessels. In roundworms and flatworms they serve as attachment between individuals particularly during mating. In annelids, a sucker can be both a functional mouth and a locomotory organ. The structure and number of suckers are often used as basic taxonomic diagnosis between different species, since they are unique in each species. In tapeworms there are two distinct classes of suckers, namely "bothridia" for true suckers, and "bothria" for false suckers. In digeneal flukes there are usually an oral sucker at the mouth and a ventral sucker posterior to the mouth. Roundworms have their sucker just in front of the anus; hence it is often called a pre-anal sucker.

<span class="mw-page-title-main">Leech collector</span>

A leech collector, leech gatherer, or leech finder was a person occupied with procuring medicinal leeches, which were in growing demand in 19th-century Europe. Leeches were used in bloodletting but were not easy for medical practitioners to obtain. The collector would sometimes gather the leeches by attracting them to the legs of animals, often old horses. More commonplace was for the collector to use their own legs, gathering the leech after it had finished sucking enough blood. Many in the profession suffered from the effects of the loss of blood and infections spread by the leeches.

Direct thrombin inhibitors (DTIs) are a class of anticoagulant drugs that can be used to prevent and treat embolisms and blood clots caused by various diseases. They inhibit thrombin, a serine protease which affects the coagulation cascade in many ways. DTIs have undergone rapid development since the 90's. With technological advances in genetic engineering the production of recombinant hirudin was made possible which opened the door to this new group of drugs. Before the use of DTIs the therapy and prophylaxis for anticoagulation had stayed the same for over 50 years with the use of heparin derivatives and warfarin which have some well known disadvantages. DTIs are still under development, but the research focus has shifted towards factor Xa inhibitors, or even dual thrombin and fXa inhibitors that have a broader mechanism of action by both inhibiting factor IIa (thrombin) and Xa. A recent review of patents and literature on thrombin inhibitors has demonstrated that the development of allosteric and multi-mechanism inhibitors might lead the way to a safer anticoagulant.

<i>Haemopis sanguisuga</i> Species of annelid

Haemopis sanguisuga is a species of freshwater leech in the family Haemopidae. It is commonly called the horse-leech, but that is due to the similarity of its appearance to the leech Limnatis nilotica, which sometimes enters the nasal cavities of livestock. Haemopis sanguisuga does not behave in this way. Another synonym for this leech is Aulastomum gulo.

Acetabulum in invertebrate zoology is a saucer-shaped organ of attachment in some annelid worms and flatworms. It is a specialised sucker for parasitic adaptation in trematodes by which the worms are able to attach on the host. In annelids, it is basically a locomotory organ for attaching to a substratum. The name also applies to the suction appendage on the arms of cephalopod molluscs such as squid, octopus, cuttlefish, Nautilus, etc.

<i>Hirudo verbana</i> Species of leech

Hirudo verbana is a species of leech.

<i>Hirudo</i> Genus of annelids

Hirudo is a genus of leeches of the family Hirudinidae. It was described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae.

Hirudo orientalis is a species of medicinal leech. It has been confused with Hirudo medicinalis, but has recently been recognized as a different species. This Asian species is associated with mountainous areas in the subboreal eremial zone and occurs in Azerbaijan, Iran, Uzbekistan and Kazakhstan. It occurs also in Georgia, and probably in Armenia.

<span class="mw-page-title-main">Bedale Leech House</span> Leech livestck house in Bedale, North Yorkshire, England

This late Georgian Bedale Leech House in Bedale, North Yorkshire, England, is a unique example of a building constructed to keep live medicinal leeches healthy prior to their sale by the local apothecary to doctors and private individuals for the purpose of blood letting as a medical procedure to cure or prevent a variety of illnesses and diseases.

Niabella drilacis is a Gram-negative and rod-shaped bacterium from the genus of Niabella which has been isolated from a leech from Biebertal in Germany.

<i>Limnatis nilotica</i> Species of annelid worm

Limnatis nilotica is a species of leech in the family Hirudinidae. It is hematophagous, living on the mucous membranes of mammals.

<span class="mw-page-title-main">Marcello Brunelli</span> Italian neurophysiologist

Marcello Brunelli was an Italian neurophysiologist and academic.

References

  1. ↑ Utevsky S, Zagmajster M, Trontelj P (2014). "Hirudo medicinalis". IUCN Red List of Threatened Species . 2014: e.T10190A21415816. doi: 10.2305/IUCN.UK.2014-1.RLTS.T10190A21415816.en . Retrieved 19 November 2021.
  2. 1 2 "The CITES Appendices". cites.org. Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Retrieved 2022-01-14.
  3. 1 2 Kutschera U, Elliott J (2014-11-18). "The European medicinal leech Hirudo medicinalis L.: Morphology and occurrence of an endangered species". Zoosystematics and Evolution. 90 (2): 271–280. doi: 10.3897/zse.90.8715 . ISSN   1860-0743.
  4. ↑ Rigbi M, Levy H, Eldor A, Iraqi F, Teitelbaum M, Orevi M, et al. (1987). "The saliva of the medicinal leech Hirudo medicinalis--II. Inhibition of platelet aggregation and of leukocyte activity and examination of reputed anaesthetic effects". Comparative Biochemistry and Physiology. C, Comparative Pharmacology and Toxicology. 88 (1): 95–98. doi:10.1016/0742-8413(87)90052-1. PMID   2890494.
  5. 1 2 3 4 5 6 Wells MD, Manktelow RT, Boyd JB, Bowen V (1993). "The medical leech: an old treatment revisited". Microsurgery. 14 (3): 183–186. doi:10.1002/micr.1920140309. PMID   8479316. S2CID   27891377.
  6. ↑ Lent CM, Fliegner KH, Freedman E, Dickinsont MH (1988). "Ingestive behaviour and physiology of the medicinal leech". Journal of Experimental Biology . 137: 513–27. doi:10.1242/jeb.137.1.513. PMID   3209972.
  7. ↑ Buczyński P, Tończyk G, Bielecki A, Cichocka J, Kitowski I, Grzywaczewski G, et al. (April 2014). "Occurrence of the medicinal leech (Hirudo medicinalis) in birds' nests". Biologia. 69 (4): 484–488. Bibcode:2014Biolg..69..484B. doi: 10.2478/s11756-014-0329-0 . ISSN   0006-3088. S2CID   255377852.
  8. ↑ Baskova IP, Zavalova LL, Basanova AV, Moshkovskii SA, Zgoda VG (July 2004). "Protein profiling of the medicinal leech salivary gland secretion by proteomic analytical methods". Biochemistry. Biokhimiia. 69 (7): 770–775. doi:10.1023/b:biry.0000040202.21965.2a. PMID   15310277. S2CID   22828659.
  9. ↑ "Biology". Sangues Medicinales. Ricarimpex. Archived from the original on October 10, 2018. Retrieved November 26, 2012.
  10. ↑ Mory RN, Mindell D, Bloom DA (July 2000). "The leech and the physician: biology, etymology, and medical practice with Hirudinea medicinalis". World Journal of Surgery. 24 (7): 878–883. doi:10.1007/s002680010141. hdl: 2027.42/42411 . PMID   10833259. S2CID   18166996.[ dead link ]
  11. ↑ "History". Arizona Leech Therapy. Retrieved 2023-01-19.
  12. 1 2 Şenel E, Taylan Özkan A, Mumcuoglu KY (October 2020). "Scientometric analysis of medicinal leech therapy". Journal of Ayurveda and Integrative Medicine. 11 (4): 534–538. doi:10.1016/j.jaim.2018.11.006. PMC   7772485 . PMID   31289001. S2CID   195871696.
  13. 1 2 "网刊加载中。。。". www.tmrjournals.com. Retrieved 2023-01-19.
  14. ↑ Montinari MR, Minelli S (May 2022). "From ancient leech to direct thrombin inhibitors and beyond: New from old". Biomedicine & Pharmacotherapy. 149: 112878. doi: 10.1016/j.biopha.2022.112878 . PMID   35364378. S2CID   247833657.
  15. ↑ Brockbank W (1952). Portrait of a Hospital. London: William Heinemann. p. 73.
  16. 1 2 Wittke-Michalsen E (March 14, 2007). "2: The History of Leech Therapy". In Michaelsen A, Roth M, Dobos G (eds.). Medicinal Leech Therapy. Thieme. pp. 4–12. ISBN   978-3-13-161891-7 . Retrieved December 18, 2013.
  17. 1 2 Altman LK (February 17, 1981). "The doctor's world; leeches still have their medical uses". The New York Times . p. 2.
  18. ↑ Mumcuoglu KY (2014). "Recommendations for the use of leeches in reconstructive plastic surgery". Evidence-Based Complementary and Alternative Medicine. 2014: 205929. doi: 10.1155/2014/205929 . PMC   3933224 . PMID   24653746.
  19. ↑ Abdelgabar AM, Bhowmick BK (March 2003). "The return of the leech". International Journal of Clinical Practice. 57 (2): 103–105. doi:10.1111/j.1742-1241.2003.tb10436.x. PMID   12661792. S2CID   28256939.
  20. ↑ Frodel JL, Barth P, Wagner J (December 2004). "Salvage of partial facial soft tissue avulsions with medicinal leeches". Otolaryngology–Head and Neck Surgery. 131 (6): 934–939. doi:10.1016/j.otohns.2004.07.005. PMID   15577793. S2CID   34041779.
  21. ↑ "Applications in General Medicine". Sangues Medicinales. Ricarimpex. Archived from the original on March 6, 2013. Retrieved November 26, 2012.
  22. ↑ "Product Classification: Leeches, Medicinal". www.accessdata.fda.gov. Retrieved 19 August 2019.
  23. ↑ Salleh A (14 December 2001). "A mechanical medicinal leech?". ABC Science Online. Retrieved 29 July 2007.
  24. ↑ Crystal C (14 December 2000). "Biomedical Engineering Student Invents Mechanical Leech". University of Virginia News. Archived from the original on 2001-04-14. Retrieved 29 July 2007.
  25. ↑ Fox M. "ENT Research Group Recognized for Mechanical Leech Project". Otoweb News . University of Wisconsin, Madison, Division of Otolaryngology. Archived from the original on December 11, 2006. Retrieved December 16, 2013.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.