Science and Technology Daily reporter Zhao Hanbin
As an important means of pain treatment for a variety of pains, leech therapy, which seems to be "heavy taste", is praised by medical institutions and patients at home and abroad. However, little is known about the mechanisms by which leeches exert analgesic or anesthetic effects. Scientists have recently started with forest leeches and found the key to decryption.
Forest leeches are leeches of the leech family, mainly inhabiting moist mountain meadows or waters, with a body length of about 3 cm, and are distributed in Indonesia, Myanmar, Vietnam, India and Yunnan, China. Compared with leeches, mountain leeches are small, have less blood sucking at a time, and require multiple feedings. The researchers therefore judged that leeches need more powerful anticoagulant, anti-inflammatory and analgesic active substances to support their efficient and rapid blood intake, and try to make the blood-sucking "unjust head" unaware.
Previously, the scientific community has always believed that vampire leeches indirectly inhibit the pain response of vampire animals by inhibiting neutrophil activation, mast cell trypsin activity and complement system, but the latest research believes that according to the life habits of leeches, they should have an active ingredient that directly plays analgesic or anesthetic effects.
Not long ago, led by Researcher Lai Ling, who has long been engaged in the functional proteomics research of natural medicines at the Kunming Institute of Zoology of the Chinese Academy of Sciences, luo Xiaodong, researcher of the Kunming Institute of Botany of the Chinese Academy of Sciences, and Professor Sun Zhaohui of the Guangzhou General Hospital of the Guangzhou Military Region, etc., isolated a new family of neurotoxic polypeptides from the salivary glands of forest leeches and named it HSTX. Members of this toxin family contain 23 to 25 amino acid residues, possess 2 intramolecular disulfide bonds, and exert neurotoxic activity by blocking some sodium ion channels in animals.
Sodium channels are the main triggering key for electrical signaling in all animals, which are the basis for the control of a range of physiological processes such as neural activity and muscle contraction. In addition, sodium ion channels are also the direct targets of many local anesthetics and a large number of neurotoxins in nature, such as snake venom, scorpion venom, spider toxin, etc. are all acting on sodium ion channels and have adverse consequences. The results of this study are entitled "Novel Sodium Ion Channel Inhibitors from Mountain Leeches", and were recently published in the authoritative journal "Pharmacological Community".
According to reports, in 2005, Europe officially approved leech therapy as a legal treatment method, and 350,000 leeches are used for medical treatment in Germany alone every year. From the perspective of treatment effect, the effect of leech therapy is more obvious than that of clinical conventional therapy. Numerous literature has reported that leech therapy has analgesic effects, and long-term clinical practice has also proved that leech therapy has a good effect on a variety of pains.