The Unlikely Doctor: Leech Therapy’s Role in Human Health

Leech therapy is one of the components of traditional medicine practiced from ancient times in humans. Leeches are used when conventional therapies fail to correct human ailments. The medicinal properties of leeches have been explored focusing on their saliva which is rich in bioactive compounds including hirudin, calin, hyaluronidase, destabilase, eglins, bdellins, tryptase inhibitors, and complement inhibitors. These compounds exhibited interesting biological activities such as anti-inflammatory, anticoagulant, antitumor, vasodilatory, and antibacterial effects. In humans, medicinal leeches are used for the treatment of various medical conditions such as inflammatory reactions, venous congestions, cardiovascular diseases, hypertension, varicose veins, osteoarthritis, thrombosis, hematomas, ophthalmic, respiratory, and dental infections and also in plastic and reconstructive surgeries. There are some minor contraindications where leech therapy is not used including absolute hemophilia, anemia, leukemia, hypotonia, and pregnancy. This review will give better insights to medical professionals based on the medicinal use of leeches that will warrant further scientific exploration in this traditional medical practice.