What are the effects and benefits of leeches? A comprehensive guide

Summary: The leech, commonly known as the bloodsucker, has leech preparations that show remarkable effects in preventing and treating cardiovascular and cerebrovascular diseases and in fighting cancer. It grows and reproduces in inland freshwater waters and is a traditional specialty medicinal aquatic animal in China; its dried products are processed for use in traditional Chinese medicine. Wild natural resources have sharply declined, and with the in-depth development of the leech's medicinal value, its market demand potential is enormous.

The leech, commonly known as the bloodsucker, has leech preparations that show remarkable effects in preventing and treating cardiovascular and cerebrovascular diseases and in fighting cancer. It grows and reproduces in inland freshwater waters and is a traditional specialty medicinal aquatic animal in China; its dried products are processed for use in traditional Chinese medicine. Wild natural resources have sharply declined, and with the in-depth development of the leech's medicinal value, its market demand potential is enormous. It has effects such as treating stroke, high blood pressure, clearing blood stasis, amenorrhea, and traumatic injuries.

The effects of leeches

Breaks blood, dispels stasis, unblocks menstruation. Treats blood accumulation, abdominal masses, accumulations and gatherings, women's amenorrhea, dry blood turning into consumption, falls and injuries, eye pain, and corneal opacities.

① "Shennong Bencao Jing": Mainly dispels bad blood, stasis blood, and monthly blockage; breaks blood masses and accumulations; treats childlessness; and promotes water passages.

② "Bielu": Induces abortion.

③ "Bencao Shiyi": When a person suffers from red and white wandering rashes and boils, swellings, and toxic swellings, take more than ten of them and let them bite the diseased area; when the skin wrinkles and the flesh turns white, there is no case that is not cured.

④ "Bencao Yanyi": Treats fractures.

The benefits of leeches

1. Anticoagulant effect. Hirudin has the effect of preventing blood coagulation, and therefore has an antithrombotic effect.

2. Thrombolytic effect. Hirudin has the effect of resisting platelet aggregation and dissolving thrombi caused by thrombin. Hirudin is a methanol extract and has the effect of activating the fibrinolytic system both in vitro and in vivo; the salivary gland secretions of leeches, when injected intravenously into rats, have a strong antithrombotic effect.

3. Anti-platelet effect. Hirudin can inhibit the binding of thrombin to platelets, promote the dissociation of thrombin from platelets, and inhibit the release of platelets stimulated by thrombin and the reactions induced by thrombin.

4. Effect on hemorheology. Administering leech extract by gavage to animals at 0.45 g/kg can reduce blood viscosity and shorten erythrocyte electrophoresis time. Gavage with leech decoction can also reduce whole blood specific viscosity, plasma specific viscosity, hematocrit, and fibrinogen content in rats with abnormal hemorheology.

5. Blood lipid-lowering effect. For rabbits with diet-induced hyperlipidemia, daily gavage of leech powder at 1 g per rabbit, whether used preventively or therapeutically, can reduce blood cholesterol and triglyceride levels, while also making aortic and coronary artery lesions milder than those in the control group, with obvious plaque regression, visible collagen fiber proliferation, and reduced cholesterol crystals.

6. Effect on cardiovascular function. Intraperitoneal injection of hirudin at 30 g/kg can significantly increase the ability of mouse myocardium to take up 86Rb, indicating an effect of increasing myocardial nutritional blood flow.

7. Pregnancy-terminating effect. Whitmania pigra has a terminating effect on early, middle, and late pregnancy in mice. Using leech decoction at 2.5-3 g/kg, subcutaneously injected twice at the above dose on the first, sixth, or tenth day of pregnancy, has a highly significant pregnancy-terminating effect in mice.

8. Effect on experimental cerebral hematoma and subcutaneous hematoma. Leech extract liquid has the effect of promoting absorption of experimental cerebral hematoma in rabbits. Experiments show that leeches can promote the absorption of cerebral hematoma and subcutaneous hematoma, reduce surrounding inflammatory reactions and edema, relieve increased intracranial pressure, improve local blood circulation, protect brain tissue from necrosis, and promote recovery of neurological function.

9. Effect on experimental kidney damage. Using 30% leech liquid at 15 mL/kg, by gavage twice, has a clear preventive and therapeutic effect on acute tubular necrosis initially induced in rats by intramuscular injection of glycerol, making the increases in blood urea nitrogen and serum creatinine values significantly lower than those in the control group. The morphological changes in kidney tissue were significantly improved. Its mechanism of action may be related to improving hemorheology and the hypercoagulable state, thereby improving renal blood circulation.

10. Other effects. Leeches also have an inhibitory effect on decidual tumors. Low-concentration leech liquid has a significant contracting effect on isolated rabbit uterus. Hirudin can also inhibit thrombin-induced fibroblast proliferation and the stimulating effect of thrombin on endothelial cells.