Earthworm (Dilong): Anticancer and Thrombolytic Effects and Its Toxicity
Dilong, commonly called earthworm (qiuyin, qushan, chongshan), is found everywhere. From ancient times to the present, Chinese people have used earthworm medicinally. The earliest Chinese pharmacopoeia, Shennong Bencao Jing (Divine Farmer's Materia Medica), classified it as a lower-grade herb; lower-grade herbs "eliminate cold and heat and pathogenic evils, break up accumulations, and cure diseases," but are "mostly toxic and cannot be taken for long periods."
Earthworm, however, is not actually a toxic substance. Its LD50 is very high: the LD50 by intravenous injection in mice is 3.85 g/kg, and by intraperitoneal injection 95-115 g/kg. The clinical dose of earthworm is usually 5-10 g, so this amount is very safe for humans.
The main toxic component of earthworm is its antithrombin; this toxic fraction has a short half-life, so repeated continuous administration of earthworm is unlikely to cause cumulative poisoning, making it a relatively safe Chinese herb. But because it has an anticoagulant effect, patients with low platelets or poor coagulation function should not take it, and pregnant women should be prohibited from taking it. Moreover, because it tastes fishy and easily affects the appetite, those who have long-standing weak spleen and stomach with poor appetite should also take it cautiously.
Traditional Chinese medicine often uses earthworm after processing. Common processing methods include wine stir-frying, dry stir-frying, gellan-powder stir-frying, and licorice-water preparation. But for external use or emergency use, earthworm is sometimes directly pounded into a paste or pressed for juice for external application or oral administration.
Earthworm has anticonvulsant and antipyretic effects, so traditional Chinese medicine commonly uses it in emergencies such as epilepsy, convulsions, and persistent high fever. It mainly treats the above symptoms caused by brain diseases. Ge Hong's Zhouhou Fang (Emergency Formulations) records: "For extreme heat six or seven days after cold damage, with vexed fullness in the chest, delirious speech, and a desire to get up and walk: take one sheng of large earthworms, slit open and remove the earth, boil in human urine until cooked, remove the dregs and take. Raw pressed juice and decoction both work well." This closely resembles hyperpyretic convulsions caused by meningitis, and modern pharmacological research has also confirmed that earthworm can be used to treat meningitis.
In addition, Wentang Jiyan Fang records that in the hot summer season, for heatstroke with inhibited urination one may: "Pound earthworms, stir into cool spring water, let settle, take half a bowl of the juice; it immediately unblocks urination. It greatly resolves heat diseases and loss of consciousness; taking it works at once." Gujin Yijian records a method for treating epistaxis (nosebleed): "Pound ten or so large earthworms, mix thin with well water. If mild, let settle and drink the clear; if severe, take the dregs and juice together." Houke Jinyao uses earthworm to treat swollen, red throat: "Seven white-headed earthworms, steep in boiling water, let settle, cool, remove the earth, mix with water chestnut juice and drink."
The above texts all record pressing earthworm juice or pounding it for oral use in treating emergencies. The ancients also recorded external use of earthworm. For example, Pujifang records a method for treating mammary abscess: "Take one or two earthworms, add ginger into a mortar, grind into a paste, apply around the lesion, and cover with paper flower." Fushou Jingfang records that for a duikou (opposite-mouth) cervical carbuncle that have ulcerated and discharged pus, one may use "earthworms, pound fine, mix with cool water and apply, changing three or four times a day." These all record external use of pounded earthworm.
Traditional Chinese medicine holds that earthworm is salty in flavor and cold in nature, entering the spleen, lung, and kidney meridians. It clears heat and stops convulsions, pacifies liver wind, unblocks the meridians and collaterals, calms wheezing, and promotes urination. It treats fever and agitation in heat diseases, convulsions and seizures, liver-yang headache, stroke hemiplegia, rheumatic arthralgia, wheezing cough from lung heat, and inhibited urination. Modern pharmacological research has further confirmed that earthworm has anticancer, thrombolytic, anticoagulant, diuretic, antihypertensive, antipyretic, and anti-asthmatic effects. Its anticancer effect in particular is rarely recorded in ancient Chinese medical texts, which further broadens its clinical application.
The anticancer effect of earthworm deserves attention. Animal experiments show that earthworm has a marked inhibitory effect on transplanted mouse sarcoma S180; when mice were given an earthworm extract by oral gavage at 1 mg per mouse daily for 58 consecutive days, the tumors shrank markedly and lifespan was significantly prolonged. Earthworm extract is effective not only against sarcoma S180 but also shows marked efficacy against many cancers, including gastric cancer, laryngeal cancer, esophageal cancer, and intestinal cancer. But if earthworm is heated, its anticancer effect weakens or disappears, so for anticancer use it is best taken in pills or powders or in capsules, rather than in decoction.
In addition, human trials have confirmed that earthworm extract can be combined with 5-fluorouracil or interleukin-2; the combination has a synergistic inhibitory effect on tumors. When earthworm is combined with the radiation-enhancing agent AK123, a stronger radiation-enhancing effect is produced; the triple combination of earthworm, 5-FU, and AK123 gives an even better tumor-inhibiting effect. Radiation-therapy patients taking earthworm extract not only improve the radiotherapy effect but also show a marked increase in nucleated cells in the thymus and spleen, suggesting an immune-enhancing effect.
Ancient texts record much experience with earthworm treating various diseases, but few record its use for tumor diseases; only Baoming Jiyao combines earthworm with mastic (Ruxiang), myrrh (Moyao), and calomel (Qingfen) ground into a powder for external application to treat ulcerated, spreading scrofula. Records of oral use for tumor diseases are essentially absent, so the discovery of earthworm's anticancer effect owes to modern pharmacological research.
Ancient records of using earthworm for cardiovascular and cerebrovascular emergencies are relatively numerous; stroke paralysis and liver-yang headache are all related, because earthworm has strong thrombolytic and anticoagulant effects, so it can be used for cardiovascular and cerebrovascular diseases.
In addition, earthworm can be used to treat hypertension, epilepsy, and schizophrenia. There are reports of using 60 g of earthworm and 10 g of white sugar, decocted in water and taken in two divided doses morning and evening, one dose daily, five doses per week, 60 doses as one course, treating 30 schizophrenia patients with a course of illness from 3 months to 11 years. Clinical observation found 2 recent cures, 7 markedly effective, 8 improved, and 13 ineffective. The effective cases all belonged to stasis-excess patterns, with a flooding, rapid, forceful pulse, a glossy deep-red or bluish-purple tongue, and yellow or greasy coating; deficiency-cold patterns were ineffective.
Another major use of earthworm is treating asthma; many famous ancient and modern formulas for asthma contain earthworm. Earthworm also has a strong diuretic effect and can be used for inhibited urination caused by prostatitis or cancerous ascites.