Centipede (Wugong): Anticancer Effects and Side Effects

The centipede, also called Wugong (Wugong, Tianlong, Baijiao, Baiwuchong), is the whole body of Scolopendra subspinipes and Scolopendra multidens of the Scolopendridae family. Centipede has a very long history of medicinal use. Shennong Bencao Jing (Divine Farmer's Materia Medica) includes centipede, holding that it "maintains ghost-zheng and gu poison, consumes the poisons of snakes, insects, and fish, kills ghosts and old essences, treats warm malaria, and expels the three worms." Mingyi Bielu (Records of Famous Physicians) holds that centipede can "treat cold-heat accumulations in the heart and abdomen, induce abortion, and expel stagnant blood."

Traditional Chinese medicine holds that centipede is acrid in flavor, warm in nature, and toxic, entering the liver meridian. Modern Chinese-medicine textbooks mostly place centipede among the liver-pacifying and wind-extinguishing herbs, specifically the wind-extinguishing and spasm-stopping herbs, holding that centipede dispels wind, calms convulsions, attacks toxins, and dissipates nodules. It treats stroke, convulsions and epilepsy, tetanus, stubborn rheumatic bi, sores, scrofula, and venomous snake bites.

Materia medica works through the ages record that centipede is toxic, but many scholars believe its toxicity is concentrated mainly in the maxillary fangs of the head, used to capture prey. A live centipede is highly toxic, but a dead centipede used medicinally is not very toxic.

However, modern pharmacological research has found that the toxicity of centipede lies mainly in its hemolytic protein and histamine; these two toxic components respectively cause hemolytic reactions and allergic reactions. The processed medicinal centipede indeed contains far less hemolytic protein capable of causing hemolysis than a live centipede, but the content of the other toxic component, histamine, is still relatively high and exists mainly in the trunk.

Symptoms of centipede poisoning include nausea and vomiting, abdominal pain and diarrhea, loss of consciousness, slow heartbeat, difficulty breathing, lowered body temperature, lowered blood pressure, soy-sauce-colored urine, black stools, hemolytic anemia, skin allergy and unbearable itching, red swollen painful eyes, photophobia and tearing, poor appetite, chest oppression, and fever; severe cases go into shock.

Traditional Chinese medicine holds that centipede fears mulberry leaf, so mulberry-leaf juice can counteract centipede poisoning; some scholars also say that centipede poisoning can be detoxified by decocting earthworm together with mulberry leaf, as Sheng Guorong and others maintain. To reduce the toxic side effects of centipede, traditional Chinese medicine requires removing the head and legs when using it. Many scholars disagree with this; Zhang Xichun, for one, maintained that centipede is not very toxic and that the head and legs should not be removed. Zhou Tianhan related that his father Zhou Ji'an found large-dose centipede very safe in treating tetanus, using 20 at a time with no toxic reaction, and held that small doses are ineffective. Zhou said that in practice he found using 25 centipedes in adults to be very safe.

Animal experiments on centipede's toxicity confirm that its safety is indeed high. The LD50 of centipede extract by subcutaneous injection in mice is 7.67 g/kg; experimental animals taking centipede continuously for a month showed no abnormal changes in body weight, hemoglobin, or internal organs, cell mitosis was normal, and no mutation occurred. These experiments show that the medicinal centipede is indeed not very toxic. But another study showed that centipede can lower pregnancy rates, increase teratogenicity, and cause death, so centipede is not suitable for pregnant women.

But individual patient variation is large; after all, the hemolytic protein and histamine in centipede are toxic, and a few patients have indeed experienced poisoning after taking centipede, so clinical use still requires attention to safety. It should be used in small doses; when using large doses, the amount must be increased gradually. On the premise that small doses are safe, increase the dose according to the patient's response.

Contrary to common intuition, centipede is a Chinese herb that can delay aging; its toxicity is not only unlikely to kill but can actually boost human immunity. The water extract of centipede significantly lowers lipid peroxides in rat serum and lipofuscin in liver and brain tissue; it markedly raises superoxide dismutase in red blood cells and glutathione peroxidase in blood; and it significantly increases the weight of the immune organs, the thymus and spleen, enhancing the phagocytic activity of phagocytes. Thus it improves immune function and delays aging. In many parts of China, centipede is soaked in wine and drunk to boost immunity and prolong life, similar to the practices of auto-immunity enthusiasts in Europe and America who inject snake venom to boost immunity.

Centipede has a strong antibacterial effect. The acidic extract of centipede inhibits 8 common fungi and has a relatively strong inhibitory effect on pathogenic fungi such as Trichophyton mentagrophytes var. , Trichophyton gypseum, and Epidermophyton rubrum. From ancient times to the present, Chinese medicine has commonly combined centipede with other herbs or media to treat various surface scabies, tinea, and swellings, and to treat snake and venomous insect bites; Chinese medicine explains this as "using poison to attack poison."

For example, scholars such as Kong Fanxiu treating herpes zoster commonly used one large centipede, 10 g of realgar (arsenic sulfide), and 3 g of dried alum, ground together into a fine powder, mixed with vinegar and applied to the affected area. If the blisters are large, they may be punctured before application, 2-4 times a day. The effect is very good; mild cases heal in 2-4 applications and severe cases in 4-6.

Another study showed that 3 g of centipede with 10 g of rock sugar in a small bowl, steamed over water for half an hour after the water boils, then the centipede removed and the liquid taken, treated scabies in 186 cases, curing 174.

Another study soaked two centipedes and 5 g of safflower (Honghua) in 75% medical alcohol for 7 days for external use; a cotton swab dipped in the liquid was applied to the affected area (for ulcerated lesions, applied around the ulcer, avoiding direct application to the open sore), treating various unknown swellings (folliculitis, acute mastitis, external hemorrhoids, insect bites, pulpitis, traumatic infection, snake bites, etc.) in 600 cases, with 560 cured.

These studies show that external use of centipede indeed has good efficacy.

Modern pharmacological research has also proven that centipede has good anticancer effects. The total alkaline protein of centipede markedly inhibits human oral epidermoid carcinoma (KB cells) and human colon cancer cells (HCT). In addition, centipede has a high effective rate for recurrent oral ulcers; taking centipede powder as an oral wash gives a total effective rate as high as 89.2%. Some scholars believe this is related to centipede's ability to boost human immunity. After patients take centipede powder granules, both IgG and the E-rosette formation rate rise significantly. The water extract of centipede markedly inhibits both sarcoma S180 and mouse liver cancer H22; its inhibition rate against human cervical cancer cells TC-26 is over 90%, and it enhances reticuloendothelial cell function.

So centipede is also a commonly used herb in contemporary Chinese-medicine treatment of cancer. In treating cancer, centipede is often used together with whole scorpion in a xiangxu (synergistic) relationship because their effects are similar. It is generally held that centipede's effect of attacking toxins and dissipating nodules is stronger than whole scorpion's, while whole scorpion's effect of extinguishing wind and stopping spasms is stronger than centipede's; combining the two not only anticancers but also stops pain.