Anticancer Effects and Side Effects of the Chinese Herb Gamboge (Tenghuang)

The Chinese herb Tenghuang (gamboge) is the resin of Garcinia hanburyi of the Clusiaceae family. This herb is uncommon; most pharmacies and hospital dispensaries do not stock it. Because gamboge is highly toxic, the lethal dose of raw (unprocessed) gamboge is very low. The Regulations on the Administration of Toxic Drugs for Medical Use promulgated by the State Council list raw gamboge as a controlled substance. However, some Chinese patent medicines contain gamboge, such as Tenghuang Jiangu Wan (Gamboge Bone-Strengthening Pill).

Clinically, gamboge must be processed before use; processing markedly reduces its toxicity. There are four methods of processing gamboge:

First, processing with goat blood: place fresh goat blood in a pot, add water, and boil for 1-2 hours; remove the blood clots, add cleaned small pieces of gamboge, and boil for another 5-6 hours; pour out the gamboge liquid, air-dry, and grind into powder. Generally, 100 kg of gamboge requires 50 kg of fresh goat blood for processing.

Second, processing with tofu: hollow out tofu, place gamboge inside, cover with more tofu, and steam in a steamer until the gamboge melts; remove and cool. Once solidified, take out the gamboge, air-dry, and grind into powder. Every 100 kg of gamboge requires 400-500 kg of tofu.

Third, processing with lotus leaf: decoct lotus leaves in water, pour gamboge powder into the lotus-leaf water to melt it, then boil into a paste; remove the paste, air-dry, and grind into powder.

Fourth, boil gamboge in clean water for 5-10 hours, continuously adding water so the pot never runs dry; after boiling, concentrate to a paste, air-dry, and grind into powder.

Because gamboge is highly toxic, pharmacists must take effective protective measures when handling it. Do not touch it directly with bare hands, and do not taste it during processing. The auxiliary materials used in processing should also be rendered harmless afterward.

Although gamboge is poisonous, it has been since ancient times a very important anticancer, swelling-dispersing herb. Traditional TCM holds gamboge to be sour, astringent, and toxic. Its main actions are to attack toxin, disperse swelling, expel necrosis and astringe sores, stop bleeding, and kill parasites. It is indicated for carbuncles and abscesses, ulcers, phlegm-nodules, stubborn tinea, traumatic injuries, traumatic bleeding, and burns. Many of these conditions belong to proliferative and neoplastic diseases in modern medicine. The patent medicine Tenghuang Jiangu Wan treats bony hyperplasia precisely because gamboge can eliminate hyperplastic tissue.

Modern pharmacology confirms that gambogic acid and morellin (isogambogic acid) contained in gamboge have anticancer effects. Gamboge shows selective anticancer activity both in vivo and in vitro. In vivo, it markedly inhibits mouse Ehrlich ascites carcinoma, S180, S37, W256, ARA4, ARS, MA737, and U14. In vitro, it significantly inhibits and kills human hepatoma BEL7402 and SMMC-7721 cells and cervical cancer HeLa cells. Gambogic acid markedly controls ascites, greatly reducing ascites volume. The anticancer mechanism is inhibition of cancer cell DNA synthesis, interference with the cancer-cell proliferation cycle, accumulation of G2 phase cells, and reduction of the percentage of S-phase cells. Modern pharmacological research supports the traditional TCM description of gamboge's actions.

Gamboge may be used externally or taken internally. For adults, a single oral dose should be controlled at 0.01-0.06 g; overdose must be avoided. Internally it is used only in pills or powders. Gamboge has a cathartic side effect; deficient patients must take it together with herbs that support zheng qi (vital qi). Overdose can cause dizziness, vomiting, abdominal pain, and diarrhea, and in severe cases can be fatal.

For external use, gamboge is usually combined with other herbs into an ointment applied to the skin. TCM mostly uses gamboge externally, which is much safer. Internal use is considered only for conditions such as bony hyperplasia and cancer. The effective rate of gamboge, whether internal or external, for skin cancer can reach 71%, and a few patients even achieve clinical cure.

Applied externally, gamboge can also treat various skin diseases such as herpes zoster or herpes simplex, local acute inflammation, and sinus-type bedsores. It may also be made into suppositories for cervical erosion and hemorrhoids.

I have used gamboge for many years. As long as it is carefully processed and the dose is controlled, its side effects are manageable. My own single dose is generally below 0.01 g, because cancer patients must take anticancer drugs over the long term; too large a single dose can cause cumulative poisoning. When using gamboge, it should be combined with Ren Shen (Ginseng), Bai Zhu (Atractylodis Macrocephalae Rhizoma), and Fu Ling (Poria). Although I took adequate precautions while processing gamboge, I still suffered poisoning no fewer than three times from inhaling gamboge dust, which shows how potent its toxicity is.

TCM anticancer treatment cannot do without "using poison to attack poison." When selecting such toxic herbs, the physician must be familiar with their toxicity. Clinical medication must be both bold and cautious. Failing to use anticancer drugs boldly often makes patients miss their chance of survival; failing to use them cautiously makes safety unpredictable. Physicians treating cancer must therefore be bold yet meticulous, closely observing the patient's response. If the patient has difficult urination and defecation and cannot sweat normally, drugs like gamboge must be used with special care.