The Anticancer Effects and Side Effects of the Chinese Herb Huzhang (Polygonum cuspidatum)
The Chinese herbal piece Huzhang is the dried rhizome and root of Reynoutria japonica (Polygonum cuspidatum), a member of the buckwheat family; it is named for the tiger-skin-like mottling on the stem of the parent plant. It is also called Dachongzhang, Banzhang, Ku Zhang, and Suanzhang, and its cross-section is yellow.
TCM holds that Huzhang is bitter and sour in taste and slightly cold in nature, entering the Liver and Gallbladder meridians. It activates blood and disperses stasis, expels wind and unblocks the collaterals, clears heat and drains dampness, and resolves toxins. It is used for amenorrhea and dysmenorrhea in women, persistent lochia after childbirth, rheumatic joint pain, damp-heat jaundice, morbid leukorrhea and strangury, sores and swellings, venomous snakebite, and burns and scalds.
Huzhang is a commonly used herb in oncology. Practical Oncology records a single-herb formula for gastric cancer: 30 g of Huzhang daily, prepared as 60 ml of syrup, taken 20–30 ml two to three times a day. Huzhang can also raise white blood cell counts; as early as the 1970s, Chinese clinicians found that a decoction of Huzhang together with Jixueteng (Spatholobus), Danggui (Angelica), and Gancao (licorice), decocted in water, could raise the white blood cell count in radiotherapy patients. Huzhang tablets made from extract are used for acute icteric hepatitis, chronic hepatitis, chronic bronchitis, rheumatoid arthritis, and the leukopenia and hyperlipidemia caused by chemotherapy and radiotherapy.
The root and rhizome contain free anthraquinones and anthraquinone glycosides, mainly emodin, physcion, resveratrol, and 6-hydroxyaloe-emodin. Huzhang and Dahuang (Rhubarb) are both buckwheat-family plants and both contain emodin and physcion, which have laxative effects; like Rhubarb, Huzhang therefore purges heat and loosens the bowels. It suits patients with heat-constipation; those with loose stools or diarrhea should use it cautiously, and pregnant women are forbidden from using it. Huzhang also has some toxicity: excessive doses of polydatin (the resveratrol glycoside) may cause peritonitis, hepatocyte necrosis, and fatty marrow hyperplasia.
Modern pharmacology finds that Huzhang lowers blood pressure and blood lipids, inhibits platelet aggregation, suppresses cough and asthma, acts as an antioxidant, antiviral, and antibacterial anti-inflammatory, raises white blood cells and platelets, has antitumor, sedative, and hemostatic effects. Huzhang decoction was effective against all seven tumor strains tested in mice—sarcoma S180, mouse breast cancer, mouse liver cancer, Ehrlich ascites carcinoma, mouse lymphosarcoma, mouse melanoma, and rat Walker carcinoma—with inhibition rates above 30% and up to 52%. Clinically, Huzhang anthraquinone tablets raise white blood cells in radio- and chemotherapy patients with an effective rate of up to 70%, and raise platelets in thrombocytopenic patients with an effective rate of up to 90%.
As early as the Tang Dynasty, Sun Simiao recorded in Qianjin Yaofang (Essential Prescriptions Worth a Thousand Gold) that a single dose of Huzhang could treat "abdominal accumulations, deficiency-distension with rumbling, heavy limbs, and blocked menstruation"—symptoms quite similar to ascites cancer. Another Huzhang-centered formula in the same book treats "closed menstruation with accumulated masses, a belly as large as a vat, and shortness of breath near death," which resembles the ascites caused by gynecological tumors. The formula reads: "One hundred jin of Huzhang root (tops and soil removed, sun-dried, sliced), and two dou each of the expressed juices of Tu Gua Gen (Trichosanthes root) and Niuxi (Achyranthes). Steep the Huzhang root overnight in one hu of water, boil to two dou the next day, add the Tu Gua and Niuxi juices, stir well, and boil to a syrup like maltose. Take one he with wine twice by day and once at night; old blood should be discharged. Stop once the illness is gone." All three herbs treat ascites, the Huzhang dose is very large, and the Niuxi and Trichosanthes are used fresh—modern doctors rarely use this method for lack of conditions. Pharmacologically, however, this formula recorded by Sun Simiao does appear effective against ascites cancer.
Huzhang's efficacy in acute infectious icteric hepatitis has been confirmed by modern pharmacology: both Huzhang decoction and Huzhang extract treat acute infectious icteric hepatitis with cure rates above 80%. Usually after 2–3 weeks of continuous use, liver function returns to normal and symptoms resolve. Huzhang also has some effect on HBsAg-positive chronic active hepatitis, improving symptoms, shrinking enlarged liver and spleen, and in some patients converting HBsAg to negative and improving or normalizing ALT. Huzhang is therefore an important herb for liver disease and is classified in modern TCM as a diuretic and jaundice-resolving herb that protects the liver and gallbladder.
When used in a decoction, the usual adult dose of Huzhang is 10–15 g, which may be increased to 30 g for jaundice and cancer. For jaundice it is often paired with Jinqiancao, Jigucao, and Yinchen; for gastric and liver cancer, with Tengligen (Actinidia root); for urinary-tract cancers, with Shiwei (Pyrrosia); and for ascites, with Niuxi, Tu Gua Gen, and Cheqiancao (Plantain).