Is Japanese Knotweed, Hu Zhang, Used in the Treatment of Cancer?
Answered by: Robert Newman, L.Ac.
Question from: Ellen Munson

Have you heard of Japanese knotweed and its uses?

Is this used in cancer treatments: Japanese Knotweed Extract?

Japanese Knotweed is Polygonum cuspidatum, or Hu Zhang (pronounced "hoo jahng," meaning "Tiger’s Cane") in Chinese, and it has indeed been used in traditional Chinese medicine (TCM) to treat cancer. The Chinese have made great efforts over the past several thousand years to understand the patients they treat and the substances they use for medicine from a very deep and detailed standpoint -- a very holistically-minded standpoint. As such, cancer is generally believed to be caused, physiologically, by 3 factors, according to TCM. All tumors, masses, cysts, nodules, etc. are viewed as being caused by a combination of phlegm (this is an accumulation of excess fluid which has congealed in a particular part of the body) and blood stasis (this is a partial or complete obstruction of blood circulation in a particular part of the body). In addition to tumors or masses, cancer also involves tissue destruction (necrosis), which is viewed in TCM as being caused by the presence of heat toxins in the body. So we have phlegm, blood stasis and heat toxins as the 3 factors, and in TCM, Hu Zhang is said to influence all 3 of those factors.

Hu Zhang’s primary TCM function is to activate the blood circulation and remove blood stasis, and its secondary functions include draining heat out and transforming (eliminating) phlegm, and clearing heat and eliminating toxins. Although this herb can address all 3 TCM factors said to be present in cancer, it is still traditionally almost always used in combination with other appropriate herbs (this is individualized for each patient) in a formula, to increase the overall desired effects and reduce the likelihood of any undesirable effects. The wonderfully deep understanding the Chinese developed about this herb determined that it is a bitter and cold herb, so when used alone as a single herb, it has a tendency to weaken the digestive system over time (in TCM, the digestion is said to be fueled by a warming energy, a "fire" -- from a western view, this is comparable to the stored energy present in our digestive enzymes which gives them the power to break down food particles in the process of digestion; so practitioners generally try to avoid putting out that "fire" by avoiding the long-term use of herbs that are only very cold or cooling ones).

Western research has also discovered potential applications of this herb for cancer -- several compounds have shown possible usefulness, including emodin, resveratrol and chrysophanol. These compounds have shown antitumor, antimetastatic, chemopreventive, chemical carcinogenesis-inhibitive, oncogene signal transduction-inhibitive and immunomodulating properties. One study also demonstrated that Hu Zhang was able to increase white blood cells (WBC’s, aka leukocytes) in patients with lowered WBC levels due to radiation treatment. For examples and further information, see:

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