Research in Japanese Botanical Medicine and Immune Modulating Cancer Therapy

Townsend Letter for Doctors and Patients, August, 2001 by Dan Kenner

Japanese botanical medicine, known as Kampo, is part of the east Asian Chinese medicine tradition. The word "Kampo" means "Han method," a reference to Chinese culture of the Han era (206BC-220AD). Kampo is fundamentally a clinical system based on the classical medical literature dating back to the Han era. Kampo is an older tradition preserved in Japan and distinct from Traditional Chinese Medicine (TCM) practiced today in China. TCM is the modern system of treatment developed in mainland China in the 1950s, based on a consensus on the traditional principles of evaluation and treatment. In Japan, Kampo has been in almost continuous use for centuries as a system of medicine with the exception of the Meiji era (1866 - 1912) when traditional medicine was banned. It was during the Meiji era, however, when pharmacological research was first used to validate the use of the herb mao (Chinese ma huang L. Ephedra sinica). In 1885 Dr. Nagayoshi Nagai isolated the alkaloid ephedrine from this herb, frequently used in fo rmulas for bronchial asthma and arthritis. The pharmacological action of ephedrine was explained by Dr. Kinnosuke Miura in a German medical journal and ephedrine subsequently became a mainstream pharmaceutical for the treatment of bronchial asthma in Europe and North America as well.

Kampo was validated as a clinical system in the 20th century. By the late 1960s, in large part due to public demand, Kampo was integrated into the medical mainstream. Today the large majority of physicians use at least some of the traditional formulas, which are available in almost all pharmacies by prescription, or under the advice of specially trained pharmacists. The Japanese national health insurance plan covers the use of many of the traditional formulas.

Hundreds of papers were published on the pharmacology of the herbs of the traditional pharmacopoeia even before the turn of the 20th century, but in recent decades clinical and animal research has been undertaken on a large scale by university hospitals and private clinics throughout Japan as well as hospitals and research institutes in China. Research in Japan has been more rigorous by western standards. In many ways Chinese research is more practical. The aim of research is often developmental, with clinical problem-solving as the chief aim. In China trials on herbal combinations are often designed to refine a clinical approach or test a formula before using it on hospital patients, rather than to validate a specific endpoint to convince skeptical colleagues. Japanese research, on the other hand, is more academic in the mold of conventional western pharmaceutical research. Japanese research on botanical medicine also uses substances that are pharmaceutical grade according to western standards.

Since 1994, Japanese manufacturers of traditional herbal medicines have been required to conform to the same standards of quality as other pharmaceutical companies. This requires that all formulas are tested for any contaminants and are "standardized" for specific levels of key chemical constituents that are used as "markers" of plant quality. This means that the herbs used in the formulas must have the required levels of at least two marker components in order for the formula to be approved as a medicament. This places the onus for quality control on the herb buyers for the Japanese manufacturers, because a single herb can have several "active" components and herbs grown in different climatic regions can have dramatically different chemical compositions. The amount of saikosaponins, important constituents of the herb Bupleurum falcatum, can vary considerably. According to one Japanese herb buyer, "Bupleurum from one region may contain seven times the saikosaponins of bupleurum from a different region. We hav e to get the best quality when we purchase because we can't afford to buy seven times as much herb to get the required level of saikosaponins in our products."

One widely researched combination that holds promise for cancer treatment is called Minor Bupleurum Combination or sho-saiko-to in Japanese, and TJ-9 in some of the research literature. Shosaiko-to has been used in Japan for over a thousand years and is probably the most popular herb formula in Japan today. Over a million Japanese patients take it every year for various complaints, but particularly for hepatitis C. There are specific symptoms and signs that indicate the use of Sho-saiko-to for various health problems. The combination is recommended when the appropriate symptoms and signs are presented at the examination. It has been used for a variety of medical diagnoses including gastroenteritis, migraine headaches, lingering colds, chronic bronchitis, bronchial asthma, gallstones, cholecystitis, epilepsy, malaria and even just to strengthen the physical constitution. Its potentially beneficial effect on cancer is attributed to its ability to regenerate liver function as well as to stimulate cytokine and NK cell activity.