Feeling Sick from Cancer Treatment? Taking Some Ginseng May Help

(image from https://www.youtube.com/watch?v=2yOuzjdzBZE)

The distinctive resemblance to a human form has encouraged Chinese to call this plant a "man root", as illustrated by the characters.

These strange-looking roots are from a plant called Panax ginseng C. A. Meyer, also known as Korean or red ginseng. The roots shown above are fresh, but when steamed and dried for preservation, they appear more dark brown-red in color.

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The word Panax comes from Greek, meaning "all heal". Panax ginseng C. A. Meyer is commonly cultivated in Korea, Japan, China, Russia, and Germany. This species is different from American ginseng or Panax quinquefolius which is found in North America.

Since the beginnings of herbal medicine about 5500 years ago in China, ginseng has been believed to promote overall well-being, improve immunity, extend longevity, lower blood pressure, lower blood sugar, reduce nausea from cancer treatment, alleviate stress, and act as a type of "natural Viagra". Compounds called ginsenosides have been studied for their contribution to these effects, and now there is another type of molecule reported in the Proceedings of the National Academy of Sciences for its ability to alleviate nausea from anti-cancer radiation therapy. 

By Physchim62 (Own work) [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons

Ginsenosides are made of a steroid (4 connected rings), connected sugar molecules (6-membered rings), and a double bond.

In research conducted by Samuel Danishefsky et al. from Memorial Sloan-Kettering Cancer Center and Columbia University, derivatives of panaxytriol (a molecule that has two acetylene and multiple alcohol functional groups) have shown to help decrease some of the deleterious effects of cancer radiation therapy among tested mice: nausea, weight loss, the destruction of red and white blood cells (hematotoxicity), and weakness in the outer limbs due to nerve damage (peripheral neuropathy).

Panaxytriol is found at higher concentrations in red ginseng. Its derivatives are studied for their effectiveness in killing cancer cells and providing some relief at subtherapeutic doses when taken with anti-cancer agents like Taxol and 5-flurouracil (5-FU) which can have toxic side effects.

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Ginseng likes to grow in shade and takes at least 4 years to grow before harvest.

 Rather than extracting panaxytriol from Korean ginseng (which can be expensive given that the roots can be as high as $1400 per pound), the compound was synthesized by using an organic reaction called a Cadiot-Chodkiewicz coupling. Here is a general form of the reaction:

Through an oxidative addition/reductive elimination and use of a copper catalyst, you can connect two acetylene functional groups a bond away from each other. Panaxytriol was successfully synthesized this way in 42% yield.

An early finding by S. J. Danishefsky's team highlighted improved activity against cancer cells when the diol was changed into an acetonide.

 

The acetonide (a combination of acetone and a diol) is known to be a good protecting group of 1,2-diols and can be removed with water and dilute acid. 

 How are acetonides made? With a little acetone and dilute acid, a 1,2-diol gains protection from a protonated acetone molecule.

 For more information:

*Multifaceted cytoprotection by synthetic polyacetylenes inspired by the ginseng-derived natural product, panaxytriol; T. C. Chou; H. Dong; X. Zhang; X. Lei; J. Hartung; Y. Zhang; J. H. Lee; R. M. Wilson; and S. J. Danishefsky; DOI: 10.1073/pnas.1111332108

*Brief Introduction of Panax ginseng C. A. Meyer; T. K. Yun; http://www.ncbi.nlm.nih.gov/pubmed/11748372