*EPF208 08/31/2004
Text: International Team Shows Why Ginseng Has Opposing Health Effects
(Results emphasize need for stronger regulation of herbal supplements) (850)

An international team of Massachusetts Institute of Technology (MIT) scientists and colleagues has discovered why the popular herbal treatment ginseng can have two different, opposing effects on the body, says an August 30 MIT press release.

Ginseng can promote the growth of blood vessels, important to healing wounded tissues, according to some scientific articles, while conflicting studies report that ginseng can halt that process. The latter is important because preventing the formation of blood vessels can be enlisted against cancer. Tumors are fed by blood vessels; cutting off their blood supply can kill tumors.

The researchers found that different varieties of ginseng -- whether Korean, American, Chinese or Sanqi -- have different chemical compositions. The different balance between theses chemicals in the various types of the herb will cause it to have opposite effects on blood vessels.

The work, to be published in the September 7 issue of Circulation: the Journal of the American Heart Association, was performed by researchers from the United States, England, the Netherlands and Hong Kong and emphasizes the need for stronger regulations of herbal drugs, according to the press release.

The new results could lead to medicines patterned after ginseng's key components. As the researchers write in Circulation, identifying one of the components in particular "opens up the exciting possibilities of harnessing [its] chemical scaffold as a prototype for wound-healing compounds."

The research was jointly funded by institutions in the United States, the United Kingdom and the Netherlands.

Text of the Massachusetts Institute of Technology press release follows:

(begin text)

Massachusetts Institute of Technology Press release, August 30, 2004

MIT team explains yin-yang of ginseng

Work emphasizes need for stronger regulations of herbal drugs

CAMBRIDGE, Mass. -- In work that emphasizes the need for stronger regulations of herbal drugs, an international team of MIT scientists and colleagues has unraveled the yin and the yang of ginseng, or why the popular alternative medicine can have two entirely different, opposing effects on the body.

Conflicting scientific articles report that ginseng can both promote the growth of blood vessels (key to wound healing) and stymie that process. The latter is important because preventing the formation of blood vessels can be enlisted against cancer. Tumors are fed by blood vessels; cutting off their supply can kill them.

In the Sept. 7, 2004, issue of Circulation: the Journal of the American Heart Association, the researchers from the United States, England, the Netherlands and Hong Kong explain these dual effects for the first time.

Chemical fingerprints of four different varieties of ginseng--American, Chinese, Korean and Sanqi--show that each has different proportions of two key ingredients. Additional studies showed that a preponderance of one ingredient has positive effects on the growth of blood vessels; more of the other component tips the scale the other way.

"We found that this composition really matters for the ultimate outcome," said Shiladitya Sengupta, a postdoctoral associate in MIT's Biological Engineering Division.

Further, the team found that the way ginseng extracts are processed can also alter the compositional ratio. "This is a very clear-cut example of why we need regulations standardizing herbal therapies through compositional analysis," said Professor Ram Sasisekharan of MIT's Biological Engineering Division. With the new results, "we can now rationally isolate the components to focus on a specific effect, such as promoting blood-vessel formation." In the United States, herbal medicines are currently regulated under the 1994 Dietary Supplement and Health Education Act, which does not require standardization or prior approval from the Food and Drug Administration. "You can basically crush it and sell it," Sasisekharan said.

The new results could also lead to medicines patterned after ginseng's key components. As the researchers write in Circulation, the identification of one of these in particular "opens up the exciting possibilities of harnessing [its] chemical scaffold as a prototype for wound-healing compounds."

Sasisekharan emphasizes the importance of Sengupta's interdisciplinary approach to the work. "He had the foresight to integrate the biology of cancer and blood-vessel formation to the pharmacological behavior of this drug and its structure."

MIT's role in the collaboration grew from Sasisekharan's expertise in complex sugars, which turn out to be key to ginseng's activity. "The sites where sugars are attached and how they are attached are unique for each of the molecular constituents, the ratio of which are distinct among the different varieties of ginseng," he explained. In 1999 Sasisekharan's lab developed a new tool for characterizing complex sugars.

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Sengupta and Sasisekharan's colleagues in the work are from the University of Cambridge (T.P. Fan, Sue-Anne Toh, Lynda A. Sellers and Jeremy N. Skepper), Gaubius Laboratory, TNO-PG, Leiden, the Netherlands (Pieter Koolwijk), and Hong Kong Baptist University (Hi Wun Leung, Hin-Wing Yeung and Ricky N.S. Wong). This work was funded by the Cambridge Nehru Trust, the U.K. Committee of Vice-Chancellors and Principals, Hong Kong RGC, the Dutch Cancer Society, and the U.S. National Institute of General Medical Sciences.

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(Distributed by the Bureau of International Information Programs, U.S. Department of State. Web site: http://usinfo.state.gov)

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