Terra Sigillata

Back in June, we reported on several botanical/non-botanical supplement studies presented at the American Society of Clinical Oncology (ASCO) meeting. One was a Mayo Clinic study of a proprietary Wisconsin-grown ginseng (Panax quinquefolius) extract showing positive effects of the preparation in relieving cancer-related fatigue. The study authors were very careful to note this study was conducted specifically with Wisconsin-sourced product.

From my own post:

Note that the extract can’t be compared to anything on the market since it was made for the study from a single source of Wisconsin ginseng. In fact, the press release states that, “The authors also cautioned against store-bought ginseng supplements, citing the lack of regulation and inconsistent quality and safety.”

Well, congressional representatives from Wisconsin (of all places) are now sponsoring legislation in the US House and Senate requiring that ginseng sold in the US would be labeled with its country of harvest. From the American Herbal Products Association (AHPA):

Senate Bill 1953, the Ginseng Harvest Labeling Act of 2007, was sponsored by Sen. Russ Feingold (D-WI) and Sen. Herb Kohl (D-WI), while the companion bill, House Resolution 3340, was introduced by Rep. Dave Obey (D-WI)…

Feingold stated that American ginseng grown in Wisconsin – where 90 percent of U.S.-grown ginseng is cultivated – “is of the highest quality,” but that “smugglers will go to great lengths to label ginseng grown in Canada or Asia as ‘Wisconsin-grown.’” He also stated that this legislation is intended to correct this problem, and is “a simple but effective way to enable consumers to make an informed decision.”

More often than not, herbal advocacy organizations will lobby against any kind of political imposition of restrictions on the industry. But AHPA is actually supporting this legislation and I can guess as to the reason why. After a series of highly-publicized herbal product failures in clinical trials, Wisconsin-grown ginseng appears to have some clinical benefit (assuming that the ASCO abstract makes it to a full, peer-reviewed publication). Hence, there are now market incentives for promoting the source of ginseng products to prevent what Wisconsin Public Radio called “trademark priacy.”

But this is apparently not a recent development. American ginseng, grown mostly in Wisconsin, has been so popular that an organization called the Ginseng Board of Wisconsin has been promoting it for over 20 years. And while ginseng is often thought of as an Asian traditional medicine, Wisconsin ginseng is so popular in China that the Ginseng Board offers a Chinese translation of their website.

Of course, we still don’t know what components of ginseng extract actually relieve cancer-related fatigue. Ginseng root contains a number of triterpenoid, steroid-like molecules known as ginsenosides. The late Yale pharmacologist Norm Gillis wrote of these 10 years ago for their ability to enhance the activity of the signaling molecule, nitric oxide. This NO-mimetic action likely accounts for ginseng’s vasodilatory activity seen in many animal models. However, I have difficulty in linking NO with relief from fatigue. Ginsenosides also improve glucose uptake and improve insulin sensitivity in animal models of diabetes, with mixed results in a small clinical trial. But again, I have difficulty in making the leap from these effects to relief of fatigue. Perhaps part of the issue is that fatigue is a subjective term that can’t be measured like blood pressure and the clinical instrument for assessing fatigue is largely a self-reporting tool.

In a larger sense, these issues reflect the current state of herbal research, at least in the US. Clinical trials are conducted well before there is an adequate basic science understanding of the plant extract being studied. In the case of ginseng, there is finally a positive clinical trial result (at the level of a meeting abstract, at least) that the industry and ginseng producers wish to seize upon. But understanding the basic science behind these effects, including the strict identification of the active compound(s), is essential if botanicals are to move forward as legitimate medicines.

Comments

  1. #1 Markk
    August 6, 2007

    Ginseng has been an under the radar moneymaker in Wisconsin for many years. I was on a bicycle ride down the Wisconsin river with a lot of non-Wisconsinites, and many wanted to know what all those fields were “with roofs on”. The thing is, you can only grow ginseng a limited number a years in one place. ( just a few I believe) and then you have to grow other things, and only certain other things for decades. A lot of effort is going into trying to find out the trace elements/environmental conditions to allow more growth. The market for the stuff is exploding due to China anyway, so I think this “Wisconsin” label is really just a way to get a brand name out there, more than a real issue.