Nature's Pharmacopeia: A World of Medicinal Plants

GINSENG

Panax spp.

Ginseng is the name associated with several species native to East Asia and North America. The major Asian species, Panax ginseng, originates in northeastern China, Korea, and adjacent parts of Siberia and has been introduced into cultivation in Japan.150 American ginseng (P. quinquefolius) comes from the eastern part of temperate North America, from southeastern Canada through the Appalachian Mountains and west to the Great Lakes.151 Ginseng is a perennial herbaceous plant growing to a height of 50 centimeters and forming a small number of leaves composed of four or five leaflets, a cluster of inconspicuous pale-green flowers, and bright-red pea-size fruits containing a seed or two each.152 The underground portion (root), which is harvested for commerce, consists of a stem and root system that can be as long as 30 centimeters or more, and 4 centimeters or more in diameter, although many specimens are much smaller. Ginseng can be collected in the wild, cultivated in wild settings, or grown in plantations.153

Ancient East Asian foragers must have noticed the contorted, branched form of the ginseng root and likened it to a human body, ascribing to it fantastic powers (figure 14.19).154 In Chinese folk and scholarly medicine, ginseng was thought to be protective and therapeutic for the whole body. First described in the Divine Husbandman’s Classic of the Materia Medica (first centuries C.E.) to “settle the ethereal soul and the corporeal soul, … expel pathogenic qi,” and “strengthen the resolve,” ginseng was believed to bolster all five organ systems of the Chinese medical framework.155 Considered one of the most powerful herbs in the traditional East Asian pharmacopeia, ginseng is widely employed in tonic preparations as an herbal tea or in alcohol, soups, and medicinal formulas mixed with other herbs (figure 14.20). It is also a tribute and gift commodity, enveloped in luxurious packaging to accentuate the size and shape of the root.156

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FIGURE 14.19   Ginseng in its regular (left) and anthropomorphic (right) forms, as depicted in a Chinese herbal. (Woodcut from Li Zongzi, Origins of the Materia Medica [1612])

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FIGURE 14.20   Ginseng for sale at an herbal medicine market in Hong Kong.

Likewise in North America, indigenous groups harvested wild ginseng and used it in their medical practices. The Iroquois employed ginseng, for example, in a liquid infusion to prevent vomiting, as a blood medicine, for earaches, to improve the appetite, and applied to wounds and boils to help heal them. The Menominee of the upper Great Lakes viewed it as a “strengthener of mental powers,” and the Cherokee of the Southeast used it “to relieve sharp pains in the breast.”157 (However, it is not possible to determine with certainty which indigenous uses of American ginseng predate contact with Westerners, since much of the ethnography related to native medical practices occurred decades or centuries after the ginseng trade was introduced by Europeans.)158 Wherever it was discovered, ginseng found itself transformed into a drug deemed capable of procuring health in a profound way: whether treating illnesses directly or strengthening the body from inside, ginseng’s purported powers are among the strongest of all the traditional medicines. Furthermore, in both East Asia and North America, ginseng was thought to be an aphrodisiac (“love medicine,” according to ethnographers of indigenous North Americans) of remarkable potency.159

During the seventeenth century, Chinese exploitation of native ginseng stands brought the species close to extinction, sparking a spike in price and a search for new sources. In the early eighteenth century, a French missionary in China reported of ginseng’s reputation as “a sovereign remedy for all weaknesses” and described its botanical features in a letter to the learned societies of Europe, which spurred a search for ginseng in the New World’s largely unexplored northern colonies.160 By 1716, French settlers located ginseng in Canada, and the British colonists found it in New England, New York, and Appalachia not long thereafter. The colonists generated a thriving trade in ginseng with the indigenous people of North America, who eagerly harvested the root on behalf of the Europeans. The European merchants then shipped it to China for sale at great profit.161 Today’s international ginseng market comprises a variety of cultivated and wild sources of ginseng, each with particular medicinal values (and therefore prices) assigned. For example, larger, older roots, especially those that closely resemble a human body, are prized over smaller, younger, less anthropomorphic examples.162 The wild-harvested (or wild-crafted, cultivated in a forest setting with minimal artificial input) roots are considered more valuable than farmed ginseng. The high value of wild-harvested ginseng has contributed to a significant conservation problem in parts of East Asia and North America, where poaching has substantially reduced or eliminated the plant. To many East Asians, P. ginseng is believed to be more potent than P. quinquefolius. While generally thought to act similarly to the Chinese ginseng, American ginseng has attracted some controversy among traditional Chinese medical authorities. Some describe the herb as a strengthener of qi, though cooler in nature than the (warm) Chinese ginseng; others find it not to be strongly medicinal at all. Modern studies indicate that the chemical properties of Chinese and American ginseng are similar but distinguishable.163

Preparations of ginseng root in alcohol, water, tablets, and lozenges contain an assortment of about 100 different triterpene saponins called ginsenosides.164 These components are collectively thought to be responsible for ginseng’s adaptogenic properties. (Adaptogens are drugs that generally improve the body’s ability to resist stresses, a traditional medical function not widely accepted by biomedical practitioners.)165 Biomedical approaches to studying ginseng’s therapeutic applications have focused on its possible role in modulating the immune system, affecting the pathways that govern diabetes, improving libido and sexual response, increasing mental function, and reducing nausea and stimulating appetite, among others.166

Triterpene saponins

Molecules made up of multiple carbon rings, often attached to a sugar component, having both water-soluble and fat-soluble aspects

While laboratory studies and experiments in animals aiming to unravel the diverse effects of ginseng’s likely active principles are plentiful, the extension of findings made on cell cultures and rodents to human beings is not always straightforward. Some clinical trials of ginseng’s possible therapeutic effects have been criticized for poor experimental design, including small sample size, potential biases, and use of nonstandardized root extracts.167 The base of evidence for ginseng’s therapeutic effects in humans remains small and equivocal, but ongoing studies aim to generate data that might confirm or refute possible effects more convincingly.