Ginseng (28/Dec/2006)

Ginseng
28/Dec/06

Herbal remedies known as "ginseng" are based on the roots of several distinct species of plants, mainly Korean or Asian ginseng (Panax ginseng), Siberian ginseng (Eleutherococcus senticosus), and American ginseng (Panax quinquefolius). All of these species are in the Araliaceae plant family, but each has its own specific effects on the body.

Ginseng products are popularly referred to as "tonics," a term that has been replaced by "adaptogens" in much of the alternative medicine literature. The term "adaptogen" connotes an agent that purportedly "increases resistance to physical, chemical, and biological stress and builds up general vitality, including the physical and mental capacity for work."

Panax ginseng is one of the most commonly used and highly researched species of ginseng. This species, which is native to China, Korea, and Russia, has been an important herbal remedy in traditional Chinese medicine for thousands of years, where it has been used primarily as a treatment for weakness and fatigue.

Pharmacology
The main active agents in Panax ginseng are ginsenosides, which are triterpene saponins. The majority of published research on the medicinal activity of Panax ginseng has focused on ginsenosides. These are the compounds to which some ginseng products are now standardized.

Research reviews postulate that extracts of Panax ginseng affect the hypothalamus-pituitary-adrenal axis and the immune system, which could account for many of the documented effects. Animal models and in vitro studies mentioned in these reviews indicate that Panax ginseng enhances phagocytosis, natural killer cell activity, and the production of interferon; improves physical and mental performance in mice and rats; causes vasodilation; increases resistance to exogenous stress factors; and affects hypoglycemic activity.

Efficacy
Panax ginseng is used primarily to improve psychologic function, exercise performance, immune function, and conditions associated with diabetes . Traditional Chinese medicine and many current research studies often use products that combine ginseng with other herbal medicines or vitamins. Because of the use of combination products and the limitations of some studies on ginseng (e.g., poor methodologic quality, research focusing on healthy volunteers, small sample size, unstandardized ginseng preparations, varying doses), it is difficult to draw conclusions about some of the clinical effects of ginseng. Many research trials have been performed on the standardized Panax ginseng extract Ginsana (G115).

REFERENCES
1. Robbers JE, Tyler VE. Tyler's Herbs of choice: the therapeutic use of phytomedicinals. New York, N.Y.: Haworth Herbal Press, 1999.
2. Mahady GB, Gyllenhall C, Fong HH, Farnsworth NR. Ginsengs: a review of safety and efficacy. Nutr Clin Care 2000;3:90-101.
3. World Health Organization. WHO monographs on selected medicinal plants. Geneva: World Health Organization, 1999.
4. Vogler BK, Pittler MH, Ernst E. The efficacy of ginseng. A systematic review of randomised clinical trials. Eur J Clin Pharmacol 1999;55:567-75.
5. Wesnes KA, Ward T, McGinty A, Petrini O. The memory enhancing effects of a Ginkgo biloba/ Panax ginseng combination in healthy middle-aged volunteers. Psychopharmacology 2000;152:353-61.