Health Care Professional Information
Scientific Name
Panax quinquefolius
Common Name
Xi yang shen, Tienchi ginseng, western ginseng, five-fingers
Clinical Summary
American ginseng is cultivated in the northwest regions of United States and Canada. Patients take this supplement to improve athletic performance, strength, and stamina, and to treat diabetes and cancer. In Chinese herbal formulas, American ginseng is frequently used to nourish “Yin” (1). The saponin glycosides, also known as ginsenosides or panaxosides, are thought responsible for American ginseng's effects.
Ginsenosides have both stimulatory and inhibitory effects on the CNS (4), alter cardiovascular tone, enhance humoral and cellular-dependent immunity, and have anticancer effects in vitro (3) (15) (16).
Current data suggest that ginseng may improve glucose control in diabetics (2) (6), but additional research is necessary. It demonstrated a modest effect in reducing the number and severity of colds (12); and enhanced working memory in healthy adults (21).
The anticancer effects of ginseng were enhanced when combined with antioxidants (14). Ginseng also acts synergistically with 5-fluorouracil against colorectal cancer cells (17) and demonstrated radioprotective effects in irradiated human lymphocytes (18).
Data from an epidemiological study show that ginseng improves survival and quality of life in breast cancer patients (13). A perspective trial also shows it can improve cancer-related fatigue (23).
Purported Uses
- Cancer prevention
- Cancer treatment
- Diabetes
- Health maintenance
- Immunostimulation
- Strength and stamina
Constituents
Mechanism of Action
Ginsenosides are thought responsible for American ginseng's activity, although the exact mechanism of action is unknown. American ginseng lowers serum glucose and may affect carbohydrate metabolism (2) (6). Related species, such as Panax ginseng, have been the focus of most laboratory and clinical research. Experiments using extracts from these species indicate that ginsenosides stimulate and inhibit the CNS (4). The extracts also stimulate TNF alpha production by alveolar macrophages (10). The Rg1 ginsenoside is associated with improvements in humoral and cell-mediated immune response and increases in T helper cells, T lymphocytes, and NK cells in mice (5). Ginseng's antagonistic effect on warfarin is not due to vitamin K (11).
Several ginsenosides demonstrated anticancer properties in vitro (3). However, current data suggest that the antiproliferative effects of American ginseng are due to compound K, a metabolite of the ginsenoside Rb1, but not Rb1 as previously thought (22).
Pharmacokinetics
Evaluation of A1, A2, B2, and C ginsenosides in the rabbit suggests one compartment pharmacokinetics for all ginsenosides following intravenous administration. Elimination half-lives range from 20-500 minutes. Ginsenoside A1 is rapidly absorbed after intraperitoneal administration. All ginsenosides are primarily eliminated unchanged in the urine.
(1)
Contraindications
Breast cancer patients should use this product with caution as ginseng may stimulate the growth of breast cancer cells (9).
Adverse Reactions
No significant reactions reported.
Herb-Drug Interactions
Insulin and sulfonylureas: American ginseng may increase the hypoglycemic effect of insulin and sulfonylureas (7).
Warfarin: Ginseng has been shown to antagonize warfarin's effects (11).
Cytochrome P450 (CYP) 3A4 substrates: Certain ginsenosides can induce CYP3A4 and may affect the metabolism of some drugs that are substrates of this enzyme (19) (20).
Literature Summary and Critique
Yuan CS, et al. Brief Communication: American Ginseng reduces Warfarin's effect in healthy patients. Annals of Internal Medicine 2004;141:23-27.
Twenty healthy adults took part in a four-week trial of ginseng and its effects on warfarin. All subjects received warfarin during weeks 1 and 4. Subjects were randomly assigned to receive either 1.0 gram American ginseng or placebo twice daily starting in week 2. Subjects receiving ginseng had significantly decreased International Normalized Ratios (INR) when compared with those receiving placebo. Peak INR and peak plasma warfarin levels were correlated. Researchers concluded that ginseng reduces warfarin's anticoagulant effect.
Dosage (Inside MSKCC Only)
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References
- Huang KC. The Pharmacology of Chinese Herbs, 2nd ed. New York: CRC Press; 1999.
- Vuksan V, et al. American ginseng (Panax quinquefolius L) reduces postprandial glycemia in nondiabetic subjects and subjects with type 2 diabetes mellitus. Arch Intern Med 2000;160:1009-13.
- Shin HR, et al. The cancer-preventive potential of Panax ginseng: a review of human and experimental evidence. Cancer Causes Control 2000;11:565-76.
- Attele AS, Wu JA, Yuan CS. Ginseng pharmacology: multiple constituents and multiple actions. Biochem Pharmacol 1999;58:1685-93.
- Chen SE. American ginseng. III. Pharmacokinetics of ginsenosides in the rabbit. Eur J Drug Metab Pharmacokinet 1980;5:161-8.
- Vuksan V, et al. American ginseng (Panax quinquefolius L.) attenuates postprandial glycemia in a time-dependent but not dose-dependent manner in healthy individuals. Am J Clin Nutr 2001;73:753-8.
- Brinker F. Herb Contraindications and Drug Interactions, 3rd ed. Sandy (OR): Eclectic Medical Publications; 2001.
- Vuksan V, et al. American ginseng improves glycemia in individuals with normal glucose tolerance: effect of dose and time escalation. J Am Coll Nutr 2000;6:738-44.
- Amato P, Christophe S, Mellon PL. Estrogenic activity of herbs commonly used as remedies for menopausal symptoms. Menopause 2002;9:145-50.
- Assinewe VA, et al. Extractable polysaccharides of Panax quinquefolius L. (North American ginseng) root stmulate TNFalpha production by alveolar macrophages. Phytomedicine 2002;9:398-404.
- Yuan CS, et al. Brief Communication: American Ginseng reduces Warfarin's effect in healthy patients. Annals of Internal Medicine 2004;141:23-27.
- Predy GN, et al. Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infectons: a randomized controlled trial. CMAJ 2005;173(9):1043-8.
- Cui Yong, et al. Association of ginseng use with survival and quality of life among breast cancer patients. Am J Epidemiol 2006; 163(7):645-53.
- Li B, Wang CZ, He TC, et al. Antioxidants potentiate American ginseng-induced killing of colorectal cancer cells. Cancer Letters. 2010;289(1):62-70.
- Li B, Zhao J, Wang CZ, et al. Ginsenoside Rh2 induces apoptosis and paraptosis-like cell death in colorectal cancer cells through activation of p53. Cancer Lett. 2011 Feb 28;301(2):185-92.
- Xie JT, Du GJ, McEntee E, et al. Effects of Triterpenoid Glycosides from Fresh Ginseng Berry on SW480 Human Colorectal Cancer Cell Line. Cancer Res Treat. 2011 Mar;43(1):49-55.
- Li XL, Wang CZ, Sun S, et al. American ginseng berry enhances chemopreventive effect of 5-FU on human colorectal cancer cells. Oncol Rep. 2009 Oct;22(4):943-52.
- Lee TK, O'Brien KF, Wang W, et al. Radioprotective effect of American ginseng on human lymphocytes at 90 minutes postirradiation: a study of 40 cases. J Altern Complement Med. 2010 May;16(5):561-7.
- Hao M, Ba Q, Yin J, et al. Deglycosylated ginsenosides are more potent inducers of CYP1A1, CYP1A2 and CYP3A4 expression in HepG2 cells than glycosylated ginsenosides. Drug Metab Pharmacokinet. 2011;26(2):201-5.
- Hao M, Zhao Y, Chen P, et al. Structure-activity relationship and substrate-dependent phenomena in effects of ginsenosides on activities of drug-metabolizing P450 enzymes. PLoS One. 2008 Jul 16;3(7):e2697.
- Scholey A, Ossoukhova A, Owen L, et al. Effects of American ginseng (Panax quinquefolius) on neurocognitive function: an acute, randomised, double-blind, placebo-controlled, crossover study. Psychopharmacology (Berl). 2010 Oct;212(3):345-56.
- Wang CZ, Du GJ, Zhang Z, et al. Ginsenoside compound K, not Rb1, possesses potential chemopreventive activities in human colorectal cancer. Int J Oncol. 2012 Jun;40(6):1970-6.
- Debra L. Barton, Heshan Liu, Shaker R. Dakhil, et al. Phase III evaluation of American ginseng (panax quinquefolius) to improve cancer-related fatigue: NCCTG trial N07C2. J Clin Oncol 30, 2012 (suppl; abstr 9001)
Consumer Information
How It Works
Bottom Line: American ginseng has not been shown to treat or prevent cancer.
American ginseng has been shown to lower blood sugar levels in humans. Scientists think that the effects of ginseng come from its components called ginsenosides. Most research has been done on another species, Panax ginseng. These studies indicate that ginsenosides both stimulate and inhibit the central nervous system in humans and stimulate the immune system in mice. Laboratory studies in mice and population studies in humans suggest that Panax ginseng has cancer-preventative properties.
American ginseng was shown to reduce the number and severity of colds, and improve working memory in healthy adults.
It also decreases the anticoagulant effects of warfarin, an anticoagulant.
Purported Uses
- To improve athletic performance
No scientific evidence supports this use. - To prevent and treat cancer
There are no data to back this claim. - To treat diabetes
A few studies show a blood glucose-lowering effect of American ginseng in humans, but there is not enough evidence to support replacing diabetes medications with American ginseng. - To stimulate the immune system
Some studies show an immunostimulant effect in animals. Human data are lacking. - For increased strength and stamina
Although ginseng is often promoted for this use, human data are lacking.
Research Evidence
Interaction with Warfarin:
Twenty healthy adults received warfarin during weeks 1 and 4 in this study. They were then randomized to receive either 1.0 gram American ginseng or placebo twice daily starting in week 2. Subjects who received ginseng had signficantly lowered International Normalized Ratios (INR) when compared with those receiving placebo. Researchers conclude that ginseng reduces warfarin's anticoagulant effect and suggest that physicians ask their patients about ginseng use before prescribing warfarin.
Do Not Take If
- You are diabetic (American ginseng may interfere with insulin or cause very low blood sugar).
- You are taking warfarin or other blood thinners (American ginseng may interfere with the action of the anticoagulant).
- You are taking drugs that are substrates of cytochrome P450 (CYP) 3A4 (American ginseng may make the drugs less effective).
Side Effects
- Inability to fall asleep (insomnia)
- Drowsiness
- Nervousness
- Fast heart rate
- Headache
- Low blood sugar (hypoglycemia)
Special Point
Ginseng should not be used continuously for more than one month.
Last updated: October 10, 2012
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