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Pokeweed

Other common name(s): common pokeweed, poke root, poke salad (or poke sallet), poke berry, poke, Virginia poke, inkberry, cancer root, American nightshade, pigeon berry

Scientific/medical name(s): Phytolacca americana

Description

Pokeweed is a perennial herb that is native to eastern North America and cultivated throughout the world. It can grow to a height of more than ten feet during the summer and dies back to the root each winter. The berries and dried roots are used in herbal remedies.

Overview

Some research has shown that a protein contained in pokeweed, called pokeweed antiviral protein (PAP), has anti-tumor effects in mice and laboratory studies. In test tube studies, PAP has also shown action against viruses such as herpes and human immunodeficiency virus (HIV). Clinical trials have not yet determined whether these effects apply to humans. All parts of the mature pokeweed plant contain chemically active substances such as phytolaccine, formic acid, tannin, and resin acid. All parts of the plant are at least mildly poisonous when eaten, although the root is most toxic.

How is it promoted for use?

Proponents claim that pokeweed can be taken internally to treat a number of conditions, including rheumatoid arthritis, tonsillitis, mumps, swollen glands, chronic excess mucus, bronchitis, mastitis, and constipation. They also say that the herb is an effective treatment for fungal infections, joint inflammation, hemorrhoids, breast abscesses, ulcers, and bad breath. Herbalists also claim that external application of a preparation made from the plant relieves itching, inflammation, and skin diseases.

What does it involve?

Pokeweed supplements are available as liquid extracts, tinctures, powders, and poultices. There is no standard dose for pokeweed. Pokeweed berries are one of the ingredients in the Hoxsey formula (see Hoxsey Formula). Pokeweed antiviral protein, or PAP, is difficult to remove from the plant in its natural form. For research purposes, scientists have learned how to create PAP. The purified, lab-created version is also less toxic than that extracted from the plant.

What is the history behind it?

Young pokeweed shoots, which contain very low levels of toxins, were used as food by Native Americans and others. In the Southeastern United States, some people still cook and eat “poke sallet.” It is thoroughly boiled in water that is changed twice during cooking. Native Americans also used pokeweed in herbal remedies as a heart stimulant and to treat cancer, rheumatism, itching, and syphilis. The pokeweed root was also used as a laxative and to induce vomiting. European settlers adopted the use of pokeweed, which went on to become a common folk medicine.

Juice from the berries was once used to make ink and dye, and it is still used by the food industry to make red food coloring. Farmers and dairymen use an alcohol extract or tincture of pokeweed to reduce swelling of cows’ udders. Followers of President James Polk wore pokeweed twigs during their candidate's election campaign, mistakenly believing that the plant was named for him.

What is the evidence?

Research has shown that pokeweed contains a compound that appears to enhance the immune system and has some anti-cancer effects in animals. According to one animal study, pokeweed antiviral protein (PAP), a protein contained in the plant, demonstrated anti-cancer effects in rodents. Another study found that PAP, when combined with an immunotherapy drug called TP-3, holds promise as a potential treatment for advanced osteosarcomas and some soft tissue sarcomas. Laboratory studies have suggested that certain formulations of PAP may be turn out to be useful against cancer cells that depend on hormones for their growth, such as cells from prostate, breast, and ovarian cancer.

PAP also acts against some viruses such as herpes and human immunodeficiency virus (HIV), and it is being studied as a possible antiviral. In laboratory studies, it seemed to help protect cells against HIV, and researchers are studying whether it might help protect people from HIV infection. However, even though animal and laboratory studies may show a certain compound looks promising, studies in people are necessary to find out whether the results hold true for humans.

Are there any possible problems or complications?

This product is sold as a dietary supplement in the United States. Unlike companies that produce drugs (which must provide the FDA with results of detailed testing showing their product is safe and effective before the drug is approved for sale), the companies that make supplements do not have to show evidence of safety or health benefits to the FDA before selling their products. Supplement products without any reliable scientific evidence of health benefits may still be sold as long as the companies selling them do not claim the supplements can prevent, treat, or cure any specific disease. Some such products may not contain the amount of the herb or substance that is written on the label, and some may include other substances (contaminants). Though the FDA has written new rules to improve the quality of manufacturing processes for dietary supplements and the accurate listing of supplement ingredients, these rules do not take full effect until 2010. And, the new rules do not address the safety of supplement ingredients or their effects on health when proper manufacturing techniques are used.
Most such supplements have not been tested to find out if they interact with medicines, foods, or other herbs and supplements. Even though some reports of interactions and harmful effects may be published, full studies of interactions and effects are not often available. Because of these limitations, any information on ill effects and interactions below should be considered incomplete.

All parts of the pokeweed are poisonous, particularly the roots. The leaves and stems are next in toxicity, and the berries have the smallest amount of poison. However, children have been poisoned by eating raw pokeweed berries, and some have died. The practice of brewing pokeweed plant parts with hot water to make tea has caused poisoning. Thoroughly cooking the plant reduces its toxicity. The effects of eating the uncooked or improperly prepared plant can include nausea, vomiting, diarrhea, abdominal cramps, headaches, blurred vision, confusion, dermatitis, dizziness, and weakness. Convulsions, low blood pressure, rapid heartbeat, heart block (a blockage of the electrical impulses that stimulate the heart to contract), and death may occur. Animals can also die of toxic effects from eating pokeweed, although it does not happen often.

Pokeweed should not be used by people who are taking antidepressants, disulfiram (Antabuse), oral contraceptives, or fertility drugs. Other potential interactions between pokeweed and other drugs and herbs should be considered. Always tell your doctor and pharmacist about any herbs you are taking.

The plant may cause menstrual cycle irregularities and may also stimulate contractions of the uterus. Women who are pregnant or breast-feeding should not use pokeweed. Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences.

Additional resources

More information from your American Cancer Society

The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-ACS-2345).

Dietary Supplements: What Is Safe?

The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management

Complementary and Alternative Methods and Cancer

Placebo Effect

Learning About New Ways to Treat Cancer

Learning About New Ways to Prevent Cancer

Hoxsey Formula

References

Allen GM, Bond MD, Main MB. 50 common native plants important in Florida’s ethnobotanical history. University of Florida Web site. Accessed at http://edis.ifas.ufl.edu/BODY_UW152 on June 6, 2008.

Anderson PM, Meyers DE, Hasz DE, et al. In vitro and in vivo cytotoxicity of an anti-osteosarcoma immunotoxin containing pokeweed antiviral protein. Cancer Res. 1995;55:1321-1327.

Bown D. New Encyclopedia of Herbs & Their Uses. New York, NY: DK Publishing Inc; 2001.

Ek O, Waurzyniak B, Myers DE, Uckun FM. Antitumor activity of TP3(anti-p80)-pokeweed antiviral protein immunotoxin in hamster cheek pouch and severe combined immunodeficient mouse xenograft models of human osteosarcoma. Clin Cancer Res. 1998;4:1641-1647.

Fetrow CW, Avila JR. Professional's Handbook of Complementary & Alternative Medicines. Philadelphia, PA: Lippincott Williams & Wilkins; 2004.

Gruenwald J. PDR for Herbal Medicines. 3rd ed. Montvale, NJ: Thomson PDR; 2004.

Pokeweed. Memorial Sloan-Kettering Cancer Center Web site. Accessed at www.mskcc.org/mskcc/html/69334.cfm on June 6, 2008.

Pokeweed poisoning. Evanston Northwestern Healthcare Web site. Accessed at www.enh.org/healthresources/encyclopedia/ency/article/002874.aspx on April 26, 2007. Content no longer available.

Qi L, Nett TM, Allen MC, et al. Binding and cytotoxicity of conjugated and recombinant fusion proteins targeted to the gonadotropin-releasing hormone receptor. Cancer Res. 2004;64:2090-2095.

Urban herbs: medicinal plants at Georgetown University. Georgetown University Medical Center Web site. Accessed at www8.georgetown.edu/departments/physiology/cam/urbanherbs/pokeweed.htm on June 6, 2008.

Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.

Last Medical Review: 11/28/2008
Last Revised: 11/28/2008