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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).
References
Allen GM, Bond MD, Main MB. 50 common native plants important
in Florida's ethnobotanical history. University of Florida Web site.
http://edis.ifas.ufl.edu/BODY_UW152. Accessed June 6, 2008.
Anderson PM, Meyers DE, Hasz DE, Covalcuic K, Saltzman D,
Khanna C, Uckun FM. 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.
http://www.mskcc.org/mskcc/html/69334.cfm. Updated September 17, 2007.
Accessed June 6, 2008.
Pokeweed poisoning. Evanston Northwestern Healthcare Web site.
http://www.enh.org/healthresources/encyclopedia/ency/article/002874.aspx.
Accessed April 26, 2007. Content no longer available.
Qi L, Nett TM, Allen MC, Sha X, Harrison GS, Frederick BA,
Crawford ED, Glode LM. 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.
http://www8.georgetown.edu/departments/physiology/cam/urbanherbs/pokeweed.htm.
Accessed 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: 11/01/2008
Last Revised: 11/01/2008
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