Polygonum cuspidatum

Related Terms

Anthraquinones, astringin, emodin, Fallopia japonica, flavonoid, fuyanke granule, Hu chang, Hu zhang, Phellodendron chinense, physcion, phytoalexin, phytoestrogens, piceatannol, piceid, polydatin, Polygonaceae (family), Polygoni cuspidati radix, Polygonum cuspidatum roots, Polygonum cuspidatum water extract, Polygonum cuspidatum, polyphenolic hydroxyanthraquinones, polyphenolic phytoalexin, Protykin?, resveratrol, Reynoutria japonica, stilbenes.

Background

Japanese knotweed (Polygonum cuspidatum), a perennial herb native to Japan, China and Korea, was imported into Great Britain and the United States in the 1800s as an ornamental plant. The shoots, leaves, and stems are edible, but contain oxalic acid, a chemical that may hinder calcium absorption. The three Latin names of Japanese knotweed are used in different regions of the world: Reynoutria japonica in much of Europe; Polygonum cuspidatum, in North America; and Fallopia japonica, in Britain.
Japanese knotweed is a common commercial source of resveratrol, a chemical well-known for its presence in red wine. Resveratrol, which is available as a dietary supplement, has reported antiaging, antioxidant, anti-inflammatory, anticancer, and lipid-lowering effects.
Traditional medicinal uses of Japanese knotweed root extracts include improvement of oral hygiene and cardiovascular health and treatment of acute hepatitis, high cholesterol, inflammation, skin rash, and constipation.

Evidence Table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory

The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

Dosing

Adults (18 years and older)
There is no proven safe or effective dose for Japanese knotweed in adults.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Interactions

Interactions with Drugs
Japanese knotweed may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin?) or heparin, anti-platelet drugs such as clopidogrel (Plavix?), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin?, Advil?) or naproxen (Naprosyn?, Aleve?).
Because Japanese knotweed contains estrogen-like chemicals, the effects of drugs believed to have estrogen-like properties may be altered.
Japanese knotweed may also interact with antibiotics, anticancer agents, antiviral drugs, anti-inflammatory agents, cardiovascular drugs, cholesterol lowering drugs, drugs used for osteoporosis, lipoxygenase inhibitors, and photosensitizing agents (agents that cause sun sensitivity).

Attribution

This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

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