''Uncaria tomentosa'' is a woody vine found in the tropical jungles of South and Central America. It is known as cat's claw or uña de gato in Spanish because of its claw-shaped thorns. The plant root bark is used in herbalism for a variety of ailments, and is sold as a

dietary supplement A dietary supplement is a manufactured product intended to supplement a person's diet by taking a pill (pharmacy), pill, capsule (pharmacy), capsule, tablet (pharmacy), tablet, powder, or liquid. A supplement can provide nutrients eithe ...

. There is no high-quality clinical evidence that it has any benefit for treating human diseases.

Description

''Uncaria tomentosa'' is a liana deriving its name from hook-like thorns that resemble the claws of a cat. ''U. tomentosa'' can grow to a length of up to 30 m (100 ft), climbing by means of these thorns. The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are elliptic with a smooth edge, and grow in opposing pairs. Cat's claw is indigenous to the

Amazon rainforest The Amazon rainforest, also called the Amazon jungle or Amazonia, is a Tropical and subtropical moist broadleaf forests, moist broadleaf tropical rainforest in the Amazon biome that covers most of the Amazon basin of South America. This basin ...

, with its habitat being restricted primarily to the

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

areas of South and Central America.

Taxonomy

There are two species of cat's claw commonly used in North America and Europe, ''Uncaria tomentosa'' and '' Uncaria guianensis'', having different properties and uses. The two are frequently confused but ''U. tomentosa'' is the more commonly used in traditional medicine. ''U. tomentosa'' is further divided into two chemotypes that remain under preliminary research for their properties and compounds. There are other plants which are known as

cat's claw Cat's claw or cat's claws (also ''uña de gato'' or ''unha de gato'' in Spanish or Portuguese) is a common name for several plants: * ''Acacia greggii'', a tree species native to the southwestern United States and northern Mexico * ''Acacia plumos ...

(or uña de gato) in Mexico and Latin America; however, they are entirely different plant species, belonging to neither the genus ''Uncaria'', nor to the family Rubiaceae.

Phytochemicals

Phytochemicals in ''Uncaria tomentosa'' root bark include oxindole and indole

alkaloid Alkaloids are a broad class of natural product, naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids. Alkaloids are produced by a large varie ...

s, glycosides, organic acids,

proanthocyanidin Proanthocyanidins are a class of polyphenols found in many plants, such as cranberry, blueberry, and grape seeds. Chemically, they are oligomeric flavonoids. Many are oligomers of catechin and epicatechin and their gallic acid esters. More complex ...

sterol A sterol is any organic compound with a Skeletal formula, skeleton closely related to Cholestanol, cholestan-3-ol. The simplest sterol is gonan-3-ol, which has a formula of , and is derived from that of gonane by replacement of a hydrogen atom on ...

s, and triterpenes, glycosides, tannins,

polyphenol Polyphenols () are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as ...

s, catechins, rhynchophylline, and beta-sitosterol.

Traditional medicine

Cat's claw bark has been used as a traditional medicine in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

n countries over centuries for its supposed health benefits, and is a common herbal supplement. There is no high-quality clinical evidence that it has any benefit in treating human diseases.

Interactions

Cat's claw has extensive interactions with numerous prescription drugs. Its safety over long-term use or during pregnancy has not been scientifically determined.

Adverse effects

Individuals allergic to plants in the family

Rubiaceae Rubiaceae () is a family (biology), family of flowering plants, commonly known as the coffee, madder, or bedstraw family. It consists of terrestrial trees, shrubs, lianas, or herbs that are recognizable by simple, opposite leaves with Petiole ( ...

and different species of '' Uncaria'' may be more likely to have adverse reactions to cat's claw. Allergic reactions can include itching, rash, and skin inflammation. Gastrointestinal discomfort, nausea, headache, impaired kidney and hormonal effects, and neuropathy are other possible effects. People requiring anticoagulation,

blood pressure Blood pressure (BP) is the pressure of Circulatory system, circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term ...

, or immune therapy should not use cat's claw.

References

External links

*
''Uncaria tomentosa'' List of Chemicals (Dr. Duke's Databases)
{{Authority control tomentosa Flora of Central America Flora of Trinidad and Tobago Flora of French Guiana Flora of Guyana Flora of Suriname Flora of Venezuela Flora of Colombia Flora of Ecuador Flora of Peru Medicinal plants