''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 Herbal medicine (also herbalism) is the study of pharmacognosy and the use of medicinal plants, which are a basis of traditional medicine. With worldwide research into pharmacology, some herbal medicines have been translated into modern remedie ...

for a variety of ailments, and is sold as a

dietary supplement A dietary supplement is a manufactured product intended to supplement one's diet by taking a pill, capsule, tablet, powder, or liquid. A supplement can provide nutrients either extracted from food sources or that are synthetic in orde ...

. There is no clinical evidence that cat's claw is effective for treating any human disease.

Description

''Uncaria tomentosa'' is a

liana A liana is a long- stemmed, woody vine that is rooted in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the canopy in search of direct sunlight. The word ''liana'' does not refer to a ...

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 are elliptic with a smooth edge, and grow in opposing pairs. Cat's claw is indigenous to the Amazon rainforest, with its habitat being restricted primarily to the

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

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 Traditional medicine (also known as indigenous medicine or folk medicine) comprises medical aspects of traditional knowledge that developed over generations within the folk beliefs of various societies, including indigenous peoples, before th ...

. ''U. tomentosa'' is further divided into two

chemotype A chemotype (sometimes chemovar) is a chemically distinct entity in a plant or microorganism, with differences in the composition of the secondary metabolites. Minor genetic and epigenetic changes with little or no effect on morphology or anatomy ...

s 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

Phytochemical Phytochemicals are chemical compounds produced by plants, generally to help them resist fungi, bacteria and plant virus infections, and also consumption by insects and other animals. The name comes . Some phytochemicals have been used as poison ...

s in ''Uncaria tomentosa'' root bark include oxindole and

indole Indole is an aromatic heterocyclic organic compound with the formula C8 H7 N. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered pyrrole ring. Indole is widely distributed in the natural environme ...

alkaloid Alkaloids are a class of basic BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Th ...

glycoside In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycoside ...

organic acid An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids, whose acidity is associated with their carboxyl group –COOH. Sulfonic acids, containing the group –SO2OH, are ...

s, proanthocyanidins,

sterol Sterol is an organic compound with formula , whose molecule is derived from that of gonane by replacement of a hydrogen atom in position 3 by a hydroxyl group. It is therefore an alcohol of gonane. More generally, any compounds that contain the g ...

s, and

triterpene Triterpenes are a class of chemical compounds composed of three terpene units with the molecular formula C30H48; they may also be thought of as consisting of six isoprene units. Animals, plants and fungi all produce triterpenes, including squal ...

tannin Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids. The term ''tannin'' (from Anglo-Norman ''tanner ...

polyphenol Polyphenols () are a large family of naturally occurring organic compounds characterized by multiples of phenol units. They are abundant in plants and structurally diverse. Polyphenols include flavonoids, tannic acid, and ellagitannin, some o ...

catechin Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids. The name of the catechin chemical family derives from '' catechu'', which is the ta ...

rhynchophylline Rhynchophylline is an alkaloid found in certain '' Uncaria'' species (Rubiaceae), notably ''Uncaria rhynchophylla'' and '' Uncaria tomentosa''. It also occurs in the leaves of ''Mitragyna speciosa'' (kratom), a tree native to Thailand. Chemicall ...

, and beta-sitosterol.

Traditional medicine

Cat's claw

bark Bark may refer to: * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Places * Bark, Germany * Bark, Warmian-Masurian Voivodeship, Poland Arts, ...

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 relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...

n countries over centuries for its supposed health benefits, and is a common herbal supplement. As of 2021, 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 drug A prescription drug (also prescription medication or prescription medicine) is a pharmaceutical drug that legally requires a medical prescription to be dispensed. In contrast, over-the-counter drugs can be obtained without a prescription. The rea ...

s. Its safety over long-term use or during pregnancy has not been scientifically determined.

Adverse effects

Individuals allergic to plants in the family

Rubiaceae The Rubiaceae are a 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 interpetiolar stipules ...

and different species of '' Uncaria'' may be more likely to have adverse reactions to cat's claw. Allergic reactions can include

itching Itch (also known as pruritus) is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to be classified as any one type of sensory experience. Itch has many similarities to pain, and while both are unpleasant ...

rash A rash is a change of the human skin which affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cr ...

, and skin

inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...

. Gastrointestinal discomfort,

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

, headache, impaired kidney and hormonal effects, and

neuropathy Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or or ...

are other possible effects. People requiring anticoagulation,

blood pressure Blood pressure (BP) is the pressure of 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 "blood pressur ...

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

References

External links

*
''Uncaria tomentosa'' List of Chemicals (Dr. Duke's Databases)
{{Taxonbar, from=Q1123391 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