''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 Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many Latin American countries **Spanish cuisine Other places * Spanish, Ontario, Can ...

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 reme ...

for a variety of ailments, and is sold as a dietary supplement. There is no clinical evidence that cat's claw is effective for treating any human disease.

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 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 ''Uncaria guianensis'', the cat's claw, is a plant species in the genus ''Uncaria'' found in the Amazon biome. Other names for the plant include ''uña de gato'', ''Paraguayo'' and ''vincaria''. ''Uncaria guianensis'' contains many phytochemica ...

'', 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 the ...

. ''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 (or uña de gato) in Mexico and Latin America; however, they are entirely different

plant species Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms ''gut flora'' or ''skin flora''. Ety ...

, belonging to neither the genus ''Uncaria'', nor to the family Rubiaceae.

Phytochemicals

Phytochemicals in ''Uncaria tomentosa'' root bark include

oxindole Oxindole (2-indolone) is an aromatic heterocyclic organic compound with the formula C6H4CHC(O)NH. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing ring. Oxindole is a modified ind ...

and

indole Indole is an aromatic heterocyclic organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other c ...

alkaloid Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar ...

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 ...

s, 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 compl ...

s, sterols, 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 squa ...

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 tanni ...

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 β-sitosterol (beta-sitosterol) is one of several phytosterols (plant sterols) with chemical structures similar to that of cholesterol. It is a white, waxy powder with a characteristic odor, and is one of the components of the food additive E499 ...

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

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 Interaction is action that occurs between two or more objects, with broad use in philosophy and the sciences. It may refer to: Science * Interaction hypothesis, a theory of second language acquisition * Interaction (statistics) * Interactions o ...

with numerous prescription drugs. Its safety over long-term use or during pregnancy has not been scientifically determined.

Adverse effects

Individuals

allergic Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic der ...

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 a ...

and different species of ''

Uncaria ''Uncaria'' is a genus of flowering plants in the family Rubiaceae. It has about 40 species.''Uncaria'' At: World Checklist of Rubiaceae At: Kew Gardens Website. (see ''External links'' below). Their distribution is pantropical, with most speci ...

'' may be more likely to have adverse reactions to cat's claw. Allergic reactions can include

itching Itch (also known as pruritus) is a Wikt:sensation, sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to be classified as any one type of Sensory system, sensory experience. Itch has many similarities to pain, ...

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, c ...

, and skin

inflammation Inflammation (from la, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molec ...

. 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 are other possible effects. People requiring

anticoagulation Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where the ...

, blood pressure, 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