Uncaria tomentosa, CC4.0 license, original by Vangeliq.petrova
Cat's Claw Summary
- This review also covers Uncaria guianensis (also called cat's claw), an interchangeable and likely preferable source of the medicine (as it grows in a much wider area).
- Widespread adulteration is a problem with both species of cat's claw, one line of evidence there is unsustainable overharvesting.
- Only confirmed cultivated material should be used (of either species).
- Lack of information greatly hampers the ability to know to what extent either species is overharvest or mis-harvested (e.g. damaging other nearby plants in the process of harvest).
- Lack of coordinated government oversight in Peru and Brazil greatly hampers development of a sustainable, transparent marketplace, harming small farmers in particular.
Even Common Plants Can Be Overharvested
Overharvesting of the extremely common Amazonian lianas known as cat's claw is substantial, resulting in widespread adulteration (substitution of non-medicinal, similar-looking materials from other plants) (Bussmann, et al. 2007). U. tomentosa is more common in Peru and grows at higher elevations than U. guianensis, which grows primarily in Brazil and in a far broader habitat (Gomes Honório, et al. 2016). This makes U. tomentosa much more susceptible to unsustainable overharvesting, and also suggests that cultivation of U. guianensis is a priority for conservation (Gomes Honório, et al. 2016). Some sources contend that planting of U. tomentosa for medicine is widespread in Peru, including by larger companies, but that a failure of the government of Peru to create a transparent, sustainable process around this valuable medicine has greatly hampered development (de Jong, et al. 2000). In an ideal world, there would be a system overseen by the government, with high transparency and absence of corruption, by which small and large farmers alike could sell cultivated raw material on the international market with excellent tracking so that sustainability would be verifiable.
It is likely that much of what is sold as U. tomentosa is actually U. guianensis in North America. When the thorns of the plants are intact, they are easy to distinguish (U. tomentosa has claws that even spiral in on themselves compared to the much less prominent hooks of U. guianensis). The stem (inferior medicinally but less destructive to harvest) and root (superior medicinally but more destructive to harvest) barks of the two are very difficult to tell apart and are both widely circulated in commerce.
It is likely that much of what is sold as U. tomentosa is actually U. guianensis in North America. When the thorns of the plants are intact, they are easy to distinguish (U. tomentosa has claws that even spiral in on themselves compared to the much less prominent hooks of U. guianensis). The stem (inferior medicinally but less destructive to harvest) and root (superior medicinally but more destructive to harvest) barks of the two are very difficult to tell apart and are both widely circulated in commerce.
Alkaloid Confusion/Distraction
The contention that U. guianensis's higher content of tetracyclic oxindole alkaloids (TOA) is more harmful or less effective, compared to the higher content of pentacyclic oxindole alkaloids (POA) in U. tomentosa (or some chemotypes of it), is driven by commercial interests and is not supported by scientific research showing both alkaloids are naturally present in both species, that both types of alkaloids have medicinal value, and that they work synergistically (Aguilar, et al. 2002; Gattuso, et al. 2004; Mohamed, et al. 2000; Sandoval, et al. 2002; Winker, et al. 2004). Using more expensive extracts that remove TOA has not been shown in any head-to-head, human clinical trial to be any better than traditional crude extracts. And pushing this line of thinking just promotes more harvesting of the less available U. tomentosa species and does nothing to support its conservation.
References
Aguilar JL, Rojas P, Marcelo A, et al. (2002) "Antiinflammatory activity of two different extracts of Uncaria tomentosa (Rubiaceae)" J Ethnopharmacol 81(2):271–276. PMID 12065162
Armas WN, de Jong W (2004) "Potentials and perspective of cat's clawse [Uncaria tomentosa (Willd ex Roem & Shcult) DC]" In: Alexiades MN, Shanley P (eds) Productos Forestales, Medios de Subsistencia y Conservación. Estudios de Caso Sobre Sistemas de Manejo de Productos Forestales No Maderables. Vol 3 (Bogor, Indonesia: CIFOR):281–298.
Bussmann RW, Sharon D, Vandebroek I, et al. (2007) "Health for sale: The medicinal plant markets in Trujillo and Chiclayo, northern Peru" J Ethnobiol Ethnomed 3:37.
De Jong W, Melnyk M, Alfaro L (2000) "A concerted approach to uña de gato development in Peru" Int Tree Crop J 10(4):321–336.
Gattuso M, Di Sapio O, Gattuso S, Pereyra EL (2004) "Morphoanatomical studies of Uncaria tomentosa and Uncaria guianensis bark and leaves" Phytomedicine 11(2–3):213–223. PMID 15070175
Gomes Honório IC, Waléria Bertoni B, Soares Pereira AM (2016) "Uncaria tomentosa and Uncaria guianensis an agronomic history to be written" Cienc Rural 46(8):1401–1410.
Mohamed AF, Matsumoto K, Tabata K, et al. (2000) “Effects of Uncaria tomentosa total alkaloid and its components on experimental amnesia in mice: Elucidation using the passive avoidance test” J Pharm Pharmacol 52(12):1553–1561. PMID 11197086
Sandoval M, Okuhama NN, Zhang XJ, et al. (2002) "Antiinflammatory and antioxidant activities of cat’s claw (Uncaria tomentosa and Uncaria guianensis) are independent of their alkaloid content" Phytomedicine 9(4):325–337. PMID 12120814
Winkler C, Wirleitner B, Schroecksnadel K, et al. (2004) "In vitro effects of two extracts and two pure alkaloid preparations of Uncaria tomentosa on peripheral blood mononuclear cells" Planta Med 70(3):205–210. PMID 15114496
Armas WN, de Jong W (2004) "Potentials and perspective of cat's clawse [Uncaria tomentosa (Willd ex Roem & Shcult) DC]" In: Alexiades MN, Shanley P (eds) Productos Forestales, Medios de Subsistencia y Conservación. Estudios de Caso Sobre Sistemas de Manejo de Productos Forestales No Maderables. Vol 3 (Bogor, Indonesia: CIFOR):281–298.
Bussmann RW, Sharon D, Vandebroek I, et al. (2007) "Health for sale: The medicinal plant markets in Trujillo and Chiclayo, northern Peru" J Ethnobiol Ethnomed 3:37.
De Jong W, Melnyk M, Alfaro L (2000) "A concerted approach to uña de gato development in Peru" Int Tree Crop J 10(4):321–336.
Gattuso M, Di Sapio O, Gattuso S, Pereyra EL (2004) "Morphoanatomical studies of Uncaria tomentosa and Uncaria guianensis bark and leaves" Phytomedicine 11(2–3):213–223. PMID 15070175
Gomes Honório IC, Waléria Bertoni B, Soares Pereira AM (2016) "Uncaria tomentosa and Uncaria guianensis an agronomic history to be written" Cienc Rural 46(8):1401–1410.
Mohamed AF, Matsumoto K, Tabata K, et al. (2000) “Effects of Uncaria tomentosa total alkaloid and its components on experimental amnesia in mice: Elucidation using the passive avoidance test” J Pharm Pharmacol 52(12):1553–1561. PMID 11197086
Sandoval M, Okuhama NN, Zhang XJ, et al. (2002) "Antiinflammatory and antioxidant activities of cat’s claw (Uncaria tomentosa and Uncaria guianensis) are independent of their alkaloid content" Phytomedicine 9(4):325–337. PMID 12120814
Winkler C, Wirleitner B, Schroecksnadel K, et al. (2004) "In vitro effects of two extracts and two pure alkaloid preparations of Uncaria tomentosa on peripheral blood mononuclear cells" Planta Med 70(3):205–210. PMID 15114496