Herb of the Month – Uncaria Tomentosa or Cat’s Claw

🌿 This month’s Herb of the Month is Cat’s Claw or Uncaria tomentosa
Family: Rubiaceae

🌿 Botanical name and description

Cat’s Claw (Uncaria tomentosa) is a member of the Rubiaceae family and is native to South and Central America (1). This robust woody vine thrives in the Amazon River basin and is indigenous to many tropical forests across Bolivia, Brazil, Colombia, Ecuador, Venezuela and Peru (4). The plant is known as ‘uña de gato’, ‘samento’, ‘minsho-mentis’ and ‘garabato’ and is revered as ‘the life-giving vine of Peru’ (6). Cat’s Claw’s name is derived from the curved and elongated thorns which protrude from the stems, reminiscent of feline claws (6). The younger stems are green, with bronze coloured tips at sites of new growth, whilst older stems are light-brown and greyish in colour, and develop a woody texture over time, with some plants recorded to be 30m in height and 15cm thick (4). Cat’s Claw prefers temperate or sub-tropical weather, and flowers in spring and summer producing large tubular yellow flowers (1). In western herbal medicine, the bark and roots are used to make herbal teas, capsules and liquids (2).

🌿 History and traditional use

Cat’s Claw has a long history within the indigenous tribes of the Amazon River basin whereby the bark and roots were prepared as a decoction to treat various ailments (3,7). Ethnic groups in the Peruvian Amazon, such as the Ashaninka, Aguaruna, Huambisa, Jivaro, Shipibo-Conibo, Bora, Mashiguenga, Campa, and Piro tribes have utilised Cat’s Claw for centuries to treat conditions including arthritis, allergies, asthma, diabetes, cancer, and bacterial and viral infections (1,6).  The Ashaninka tribal healers would use the decoctions to treat sick tribe members suffering from infections, high blood pressure, tumours, abscesses, boils, wounds, and generalised aches and pains (2,7). Additionally the bark was used for male and female reproductive concerns including prostatitis, irregular menstrual cycles, female discharges, contraception, gonorrhoea, and inflammation of the urinary tract (1,6).  Furthermore, this medicine was used in respiratory and gastrointestinal disease, specifically stomach ulcers to sooth and prevent recurrence (5,6).

🌿 Actions and usage today

Today, Cat’s claw is used for conditions such as fever, fatigue, muscle and joint aches associated with bacterial and viral infections (1,7).  Studies have demonstrated antiviral, antibacterial, immunostimulatory, and immunomodulatory actions on TNF-α production, macrophage migration, and cytokine release in the body (4,5).  However, the most reported activity of Cat’s Claw is as an anti-inflammatory, particularly for arthritis (rheumatoid and osteoarthritis) (4). The herb has extensive clinical evidence in South America for successfully treating arthritis at a dose of 30 to 300 mg per day to reduce inflammation and pain at joint sites, and negate the side effects of anti-inflammatory medications (NSAID’s) on the stomach and small intestines (5,6). Additionally, studies indicate therapeutic efficacy for gastrointestinal inflammation via gastroprotective, antioxidant, and mucous membrane trophorestorative actions which may reduce the recurrence of gastric ulcers in some patients (6).  More recently, evidence suggests potential benefits in Cat’s Claw’s ability to preserve glucose homeostasis, reduce hepatic steatosis, and reduce the severity of symptoms from the SARS-CoV-2 virus (3,6,7).

🌿 Science and clinical trials

Cat’s Claw contains a variety of constituents such as oxindole alkaloids, indole alkaloidal glucosides, quinovic acid glycosides, tannins, polyphenols, catechins, and beta-sitosterol’s that contribute to its medicinal properties (3,5). As an antioxidant and anti-inflammatory agent, the herb demonstrated efficacy via in-vivo, and in-vitro trials through the suppression of transcription factor NF-κB, which inhibited the inflammatory gene expression in patients with arthritis (3,5). In addition, it had positive effects on NSAID-induced gastropathy and enteropathy in these patients by reducing the release of LPS-induced mediators and iNOS expression, suggesting Cat’s Claw may potentially work as an adjunct therapy for arthritis and pharmaceutical induced gastrointestinal inflammation (6).  In another study, Cat’s Claw’s antioxidant and anti-inflammatory actions were investigated, via a trial conducted on patients with osteoarthritis of the knees.  30 patients were treated with the freeze dried herbal extract, whilst 15 patients were given a placebo for four weeks (4).  Pathology parameters were assessed at the beginning and end of the trial, and pain scores, adverse effects, and subject assessment scores were collected at weeks one, two and four (4).  At the end of the study, the Cat’s Claw group had no adverse effects when compared to the placebo group, and no haematological abnormalities, specifically, liver function tests were all normal (4).  Pain scores were significantly reduced in the control group when compared to placebo, with improvements occurring within week one of treatment (4). Therefore, further investigations into Cat’s Claw as an alternative, or adjuvant treatment alongside standard pharmaceuticals for osteoarthritis are warranted.  As an antibacterial, recent in vitro investigations suggest its efficacy against the bacterium Borrelia burgdorferi which is responsible for Lyme disease, both in its latent and active forms (1). More recently, in vitro and animal studies suggest anti-inflammatory, virucidal and immune modulating effects on the SARS-CoV-2 virus due to the plants oxindole alkaloids (2,7).  Despite its widespread and broad therapeutic uses worldwide, evidence supporting its efficacy and mechanisms of action in human studies is limited.

🌿 References

  1. Blanck JJ, Huebner TM, Rolls AM, Cornell JS, Hwang CS. Comprehensive Review of the Components in Cat’s Claw (Uncaria tomentosa) and Their Antibacterial Activity. AppliedChem. 2022;2(1):1-29. Available from: https://doi.org/10.3390/appliedchem2010001
  2. De Lima RC, Valente LMM, Familiar Macedo D, de-Oliveira-Pinto LM, dos Santos FB, Mazzei JL, Siani AC, Nunes PCG, de Azeredo EL. Antiviral and Virucidal Activities of Uncaria tomentosa (Cat’s Claw) against the Chikungunya Virus. Viruses. 2024; 16(3):369. Available from: https://doi.org/10.3390/v16030369
  3. Miller M, Zhang XJ, Charbonnet R, et al. The Anti-Inflammatory Actions of the Herbal Medicine, Cat’s Claw, Are Due to a Suppression of NF-κB Activation and Inhibition of Gene Expression. Pediatr Res. 1999;45:114. Available from: https://doi.org/10.1203/00006450-199904020-00676
  4. Piscoya JZ, Rodriguez Z, Bustamante SA, Okuhama NN, Miller M, Sandoval M. Efficacy and safety of freeze-dried cat’s claw in osteoarthritis of the knee: Mechanisms of action of the species Uncaria guianensis. Inflammation research : official journal of the European Histamine Research Society … [et al.]. 2001;50:442-8. Available from: https://doi.org/10.1007/PL00000268
  5. Sandoval M, Okuhama NN, Zhang X, Condezo L, Lao J, Angeles FM, Musah R, Bobrowski P, Miller M. Anti-inflammatory and antioxidant activities of cat’s claw (Uncaria tomentosa and Uncaria guianensis) are independent of their alkaloid content. Phytomedicine : International journal of phytotherapy and phytopharmacology. 2002;9:325-37. Available from: https://doi.org/10.1078/0944-7113-00117
  6. Simomura VL, Miorando D, Oliveira BM, Mânica A, Bohnen LC, Buzatto MV, Kunst FM, Ansolin LD, Somensi LB, Gutiérrez MV, Venzon L, Queiroz e Silva TF, Silva LM, Roman Junior WA. Aqueous extract of the bark of Uncaria tomentosa, an Amazonian medicinal plant, promotes gastroprotection and accelerates gastric healing in rats. J Ethnopharmacol. 2024;321:117542. Available from: https://doi.org/10.1016/j.jep.2023.117542.
  7. Yepes-Pérez AF, Herrera-Calderon O, Quintero-Saumeth J. Uncaria Tomentosa (Cat’s Claw): A Promising Herbal Medicine against SARS-CoV-2/ACE-2 Junction and SARS-CoV-2 Spike Protein Based on Molecular Modeling. Journal of Biomolecular Structure and Dynamics. 2022;40(5):2227–43. Available from: https://doi.org 10.1080/07391102.2020.1837676