Cat's claw has grown quite popular in the natural products industry and is mostly taken today to boost immune function, as an all over tonic and preventative to stay healthy, for arthritis and inflammation, for bowel and colon problems, and as an complementary therapy for cancer.* Are you looking for a "TOA-Free" product? For more complete information follow this link to read about The TOA / POA Controversy.

For more complete information on this unique rainforest plant, please see the Plant Database File on Cat's Claw. To see pictures of cat's claw growing in the Peruvian Amazon, click here. More information on cat's claw can also be found in the new Anti-Cancerous Guide

Traditional Uses:* as an immune stimulant and an adjunctive therapy for cancer (to reduce side effects of chemotherapy and protect cells); as a bowel cleanser and anti-inflammatory for Crohn's, colitis, diverticulitis, irritable bowel syndrome (IBS), and other bowel problems; as an anti-inflammatory for arthritis (all kinds) and muscle pains/strains/injuries; as a general daily tonic (to tone, balance, and strengthen all body functions); for stomach ulcers and ulcerative colitis and as an ulcer preventative/ stomach and bowel protector)

Suggested Use: Take 1 gram twice daily, or as directed by a healthcare professional.

Contraindications:

• 1. Cat's claw has been clinically documented with immunostimulant effects and is contraindicated before or following any organ or bone marrow transplant or skin graft.
• 2. Cat's claw has been documented with antifertility properties and is contraindicated in persons seeking to get pregnant. However, this effect has not been proven to be sufficient for the product to be used as a contraceptive, and it should not be relied on for such.
• 3, Cat's claw has chemicals that can reduce platelet aggregation and thin the blood. Check with your doctor first if you are taking coumadin or other blood-thinning drugs and discontinue use one week to ten days prior to any major surgical procedure.
• 4. Cat's claw vine bark requires sufficient stomach acid to help break down the tannins and alkaloids during digestion and to aid in absorption. Avoid taking bark capsules or tablets at the same time as antacids. Avoid taking high tannin (dark-colored) liquid extracts and tinctures directly by mouth and dilute first in water or acidic juice (such as orange juice).
• 5. Large dosages of cat's claw (3-4 gram dosages at a time) have been reported to cause some abdominal pain or gastrointestinal problems, including diarrhea (due to the tannin content of the vine bark) in some people. The diarrhea or loose stools tend to be mild and go away with continued use. Discontinue use or reduce dosage if diarrhea persists longer than three or four days.

Drug Interactions:

• 1. Due to its immunostimulant effects, cat's claw should not be used with medications intended to suppress the immune system, such as cyclosporin or other medications prescribed following an organ transplant. (This theory has not been proven scientifically.)
• 2. Based upon in vivo rat studies, cat's claw may protect against gastrointestinal damage associated with nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen.
• 3. Cat's claw may potentiate coumadin and blood-thinning drugs.

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Published Research on Cat's Claw

All available third-party research on cat's claw can be found at PubMed. A partial listing of the published research on cat's claw updated through Feb 2019 is shown below:

Immunostimulant & Immunomodulatory Actions:
Baraya, Y., et al. "The immunomodulatory potential of selected bioactive plant-based compounds in breast cancer: A review." Anticancer Agents Med. Chem. 2017; 17(6):770-783.
Núñez C, et al. "[Immunomodulation of Uncaria tomentosa over dendritic cells, il-12 and profile TH1/TH2/TH17 in breast cancer]." Rev. Peru Med. Exp. Salud. Publica. 2015 Oct; 32(4): 643-51.
Lozada-Requena, I., et al. "[Lymphocyte subsets, dendritic cells and cytokine profiles in mice with melanoma treated with Uncaria tomentosa]." Rev. Peru Med. Exp. Salud Publica. 2015 Oct; 32(4): 633-42.
Yunis-Aguinaga, J., et al. "Uncaria tomentosa increases growth and immune activity in Oreochromis niloticus challenged with Streptococcus agalactiae." Fish Shellfish Immunol. 2015 Nov; 47(1): 630-8.
Montserrat-de la Paz, S., et al. "Pharmacological effects of mitraphylline from Uncaria tomentosa in primary human monocytes: Skew toward M2 macrophages. J. Ethnopharmacol. 2015 Jul; 170: 128-35.
Lima-Junior, R., et al. "Uncaria tomentosa alkaloidal fraction reduces paracellular permeability, IL-8 and NS1 production on human microvascular endothelial cells infected with dengue virus." Nat. Prod. Commun. 2013 Nov; 8(11): 1547-50.
Domingues, A., et al. "Prevention of experimental diabetes by Uncaria tomentosa extract: Th2 polarization, regulatory T cell preservation or both?" J. Ethnopharmacol. 2011 Sep; 137(1): 635-42.
Domingues, A., et al. "Uncaria tomentosa aqueous-ethanol extract triggers an immunomodulation toward a Th2 cytokine profile." Phytother Res. 2011 Aug; 25(8): 1229-35
Erowele, G., et al. "Pharmacology and therapeutic uses of cat's claw." Am. J. Health Syst. Pharm. 2009 Jun; 66(11): 992-5.
Reis, S., et al. "Immunomodulating and antiviral activities of Uncaria tomentosa on human monocytes infected with Dengue Virus-2." Int. Immunopharmacol. 2008; 8(3): 468-76.
Holderness, J., et al. "Select plant tannins induce IL-2 Ralpha up-regulation and augment cell division in gammadelta T cells." J. Immunol. 2007 Nov; 179(10): 6468-78.
Groom, S., et al. "The potency of immunomodulatory herbs may be primarily dependent upon macrophage activation." J. Med. Food. 2007 Mar; 10(1): 73-9.
Spelman, K., et al. "Modulation of cytokine expression by traditional medicines: a review of herbal immunomodulators." Altern. Med. Rev. 2006 Jun; 11(2): 128-50.
Eberlin, S., et al. "Uncaria tomentosa extract increases the number of myeloid progenitor cells in the bone marrow of mice infected with Listeria monocytogenes." Int. Immunopharmacol. 2005; 5(7-8): 1235-46.
Deharo, E., et al. "In vitro immunomodulatory activity of plants used by the Tacana ethnic group in Bolivia." Phytomedicine. 2004 Sep; 11(6): 516-22.
Lamm, S., et al, "Persistent response to pneumococcal vaccine in individuals supplemented with a novel water soluble extract of Uncaria tomentosa, C-Med-100." Phytomedicine. 2001; 8(4): 267-74.
Sheng Y, et al., "Treatment of chemotherapy-induced leukopenia in a rat model with aqueous extract from Uncaria tomentosa." Phytomedicine. 2000; 7(2): 137-43.
Lemaire, I., et al. "Stimulation of interleukin-1 and -6 production in alveolar macrophages by the neotropical liana, Uncaria tomentosa (una de gato)." J. Ethnopharmacol. 1999; 64(2): 109-15.
Marina, M., et al. "Evaluacion de la actividal immunoestimulante de Uncaria tomentosa (Willd.) DC. Una de gato en ratones albinos." Biodiversidad Salud. 1998; 1(1): 16-19.
Keplinger, H., et al. "Oxindole alkaloids having properties stimulating the immunologic system and preparation containing same." United States patent 5,302,611; April 12, 1994
Wagner, H., et al. "Die Alkaloide von Uncaria tomentosa und ihre Phagozytose-steigernde Wirkung." Planta Med. 1985; 51: 419-23.
Hemingway, S. and J. Phillipson. "Alkaloids from South American species of Uncaria (Rubiaceae)." J. Pharm. Pharmacol. 1974 suppl.; 26: 113p.

Anti-inflammatory Actions:
Serrano, A., et al. "Bioactive compounds and extracts from traditional herbs and their potential anti-inflammatory health effects." Medicines. 2018 Jul; 5(3).
Azevedo, B., et al. "Aqueous extracts from Uncaria tomentosa (Willd. ex Schult.) DC. reduce bronchial hyperresponsiveness and inflammation in a murine model of asthma." J. Ethnopharmacol. 2018; 218: 76-89.
Yatoo, M., et al. "Anti-inflammatory drugs and herbs with special emphasis on herbal medicines for countering inflammatory diseases and disorders -A review." Recent Pat. Inflamm. Allergy Drug Discov. 2018; 12(1): 39-58.
Montserrat-de la Paz, S., et al. "Mitraphylline inhibits lipopolysaccharide-mediated activation of primary human neutrophils." Phytomedicine. 2016 Feb; 23(2): 141-8.
Dietrich, F., et al. "The quinovic acid glycosides purified fraction from Uncaria tomentosa protects against hemorrhagic cystitis induced by cyclophosphamide in mice." PLoS One. 2015 Jul; 10(7): e0131882.
Castilhos, L., et al. "Effect of Uncaria tomentosa extract on purinergic enzyme activities in lymphocytes of rats submitted to experimental adjuvant arthritis model." BMC Complement. Altern. Med. 2015 Jun; 15: 189.
Tay, L., et al. "Uncaria tomentosa gel against denture stomatitis: Clinical Report." J. Prosthodont. 2015 Oct; 24(7): 594-597.
Tay, L., et al. "Evaluation of different treatment methods against denture stomatitis: a randomized clinical study." Oral Surg. Oral Med. Oral Pathol. Oral Radiol. 2014 Jul; 118(1): 72-7.
Akhtar, N., et al. "Current nutraceuticals in the management of osteoarthritis: a review." Ther. Adv. Musculoskelet. Dis. 2012 Jun; 4(3): 181-207.
Rojas-Duran, R., et al. "Anti-inflammatory activity of Mitraphylline isolated from Uncaria tomentosa bark." J Ethnopharmacol. 2012 Oct; 143(3): 801-4.
Allen-Hall, L., et al. "Uncaria tomentosa acts as a potent TNF-alpha inhibitor through NF-kappaB." J. Ethnopharmacol. 2010 Feb; 127(3): 685-93.
Zeng, K., et al. "Synthesis and biological evaluation of quinic acid derivatives as anti-inflammatory agents." Bioorg. Med. Chem. Lett. 2009 Sep; 19(18): 5458-60.
Erowele, G., et al. "Pharmacology and therapeutic uses of cat's claw." Am. J. Health Syst. Pharm. 2009 Jun 1; 66(11): 992-5.
Amaral, S., et al. "Plant extracts with anti-inflammatory properties--a new approach for characterization of their bioactive compounds and establishment of structure-antioxidant activity relationships." Bioorg. Med. Chem. 2009 Mar; 17(5): 1876-83.
Yuan, D., et al. "Anti-inflammatory effects of rhynchophylline and isorhynchophylline in mouse N9 microglial cells and the molecular mechanism." Int. Immunopharmacol. 2009 Dec; 9(13-14): 1549-54.
Pero, R. "Method of preparation and composition of a water soluble extract of the bioactive component of the plant species Uncaria for enhancing immune, anti-inflammatory, anti-tumor and DNA repair processes of warm blooded animals." United States Patent No. 7,595,064. September 29, 2009
Hardin, S. "Cat's claw: An Amazonian vine decreases inflammation in osteoarthritis." Complement. Ther. Clin. Pract. 2007 Feb; 13(1): 25-8.
Allen-Hall, L., et al. "Treatment of THP-1 cells with Uncaria tomentosa extracts differentially regulates the expression if IL-1beta and TNF-alpha." J. Ethnopharmacol. 2007 Jan; 109(2): 312-7.
Badilla, B., et al. "Edema induced by Bothrops asper (Squamata: Viperidae) snake venom and its inhibition by Costa Rican plant extracts." Rev. Biol. Trop. 2006 Jun; 54(2):245-52.
Miller, M. J., et al. "The chrondoprotective actions of a natural product are associated with the activation of IGF-1 production by human chondrocytes despite the presence of IL-1beta." BMC Complement. Altern. Med. 2006 Apr; 6: 13.
Miller, M., et al. "Early relief of osteoarthritis symptoms with a natural mineral supplement and a herbomineral combination: a randomized controlled trial [ISRCTN38432711]." J. Inflamm. 2005 Oct; 2:11.
Valerio, L., et al. "Toxicological aspects of the South American herbs cat's claw (Uncaria tomentosa) and Maca (Lepidium meyenii): a critical synopsis." Toxicol. Rev. 2005; 24(1): 11-35.
Setty, A., et al. "Herbal medications commonly used in the practice of rheumatology: mechanisms of action, efficacy, and side effects." Semin. Arthritis Rheum. 2005; 34(6): 773-84.
Sheng, Y., et al. "An active ingredient of Cat's Claw water extracts: identification and efficacy of quinic acid." J. Ethnopharmacol. 2005 Jan; 96(3):
Aguilar, J., et al. "Anti-inflammatory activity of two different extracts of Uncaria tomentosa (Rubiaceae)." J. Ethnopharmacol. 2002; 81(2): 271-76.
Sandoval, M., et al., "Anti-inflammatory and antioxidant activities of cat's claw (Uncaria tomentosa and Uncaria guianensis) are independent of their alkaloid content." Phytomedicine. 2002; 9(4): 325-37.
Mur, E., et al. "Randomized double blind trial of an extract from the pentacyclic alkaloid-chemotype of Uncaria tomentosa for the treatment of rheumatoid arthritis." J. Rheumatol. 2002 Apr; 29(4): 678-81.
Sandoval-Chacon, M., et al. "Anti-inflammatory actions of cat's claw: the role of NF-kappaB." Aliment. Pharmacol. Ther. 1998; 12(12): 1279-89.
Recio, M., et al. "Structural requirements for the anti-inflammatory activity of natural triterpenoids." Planta Med. 1995; 61(2): 182-85.
Aquino, R., et al. "Plant metabolites. New compounds and anti-inflammatory activity of Uncaria tomentosa." J. Nat. Prod. 1991; 54: 453-59.
Cerri, R., et al. "New quinovic acid glycosides from Uncaria tomentosa." J. Nat. Prod. 1988; 51: 257-61.

Anticancerous & Antitumor Actions:
Ciani, F., et al. "Anti-proliferative and pro-apoptotic effects of Uncaria tomentosa aqueous extract in squamous carcinoma cells." J. Ethnopharmacol. 2018 Jan; 211: 285-294.
Allen, L., et al. "Uncaria tomentosa (Willd. ex Schult.) DC (Rubiaceae) Sensitizes THP-1 cells to radiation-induced cell death." Pharmacognosy Res. 2017 Jul-Sep; 9(3): 221-229.
Navarro, M., et al. "Fractioning of proanthocyanidins of Uncaria tomentosa. Composition and structure-bioactivity relationship." Antioxidants (Basel). 2017 Jul; 6(3). pii: E60.
Komider, A., et al. "Uncaria tomentosa leaves decoction modulates differently ros production in cancer and normal cells, and effects cisplatin cytotoxicity." Molecules. 2017 Apr 12; 22(4).
Baraya, Y., et al. "The immunomodulatory potential of selected bioactive plant-based compounds in breast cancer: A review." Anticancer Agents Med. Chem. 2017; 17(6): 770-783.
Santos, K., et al. "Uncaria tomentosa extract alters the catabolism of adenine nucleotides and expression of ecto-5'-nucleotidase/CD73 and P2X7 and A1 receptors in the MDA-MB-231 cell line." J. Ethnopharmacol. 2016 Dec 24; 194: 108-116.
Kaiser, S., et al. "Genotoxicity and cytotoxicity of oxindole alkaloids from Uncaria tomentosa (cat's claw): Chemotype relevance. J. Ethnopharmacol. 2016 Aug; 189: 90-8.
Mentor, J., et al. "Topical AC-11 abates actinic keratoses and early squamous cell cancers in hairless mice exposed to ultraviolet A (UVA) radiation." Dermatol. Online J. 2015 Apr 16; 21(4).
de Paula, L., et al. "Uncaria tomentosa (cat's claw) improves quality of life in patients with advanced solid tumors." J. Altern. Complement. Med. 2015 Jan; 21(1): 22-30.
Menghini, L., et al. "A natural formulation (imoviral ) increases macrophage resistance to LPS-induced oxidative and inflammatory stress in vitro." J. Biol. Regul. Homeost. Agents. 2014 Oct-Dec; 28(4): 775-82.
de Oliveira, L., et al. "Effect of Uncaria tomentosa extract on apoptosis triggered by Oxaliplatin exposure on HT29 Cells." Evid. Based Complement. Alternat. Med. 2014; 2014: 274786.
Dietrich, F., et al. "Quinovic acid glycosides purified fraction from Uncaria tomentosa induces cell death by apoptosis in the T24 human bladder cancer cell line." Food Chem. Toxicol. 2014 May; 67: 222-9.
Deiab, S., et al. "High-throughput screening to identify plant derived human LDH-A inhibitors." European J. Med. Plants. 2013; 3(4): 603-615.
Kaiser, S., et al. "Cat's claw oxindole alkaloid isomerization induced by cell incubation and cytotoxic activity against T24 and RT4 human bladder cancer cell lines." Planta Med. 2013 Oct; 79(15): 1413-20.
Santos Araujo Mdo, C., et al. "Uncaria tomentosa - Adjuvant treatment for breast cancer: Clinical trial." Evid. Based Complement. Alternat. Med. 2012; 2012: 676984.
Farias, I., et al. "Uncaria tomentosa for Reducing side effects caused by chemotherapy in CRC patients: Clinical Trial." Evid. Based Complement. Alternat. Med. 2012; 2012: 892182.
Anter, J., et al.. "Antigenotoxicity, cytotoxicity, and apoptosis induction by apigenin, bisabolol, and protocatechuic acid." J. Med. Food. 2011 Mar; 14(3): 276-83.
Gurrola-Diaz, C., et al. "Inhibitory mechanisms of two Uncaria tomentosa extracts affecting the Wnt-signaling pathway." Phytomedicine. 2011 Jun; 18(8-9): 683-90.
Pilarski, R., et al. "Anticancer activity of the Uncaria tomentosa (Willd.) DC. preparations with different oxindole alkaloid composition." Phytomedicine. 2010 Dec; 17(14): 1133-9.
Dreifuss, A., et al. "Antitumoral and antioxidant effects of a hydroalcoholic extract of cat's claw (Uncaria tomentosa) (Willd. Ex Roem. & Schult) in an in vivo carcinosarcoma model." J. Ethnopharmacol. 2010 Jul; 130(1): 127-33.
Garcia Gimenez, D., et al. "Cytotoxic effect of the pentacyclic oxindole alkaloid mitraphylline isolated from Uncaria tomentosa bark on human Ewing's sarcoma and breast cancer cell lines." Planta Med. 2010 Feb; 76(2):133-6.
Rinner, B., et al. "Antiproliferative and pro-apoptotic effects of Uncaria tomentosa in human medullary thyroid carcinoma cells." Anticancer Res. 2009; 29(11): 4519-28.
Erowele, G., et al. "Pharmacology and therapeutic uses of cat's claw." Am. J. Health Syst. Pharm. 2009 Jun 1; 66(11): 992-5.
Pilarski, R., et al. "Antiproliferative activity of various Uncaria tomentosa preparations on HL-60 promyelocytic leukemia cells." Pharmacol. Rep. 2007 Sep-Oct; 59(5): 565-72.
Chen, A., et al. "Induction of apoptosis by Uncaria tomentosa through reactive oxygen species production, cytochrome c release, and caspases activation in human leukemia cells." Food Chem. Toxicol. 2007; 45(11): 2206-18.
Garcia Prado, E., et al. "Antiproliferative effects of mitraphylline, a pentacyclic oxindole alkaloid of Uncaria tomentosa on human glioma and neuroblastoma cell lines." Phytomedicine. 2007; 14(4): 280-4.
Gonzales, G., et al. "Medicinal plants from Peru: a review of plants as potential agents against cancer." Anticancer Agents Med. Chem. 2006 Sep; 6(5): 429-44.
De Martino, L., et al. "Proapoptotic effect of Uncaria tomentosa extracts." J. Ethnopharmacol. 2006 Aug; 107(1): 91-4.
Bacher, N., et al. "Oxindole alkaloids from Uncaria tomentosa induce apoptosis in proliferating, G0/G1-arrested and bcl-2-expressing acute lymphoblastic leukaemia cells." Br. J. Haematol. 2006 Mar; 132(5): 615-22.
Riva, L., et al. "The antiproliferative effects of Uncaria tomentosa extracts and fractions on the growth of breast cancer cell line." Anticancer Res. 2001; 21(4A): 2457-61.
Muhammad, I., et al. "Investigation of Una de Gato I. 7-Deoxyloganic acid and 15N NMR spectroscopic studies on pentacyclic oxindole alkaloids from Uncaria tomentosa." Phytochemistry. 2001; 57(5): 781-5.
Sheng, Y., et al. "Induction of apoptosis and inhibition of proliferation in human tumor cells treated with extracts of Uncaria tomentosa." Anticancer Res. 1998; 18(5A): 3363-68.
Salazar, E., et al. "Depletion of specific binding sites for estrogen receptor by Uncaria tomentosa." Proc. West. Pharmacol. Soc. 1998; 41(1): 123-124.
Stuppner, H., et al. "A differential sensitivity of oxindole alkaloids to normal and leukemic cell lines." Planta Med. (1993 suppl.); 59: A583.
Rizzi, R., et al. "Mutagenic and antimutagenic activities of Uncaria tomentosa and its extracts." J. Ethnopharmacol. 1993; 38: 63-77.
Peluso, G., et al. "Effetto antiproliferativo su cellule tumorali di estrattie metaboliti da Uncaria tomentosa. Studi in vitro sulla loro azione DNA polimerasi." 11 Congreso Italo-Peruano de Etnomedicina Andina, Lima, Peru, October 27-30, 1993, 21-2.
Rizzi, R., et al. "Bacterial cytotoxicity, mutagenicity and antimutagenicity of Uncaria tomentosa and its extracts. Antimutagenic activity of Uncaria tomentosa in humans." Premiere Colloque Européan d'Ethnopharmacologie, Metz, France, March 22-24, 1990.

Antimutagenic, Cellular Protective & Antioxidant Actions:
Elgawish, R., "Hepatoprotective activity of Uncaria tomentosa extract against sub-chronic exposure to fipronil in male rats." Environ. Sci Pollut. Res. Int. 2019 Jan; 26(1): 199-207.
Navarro-Hoyos, M., et al. "Polyphenolic composition and antioxidant activity of aqueous and ethanolic extracts from Uncaria tomentosa bark and leaves." Antioxidants (Basel). 2018 May 11; 7(5).
Santo, G., et al. "Protective effect of Uncaria tomentosa extract against oxidative stress and genotoxicity induced by glyphosate-Roundup® using zebrafish (Danio rerio) as a model." Environ. Sci. Pollut. Res. Int. 2018 Apr; 25(12): 11703-11715.
Almeida, I., "Chemotherapeutical effects of the herbal medicine Uncaria tomentosa (Willd.) DC." Genet. Mol. Res. 2017 Sep 27; 16(3).
Navarro-Hoyos, M., et al. "Proanthocyanidin characterization and bioactivity of extracts from different parts of Uncaria tomentosa L. (Cat's Claw)." Antioxidants (Basel). 2017 Feb 4; 6(1): E12.
Navarro, M., et al. "Fractioning of proanthocyanidins of Uncaria tomentosa. Composition and structure-bioactivity relationship." Antioxidants (Basel). 2017 Jul; 6(3). pii: E60.
Komider, A., et al. "Uncaria tomentosa leaves decoction modulates differently ros production in cancer and normal cells, and effects cisplatin cytotoxicity." Molecules. 2017 Apr 12; 22(4).
Mentor, J., et al. "Topical AC-11 abates actinic keratoses and early squamous cell cancers in hairless mice exposed to Ultraviolet A (UVA) radiation." Dermatol. Online J. 2015 Apr 16; 21(4).
Dreifuss, A., et al. "Uncaria tomentosa exerts extensive anti-neoplastic effects against the Walker-256 tumour by modulating oxidative stress and not by alkaloid activity. PLoS One. 2013; 8(2): e54618.
Zhang, L., et al. "Quinic acid could be a potential rejuvenating natural compound by improving survival of Caenorhabditis elegans under deleterious conditions." Rejuvenation Res. 2012 Dec; 15(6): 573-83.
Bukowska, B., et al. "Uncaria tomentosa extracts protect human erythrocyte catalase against damage induced by 2,4-D-Na and its metabolites." Food Chem. Toxicol. 2012 Jun; 50(6): 2123-7.
Farias, I., et al. "Uncaria tomentosa stimulates the proliferation of myeloid progenitor cells." J. Ethnopharmacol. 2011 Sep; 137(1): 856-63.
Guthrie, O., et al. "Carboxy alkyl esters of Uncaria tomentosa augment recovery of sensorineural functions following noise injury." Brain Res. 2011 Aug; 1407: 97-106.
Bors, M., et al. "Protective activity of the Uncaria tomentosa extracts on human erythrocytes in oxidative stress induced by 2,4-dichlorophenol (2,4-DCP) and catechol." Food Chem Toxicol. 2011 Sep; 49(9): 2202-11.
de Fatima, F., et al. "[Uncaria tomentosa and acute ischemic kidney injury in rats]." Rev Esc Enferm USP. 2011 Mar; 45(1): 194-8
Filip, A., et al. "Photochemoprevention of cutaneous neoplasia through natural products." Exp. Oncol. 2009 Mar; 31(1): 9-15.
Amaral, S., et al. "Plant extracts with anti-inflammatory properties--a new approach for characterization of their bioactive compounds and establishment of structure-antioxidant activity relationships." Bioorg. Med. Chem. 2009 Mar; 17(5): 1876-83.
Paniagua-Perez, R., et al. "Antigenotoxic, antioxidant and lymphocyte induction effects produced by pteropodine." Basic Clin. Pharmacol. Toxicol. 2009; 104(3): 222-7.
Chen, A., et al. "Induction of apoptosis by Uncaria tomentosa through reactive oxygen species production, cytochrome c release, and caspases activation in human leukemia cells." Food Chem. Toxicol. 2007; 45(11): 2206-18.
Mammone, T., et al. "A water soluble extract from Uncaria tomentosa (Cat's Claw) is a potent enhancer of DNA repair in primary organ cultures of human skin." Phytother. Res. 2006; 20(3): 178-83.
Kuras, M., et al. "Changes in chromosome structure, mitotic activity and nuclear DNA content from cells of Allium Test induced by bark water extract of Uncaria tomentosa (Willd.) DC." J. Ethnopharmacol. 2006 Sep; 107(2): 211-21.
Pilarski, R., et al. "Antioxidant activity of ethanolic and aqueous extracts of Uncaria tomentosa (Willd.) DC." J. Ethnopharmacol. 2006 Mar; 104(1-2): 18-23.
Cisneros, F., et al. "An Uncaria tomentosa (cat's claw) extract protects mice against ozone-induced lung inflammation." J. Ethnopharmacol. 2005 Jan; 96(3): 355-64.
Goncalves, C., et al. "Antioxidant properties of proanthocyanidins of Uncaria tomentosa bark decoction: a mechanism for anti-inflammatory activity." Phytochemistry. 2005; 66(1): 89-98.
Romero-Jimenez, M., et al. "Genotoxicity and anti-genotoxicity of some traditional medicinal herbs." Mutat. Res. 2005 Aug; 585(1-2): 147-55.
Pilarski, R., et al. "Antioxidant activity of ethanolic and aqueous extracts of Uncaria tomentosa (Willd.) DC." J. Ethnopharmacol. 2006 Mar; 104(1-2): 18-23.
Sheng, Y., et al. "DNA repair enhancement of aqueous extracts of Uncaria tomentosa in a human volunteer study." Phytomedicine. 2001; 8(4): 275-82.
Sheng, Y., et al. "Enhanced DNA repair, immune function and reduced toxicity of C-Med-100, a novel aqueous extract from Uncaria tomentosa." J. Ethnopharmacol. 2000; 69(2): 115-26.
Sandoval, M., et al. "Cat's claw inhibits TNFalpha production and scavenges free radicals: role in cytoprotection." Free Radic. Biol. Med. 2000; 29(1): 71-8.
Desmarchelier, C., et al. "Evaluation of the in vitro antioxidant activity in extracts of Uncaria tomentosa (Willd.) DC." Phytother. Res. 1997; 11(3): 254-256.
Chan-Xun, C., et al. "Inhibitory effect of rhynchophylline on platelet aggregation and thrombosis." Acta Pharmacologica Sinica 1992; 13(2): 126-30.

Anti-Diabetic Actions:
Araujo, L., et al. "Uncaria tomentosa improves insulin sensitivity and inflammation in experimental NAFLD." (non-alcohol fatty liver disease) Sci. Rep. 2018 Jul; 8(1): 11013.

Actions on the Brain, Memory & Alzheimer's:
Li, C., et al. "Effects of rhynchophylline on the hippocampal miRNA expression profile in ketamine-addicted rats." Prog. Neuropsychopharmacol. Biol. Psychiatry. 2018 Aug; 86: 379-389.
Chowdhury, S., et al. "In vitro anti-acetylcholinesterase activity of an aqueous extract of Uncaria tomentosa and in silico study of its active constituents." Bioinformation. 2016 Jun; 12(3): 112-118.
Shi, Z., et al. "Neuroprotective effects of aqueous extracts of Uncaria tomentosa: Insights from 6-OHDA induced cell damage and transgenic Caenorhabditis elegans model." Neurochem. Int. 2013 Jun; 62(7): 940-7.
Bigliani, M. "Anxiogenic-like effects of Uncaria tomentosa (Willd.) DC. aqueous extract in an elevated plus maze test in mice: a preliminary study." Nat. Prod. Res. 2013; 27(18): 1682.
Snow, A., et al. "Compounds, compositions and methods for the treatment of amyloid diseases and synucleinopathies such as Alzheimer's disease, type 2 diabetes, and Parkinson's disease." United States Patent No. 7,514,583 April 7, 2009
Castillo, G., et al. "Methods of isolating amyloid-inhibiting compounds and use of compounds isolated from Uncaria tomentosa and related plants." United States Patent No. 7,314,642 January 1, 2008.
Frackowiak, T., et al. "Binding of an oxindole alkaloid from Uncaria tomentosa to amyloid protein (Abeta1-40)." Z. Naturforsch C. 2006 Nov-Dec; 61(11-12): 821-6.
Jurgensen, S., et al. "Involvement of 5-HT2 receptors in the antinociceptive effect of Uncaria tomentosa." Pharmacol. Biochem. Behav. 2005 Jul; 81(3): 466-77.
Kang, T., et al. "Pteropodine and isopteropodine positively modulate the function of rat muscarinic M(1) and 5-HT(2) receptors expressed in Xenopus oocyte." Eur. J. Pharmacol. 2002 May; 444(1-2): 39-45.
Mohamed, A., et al. " Effects of Uncaria tomentosa total alkaloid and its components on experimental amnesia in mice: elucidation using the passive avoidance test." J. Pharm. Pharmacol. 2001; 52(12): 1553-61.
Roth, B., et al. "Insights into the structure and function of 5-HT(2) family serotonin receptors reveal novel strategies for therapeutic target development." Expert Opin. Ther. Targets 2001 Dec; 5(6): 685-695.
Castillo, G. "Methods of isolation of amyloid inhibitory ingredients within Uncaria tomentosa." US Patent No 7,029,710, April, 18, 2006.
Castillo, G. " Methods of isolating amyloid-inhibiting compounds and use of compounds isolated from Uncaria tomentosa and related plants." US Patent No. 6,929,808, August 16, 2005.
Castillo, G., et al. "Pharmaceutical compositions containing Uncaria tomentosa extract for treating Alzheimer's disease and other amyloidoses." Patent-Pct. Int. Paol. 1998; 00 33,659: 67 pp.

Anti-asthmatic Actions:
Azevedo, B., et al. "Aqueous extracts from Uncaria tomentosa (Willd. ex Schult.) DC. reduce bronchial hyperresponsiveness and inflammation in a murine model of asthma." J. Ethnopharmacol. 2018; 218: 76-89. (Leaves)

Antimicrobial Actions:
Moraes, R., et a. "In vitro synergism of a water insoluble fraction of Uncaria tomentosa combined with fluconazole and terbinafine against resistant non-Candida albicans isolates. Pharm Biol. 2017 Dec; 55(1): 406-415.
Herrera, D., et al. "Antimicrobial activity and substantivity of Uncaria tomentosa in infected root canal dentin." Braz. Oral Res. 2016; 30(1): e61.
Caon, T., et al. "Antimutagenic and antiherpetic activities of different preparations from Uncaria tomentosa (cat's claw)." Food Chem Toxicol. 2014 Apr; 66: 30-5.
Lima-Junior, R., et al. "Uncaria tomentosa alkaloidal fraction reduces paracellular permeability, IL-8 and NS1 production on human microvascular endothelial cells infected with dengue virus." Nat. Prod. Commun. 2013 Nov; 8(11): 1547-50.
Herrera, D., et al. "In vitro antimicrobial activity of phytotherapic Uncaria tomentosa against endodontic pathogens." J. Oral Sci. 2010 Sep; 52(3): 473-6.
Chen, X., et al. "Effects of rhynchophylline and isorhynchophylline on nitric oxide and endothelin-1 secretion from RIMECs induced by Listeriolysin O in vitro." Vet. Microbiol. 2010 Jul; 143(2-4): 262-9.
Reis, S., et al. "Immunomodulating and antiviral activities of Uncaria tomentosa on human monocytes infected with Dengue Virus-2." Int. Immunopharmacol. 2008; 8(3): 468-76.
Cahuana-Vasquez, R., et al. "Antimicrobial activity of Uncaria tomentosa against oral human pathogens." Braz. Oral Res. 2007 Jan-Mar; 21(1): 46-50.
Kloucek, P., et al. "Antibacterial screening of some Peruvian medicinal plants used in Calleria District." J. Ethnopharmacol. 2005 Jun; 99(2): 309-12.
Garcia, R., et al. "Antimicrobial activity of isopteropodine." Z. Naturforsch. 2005; 60(5-6): 385-8.
Aquino, R., et al. "Plant metabolites. Structure and in vitro antiviral activity of quinovic acid glycosides from Uncaria tomentosa and Guettarda platypoda." J. Nat. Prod. 1989; 4(52): 679-85.

Actions Against Endometriosis:
Nogueira, N., et al. "Experimental endometriosis reduction in rats treated with Uncaria tomentosa (cat's claw) extract." Eur. J. Obstet. Gyneco.l Reprod Biol. 2011 Feb; 154(2): 205-8.

Toxicity Studies & Reviews:
Almeida, I., "Chemotherapeutical effects of the herbal medicine Uncaria tomentosa (Willd.) DC." Genet. Mol. Res. 2017 Sep 27; 16(3).
Yunis Aguinaga, J., et al. "Acute toxicity and determination of the active constituents of aqueous extract of Uncaria tomentosa bark in Hyphessobrycon eques." J. Toxicol. 2014; 2014: 412437.
Bors, M., et al. "Evaluation of the effect of Uncaria tomentosa extracts on the size and shape of human erythrocytes (in vitro)." Environ. Toxicol. Pharmacol. 2012 Mar; 33(2): 127-34.
Bors, M., et al. "Studies of biological properties of Uncaria tomentosa extracts on human blood mononuclear cells." J. Ethnopharmacol. 2012 Aug; 142(3): 669-78.
Erowele, G., et al. "Pharmacology and therapeutic uses of cat's claw." Am. J. Health Syst. Pharm. 2009 Jun 1; 66(11): 992-5.
Pilarski, R., et al. "Evaluation of biological activity of Uncaria tomentosa (Willd.) DC. using the chicken embryo model." Folia Biol. (Krakow). 2009; 57(3-4): 207-12.
Kuras, M., et al. "Effect of alkaloid-free and alkaloid-rich preparations from Uncaria tomentosa bark on mitotic activity and chromosome morphology evaluated by Allium Test." J. Ethnopharmacol. 2009; 121(1): 140-7.

Antifertility Action:
Nogueira Neto, J., et al. "Contraceptive effect of Uncaria tomentosa (cat's claw) in rats with experimental endometriosis." Acta Cir Bras. 2011; 26 Suppl 2: 15-9.

Possible Drug Interactions:
Quilez, A., et al. "Uncaria tomentosa (Willd. ex. Roem. & Schult.) DC. and Eucalyptus globulus Labill. interactions when administered with diazepam." Phytother Res. 2012 Mar; 26(3): 458-61.
Cosentino, C., et al. "Reversible worsening of Parkinson disease motor symptoms after oral intake of Uncaria tomentosa (cat's claw)." Clin. Neuropharmacol. 2008 Sep-Oct; 31(5): 293-4.
Lopez Galera, R., et al. "Interaction between cat's claw and protease inhibitors atazanavir, ritonavir and saquinavir." Eur. J. Clin. Pharmacol. 2008; 64(12): 1235-6.
Moreno, S., et al. "Effect of oral ingestion of an extract of the herb Uncaria tomentosa on the biodistribution of sodium pertechnetate in rats." Braz. J. Med. Biol Res. 2007; 40(1): 77-80.

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