Cat's claw (Uncaria tomentosa or Una do Gato) is a medicinal herb from the Amazon River basin that is widely used as a treatment for inflammatory disorders. Cat's claw contains gluco indole alkaloids. This herb is promoted as having anti-cancer anti-inflammatory properties and as a natural remedy for arthritis. In the traditional Peruvian medicine hot aqueous extracts have been used for the treatment of a wide range of health problems, particularly digestive complaints and arthritis. What does the research say?

Now Foods, Cat's Claw Extract, 120 Vcaps

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Dosage: One or two pills a day as needed.

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Cats claw is a natural extract of the highest quality inner bark of authentic Uncaria tomentosa, an exciting herbal discovery from the Peruvian Rainforest. Also called Una de Gato, cat's claw herb has been used for hundreds of years by the native Ashanica Indians.

This is a concentrated water and alcohol extract standardized to contain a minimum of 3% total alkaloids (calculated as mitraphylline) and 15% total Polyphenols.

Supplement Facts: Cat's Claw (Uncaria tomentosa) (inner bark) 334 mg of 15:1 standardized extract
 

Joint Power Rx
This powerful formula includes several additional herbal extracts and nutrients that play a role in joint health. Glucosamine sulfate (from shellfish), chondroitin sulfate, MSM, CMO complex, boswellia serrata extract, curcumin and turmeric, cat's claw extract, devil's claw extract, grape seed extract, and sea cucumber.

Potential benefit of cat's claw herb and research studies
Anti-inflammatory benefit
Cat's claw is a remarkably potent inhibitor of TNFalpha production. The primary mechanism for cat's claw anti-inflammatory actions appears to be immunomodulation via suppression of TNFalpha synthesis. TNF stands for tumor necrosis factor. It is not clear how it compares to NSAIDs such as ibuprofen or naproxen.

Antioxidant
Cat's claw is an effective antioxidant.

Antioxidant properties of proanthocyanidins of Uncaria tomentosa bark decoction: a mechanism for anti-inflammatory activity.
Phytochemistry. 2005.
Decoctions prepared from the bark of Uncaria tomentosa are widely used in the traditional Peruvian medicine for the treatment of several diseases, in particular as a potent anti-inflammatory agent. Therefore, the main purpose of this study was to determine if the well-known anti-inflammatory activity of cat's claw decoction was related with its reactivity with the oxidant species generated in the inflammatory process and to establish a relationship between such antioxidant ability and its phenolic composition. We observed that the cat's claw decoction prepared according to the traditional Peruvian medicine presented a potent radical scavenger activity, as suggested by its high capacity to reduce the free radical diphenylpicrylhydrazyl, and by its reaction with superoxide anion, peroxyl and hydroxyl radicals as well as with the oxidant species, hydrogen peroxide and hypochlorous acid. The phenolic profile shows the presence of proanthocyanidins (oligomeric procyanidins) and phenolic acids, mainly caffeic acid.

Antitumor
Cat's claw extracts exert a direct anti-proliferative activity on MCF7 (a breast cancer cell line).

Arthritis
This plant is an effective treatment for osteoarthritis and probably rheumatoid arthritis (see bottom of page). The species, U guianensis and U tomentosa are equiactive. They are effective antioxidants, but their anti-inflammatory properties may result from their ability to inhibit TNFalpha and to a lesser extent PGE2 production.

Cancer prevention or treatment
An extract of Uncaria tomentosa inhibiting cell division.
We have confirmed that cat's claw C-Med 100, a hot water extract of this plant, inhibits tumor cell proliferation albeit with variable efficiency. We extend these findings by showing that this extract also inhibits proliferation of normal mouse T and B lymphocytes and that the inhibition is not caused by toxicity or by induction of apoptosis. We provide direct evidence that cat's claw C-Med 100 inhibits nuclear factor kappa B (NF-kappa B) activity and propose that this at least partially causes the inhibition of proliferation.

J Altern Complement Med. 2015. Uncaria tomentosa (cat's claw) improves quality of life in patients with advanced solid tumors.

Diabetes and blood sugar
Please let me know how Cat's claw extract might effect an insulin dependant diabetic. I have been using your Joint Power Rx with much success, thank you.
   Thank you for the feedback. We did a medical research search and did not come up with any information regarding the influence of cat's claw supplement on blood sugar or diabetes. It may have an influence, but we just have not seen such research.

DNA repair
Human volunteers who took cat's claw herb for 8 weeks had improved DNA repair.

DNA repair enhancement of aqueous extracts of Uncaria tomentosa in a human volunteer study.
Phytomedicine. 2001.
The Uncaria tomentosa water extracts (cat's claw, C-Med-100) have been shown to enhance DNA repair, mitogenic response and leukocyte recovery after chemotherapy-induced DNA damage in vivo. Twelve apparently healthy adults working in the same environment were randomly assigned into 3 groups with age and gender matched. One group was daily supplemented with a 250 mg tablet containing an aqueous extract of cat's claw, and another group with a 350 mg tablet, for 8 consecutive weeks. There were no drug-related toxic responses to cat's claw supplement when judged in terms of clinical symptoms, serum clinical chemistry, whole blood analysis and leukocyte differential counts. There was a statistically significant decrease of DNA damage and a concomitant increase of DNA repair in the supplement groups (250 and 350 mg/day) when compared with non-supplemented controls. There was also an increased tendency of PHA induced lymphocyte proliferation in the treatment groups. Taken together, this trial has confirmed the earlier results obtained in the rat model when estimating DNA repair enhancement by cat's claw.

Immune system influence
In vitro effects of two extracts and two pure alkaloid preparations of Uncaria tomentosa on peripheral blood mononuclear cells.
Planta Med. 2004.
In this study, the effects of two cat's claw extracts and two mixtures of tetracyclic and pentacyclic oxindole alkaloids were investigated in freshly isolated human peripheral blood mononuclear cells (PBMC) stimulated with the mitogens phytohaemagglutinin (PHA) and concanavalin A (Con A) in vitro. These data demonstrate that cat's claw extracts and mixtures of alkaloids modulate the immunobiochemical pathways induced by interferon-gamma. The findings imply a potential application of the cat's claw extracts as immunoregulators and would be in line with observations in patients using these extracts.

Memory
Cat's claw herb total alkaloids exert a beneficial effect on memory impairment induced by the dysfunction of cholinergic systems in the brain and that the effect of the total alkaloids is partly attributed to the oxindole alkaloids tested.

Rheumatoid arthritis
Randomized double blind trial of an extract from the pentacyclic alkaloid-chemotype of uncaria tomentosa for the treatment of rheumatoid arthritis.
J Rheumatol. 2002.
To evaluate safety and clinical efficacy of a plant extract from the pentacyclic chemotype of Uncaria tomentosa (cat's claw) in patients with active rheumatoid arthritis. Forty patients undergoing sulfasalazine or hydroxychloroquine treatment were enrolled in a randomized 52 week study. During the first phase (24 weeks, double blind, placebo controlled), patients were treated with cats claw extract or placebo. In the second phase (28 weeks) all patients received the plant extract. Twenty-four weeks of treatment with the cats claw extract resulted in a reduction of the number of painful joints compared to placebo (by 53% vs 24%). Patients receiving the cat's claw extract only during the second phase experienced a reduction in the number of painful and swollen joints and the Ritchie Index compared to the values after 24 weeks of placebo. Only minor side effects were observed. This small preliminary study demonstrates relative safety and modest benefit to the tender joint count of a highly purified extract from cat's claw in patients with active rheumatoid arthritis taking sulfasalazine or hydroxychloroquine.

Safety, side effects, toxicity, risks
As of 2013 no major safety issues have been mentioned in the medical literature and no major side effects have been reported. However, as more people use this herbal product adverse events could be found.

Substances in the plant
Oleanan-type triterpenes and cincholic acid glycosides along with alkaloids such as mitraphylline and polyphenols.

More about Cat's Claw
Generations of Ashaninka Indians have used cat's claw in the Amazon rainforest. Cat's claw is a woody vine that gets it name from the two curved thorns at the base of each leaf. This plant grows wild in the Peruvian rain forest where is grows into the trees. The inner bark of the vine contains the same beneficial properties as the root and is the preferred part since it can be gathered without destroying the plant.

Cat's Claw Laboratory studies
Anti-inflammatory and antioxidant activities of cat's claw (Uncaria tomentosa and Uncaria guianensis) are independent of their alkaloid content.
Phytomedicine. 2002.
Cat's claw is an herbal medicine from the Amazon that is used widely to treat inflammatory disorders. The purpose of this study was to characterize the antioxidative and antiinflammatory properties of cat's claw, Uncaria tomentosa and Uncaria guianensis. These results indicate that while both species of cat's claw provide effective antioxidant and anti-inflammatory activities, U. guianensis is more potent. In conclusion, the presence of oxindole or pentacyclic alkaloids did not influence the antioxidant and anti-inflammatory properties of cat's claw.

The antiproliferative effects of Uncaria tomentosa extracts and fractions on the growth of breast cancer cell line.
Anticancer Res. 2001.
Uncaria tomentosa is widely used in South-American folk medicine for the treatment of cancer, arthritis, gastritis and epidemic diseases. Extracts of the plant have been shown to possess cytostatic and anti-inflammatory activity as well as mutagenic and antimutagenic properties. However, to date no studies have been carried out to verify the direct antitumor activity of the cat's claw extracts. The present study investigates the effects of some extracts and their chromatographic fractions from the bark of cat's claw on the growth of a human breast cancer cell line (MCF7). Our data indicated that, in addition to the antimutagenic activity, cat's claw extracts and fractions exert a direct antiproliferative activity on MCF7.

Emails
Having read somewhere that Cat's Claw supplement is helpful in cases of food sensitivity, and having a husband with regular bad bouts of gout I suggested he try it, since everyone always mentions various foods as being the cause of gout. He takes one capsule per day and hasn't had a trace of gout for two years.

Please let me know how cat's claw supplement might effect an insulin dependant diabetic. I have been using Joint Power RX with much success, thank you.
    Thank you for the feedback. We did a medical research search and did not come up with any information regarding the influence of cat's claw on blood sugar or diabetes. Cat's claw may have an influence, but we just have not seen such research.

In 2010 Dr. Oz from The Oz Show, had a segment on the benefits of this herb as an anti-inflammatory natural product. Were the claims made on the Dr. Oz show accurate?
    Although lab studies indicate that this herb has such potential, as of March 2010 I have seen only preliminary human studies regarding the use of this herb reduces symptoms of arthritis, rheumatoid arthritis, or other conditions involving inflammation. I await the results of additional investigations to have a clearer idea regarding benefits, dosage, and long term safety.

Other popular products in health food stores
NOW Foods buy Cat's Claw "5000" supplement extract. Cat's Claw "5000" is a concentrated water and alcohol extract standardized to contain a minimum of 3% total alkaloids (calculated as mitraphylline) and 15% total Polyphenols.

Is the NOW foods cat's claw supplement free of T.O.A, also known as tetra cyclic oxindole alkaloids?
    We sent an email to NOW Foods and did not receive a reply.

Do you know if the cat's claw supplement by NOW Foods is TOA free or do I not need to be concerned about that?
    I have not seen any human studies regarding TOA tetracyclic alkaloids as ingested in small amounts in cat's claw supplements causing health problems. If those who are raising such concerns have human studies to support their viewpoint, we would like to see these studies.