Herb Feature

Herb Feature


A woody vine which grows in the tropical jungles of Central and South America that has remarkable properties in influencing our immune system is our focus this month. Una de Gato (Cat’s Claw in Spanish) derives its name from its hook-like thorns which resemble the claws on cat’s paws. It grows by climbing other rainforest plants using its “claws” to ascend to the canopy, up to an impressive thirty meters. Uncaria Tomentosa has anti-inflammatory and anti-oxidant properties, but is best known as a powerful immune modulator. Poor immunity leading to increased susceptibility to infections, chronic inflammatory conditions including arthritis, recovery from illness or injury and even as a supportive therapy in cancer treatment, are some of the therapeutic uses for this amazing plant.

Traditionally it is used in Peru for chronic and acute infections, cancer, arthritis, diabetes, ulceration of the stomach, asthma, inflammation of the urinary tract and skin conditions. It is highly valued as a restorative tonic in the weak and sickly. Modern pharmacologic research has demonstrated interesting beneficial affects including anti-inflammatory actions by modulating a highly inflammatory immune molecule called Tumour Necrosis Factor alpha.[1]  TNF- alpha is a cytokine or cell signalling protein that helps to regulate our immune system; like all cytokines, we absolutely need it, but too much TNF-alpha produces undesirable consequences. Excess activity has been associated with Rheumatoid Arthritis, Alzheimer’s Disease, Inflammatory Bowel Disease, Psoriasis and even major depression![2] Cat’s Claw has also shown to positively influence other cytokines such as interleukins one and six, and induce the production of lymphocytes, a type of white blood cell which is critical for most aspects of immune function. In addition to this, it can also increase the activity of macrophages, large white cells that “eat” bacteria and any foreign or damaged tissue. Macrophage literally means “Big Eater”!

If you’ve ever used Cat’s Claw and were disappointed with the results, it may be due to a surprising botanical fact: there are two types of Uncaria Tomentosa and only one of them works! These two “chemotypes” appear to be identical; however, they contain two different types of active ingredients: POA and TOA’s. Without going into great detail about the biochemistry of the plant compounds, POAs (pentacyclic oxindole alkaloids) seem to be responsible for the immune modulating benefits of Cat’s Claw while the TOAs (tetracyclic oxindole alkaloids) seem to inhibit the beneficial affects! So, make sure your qualified herbalist provides you only with medicines containing the variety of Cat’s Claw that actually works!! No wonder herbal medicine is viewed by some cynics as ineffective- we need to make sure people are given the highest quality botanical medicines at the correct dosages for the appropriate duration by well-trained professionals.

Clinical studies using Cat’s Claw have shown impressive results: In patients with HIV treated for several months, lymphocyte counts increased by an average of 35%; In another study HIV patients showed a significant increase in CD4 cells (T-helper lymphocytes), and also B-Cells which produce antibodies to assist the destruction of viruses/ bacteria etc. One study in smokers showed a very interesting affect: the levels of mutagens (cancer-causing molecules) were reduced in the urine of smokers who were taking an extract of U.Tomentosa, and the more they took, the better it worked![3] The herbal extract seemed to be reducing the carcinogenic affects of the tobacco smoke. Of course, it’s better not to smoke, but if you or your loved ones do, perhaps Cat’s Claw can reduce the devastating effects of this terrible habit somewhat. In a long-term uncontrolled trial (no placebo group), cancer patients using Cat’s Claw as a decoction had a slowed progression of their disease, and the side effects of chemotherapy and radiation were reduced. They also reported more vitality. A decoction is a liquid preparation where the dried plant parts are put into water and simmered and then drunk like a tea.

Another randomised controlled trial of patients with Rheumatoid Arthritis showed a significant reduction in the number of painful joints compared to the placebo group. These preparations contained only POAs and no TOAs, indicating the importance of getting the correct type of Cat’s Claw. And finally, an earlier Peruvian study of this herb taken by patients with Rheumatoid Arthritis for six months showed a significant improvement in pain, morning stiffness, and the number of painful, swollen joints compared to placebo. This demonstrates the ability of this and many other herbs to have wide-reaching benefits for your health, not just for your immune system. Of course, conditions such as cancers and autoimmune disorders are complex and require specialised treatments so please contact your health care professionals for comprehensive help. An interesting side effect that some people experience with Cat’s Claw is that it seems to make white hair start to return to its original colour! I’ve seen it happen with a few patients and may be due to increasing tyrosine conversion to melanin in the hair follicle cells. Whatever the reason, this is another fascinating plant from Natures Medicine Cabinet. Enjoy your holiday season and stay healthy!

[1] Bone K, A Clinical Guide to Liquid Herbs (Churchill Livingstone)


[3] Bone K, A Clinical Guide to Liquid Herbs (Churchill Livingstone)

  1. Mediherb Phytotherapist’s Perspective no.10 June 2010

David Peirce is a practicing Naturopath/ Herbalist.

Bachelor of Health Science - Complementary Medicine

Contact: 07 4032 0038

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