Rheumatoid arthritis is the most common form of arthritis. It is an autoimmune form of arthritis wherein the immune system attacks the tissues of the joints and the bones in a similar manner as it would attack any pathogen.
This leads to inflammation at the affected joint thereby influencing joint function and leading to pain. This inflammation can spread to other parts of the body such as heart and lungs.
The major symptoms include pain, swelling, tenderness and stiffness that worsens in the morning. Chronic persistent pain leads to sleeplessness, fatigue and weight loss.
Complications of rheumatoid arthritis include systemic inflammation, dry eyes and mouth, rheumatoid nodules, carpel tunnel syndrome.
Treatment involves administration of painkillers, non steroidal anti-inflammatory drugs, anti-rheumatic drugs and steroids. Exercise, diet and alternative therapies are also recommended as part of treatment.
Today we are going to examine the effectiveness of herb, cat’s claw in treatment of rheumatoid arthritis.
What is cat’s claw?
Cat’s claw grows wild in Central and South America, especially in the Amazon forest. It is a tropical vine that has small curved spines on the stem at leaf juncture.
There are 34 reported species of Uncaria. The two major species are U.tomentosa and U. Guianensis both of which are known as uña de gato (Spanish for cat’s claw).
Traditionally it has been used to treat wounds, gastric ulcers, arthritis, dysentery, gonorrhoea, gastric ulcers, cancer of urinary tract.
The major constituents are indole alkaloids (0.15–4.60%), primarily pentacyclic oxindoles.
The most important alkaloid is oxindole alkaloid which works as an immune system stimulant. Another active alkaloid is Isopteropodin which is an immune stimulant and strong antioxidant.
Compounds in cat’s claw have anti-microbial activity. They also possess anti-cancer and anti-proliferative effect.
Cat’s claw is therapeutic in many stomach related conditions like colitis, IBS, Crohn’s disease, leaky bowel syndrome.
Cat claw’s anti-inflammatory action is useful in inflammatory disorders like arthritis and gout. It also hastens wound healing.
The bark extract is said to be useful in treating AIDS. Other reported uses include treatment for abscesses, asthma, chemotherapy adverse effects, fever, hemorrhage, etc.
How does cat’s claw help in rheumatoid arthritis?
Cat’s claw anti-inflammatory activity makes it therapeutic in treatment of rheumatoid arthritis.
1. It has anti-inflammatory and antioxidant activity
Cat’s claw has anti-inflammatory action. Many active ingredients found in cat’s claw contribute to its anti-inflammatory action.
Mitraphylline is the major alkaloid present in this herb and is held partially responsible for its anti-inflammatory action.
An animal model of intestinal inflammation was prepared to assess the anti-inflammatory activity of cat’s claw extract. Cat’s claw was found to protect from oxidative stress and inhibited the activation of nuclear factor kappa B- a protein that regulates inflammatory process.
Sandoval et. al have demonstrated that the antioxidant and anti-inflammatory activity of cat’s claw is independent of its alkaloid content.
Another mechanism by which cat’s claw exerts anti-inflammatory effect is by inhibiting the activity of tumor necrosis factor-alpha, a protein that stimulates production of inflammatory chemicals in inflammation.
This mechanism contributes to cat’s claw immunomodulatory effect which can aid in treatment of rheumatoid arthritis, since it involves immune system dysfunction.
Water soluble extract of cat’s claw is proven to facilitate DNA repair and improve white blood cell count and improve immune function.
Free oxygen radicals contribute to tissue damage in rheumatoid arthritis. Antioxidant status in rheumatoid arthritis patients is impaired and co-administration of antioxidants along with conventional drugs can aid in treatment of rheumatoid arthritis.
Cat’s claw, by virtue of its antioxidant activity, scavenges such free oxygen radicals and reduces tissue damage in rheumatoid arthritis. Proanthocyanidins are compounds present in cat’s claw which contribute to its antioxidant and anti-inflammatory activity.
What does this mean?
Various compounds present in cat’s claw contribute to its anti-inflammatory action. It inhibits the activity of major proteins such as TNF-alpha and nuclear factor kappa B which are involved in inflammatory process.
As an antioxidant, it scavenges free radical species which cause tissue damage in rheumatoid arthritis.
2.It reduces pain in rheumatoid arthritis
Inflammation is a process that is regulated by multiple factors. Extracellular nucleotides are essential molecules that control the onset and maintenance of inflammatory processes.
These extracellular nucleotides cause release of pro-inflammatory chemicals from activated inflammatory cells.
Enzymes such as E-NTPDase and E-ADA control the activity of these extracellular nucleotides and are responsible for proliferation and activation of immune cells.
A study was conducted to assess the effect of cat’s claw on the activity of these enzymes and inflammatory process in animal model of arthritis. Results showed that cat’s claw extract prevents the rise of these enzymes in arthritis inflammation and can work as an adjuvant therapy in inflammation.
Winkler et. al demonstrated that extracts of cat’s claw demonstrate immunomodulatory effect and this effect can be beneficial in treatment of arthritis.
By virtue of its antioxidant activity, cat’s claw is identified as a dietary supplement for treatment of rheumatoid arthritis or osteoarthritis.
Mur et. al conducted a clinical trial that assessed the effect of cat’s claw extract in treatment of rheumatoid arthritis. It was a 52 week, 2 phase study. 40 patients who received sulfasalazine and hydroxychloroquine for rheumatoid arthritis treatment were enrolled in the study.
In the first phase (24 weeks), patients received cat’s claw extract or placebo while in the second phase (28 weeks) all patients received cat’s claw extract.
24 weeks treatment brought about 53.2% reduction of number of painful joints compared to 24.1% reduction in placebo group. In the second phase, patients experienced further reduction in painful or swollen joints.
Researchers concluded that purified extract of cat’s claw is safe and effective in reducing tender joints in rheumatoid arthritis patients receiving sulfasalazine and hydroxychloroquine.
What does this mean?
Clinical trial demonstrates that purified extract of cat’s claw reduces joint pain and tenderness in rheumatoid arthritis patients. It acts by inhibiting the production of inflammatory cytokines and regulating the immune system.
The inner bark of cat’s claw is used to make liquid extracts, capsules and teas. The bark of cat’s claw vine is crushed to make tea. Topical formulations are also available.
1 gram of root bark 2-3 times a day is recommended whereas the dose for root bark extract is 20 to 30g.
Standardized extracts (containing 3% alkaloids and 15% phenols) are also available in either liquid or capsule forms.
The dosage for capsules is 300-500mg (1 capsule 2-3 times a day) ; however in studies dose of 250-300mg is used.
Consult a physician for appropriate dosage of cat’s claw extract.
When taken at recommended doses, no side effects are reported. Rare side effects include headaches, dizziness and vomiting.
Women who are pregnant or trying to get pregnant, should not take cat’s claw as it can cause abortion.
Since cat’s claw interferes with immune system function, people with autoimmune diseases, skin grafts, tuberculosis, or those receiving organ transplants should not use cat’s claw.
People suffering from leukaemia, low blood pressure, kidney or liver disease should not take cat’s claw unless advised by physician.
Possible drug interactions could be with blood thinning medications, immunosuppressants, diuretics and blood pressure medications.
Cat’s claw has anti-inflammatory property that is useful in treatment of rheumatoid arthritis. Limited clinical trials have investigated the role of cat’s claw in rheumatoid arthritis and shown moderate efficacy.
Further research is required to confirm the role of cat’s claw in rheumatoid arthritis. Based on the evidence available now we can conclude that cat’s claw can provide mild to moderate relief from pain and inflammation in rheumatoid arthritis.
If you have used cat’s claw for arthritis, please share your experience with us.