Una de Gato, otherwise known as cat’s claw, is properly Unicaria tomentosa. It has been used as an herbal medicine for at least two thousand years by the people of Central and South America who gave it the name vilcacora.
It grows in jungle areas and rainforest in South America and Asia, and gets its name from the small claw-like thorns at the base of the leaves. One of the environmental benefits of the Una de Gato is that when it is harvested at three feet above the ground, it grows back to its full size of up to 100 feet within a few years when it can be harvested again to three feet. Cat’s claw has been given dietary supplement status by the FDA.
The Peruvian Asháninka tribe has used the plant as a contraceptive and for the treatment of rheumatic conditions, diabetes, acne, diarrhea, cancer, urinary tract diseases and as an anti-inflammatory, and many of the studies of cat’s claw have centered on this tribe. The studies quickly showed the active ingredients to be alkaloids, both tertracyclic oxindole alkaloids and pentacyclic alkaloids that have been found both in the bark and in the root.
The extract is obtained by boiling both the inner part of the bark and the root, each of which differs in concentration of the various alkaloids. The root is believed to better for its anti-inflammatory powers due to the quinovic acid glycoside it contains, although the relative concentrations of the various alkaloids can vary according to the time of year and to the chemotype of the plant.
Cat’s Claw comes in two chemotypes, each of which differs in the relative concentrations of the two different alkaloid types. One predominates in the pentacyclic alkaloids that strengthen the immune system, and the other chemotype in the tetracyclic alkaloids that counter that effect and reduce the speed and strength of the contractions of the heart. It is not possible to tell which chemotype a particular plant is until it has been chemically tested. They look exactly the same and it is possible for both to grow sided by side. However, the root is generally richer in alkaloids, and sells at about twice the price of the bark.
Alkaloids are not the only active ingredients in Una de Gato, and it also contains tannins and phytochemicals that have an antioxidant effect and are useful free radical scavengers. They have been studied for their effects in the treatment of HIV and cancer, though mainly due to the glycoside content that will be discussed shortly. The National cancer Institute has confirmed some anti-cancer properties of quinovic glycosides derived from cat’s claw.
The four pentacyclic alkaloids have been found to have a boosting effect on the human immune system, which it does by enhancing the ability of the white blood cells and macrophages to digest and kill off foreign organisms and debris in tissue and the bloodstream. The inference is that the herb is able to be used to treat a wide variety of infectious diseases, including many immune and autoimmune conditions including AIDS. The results with AIDs are inconclusive, although one particular study showed that cat’s claw produced accelerated healing of cold sores and genital herpes (herpes simplex virus) and shingles (caused by herpes zoster virus). Although the evidence is slight, there are indications of its possible use in treating viral conditions.
It is used in homeopathy for the treatment of a number of digestive ailments, such as Crohn’s disease, leaky bowel syndrome, colitis, gastritis and gastric ulcers among others. It is also used in the treatment of inflammatory conditions such as arthritis, rheumatism and some conditions of the prostate gland.
The tertracyclic indole alkaloids that appear to counter the immune-boosting properties of their pentacyclic cousins include rhynchophylline, hirsutine, and mitraphylline. Rhynchophylline prevents blood clots in the veins and arteries by reducing the formation of platelets, and can dilate the peripheral blood vessels of the hands and feet. It can also lower blood cholesterol levels and reduce the heart rate. Due to this effect on blood vessels, it is though to be able to improve the circulation in the brain and be a useful treatment for Alzheimer’s sufferers. Hirsutine inhibits contractions of the smooth muscle of the bladder, and so finds uses in the treatment of urinary incontinence.
The pentacyclic alkaloids pteropodine and isopteropodine are believed to have important properties beyond their phagocytosis effect on the immune system. It has been reported that they have an effect on the 5-HT(2) receptors in the brain. These neurotransmitters are used as targets for many drugs used to treat a variety of conditions such as depression, eating disorders and anxiety, and such alkaloids have a positive modulating effect on them.
The anti-inflammatory properties of cat’s claw are largely due to the very potent quinovic acid glycosides previously referred to. These have been known about only recently, and they are thought to work synergistically to reduce the tissue swelling (edema) associated with the immune system’s inflammatory reaction. Although this is believed to be largely due to the glycosides, three of the alkaloids also possess anti-inflammatory properties. This property provides the scientific background for the traditional use of Una de Gato for rheumatism and arthritis, both inflammatory conditions. Many of the digestive conditions for which the plant has traditionally used are also inflammatory in nature.
A threat to cat’s claw is the destruction of the Peruvian rainforest, although not as much as a threat as the destruction of the plant itself. Cat’s claw has reached levels of popularity so high that it is in danger of extinction due to improper harvesting. New laws being enacted by the Peruvian government should help to protect the plant, and to promote its harvesting over cocoa.
When buying cat’s claw, make sure that it is the Uncaria tomentosa form you are purchasing since there is another type, Uncaria Guianensis that contains different alkaloids and is not as potent as the real Una de Gato. Also beware of a shrub known as cat’s claw acacia, grown in Mexico and the southwest USA, since it contains cyanide derivatives and could be very dangerous if taken by mouth.