Herb, in botany, soft-tissued plant that does not develop permanent woody tissues above ground. Such plants may be annual, biennial, or perennial. Herbaceous plants are generally considered to include soft-tissued angiosperms, or flowering plants, but may also include the ferns, clubmosses, and horsetails. The term "herb" is applied by pharmacists to any plant or plant part that has medicinal properties. Herb parts that are used as food or seasoning are often distinguished as culinary herbs or potherbs. There are two species of cats claw herb. Both of them are harvested for medicinal purposes and in South America they are even considered to be interchangeable. Uncaria guianensis is popular in Europe while Uncaria tomentosa is widely used in the USA.
For centuries people living in the Amazon basin used cats claw for different conditions, such as arthritis, liver and stomach disorders, cancer, skin conditions and even contraception. Traditionally it was used in the form of a decoction or crude extract which was prepared by means of boiling the inner bark of the stem and parts of the root. Scientists say cats claw possesses anti-inflammatory, immune-boosting, antiviral and even cancer-fighting properties. In recent years scientists have singled out two separate subspecies of Uncaria tomentosa which are different in their chemical properties. The first one possesses substances responsible for the most well-researched effect of cat's claw, that is immune stimulation. The other type affects brain and central nervous system.
In the mid- 1990s cats claw herb became one of the top-selling herbs in the United States. It happened because researchers proclaimed the plant possessing the potential to cure such serious conditions as arthritis, cancer, and even HIV infections. Unfortunately, this proclamation was not confirmed by much clinical evidence. A lot of laboratory and animal studies have been conducted. And the number of well-designed clinical trials with human subjects is very small.
A word of mouth only indicates that cats claw herb may help to improve such inflammatory problems as prostatitis and osteoarthritis, such immune disorders as rheumatoid arthritis and lupus and conditions when stronger immune system is required, for example cancer and HIV. At the same time some researches show that if used for a long time cats claw may overstimulate the immune system and even be harmful for some of the conditions.
The research on cat's claw herb is going to be intensified because of the worldwide concern over viral diseases. In spite of the fact that these areas have not been fully explored, some scientists believe that cat's claw herb may be effective in fighting chronic viral infections like AIDS, and also combating cancer and immune-related conditions associated with aging.
Several laboratory experiments have shown that cats claw herb demonstrates anti-inflammatory effects. However, very few clinical studies have been conducted on its properties. Such conditions as asthma, allergies, rheumatoid arthritis, tendonitis, Crohn's disease, bursitis are also being investigated in association with cat's claw. In Germany and Austria cat's claw plant extract is taken by some cancer patients under doctor's supervision. These standardized extracts are available by prescription only. Being an immune-boosting agent, cat's claw can increase the general health of people who have to undergo radiation, chemotherapy and other medical cures for cancer. Nevertheless this effect proper, has not been completely proven.