Cat's Claw Bark (Uncaria tomentosa). This is considered one of the most powerful botanicals of the Amazon Peruvian rain forest. The native Indians have a wide use of applications for it, ranging from such acute conditions as headaches, colds, influenza, and fevers, to the treatment of gastrointestinal problems (especially colitis, irritable bowel syndrome, Crohn’s disease and ulcers); tumors, arthritis, fibromyalgia, asthma and cardiovascular diseases, and as an immune tonic. Cat’s Claw is also a rich source of proanthocyanidin (pycnogenol), which is a powerful antioxidant and free radical scavenger.