An extract of Uncaria tomentosa (U. tomentosa), also called Cat's claw, a native Amazonian plant belonging to the Rubiaceae species, with potential anti-inflammatory, immunomodulating, antioxidant and antineoplastic activities. Although the exact mechanism(s) by which U. tomentosa extract exerts its effect(s) has yet to be fully elucidated, this extract may inhibit the proliferation of certain types of cancer cells. This extract may modulate inflammatory and immune responses through the stimulation of T- and B-lymphocytes and certain cytokines, including interleukin (IL)-1, IL-6 and tumor necrosis factor-alpha (TNF-a). Components in U. tomentosa may both induce repair of chemically-induced DNA damage and scavenge free radicals, which may protect against reactive oxygen species (ROS)-mediated cellular damage. In addition, this extract stimulates myelopoiesis, which may prevent chemotherapy-induced neutropenia.