Pharmacology and therapeutic uses of cat’s claw

Abstract

Cat’s claw, also known as the “life-giving vine of Peru,” “saventaro,” or “uña de gato,” is a thick woody vine indigenous to the Amazon rain forest and other tropical areas of South and Central America.1 It has been used as a sacred plant of healing for over 2000 years. The plant, described by its Spanish folk name “uña de gato,” has a hooklike thorn that grows largely along the vine in a leafy pattern that resembles the claws of a cat.1 There are several species of cat’s claw, but the two most common species used and marketed interchangeably for their various properties are Uncaria tomentosa and Uncaria guianensis.2,3U. tomentosa, evidently the preferred species because of its higher alkaloid content and the ease of standardization, is the focus of this article. U. tomentosa may be contaminated with other Uncaria species, including Uncaria rhynchophylla, which has been used in Chinese herbal preparations. In some European countries (e.g., Germany, Austria), cat’s claw can only be dispensed with a prescription. Currently, cat’s claw is widely used and is one of the top herbal remedies sold in the United States, despite a lack of high-quality human evidence supporting its benefits. Its popularity in the alternative medicine market might be partly because of its proposed abilities to strengthen the immune system, inhibit inflammation, inhibit tumor growth, and suppress viral replication.4 Despite the alleged medical benefits associated with cat’s claw use, relatively few scientific studies have been conducted to establish the safety and efficacy of this plant.