Uncaria tomentosa (Willdenow ex Roemer and Schultes) DC. and its relative Uncaria guianensis (Aublet) Gmell., both from the Rubiaceae family, are vines growing in jungles of South and Central America. They are widely used in folk and complementary medicine under traditional names: 'Vilcacora', 'una de gato', 'cat's claw', 'cat's crew', 'saventaro', 'hawk's claw', 'samento', 'garabato amarillo' and 'Katzenkralle'. In the genus Uncaria there are also other plants with well-known healing properties, eg. Uncaria rhynchophylla and Uncaria sinensis, one of the most interesting medicinal plants of Asia, similar to Uncaria macrophylla and Uncaria formosana. Vilcacora and its components are of interest to various scientists (physicians, pharmacologists, botanists, and economists) due to their pharmacological properties, as well as ecologic and economic significance. In the reviewed scientific literature more than 45 papers on Vilcacora (chemical constitution, extracts' standardization and quality control, toxicology and pharmacology of crude extracts - experiments in vitro or animal or human experiments in vivo) were published. Scientific literature on active substances present in Vilcacora includes more than a few thousand papers. In this paper, the most significant data on Vilcacora are reviewed, excluding case-reports and other data not confirmed in scientific literature (eg. single patients' or physicians' relations, popular science articles, manufacturers' publications etc.). Only papers published in peer-reviewed scientific journals, indexed in the databases: 'Index Medicus (Medline)', 'EMBASE - Drugs and Pharmacology', 'Chemical Abstracts', 'Biological Abstracts' and 'Review on Medicinal and Aromatic Plants' were covered.

Keywords: Rubiaceae, UNCARIA TOMENTOSA, UNCARIA GUIANENSIS, Indoles, Alkaloids, Medicinal plants, traditional medicine