Abstract
The species Uncaria tomentosa (Willd.) DC. and U. guianensis (Aubl.) Gmel. (Rubiaceae), known as cat’s claw, are large woody vines occurring in the Amazon rain forest and other tropical areas of South and Central America. They have been used medicinally by indigenous peoples for at least two thousand years for several diseases. Their therapeutical properties, the structural complexity and diversity of their components and their mechanisms of action as well their ecologic and economic aspects have interested in the last thirty years physicians, pharmacologists, chemists, botanists, agronomists and economists. This work presents an overview of the main aspects concerned with these species, by congregating the more relevant informations from the several papers found in peerreview scientific journals, patents, books and the ample material at the internet.