[Curares and timbós, poisons used in the Amazon]

The natives that dwell along the banks of the Orinoco and Amazon rivers have used different poisons from plants for centuries. The study reviews the historical and ethnographic aspects of the use of curares and timbós in the Amazonian region.

Curare is prepared by boiling the roots, bark and stalks of different plants belonging to the Loganiaceae (Strychnos) and Menispermaceae families (Chondrodendron, Curarea and Abuta). The curares of the eastern Amazon are extracted from different species of Strychnos that contain quaternary alkaloids, which act by blocking the neuromuscular junction. They are used to hunt wild animals and death comes about due to paralysis of the skeletal muscles. The first muscles to be paralysed are those of the eyes, nose and neck, and then those in the limbs; the diaphragm is the muscle that takes the longest to become paralysed. The earliest chronicles reporting their use were written by Fernandez de Oviedo, Cristoval de Acuna, Antonio de Ulloa and Jose Gumilla. La Condamine, Humbolt, Waterton and Schomburgk, among others, carried out a number of different ethnobotanical studies on curare. The ichthyotoxic poisons from plants, which are known as timbós or barbascos, are characterised by their high level of solubility, their fast diffusion and their high rate of activity. At least 70 plant species are used to poison the fish in the tributaries of the Amazon with the aim of make fishing easier. Sapindaceae, Papilionaceae, Euphorbiaceae and Theophrastaceae contain ichthyotoxic substances, such as rotenone or saponins.

Ethnohistorical and ethnographic accounts show that the Amazonian cultures have a deep understanding of the toxic properties of curares and timbós.