Ritual use of plants with possible action on the central nervous system by the Kraho Indians, Brazil.

The aim of the present study was to document the use of plants, probably acting on the central nervous system (CNS), in rituals carried out by the Kraho Indians, who occupy the cerrado biome in the central region of Brazil. The 2 years of fieldwork were guided by methods of anthropology and botany. The local shamans have indicated 286 formulas, consisting of 138 plant species in 50 uses that could be associated with some type of action on the CNS; of which 98 formulas, 87 plants and 25 uses, appear to involve psychoactive properties, such as: 'to get slow', 'stimulant effect', 'to calm down', 'to enhance memory', 'to reduce anxiety' and 'to induce sleep'. Phytochemical and pharmacological literature data were queried to establish any correlation between indigenous knowledge and scientific indications, for each one of the 138 plant species. Studies were available for 11 of these plants; and for two of them, scientific data coincided with indigenous information. Copyright 2005 John Wiley & Sons, Ltd.