Carqueja (Baccharis sect. Caulopterae), a critical review of its history, phytochemistry and medicinal use: problems of ethnopharmacology in Latin America

The Latin American medicinal plant carqueja got its name from a morphologically similar plant from the Iberian peninsula. The popular name came in general use to indicate all species from the section Caulopterae from the genus Baccharis, which are often difficult to distinguish. Phytochemical studies indicate that the different species from this section contain similar compound classes, especially essential oils, flavonoids and diterpenes, but much variation is encountered in relation to the individual compounds within the species. There are also some indications for the existance of different chemotypes within species. Recovered information from manuscripts, elaborated in the Jesuit missions, and originally authored by the Jesuit friar Pedro de Montenegro around 1710, indicate that carqueja was used by the Guarani indians of Southern Latin America for wound treatment. This traditional use was largely lost and nowadays the plant is mainly indicated for intestinal problems, as a tonic or for treatment of diabetes. It might be possible that this is caused by a confusion with quina, around 1800, which led to the alternative popular name "Quina de Condamine". The confusion about the identification of individual species persists up to today. In pharmacological studies performed with crude extracts, doubts arise about the species used and its phytochemical composition. Also in medicinal teas different species are used indiscriminantly leading to great differences in phytochemical profile. In this paper information about the phytochemistry, medicinal use, botanical specimens and nomenclature is extensively reviewed and recommendations for further studies and increased reproducibility of pharmacological studies are given.