Bitter plants used as substitute of Cinchona spp. (quina) in Brazilian traditional medicine

Bitter tasting plant species are used as tonics and have been previously used to treat intermittent fevers in Brazil, the principal symptom of malaria. Many of these species were named quina and were used as substitutes of Cinchona spp., the source of quinine. To present data on these bitter species named quina and to discuss their potential as sources of bioactive substances. Data about the plants were obtained from a survey of the literature and documents written by early naturalists and clinical doctors living in the 18th and 19th centuries in Brazil. Correlated pharmacological studies were obtained from different scientific databases. A total of 29 species were recorded. The largest number of species belonged to the Rubiaceae family (14), being Remijia ferruginea (A. St.-Hil) DC. the most representative. Strychnos pseudoquina A. St.-Hil. (Loganiaceae), Hortia brasiliana Vand. ex DC. (Rutaceae) and Solanum pseudoquina A. St.-Hil. (Solanaceae) were also frequently mentioned in the historical bibliography. Pharmacological studies have shown the presence of bitter bioactive substances useful to treat digestive disorders and/or with antimalarial activities, in all of the recorded botanic families. This study shows that several bitter species named quina were used in the past as substitute of Cinchona spp. and studying these plants can lead to the development of new products. [Display omitted]