Medicinal plants with bioprospecting potential used in semi-arid northeastern Brazil

Objectives Many species of the Caatinga flora are used as medicines in local communities. In recent decades, the knowledge and use of these species has been expanding within this region. We attempted to record the local diversity of medicinal plants used to treat various diseases in a rural community in the state of Ceara, Brazil, and to evaluate the promising medicinal species for bioprospecting studies. Methods An ethnobotanical survey was conducted using free list and semi-structured interviews. To indicate medicinal plants that stood out, the relative importance (RI) of species mentioned by key-informants (20), by general informants in the community (71) and by all informants (91), was analyzed. The group of species that stood out for human body systems based on the informant consensus factor (ICF) was also evaluated. Results A total of 119 species were recorded that were associated with 92 health problems. Of these species, 100 were cited by key-informants and 86 were cited by general informants. Nineteen species showed a great versatility of use, including the following: Myracrodruon urundeuva Allemao, Bauhinia cheilanta (Bong.) Steud., Hymenaea courbaril L., Mentha x villosa Huds., Ziziphus joazeiro Mart., and Ruta graveolens L. Key-informants cited 33 exclusive species, from which nine presented greater relative importance. General informants cited 19 exclusive species, 2 with greatest relative importance. The therapeutic properties were grouped into 16 body system categories. These grouping categories included skin diseases and diseases of the subcutaneous tissue; sensory system (ears) disorders; respiratory disorders; and injuries, poisoning and other external symptoms. Conclusion The great diversity of medicinal plants used in the community is evident. Some species had both high relative importance and high consensus factors among the informants; these particular species are recommended for bioprospecting studies.