This work describes the local knowledge of the medicinal use of Stryphnodendron rotundifolium Mart., Fabaceae, according to informants in two areas of the Araripe bioregion, in the Northeast Region of Brazil. We used interviews to investigate the ethnomedicinal use of the local species to determine the mode of use, frequency of administration, duration of treatment and restrictions of use. In traditional medicine, the use of S. rotundifoliumis associated with the treatment of inflammatory and infectious diseases. The part of the plant most used was the stem bark (86.11%), the predominant mode of preparation was immersion in water (52.83%), and oral administration was the most cited (48.43%). For inflammatory and infectious diseases, the treatment lasted 3-10 days and the frequency of administration was 2-3 times/day. For gastroprotective effects, treatment lasted up to 30 days, and the herb was administered 1-3 times/day. For pain complaints, the therapy varied from 2-3 days to continuous administration.The informants (46.87%) did not mention restrictions of use, except for pregnant women, with a rate of 25%. A comparison of these results with the ethnopharmacological information from other studies showed that some of the traditional indications are scientifically supported by the literature or clinical studies. Nevertheless, the results showed that pharmacologists have not fully investigated all the possible bioactivities that healers credit to this plant.

The chemical composition of the essential oil obtained from the fresh and dried leaves of Lippia gracillis Schauer, Verbenaceae, was analyzed by gas chromatography and gas chromatography/mass spectrometry (GC⁄MS). The yield of essential oil extracted from the dried leaves was significantly higher (p<0.05) when compared to the fresh leaves. Seventeen components were identified. The monoterpenes and sesquiterpene hydrocarbons with 96.26% (w/w) of the total oil obtained of fresh leaves and 86.99% (w/w) of the total oil obtained of dried leaves were the principal compound groups. Thymol was observed dominant (44.42%; 21.3%), followed by carvacrol (22.21%; 21.30%), p-cymene (6.23%; 8.58%), α-pinene (5.65%; 19.42%), β-caryophyllene (5.61%; 3.57%) and other minor constitutes, respectively. Microbiological results obtained by agar diffusion method, micro dilution method and minimum inhibitory concentration (MIC) showed that the essential oil has a relevant antimicrobial activity against E. coli (ATCC 10536), E. coli (Ec 27), Pseudomonas aeruginosa (ATCC 15442), S. aureus (ATCC 12692) and S. aureus (Sa 358), with their inhibition zones ranging from 9 to 13 mm and the MIC ranging from 64 to 512 μg/mL.