Bioprospecting the Cerrado’s Aromatic Flora: Chemical and Biological Studies of Three Essential Oils

: Chemical and pharmacological potentials of botanical species found in the Cerrado are well-known and widely studied. Chemical diversity of secondary metabolites produced by plants that belong to this Brazilian biome has triggered several studies in the fields of farming, pharmaceutical and cosmetic industries. Therefore, this study aimed at evaluating the chemical composition of essential oils (EOs) from fresh leaves of three species found in the Brazilian Cerrado : Cardiopetalum calophyllum Schltdl. (EO-CC), Campomanesia adamantium (Cambess.) O. Berg (EO-CA) and Protium ovatum Engl. (EO-PO) and at determining their anti- Malassezia furfur and anti-inflammatory activities . Both GC-FID and GC-MS showed that the most abundant chemical class of the oils was the one of sesquiterpene hydrocarbons. The major constituents identified in EO-CC were germacrene D (34.9%) and bicyclogermacrene (26.8%). EO-CA exhibited mainly germacrene D (21.7%) while EO-PO had high concentrations of germacrene D (25.0%) and γ-muurolene (18.6%). EOs were tested by the broth microdilution method on 96-well microplates and exhibited satisfactory activity against M. furfur , i. e., EO-CA had MIC = 375 µg/mL while EO-CC and EO-PO HIGHLIGHTS had MIC = 750 µg/mL. The chemotaxis model, which was used for evaluating their anti-inflammatory activity, showed that EOs exhibited effective results: C . calophyllum (EO-CC; IC 50 = 24.4 µg/mL), C. adamantium (EO-CA; IC 50 = 15.7 µg/mL) and P. ovatum (EO-PO; IC 50 = 32.5 µg/mL). In short, biological activities of EO-CC, EO-CA and EO-PO, such as anti- Malassezia furfur and anti-inflammatory ones, were investigated and described for the first time. on neutrophil motility in suspension (upper compartment) towards the chemotactic agent fMLP 10 -8 M (lower compartment), determined by the space used by neutrophils through the polycarbonate filter placed between chamber compartments. EOs was dissolved in leukocyte solution at concentrations of 5, 10, 15.7, 24,4 and 32.5 µg/mL and incubated at 37◦C for 30 min. Plasma collected from rats was incubated at 37 ºC for 30 min with 65 µg/mL of LPS (lipopolysaccharide from Escherichia coli – the positive control). The plasma was diluted in Hanks buffer at 20% concentration (v/v). An optical microscope (40x magnification) was used for reading the filters. Its focus was initially adjusted to the upper plane of the filter and then slowly deepened to focus on two cells. Reading was carried out in five fields of every filter and the migrating capacity of neutrophils was evaluated in terms of distance, as micrometers, measured between the upper plane of the filter and the final plane of observation Results showed the mean of distances found by the readings. Results were expressed as mean+/-standard deviation, analyzed by the Student’s t-test and compared with the mean of distances determined for non-treated control cells The difference was considered statistically significant when p ≤ 0.05. Measurements were taken from five fields across each one of duplicate filters and results were expressed as mean ± standard error of the mean (SEM) and analyzed by one way analysis of variance (ANOVA) followed by the Tukey multiple range