Chemical composition, antioxidant, antifungal and hemolytic activities of essential oil from Baccharis trinervis (Lam.) Pers. (Asteraceae)

[Display omitted] •Baccharis trinervis, essential oil was investigated for the biological properties.•Essential oil contains 26 compounds, showed antioxidant activity.•Essential oil possesses antifungal activity against dermatophytes.•Essential oil showed synergistic effect with ketoconazole.•Essential oil showed low cytotoxic action. Baccharis trinervis (Lam.) Pers. (Asteraceae) is a species found in Latin America used in folk medicine as an antiseptic, digestive aid and for treatment of snakebites. This study aimed to describe the chemical composition of essential oil from B. trinervis, collected in the mountainous region of Meruoca in the state of Ceará, and to investigate its antioxidant and antimicrobial activities. The antioxidant activity was evaluated by the free radical DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging assay, β-carotene/linoleic-acid oxidation model system and the brine shrimp (Artemia salina) lethality bioassay. The evaluation of the antifungal activity in vitro was performed by broth microdilution using strains of dermatophytic fungi and yeasts. The modulatory activity assays were performed by the checkerboard technique using ketoconazole as standard. The chromatographic analysis showed that the main constituents of the essential oil were β-phellandrene (27.79%), (Z)-lachnophyllum (14.04%), sabinene (13.03%), (Z)-β-ocimene (8.13%) and α-thujene (6.65%). The lethality assay with A. salina demonstrated potential biological activity. The essential oil showed antifungal activity against all strains, with MIC values ranging from 0.31mg/mL to 0.15mg/mL. In the test of ketoconazole modulation against strains of Trichophyton rubrum, there was clear synergism of essential oil on the strains of dermatophytic fungi when combined with ketoconazole. The essential oil also showed significant antioxidant activity, with IC50 values of 49.0mg/mL and 28.87mg/mL by the free radical DPPH scavenging assay and β-carotene/linoleic-acid oxidation model system, respectively. This is the first study to investigate the antioxidant and modulatory activities of the essential oil of B. trinervis. The results demonstrate antioxidant and antimicrobial potential. The essential oil inhibited growth of dermatophytic fungi and enhanced the effect of ketoconazole via synergistic activity.