Purpose: To identify the main components of the essential oil (EO) of
Baccharis trimera
Less and
investigate their
in vitro antifungal activity against seven fungal strains that cause onychomycosis.
Methods: The chemical composition of EO was determined using gas chromatography, and its
minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and antifungal
activity were compared with those of terbinafine and ketoconazole. Scanning electron microscopy
(SEM) was used to investigate morphological changes in the strains of interest.
Results: Twenty compounds, with β-pinene being the major constituent (23.4 %), were identified in EO.
EO exhibited fungicide potential, with MFC values in the range of 0.06 to 125 μg mL
−1, which were lower
than those of the reference drugs against
Trichophyton rubrum
CCT 5507 URM1666 and
Microsporum canis
ATCC 32903. MIC range for the compounds was from 0.03 to 125 μg mL
−1 for five strains of the
fungi evaluated. For
Trichophyton mentagrophytes
ATCC 11481 and
Epidermophyton floccosum
CCFIOC
3757, MIC was ≥ 1000 μg mL
−1. Flattening, distortions, and shrinkage were observed in the SEM
images of structures of the five fungal species that were subjected to the action of the EO.
Conclusion: The results indicate that EO has antifungal activity against filamentous fungi and may be
developed as an alternative for the treatment of onychomycosis.
