Antifungal Action of the Dillapiole-rich Oil of Piper aduncum against Dermatomycoses Caused by Filamentous Fungi

Aims and Study Design: Piper aduncum L. is a Brazilian plant with many biological properties attributed to its dillapiole-rich essential oil. Despite the development of antibiotics, bacterial and fungal infections are still a public health issue in the medical field. This study measured the antimicrobial activity of the dillapiole-rich essential oil of P. aduncum against pathogenic skin microorganisms.

Place of Study: Faculty of Pharmacy and Graduate Program in Pharmaceutical Science, Federal University of Pará, Brazil. This work was performed in 2014.

Methodology: Gas Chromatography (GC) and Gas Cromatography-Mass spectrometry (GC-MS) have analyzed the oil and its dillapiole-rich fraction. The determination of Minimum Inhibitory Concentration (MIC) and Minimum fungicidal concentration (MFC) values was carried out by microdilution method and counting of formed colonies.

Results: For the strains of Trichophyton mentagrophytes (ATCC 9533 and clinical isolate), the oil and its dillapiole-rich fraction exhibited MIC values of 500 μg/ml while the MFC values were 1,500 μg/ml for the oil and 1,000 μg/ml for the fraction rich in dillapiole. For clinical isolates of T. rubrum and Epidermophyton floccosum, MIC values of 500 μg/ml and MFC 1,500 μg/ml were equal for the oil and the dillapiole-rich fraction, respectively. For clinical isolates of Microsporum canis and M. gypseum, the MIC and MFC values were 250 μg/ml and 500 μg/ml, respectively. For strains of Aspergillus fumigatus (ATCC 40152 and clinical isolate), the oil and its dillapiole-rich fraction have shown the same MIC value of 3.9 μg/ml while the MFC values were 7.8 μg/ml for the strain ATCC 40152, and 15.6 μg/ml for the clinical isolate. The oil and dillapiole-rich fraction did not show antibacterial activity against the strain of Staphylococcus aureus ATCC 6538 and its clinical isolate

Conclusion: The dillapiole-rich essential oil of P. aduncum and its dillapiole-rich fraction demonstrates significant antifungal activity against dermatophytes, filamentous fungi and potent antifungal activity against non-dermatophyte filamentous fungi.