Artemisia annua L. (Asteraceae) is the source of the unique sesquiterpene endoperoxide lactone artemisinin used in the treatment of the chloroquine-resistant and cerebral malaria. The essential oil, rich in mono- and sesquiterpenes, represents a by-product with medicinal properties. Besides significant variations in its percentage and composition have been reported (major constituents can be camphor (up to 48%), germacrene D (up to 18.9%), artemisia ketone (up to 68%), and 1,8 cineole (up to 51.5%)), numerous studies support exciting antibacterial and antifungal activities of the essential oil [1].
In continuing our studies on A. annua essential oil [2,3] we investigated the activity against some Malassezia species closely related to many skin disorders in man and animals. Tests were carried out either in liquid phase and in vapor phase. Essential oil of A. annua showed strong antimicrobial activity in both tests and towards every species of Malassezia analyzed.
The MFC results demonstrated a strong fungicidal activity of A.annua EO on most of Malassezia strains tested, with values from 0.78 µL/mL to 1.56 µL/mL. Only three strains of M.sympodialis have required a higher concentration of 3.125 µL/mL.
Overall the MICs obtained by the vapor diffusion assay were lower than those obtained by the liquid method. For example, by comparing for each species the average values of MIC obtained by the two methods at 72 h, they are higher (1.3 to 8 times) in liquid method, respect to those in the vapor phase.
REFERENCES
[1] Bilia AR, Santomauro F, Sacco C, Bergonzi MC, Donato R. Evid Based Complement Alternat Med. 2014;2014:159819.
[2] Santomauro F, Donato R, Sacco C, Pini G, Flamini G, Bilia AR. Planta Med. 2016 Jul;82(11-12):1016-20.
[3] Tasdemir D, Tierney M, Sen R, Bergonzi MC, Demirci B, Bilia AR, Baser KH, Brun R, Chatterjee M. Planta Med. 2015 Aug;81(12-13):1029-37. doi: 10.1055/s-0035-1546125.