Abstract
Candida spp. are often the cause of infection in immune-compromised individuals. They are
characterized by a strong resistance to antimicrobial drugs and disinfectants. The
activity of Artemisia annua essential oil against Candida spp. was determined by vapour contact and microdilution assay. The oil was characterized
by the presence of oxygenated monoterpenes (more than 75 % of the constituents), mainly
represented by the irregular monoterpene artemisia ketone (ca. 22 %), and the widespread
monoterpenes 1,8 cineole (ca. 19 %) and camphor (ca. 17 %). Other representative constituents
were artemisia alcohol (5.9 %), α-pinene (5.7 %), and pinocarvone (3.0 %). Thujone, a typical toxic constituent of
the Artemisia species, was not detected. The results are reported as minimum inhibitory concentration,
minimum fungicidal concentration, and diameter of inhibition zone obtained by the
vapour diffusion assay. We tested 10 clinical Candida strains, coming from both clinical samples and international collections. The results
show that the antifungal activity of A. annua is influenced by the type of method adopted. The inhibitory action of the essential
oil was, in fact, higher in the vapour than in the liquid phase. Our results show
an average minimum inhibitory concentration in the liquid phase of 11.88 µL/mL, while
in the vapour phase, the growth of all Candida strains tested at a concentration of 2.13 µL/cm3 was inhibited. A strain of Candida glabrata was found to be less susceptible to the liquid medium than the vapour assay (50 µL/mL
vs. 0.64 µL/cm3, respectively). Candida albicans and Candida dubliniensis were the most susceptible to the vapour test, while Candida parapsilosis was the most resistant.
Key words
Artemisia annua
- Asteraceae -
Candida spp. - vapour diffusion assay - broth microdilution assay
