Isolation of essential oils. The EO was obtained by hydrodistillation, according to Ph. Eur. 5.0 [3], by using a modified Clevenger apparatus (with the EO collection area cooled to prevent the emergence of artifacts). The EO was dried on anhydrous sodium sulfate (Sigma-Aldrich Chemie GmbH) and stored in a tightly sealed brown glass bottle at 0-4°C for testing.