Chemical composition and biological evaluation of the Tunisian Achillea cretica L. essential oils

The essential oils (EOs) of different organs (flowers, vegetative parts (stems + leaves) and roots) of Achillea cretica were investigated. Antioxidant and antimicrobial activity of the essential oils were also evaluated. They have been analyzed by a combination of GC and GC/MS. Twenty-five, twenty-nine and twenty-five compounds, accounting for 97.9%, 98.80% and 96.20% of the root, (stem + leaf), and flower oils, were identified, respectively. The EOs were rich in monoterpenes (camphor, borneol, camphene and 1,8-cineola) and camphor was identified as a major constituent. Furthermore, the antioxidant activity was evaluated by DPPH, ABTS and ferric reducing assays. The isolated oils showed significant radical-scavenging activity evidenced by IC50 value for ABTS radical (in between IC50 =62 µg/mL and IC50 = 70 µg/mL). The antibacterial activity was tested against two Gram-positive and three Gram-negative bacteria using the broth dilution method. The flowers essential oil shows an excellent inhibitory effect on S. aureus.