Variability in the volatile constituents and biological activities of Achillea millefolium L. essential oils obtained from different plant parts and by different solvents

Abstract

Achillea millefolium Linn. is an aromatic edible plant used traditionally for the remediation of wounds, liver disorders, and as an herbal tea for the treatment of various gastrointestinal disorders. The plant's volatile oils have economical value in cosmetic preparation and as an insect repellant. The essential oils obtained from different plant parts, i.e., leaves, stems, and aerial portions, by hydrodistillation and by non-polar solvents, i.e., n-hexane and diethyl ether, were phytochemically analyzed and biologically investigated from the plant species cultivated in Saudi Arabia for their potential antioxidant and anticancer activities. The GC-analysis revealed substantial variations among the major constituents and classes of volatile oils in all batches of the plant, characterized by the significant high percentages of monoterpenes, e.g., myrcene, 1,8 cineole, camphor, α-thujone, and β-thujone, in the distilled oils and sesquiterpenes in the non-polar extracts of the plant. Furthermore, the ketonic monoterpenes α-thujone and β-thujone were found to be the most representative compounds in the distilled and extracted batches of the plant. Variable antioxidant activity of different batches of the plant was recognized; however, distilled batches of leaves, stems, and aerial parts exhibited better total antioxidant activity (TAA) compared to the plant’s non-polar extracts. With the little cytotoxic activity of distilled batches, the non-polar extracts exhibited remarkable cytotoxic effects against Panc-1 and MCF-7-Adr (35 and 43.3 μg/mL and 41.3 and 57.1, respectively, in the n-hexane and diethyl ether extracts), which were attributed to their comparatively higher contents of germacrene D, viridiflorol, and caryophyllene oxide. The n-hexane extract induced a concentration- and time-dependent apoptotic effect in Panc-1 and MCF-7 Adr cells, as observed by staining with FITC/PI and flow cytometry analysis. The docking simulation of the major n-hexane extract constituents indicated the prospective mechanism behind the ability of the extract to inhibit MCF-7-Adr cells by inhibiting P-glycoprotein/multidrug resistance 1/adenosine triphosphate-binding cassette.

Keywords

• Achillea millefolium L.
• Yarrow
• Essential Oils
• GC-Analysis
• Cytotoxicity
• Antioxidants