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

Achillea millefolium Linn. is an aromatic edible plant used traditionally for the remedi-ation 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 por-tions, by hydrodistillation and by non-polar solvents, i.e., n-hexane and diethyl ether, were phyto-chemically analyzed and biologically investigated from the plant species cultivated in Saudi Arabia for their potential antioxidant and anticancer activities. The GC-analysis revealed substantial vari-ations among the major constituents and classes of volatile oils in all batches of the plant, charac-terized by the significant high percentages of monoterpenes, e.g., myrcene, 1,8 cineole, camphor, a-thujone, and b-thujone, in the distilled oils and sesquiterpenes in the non-polar extracts of the plant. Furthermore, the ketonic monoterpenes a-thujone and b-thujone were found to be the most repre-sentative compounds in the distilled and extracted batches of the plant. Variable antioxidant activ-ity 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 lg/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.& COPY; 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Achillea millefolium Linn. is traditionally used for its medicinal properties and has economic value in cosmetic and insect repellent industries. The essential oils obtained from different parts of the plant were analyzed and investigated for their antioxidant and anticancer activities. The major constituents of the volatile oils varied among different batches of the plant, with monoterpenes being predominant in the distilled oils and sesquiterpenes in the non-polar extracts. The distilled batches exhibited better antioxidant activity, while the non-polar extracts showed remarkable cytotoxic effects against cancer cells.