Phytochemical Analysis, Antimicrobial, and Antioxidant Activities of North Macedonia Achillea setacea Essential Oil

The complex genus Achillea L. comprises more than 140 species distributed widely throughout the Northern Hemisphere. Several species are widely used in traditional medicine for their therapeutic properties, yet few studies have correlated their biological properties with the plant’s phytochemical composition. Among these, Achillea setacea Waldst. & Kit. is a perennial species traditionally used to treat digestive and inflammatory disorders. In this study, the essential oil of A. setacea, collected wild in North Macedonia, was analyzed spectrometrically and spectroscopically by GC-MS and NMR, respectively. A total of nineteen compounds were identified, with camphor (31.3%), 4-terpineol (11.3%), and eucalyptol (10.6%) being the main constituents. Furthermore, the biological activities of pure oil were evaluated, showing notable antioxidant properties, as well as antimicrobial effects against a panel of clinically relevant microorganisms, including Gram-positive and Gram-negative bacteria. Furthermore, its impact on human intestinal epithelial (Caco-2) cells was assessed, highlighting its potential relevance for gastrointestinal applications, in agreement with the traditional use of Achillea species for digestive disorders.