Assessing Salvia dominica L.: from chemical profiling to antioxidant, antimicrobial, anticancer, α-amylase, and α-glycosidase activities of the plant essential oil

Abstract Salvia dominica L. is a fragrant perennial shrub densely adorned with trichomes, found throughout the eastern Mediterranean, especially Palestine, Jordan, Lebanon and Syria. It is commonly used by the Bedouins for the remedy of many diseases. In recent years, essential oils (EOs) have attracted interest due to their biological qualities. This study sought to examine the chemical composition of EOs extracted from the dry and fresh leaves of Salvia dominica L. and to evaluate their in vitro antioxidant, anticancer, antibacterial and α-amylase and lipase inhibitory activity. The chemical compositions of EOs obtained by steam distillation were determined using gas chromatography–mass spectrometry. The principal constituents of the oil derived from fresh Salvia dominica L. leaves comprised linalyl acetate (43.69%), α-terpinyl acetate (12.35%), germacrene D (10.22%), linalool (9.40%), 1,8-cineole (7.07%), and α-terpineol (4.97%), with the predominant category being oxygenated monoterpenes (OM) at 74.60%. The principal constituents of the EO obtained from air-dried leaves included linalyl acetate (70.17%), germacrene D (10.20%), terpinyl acetate (7.49%), and 1,8-cineole (4.08%), with oxygenated monoterpenes (OM) representing the predominant class at 80.87%. The air-dried flowers of Salvia dominica L. were extracted with CO2–CH2Cl2, yielding a dark brown sticky oil that was fractionated into five fractions via silica gel chromatography. Interestingly, fractions (F3 and F4) showed significant anticancer activity against MCF-7 and HeLa cell lines, with IC50 values ranging from 25.41 ± 1.27 to 40.94 ± 2.05 μg/mL, while both EOs showed reduced anticancer properties and poor α-amylase and lipase activities. Both EOs displayed outstanding antioxidant activity, and modest antibacterial activity against K. pneumonia and S. aureus with MIC values between 0.39 and 3.125 μL/mL. The fractions 4 and 5 of the CO2 extract showed enhanced antibacterial efficacy relative to the commonly employed antibiotic gentamicin (31.25–125 µg/mL) against all tested microorganisms, with MIC values between 6.25 and 25 µg/mL. Graphical Abstract