Antioxidant Activity, Chemical Composition, and Therapeutic Activity of Essential Oils From Certain Lamiaceae Species in Türkiye

Abstract

The study examined the antioxidant, antimicrobial, and potential anticancer properties of lavandin (Lavandula x intermedia 'Grosso'), oregano (Origanum vulgare 'Ulu & gbreve; Bey'), and sage (Salvia officinalis 'Beyhekim') essential oils (EOs). Chemical analysis revealed that oregano is rich in carvacrol (81.23%), cymene (5.51%), and 18-cineole (2.13%). Sage contains notable quantities of alpha-thujone (17.47%), camphor (13.59%), and borneol (12.14%). Lavandin is predominantly composed of linalool (41.10%), linalyl acetate (16.66%), and camphor (10.01%). The antimicrobial tests demonstrated that lavandin EOs exhibited a high inhibition rate of 90.77% at 1000 pg/mL, which subsequently decreased with lower concentrations. The oregano essential oils demonstrated robust antimicrobial activity across all concentrations, with a 10.97% inhibition rate observed even at the lowest concentration. The sage EOs exhibited a rapid decline in antimicrobial activity, reaching 4.97% at the lowest concentration. Both the DPPH and ABTS assays demonstrated that the antioxidant capacity of the essential oils was concentration-dependent. The cytotoxicity values of oregano essential oil were 35.58 at 50 pg/mL, 32.39 at 25 pg/mL, and 30.92 at 12.5 pg/mL. Similar cytotoxicity results were observed for sage and lavandin essential oils. These findings indicate that plant essential oils exert a dose-dependent cytotoxic effect on cell growth, significantly inhibiting cells at high concentrations. The research indicates that essential oils derived from Lamiaceae plants exhibit robust antimicrobial effects against a range of pathogens, suggesting potential applications as alternative therapies for specific microbial infections, comparable to ciprofloxacin at certain concentrations.