Essential oil profile and biological activity of the paleoendemic species Salvia dorystaechas B.T. Drew

Salvia dorystaechas B.T. Drew (syn. Dorystaechas hastata Boiss. & Heldr. ex Benth.) is an endemic plant native to Antalya and its surroundings, known as “Dağ çayı” and “Çalba Çayı”. In the present study, n-hexane, ethyl acetate, ethanol 70% extracts and essential oil were obtained from the aerial parts of S. dorystaechas. The oil was obtained by the hydrodistillation method. The chemical composition of oil was determined by GC/FID and GC/MS analysis. Twenty-seven compounds were identified representing 99% of the oil. 1,8-cineole (26.4%), myrcene (19.2%) and α-pinene (10.1%) were determined as the main components. The extracts of the plant were screened for antioxidant activity by using a DPPH• free radical scavenging assay. The ordering of extracts in terms of antioxidant activity from highest to lowest was ethyl acetate, ethanol 70% and n-hexane. The extracts and hydrodistilled oil of S. dorystaechas were evaluated for their antimicrobial activity using standard broth microdilution protocols. The ethyl acetate extract exhibited the highest antibacterial and anticandidal activities against S. aureus, S. typhimurium, C. utilis, and C. tropicalis, with a minimum inhibitory concentration (MIC) of 62.5 µg/mL. The essential oil and the ethanolic extract demonstrated moderate to weak inhibitory effects (62,5 to >2000 µg/mL, MIC) against tested microorganisms. S. dorystaechas extracts demonstrate strong antimicrobial properties against various pathogens, suggesting potential use as a natural antibiotic, especially in light of increasing antibiotic resistance. Furthermore, the plant's aromatic components may be beneficial in aromatherapy. S. dorystaechas presents a promising candidate for natural therapeutic interventions, warranting further investigation into its pharmacological benefits.