Phytochemical Characterization of Sideritis akmanii Extract by LC–MS/MS and Evaluation of Its Multifunctional Biological Activities

Abstract

Sideritis species (Lamiaceae) are traditionally used in Mediterranean and Anatolian folk medicine and are recognized for their diverse phytochemical constituents and biological properties. This study investigated the phytochemical composition and biological activities of an ethanol–water extract of Sideritis akmanii (S. akmanii) , an endemic species from Türkiye. Targeted LC–ESI–MS/MS analysis identified verbascoside (13,634 ± 306 µg/g extract) and chlorogenic acid (9299 ± 123 µg/g extract) as the predominant compounds. Total phenolic and flavonoid contents were 61.45 ± 0.12 mg GAE/g extract and 27.35 ± 0.18 mg QE/g extract, respectively. The extract exhibited antioxidant and enzyme‐inhibitory activities, as well as antimicrobial and antibiofilm effects. In A549 lung cancer cells, the extract reduced cell viability in a concentration‐dependent manner and altered oxidative stress parameters, inflammatory mediators, and apoptosis‐related gene expression. However, since a reference chemotherapeutic agent and a non‐cancerous cell line were not included, comparative cytotoxic potency and cancer‐cell selectivity could not be determined; therefore, these cellular findings should be considered preliminary. Overall, the findings expand current knowledge of the phytochemical composition and biological properties of S. akmanii and support further investigation using more comprehensive experimental models.