This study evaluated the anticancer potential of Satureja sahendica essential oil (SSEO) against MDA-MB-231 (breast cancer) and A549 (lung cancer) cell lines. The chemical composition of SSEO, determined by GC-MS, revealed thymol (57.11%) and γ-terpinene (25.27%) as the major constituents. The MTT assay demonstrated that SSEO induced concentration- and time-dependent cytotoxicity, with IC₅₀ values of 0.69 mg/mL (24 h) and 0.28 mg/mL (72 h) for MDA-MB-231 cells, and 0.59 mg/mL (24 h) and 0.37 mg/mL (72 h) for A549 cells. Apoptosis was identified as the primary mode of cell death, confirmed by acridine orange/ethidium bromide dual staining and Annexin V-FITC/propidium iodide flow cytometry. Flow cytometric analysis quantified early apoptosis, showing 41.2% of treated MDA-MB-231 cells and 35.5% of treated A549 cells in the Annexin V+/PI- quadrant. To elucidate the molecular basis of these effects, a comprehensive in silico analysis, incorporating target prediction, protein-protein interaction network, and gene ontology enrichment, was performed. This approach identified key cancer-related proteins, including MAPK14, PIM1, CTSD, TOP2A, PDK1, KIFC1, and NF-κB, as potential targets of the major SSEO constituents. Additionally, the cytotoxic effect of SSEO was evaluated on the normal L929 cell line, where IC₅₀ values of 1.082 mg/mL (24 h) and 0.89 mg/mL (72 h) were observed, indicating notably lower toxicity toward normal cells compared to cancer cells. Collectively, these findings demonstrate that SSEO exerts cytotoxic effects primarily through the induction of apoptosis in both breast and lung cancer cells, highlighting its potential as a complementary anticancer agent.
