Unraveling the therapeutic potential of Satureja nabateorum extract: inducing apoptosis and cell cycle arrest through p53, Bax/Bcl-2, and caspase-3 pathways in human malignant cell lines, with in silico insights.

Satureja nabateorum, known as Nabatean savory is a Lamiaceae plant native to the Arabian Peninsula, specifically in the mountainous regions of Saudi Arabia. The study aims to investigate the phytochemical components of the S. nabateorum leaves (SNL) and stems (SNS) extract and to assess their antioxidant, antimicrobial, and antiproliferative properties. Methanol extracts from leaves and stems were analyzed for chemical constituents using the GC-MS technique. Antioxidant capacities were measured using hydrogen peroxide and ABTS radical-scavenging methods, and antimicrobial activity was tested against various microorganisms. Cytotoxic activity on four human malignant cell lines was assessed using MTT and flow cytometry. Molecular docking and molecular dynamics studies were conducted to understand the interactions and binding modes of the extracted compounds at a molecular level. GC-MS analysis of SNL extract revealed thymol, carvacrol, and p-cymen-8-ol as major constituents. SNS extract contained β-sitosterol, stigmasterol, lupeol, and lup-20(29)-ene-3β,28-diol. SNS extract exhibited more potent antioxidant, antimicrobial, and anticancer effects than SNL extract. The extract, SNS, exhibited potential toxicity in A549 cells with an IC₅₀ value of 3.62 µg/mL and induced marked apoptotic effects with S phase-cell cycle arrest. SNS extract also showed higher levels of Caspase 3, Bax, p53, and the Bax/Bcl2 ratio and lower levels of Bcl-2. Molecular docking and dynamic simulation supported these findings, targeting the EGFR TK domain. The study suggests that the S. nabateorum stem extract holds promise as a potent antimicrobial, antioxidant, and anticancer agent. It provides valuable insights for considering the extract as a substitute for chemotherapy and/or protective agents.