Deciphering the Anticancer, Antioxidant, Enzyme Inhibition Potentials, and Phytochemical Compositions of Some Endemic <i>Centaurea</i> Species

Plants have been used in traditional medicine for centuries, providing a variety of biological benefits, including antioxidant and anticancer activity, due to their phytochemical composition. This study investigates the biological activity and chemical composition of Centaurea saligna, Centaurea bingoelensis, and Centaurea pyrrhoblephara, key species of the Asteraceae family, to explore their potential for developing novel therapeutic strategies. Methanol extracts of these species were analyzed for their inhibitory effects on α-glucosidase, AChE, and BuChE enzymes. Their lipophilic components were characterized using GC-MS, phenolic profiles via Orbitrap HPLC-HRMS, and total phenol and flavonoid contents were quantified using established methods. Antioxidant activities were evaluated through DPPH, ABTS, ferric ion reducing, and ferrous ion chelating assays. Cytotoxic effects were assessed on HT-29 colorectal and A549 lung cancer cells through WST-1 analysis, determining IC₅₀ values. In addition, anticancer activity findings were supported by colony survival and cell migration analyses. Apoptotic activity of the applied treatments was observed by AO/EB dual staining, caspase-3 ELISA, and Western blot analysis. Notably, the extracts significantly induced apoptosis in HT-29 cells, evidenced by increased apoptotic indices, cleaved PARP, and p53 expression, with C. pyrrhoblephara exhibiting the strongest proapoptotic activity.