Supercritical CO 2 Extracts of Onosma Decorticans Riedl: Phytochemical Profiling and Antioxidant, Antibacterial, and Anticancer Activities

ABSTRACT This study investigated the chemical composition, antioxidant activity, and in vitro cytotoxicity inducing potential of supercritical CO 2 extracts obtained at different pressures from the aerial parts of Onosma decorticans (Boraginaceae). The extract produced at 100 bar (O 100 ) was characterized by LC–MS/MS, identifying 19 phytochemicals, with fumaric acid, cyranoside, cosmosiin, and quinic acid detected as the predominant constituents. Antioxidant activity was evaluated using the DPPH radical scavenging assay, with ascorbic acid (AA) as positive controls. At 400 µg/mL, O 100 and O 150 scavenged 65% ± 3.1% and 43% ± 5.2% of DPPH radicals, respectively, indicating moderate antioxidant capacity. Dose–response analysis revealed statistically significant radical scavenging activity compared to the control at 50 µg/mL for O 100 and 150 µg/mL for O 150 ( p < 0.05).