Abstract
This study investigates the phytochemical composition and biological activities of six solvent extracts-hexane, ethyl acetate, and hydroethanolic fractions-from the roots and aerial parts of Ajania fastigiata (C. Winkl.) Poljakov (Asteraceae), collected in the mountain regions of southeastern Kazakhstan. Phytochemical analysis revealed that the aerial ethyl acetate extract contained the highest levels of bioactive metabolites, including phenolic compounds (34.22 ± 1.98 mg GAE/g), flavonoids (2.74%), organic acids (1.91%), and coumarins (0.54%). Antioxidant potential was evaluated using DPPH and ABTS radical-scavenging assays, with values of SC50 = 133.98 ± 12.91 µg/mL (DPPH) and 209.21 ± 3.70 mg Trolox/g (ABTS). The minimum inhibitory concentration (MIC), determined by the broth microdilution method, showed strong antimicrobial activity of the aerial ethyl acetate fraction, particularly against P.aeruginosa (MIC = 9 µg/mL) and E.faecalis (MIC = 39 µg/mL). Cytotoxicity was assessed by the MTT assay on NIH-3T3, K562, and Saos cell lines. The aerial ethyl acetate fraction exhibited selective cytotoxic effects, with IC50 values of 210 µg/mL for K562 and 360 µg/mL for Saos, while showing negligible activity toward normal fibroblasts (IC50 > 2500 µg/mL). These results confirm the pharmacological potential of A.fastigiata as a promising natural source of antioxidant, antimicrobial, and anticancer agents.