Comprehensive phenolic profiling and biological evaluation of Centaurea glastifolia L. (Asteraceae)

The present investigation focused on the comprehensive analysis of the phenolic profile of Centaurea glastifolia L. (Asteraceae) and the assessment of its diverse biological activities. Utilising LC-MS/MS, the phytochemical composition of the 70% methanol extract of Centaurea glastifolia (CG-ME) was thoroughly elucidated, revealing the presence of 30 distinct phytochemical compounds. Notably, major phenolic constituents identified in the extract included quinic acid, chlorogenic acid, luteolin-7-O-glucoside, kaempferol-3-O-glucoside, luteolin, and apigenin-7-O-glucoside. The antioxidant, antibacterial, antiproliferative, and cytotoxic activities of CG-ME were investigated. The CG-ME exhibited a moderate capacity for scavenging DPPH radicals (IC₅₀: 50.05 ± 1.58 µg/mL) and FRAP (63.96 ± 0.39 mg TE/g extract), indicating a moderate level of antioxidant activity. Moreover, CG-ME demonstrated significant antiproliferative effects (GI₅₀: 1.10 and 1.30 µg/mL) on cancer cells (C6 and HTC cancer cell lines, respectively) while displaying low cytotoxicity towards normal cells (LC₅₀: >1000 µg/mL). In terms of antibacterial activity, CG-ME was found to be inactive against tested both Gram-positive and Gram-negative bacterial strains (MIC > 500 µg/mL). The extracts had a promising antiproliferative effect on C6, HeLa, and HT29 cancer cell lines with a less cytotoxic effect (10.5-14.2%) against normal cells.