Preliminary Assessment of the Neuroprotective Potential of the Above-Ground Parts of Two Carlina Species (Asteraceae)

The aim of this study was to evaluate the phytochemical profile and neuroprotective potential of extracts from underground and aerial parts of two Carlina species: Carlina acaulis (CA) and Carlina vulgaris (CV). Metabolic profiling performed via UHPLC-UV-MS/MS revealed a distinct chemotaxonomic differentiation between the taxa. C. acaulis was defined as a “phenolic-acid” chemotype dominated by 5-O-caffeoylquinic acid (up to 32.11 mg/g in leaves), whereas C. vulgaris was characterized as a “flavonoid” chemotype, distinguished by a unique C-glycoside signature, including carlinoside and schaftoside. A significant aspect of scientific novelty is the first-ever identification of flavonolignans (e.g., salcolin A/B and tricin derivatives) in the roots of both species. In biological assays, the extracts demonstrated a multidirectional neuroprotective mechanism. Good antioxidant properties (DPPH, FRAP assays) were confirmed, particularly in CA leaves and CV inflorescences which revealed 61% of DPPH scavenging, along with the capacity to chelate Fe(II) ions (above 60% for CA inflorescence, CV leaves and CV root), a crucial mechanism in ferroptosis prevention. Furthermore, leaf extracts of both species exhibited effective inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) exceeding 50%, showing kinetic selectivity towards BChE inhibition. These results position Carlina species as a promising source of metabolites supporting the therapy of neurodegenerative diseases.