Bioactivity and GC-MS Profiling of Essential Oils from Three Algerian Medicinal Plants (Mentha spicata, Artemisia herba-alba, and Salvia rosmarinus)

Aromatic plants from the Algerian flora are rich sources of bioactive essential oils with significant medicinal potential. Therefore, this study investigated the chemical composition and biological activities of essential oils (EOs) from three Algerian aromatic species: Mentha spicata L., Artemisia herba-alba Asso., and Salvia rosmarinus Spenn. The EOs were obtained via hydrodistillation and analyzed using GC–MS in the full scan mode. Biological evaluation included antioxidant activity (DPPH assay), protein anti-denaturation capacity (BSA model), and acute toxicity (Artemia salina lethality test). The extraction yields ranged from 0.48 ± 0.03% to 1.15 ± 0.06% (v/w), with S. rosmarinus exhibiting the highest yield. GC–MS profiling revealed monoterpene-rich compositions, with S. rosmarinus dominated by 1S-α-pinene (22.52%) and camphor (21.10%), A. herba-alba by camphor (13.47%) and davana ether (9.03%), and M. spicata characterized by a high carvone content (41.58%). In the DPPH assay, A. herba-alba exhibited the strongest antioxidant activity (IC₅₀ = 15.2 ± 0.9% v/v). For protein anti-denaturation, S. rosmarinus demonstrated the most potent inhibitory effect (12.50 ± 0.66%), significantly outperforming the aspirin standard (0.5%). Toxicity assessments indicated LC₅₀ values ranging from 18.6 to 25.4% v/v, suggesting a favorable safety profile. Integrated performance indices confirmed that S. rosmarinus is the most promising candidate for therapeutic applications. These findings validate the traditional use of these Algerian ecotypes and highlight their potential as safe and natural bioactive agents.