Improving the yield and biological activity of sage essential oil using NADES: in vitro and in silico insights

This study investigates the efficacy of Natural Deep Eutectic Solvents (NADESs) as innovative green pretreatments for the hydrodistillation of sage (Salvia officinalis L.) leaves, focusing on essential oil (EO) yield, phytochemical modulation, and biological activity. Three choline chloride (ChCl)-based NADESs were synthesized and characterized via ATR-FTIR. The results revealed that NADES pretreatments significantly enhanced extraction efficiency, with the ChCl: Malic acid pretreatment achieving the highest EO yield of 2.53% (v/w) compared to 2.31% for the water-based control. GC-MS analysis identified up to 24 volatile compounds, showing that NADES applications notably increased the proportion of oxygenated monoterpenes, reaching a maximum of 78.45% in ChCl: Citric acid-treated oils. In vitro assays demonstrated that specific NADES-treated EOs possessed superior antioxidant capacities, and all extracted EOs exhibited potent, dose-dependent cytotoxic activity against SH-SY5Y human neuroblastoma cells. Mechanistic insights from molecular docking identified β-caryophyllene as a lead bioactive constituent, displaying strong binding affinities toward the VEGFR2 and Keap1 domains. A 100 ns molecular dynamics simulation of the VEGFR2-β-caryophyllene complex confirmed robust structural stability, as evidenced by consistent potential energy, stable root mean square deviation values, and a compact radius of gyration. These findings establish NADES-assisted hydrodistillation as a superior, sustainable technology for producing high-quality sage essential oils with enhanced therapeutic potential.