Comparison of Three Different Extraction Methods on Schizonepeta tenuifolia (Benth.) Briq Essential Oil: Chemical Constituents and in Vitro and in Silico Biological Activities

This study evaluated the effects of three extraction methods, hydrodistillation (HD), steam distillation (SD), and lipophilic solvent extraction (LSE), on the yield, chemical composition, and in vitro / in silico biological activities of Schizonepeta tenuifolia (Benth.) Briq essential oil (STEO). The highest yield of STEO was obtained by HD (0.750±0.040%), followed by SD (0.440±0.020%) and LSE (0.350±0.030%). Although their contents varied, menthone and pulegone predominated in HDEO, SDEO, and LSEO. HDEO displayed the strongest antioxidant ability, with a 2,2-diphenyl-1-picrylhydrazyl (DPPH) IC50 value of 14.164±0.090 mg/mL and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) value of 0.326±0.023 mg/mL. SDEO demonstrated the highest antimicrobial activity against Staphylococcus aureus and Escherichia coli and HDEO the highest potent anti-inflammatory activity. The molecular docking of menthone and pulegone demonstrated strong binding to inflammatory targets, including prostaglandin-endoperoxide synthase 1 (PTGS1) and 2 (PTGS2) and tumor necrosis factor alpha (TNF-α). In short, the extraction method significantly affected the yield, composition, and biological activity of STEO.