Salvia aristata Essential Oil: Chemical Composition, Cholinesterase Inhibition, and Neuroprotective Effects against Oxidative Stress in PC12 Cells

Background and objectives: The cholinergic system plays a crucial role in CNS modulation, where dysfunctions are linked to cognitive and motor impairments. Cholinesterases (ChEs), essential enzymes for synaptic transmission in the CNS, are key therapeutic targets for neurodegenerative diseases. Moreover, these conditions feature elevated reactive oxygen species that compromise cellular integrity, leading to neuronal death. This study investigated the neuroprotective effects of Salvia aristata essential oilfocusing on its phytochemical composition and ChE inhibitory properties. Methods: The essential oil of S. aristata was extracted via hydrodistillation method and its chemical composition was analyzed by GC-MS. The ChE inhibitory effects were assessed using the modified Ellman’s method. Cell viability and neuroprotective effects of the essential oil were evaluated on PC12 cells under H₂O₂-induced oxidative stress by AlamarBlue assay. Results: analysis identified 74 compounds, primarily sesquiterpene hydrocarbons (32.79%), with β-trans-caryophyllene (8.37%), caryophyllene oxide (8.26%), and bicyclogermacrene (5.73%) as the major components. The essential oil showed more potent butyrylcholinesterase (BChE) inhibitory activity (IC50 = 2.72 ± 0.21 µg/mL) than anti-acetylcholinesterase activity. Based on kinetic analysis, it exhibited a mixed-type inhibition against BChE (Ki = 4.81, Kis = 3.39 µg/mL). Additionally, it effectively protected PC12 cells against H₂O₂-induced oxidative stress (p<0.001). Conclusion: The essential oil of S. aristata exhibited selective BChE inhibition and significant neuroprotective effects against oxidative stress in PC12 cells. These bioactivities, likely driven by major compounds like β-trans-caryophyllene, support the potential therapeutic use of the essential oil as a neuroprotective agent. However, further in vivo and clinical studies are suggested.