Intervention Effects of <i>Cyperus rotundus</i> Essential Oil on PCPA‐Induced Insomnia in Mice and Analysis of Human EEG Rhythm Regulation

ABSTRACT In this study, we systematically elucidated the sleep‐promoting mechanisms of Cyperus rotundus essential oil (CRO) utilising a comprehensive multidimensional approach encompassing network pharmacology, animal models, and human electroencephalography (EEG). Gas chromatography–mass spectrometry (GC–MS) identified key volatile constituents, notably cyperene and thujopsene. Subsequent network pharmacology and molecular docking analyses revealed 76 intersecting targets between CRO and insomnia, pinpointing ESR1, GSK3B, and MMP9 as core therapeutic proteins mediating the sedative effects. These computational predictions were robustly validated in vivo using a * p *‐chlorophenylalanine (PCPA)‐induced insomnia mouse model. Behavioural assessments demonstrated that CRO inhalation significantly reduced sleep latency, prolonged sleep duration, and ameliorated anxiety‐like behaviours. Mechanistically, CRO successfully reversed central hyper‐arousal by suppressing hypothalamic–pituitary–adrenal (HPA) axis hyperactivity, restoring neurotransmitter homeostasis (upregulating GABA and 5‐HT, downregulating GLU and DA), mitigating oxidative stress, and attenuating neuroinflammation. Furthermore, histological and immunohistochemical evaluations confirmed that CRO protected hippocampal neuronal architecture and significantly upregulated 5‐HT1A and GABAA receptor expression, thereby validating the predicted receptor signalling pathways. Translating these findings to human subjects, EEG spectral and topographic analyses demonstrated that CRO olfactory stimulation effectively enhanced low‐frequency delta and theta wave energies, successfully inducing a profound state of cortical relaxation. Collectively, these multidimensional in vivo and clinical findings strongly corroborate the in silico predictions, highlighting CRO as a highly promising, multi‐target natural therapeutic agent for the management of insomnia.