Comparative Analysis of Volatile Components in Chi-Nan and Ordinary Agarwood Aromatherapies: Implications for Sleep Improvement

Abstract

Agarwood, a precious traditional medicinal herb and fragrant material, is known for its sedative and sleep-improving properties. This study explores the mechanisms underlying the aromatherapy effects of Chi-Nan agarwood and ordinary agarwood in improving sleep. Using a combination of gas chromatography–mass spectrometry (GC-MS), network pharmacology, and molecular docking techniques, we identified and c ompared the chemical compositions and potential molecular targets of both types of agarwood. The GC-MS analysis detected 87 volatile components across six types of agarwood aromatherapy, with 51 shared between Chi-Nan and ordinary agarwood, while each type also had 18 unique components. Ordinary agarwood was found to be richer in sesquiterpenes and small aromatic molecules, whereas Chi-Nan agarwood contained higher levels of chromones. These differences in chemical composition are likely responsible for the distinct sleep-improving effects observed between the two types of agarwood. Through network pharmacology, 100, 65, and 47 non-repetitive target genes related to sleep improvement were identified for components shared by both types of agarwood (CSBTs), components unique to common agarwood (CUCMs), and components unique to Chi-Nan agarwood (CUCNs), respectively. The constructed protein–protein interaction (PPI) networks revealed that key targets such as MAOA, MAOB, SLC6A4, and ESR1 are involved in the sleep-improving mechanisms of agarwood aromatherapy. Molecular docking further confirmed the strong binding affinities of major active components, such as 5-Isopropylidene-6-methyldeca-369-trien-2-one and 2-(2-Phenylethyl)chromone, with these core targets. The results suggest that agarwood aromatherapy enhances sleep quality through both hormonal and neurotransmitter pathways, with ordinary agarwood more deeply mediating hormonal regulation, while Chi-Nan agarwood predominantly influences neurotransmitter pathways, particularly those involving serotonin and GABA. This study provides valuable insights into the distinct therapeutic potentials of Chi-Nan and ordinary agarwood, highlighting their roles in sleep improvement and offering a foundation for future research in the clinical application of agarwood-based aromatherapy.