Magnoliae flos (Shin-i) Essential Oil and Its Principal Component Eucalyptol Inhibit JAK1 to Counteract the...

Magnoliae flos (Shin-i) has been traditionally utilized in Chinese medicine for rhinitis, sinusitis, and headaches. However, the underlying anti-inflammatory mechanisms of Shin-i essential oil (SIEO), especially its effects on the Janus kinase/signal transducer and activator of transcription (JAK-STAT) signaling pathway, remain inadequately elucidated. The chemical composition of SIEO was characterized using gas chromatography-mass spectrometry (GC-MS). Network pharmacology and gene ontology (GO) enrichment analyses predicted that SIEO may target the JAK-STAT signaling pathway. Cellular experiments revealed that the excellent anti-inflammatory effects of SIEO were dose-dependent and attributed to the main component, eucalyptol, which reduced nitric oxide (NO) levels and reactive oxygen species (ROS), respectively. Molecular docking results indicated favorable binding affinities between eucalyptol and both JAK1 and STAT1. Western blot analysis further confirmed that SIEO and eucalyptol inhibited the phosphorylation levels of JAK1 to 68.63% and 84.43%, respectively, STAT1 to 47.61% and 74.90%, respectively, and inducible nitric oxide synthase (iNOS) expression to 38.70% and 74.58%, respectively. Therefore, it is suggested that the component eucalyptol plays a key role in the anti-inflammatory functions of SIEO, acting via the JAK1/STAT1/iNOS axis. This study provided insights for the research on the anti-inflammatory mechanisms of SIEO and suggested its potential application prospects in functional cosmetics and medical care.