The Aqueous Extract of De-Oiled Lavender Exerts Hypnotic Effect Through the GABAergic System in Mice

Lavender is a globally recognized herb that possesses ornamental, industrial, and medicinal value. Although extensive research has focused on its essential oils, the residual plant material remaining after oil extraction has received comparatively little attention. The ethanol precipitate (EP) from the aqueous extract of de-oiled lavender was investigated on the hypnotic effect and mechanism for the first time. The results showed that EP at the dosage of 120 mg/kg treatment reduces the locomotor activity in the open field test, prolonged pentobarbital-induced sleep duration in a PCPA-induced insomnia mouse model, increased 5-HT levels in serum and brain regions (cortex, hippocampus, hypothalamus), and elevated the content of GABA, upregulated GAD67 and downregulated both the GABAA α1 subunit and GAT-1 in these three brain areas which was predicted by the UPLC-MS data analysis and network pharmacology, and the potentially pharmacological substance of phenolics and flavonoids. The present data suggested that the aqueous extract of de-oiled lavender exerts the hypnotic effect through a GABAergic system in mice and brought substantial evidence for its extensive application and development in the future.