Chemical Constituents and Antidepressant-Like Activity of the Ethanol Extract of Lindera fragrans Leaves

The leaves and bark of Lindera fragrans herbs have been conventionally used in Traditional Chinese Medicine (TCM) as qi regulating drugs. This work was aimed to study the chemical constituents, possible antidepressant activity and mechanism of ethanol extract from L. fragrans leaves. In this study, ultra-high performance liquid chromatography (UPLC) coupled with hybrid quadrupole-orbitrap high-resolution mass spectrometry (UPLC-Q-Orbirap HRMS) technology was used to analyze and identify chemical components of the ethanol extract of L. fragrans leaves. In addition, chronic unpredictable mild stress (CUMS) model was established to measure the behavioral indexes of L. fragrans leaves extract on depressed mice, including weight, sucrose preference, tail suspension time, and serum corticosterone (CORT), serotonin (5-HT) and norepinephrine (NE) detected by ELISA. The results indicate that L. fragrans leaves extract contains approximately 22 compounds and can significantly increase the sucrose preference, reduce the tail suspension time, and regulate the levels of CORT, 5-HT and NE in CUMS depressed mice. This research proved for the first time that L. fragrans leaves extract treatment successfully reduced chronic mild stress-induced depressive-like behaviors in mice, as well as CUMS mice hyperactivity on the hypothalamus-pituitary-adrenal (HPA) axis.