Comparing Effects of Aromatherapy with Five Herbs Essential Oils on PCPA-induced Insomnia Mice

Delayed treatment of insomnia-related symptoms can harm physical health and increase the psychological burden. In addition to oral medications and some physical therapies, aromatherapy can help overcome some treatment-related side effects. Herein, parachlorophenylalanine (PCPA)-induced insomnia was established in Kunming (KM) mice, which were subjected to aromatherapy using five plants (<i>Jasminum sambac</i>, <i>Magnolia denudata</i>, <i>Rosa rugosa</i>, <i>Aloysia citriodora</i>, and <i>Abies balsamea</i>) essential oils (EOs). To determine the sleep-inducing effect of the five EOs, the rate of change in body weight, sleep latency, and total sleep time in mice were measured. Specific serum indices were used to evaluate the therapeutic effects of the tested drugs and PCPA modeling. Gas chromatography-mass spectrometry (GC-MS) was employed to identify active components in EOs. The five EOs contained multiple identical constituents and were rich in terpenoids, such as α-farnesene (28.42%), linalool (68.84%), and citronellol (23.78%). The EOs exhibiting varying effects on insomnia-induced weight loss. Nissl staining was used to examine and the number of neurons was elevated in the EO-treated groups when compared with the PCPA-induced group; however, the neuronal number was reduced in the hypothalamic tissues of the <i>R. rugosa</i> EO (RREO)-treated group. All EOs upregulated the expression of 5-HT1A and GABA_ARα1, as demonstrated by immunohistochemistry, western blotting, and reverse transcription-quantitative PCR results. In addition, EOs of <i>A. citriodora</i> and <i>A. balsamea</i> significantly upregulated the expression of 5HT_1A protein, whereas EOs of <i>J. sambac</i> and <i>M. denudata</i> exerted significantly different effects when compared with the model group, as determined by western blotting.