Suppressive Effects of Isofraxidin on Depressive-like Behaviors Induced by Chronic Unpredictable Mild Stress in Mice.

Isofraxidin is an active component of several traditional and functional plants that have beneficial properties for neurodegenerative diseases. In this study, we examined whether isofraxidin exhibited antidepressant-like effects in chronic unpredictable mild stress (CUMS)-induced mice. Firstly, isofraxidin could reverse CUMS-induced decrease in body weight gain in mice. Additionally, in the sucrose preference test (SPT), isofraxidin reversed the decrease in sucrose consumption due to CUMS-induced depressive-like behavior. Isofraxidin also increased locomotor activity in the open field test (OFT) and alleviated immobility duration in the forced swimming test (FST) and tail-suspension test (TST). Furthermore, isofraxidin decreased levels of corticosterone (CORT), adrenocorticotropic hormone (ACTH), and hypothalamus corticotrophin-releasing hormone (CRH) in the serum after CUMS-induced hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. Also, isofraxidin suppresses tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 expression in the hippocampus of CUMS mice. Further investigations demonstrated that isofraxidin inhibited CUMS-induced activation of nuclear factor kappa B (NF-κB) and NOD-like receptor protein 3 (NLRP3) inflammasomes in the hippocampus. Summarily, in CUMS-induced mice, isofraxidin reduced depressive-like behaviors, accompanied by its inhibitory effects on hyperactivity of the HPA axis and NF-κB /NLRP3 inflammasomes pathways.