1,4-Naphthoquinone improves depressive-like behaviors by modulating neuronal factors and neuroinflammatory mediators

Depression is a chronic mental disorder characterized by alternations in emotions, thoughts, physical condition, and behavior. Using the natural product database Compound Combination-Oriented Natural Product Database with Unified Terminology (COCONUT) and the bioinformatics tool CODA (Context-Oriented Directed Associations), we screened and identified 1,4-naphthoquinone (1,4-NQ) as a promising candidate for depression treatment. Oral administration of 1,4-NQ attenuated the depressive-like behaviors in the open field test (OFT), elevated plus maze test (EPM) and forced swim test (FST) in a chronic restraint stress (CRS)-induced depressive-like mouse model. Real-time PCR analysis demonstrated that 1,4-NQ increased the mRNA levels of 5-HT1A and BDNF in the hippocampus of mouse brains. The expression level of glucocorticoid receptor (GR) in the hippocampus was increased by 1,4-NQ treatment in both CRS- and corticosterone-induced depression mouse models. We confirmed that 1,4-NQ has anti-neuroinflammatory efficacy by suppressing the levels of IL-6, TNF-α and IL-1β in LPS-stimulated BV2 microglial cell line. The western blot and real-time PCR analysis demonstrated that 1,4-NQ increased the level of GR in both the U-138 MG glial cell line and the SH-SY5Y neuronal cell line. In conclusion, 1,4-NQ is supposed to have anti-depressive efficacy by alleviating depressive-like behaviors through modulation of neuroinflammatory mediators and GR expression in the nervous system.