Antidepressant-like effect of zileuton is accompanied by hippocampal neuroinflammation reduction and CREB/BDNF upregulation in lipopolysaccharide-challenged mice

Abstract

Background: Recent studies demonstrated beneficial effects of zileuton, a 5-lipoxygenase (5LO) inhibitor, on some brain diseases in animal models, but the role of zileuton in the depression remains unknown.

Methods: We investigated the effects of zileuton on depressive behaviors using tail suspension test (TST), forced swimming test (FST) and novelty-suppressed feeding test (NSFT) in mice injected with lipopolysaccharide (LPS). The 5LO level, activation of microglia, NF-κB p65, TNF-α, IL-1β, brain-derived neurotrophic factor (BDNF), and c-AMP response element-binding protein (CREB) were determined in the mouse hippocampus.

Results: We firstly found that the expression of hippocampal 5LO was gradually increased over LPS exposure and was reversed by fluoxetine administration. Zileuton significantly suppressed LPS-induced depressive behaviors, evidenced by the decreases in immobility time in TST and FST, as well as the latency to feed in NSFT. This treatment pronouncedly alleviated LPS-induced neuroinflammatory response, characterized by decreased 5LO, suppressed activation of microglia, decreased NF-κB p65, TNF-α and IL-1β, and significantly increased the ratio of p-CREB/CREB or mBDNF/proBDNF in the hippocampus of the LPS-challenged mice.

Conclusions: Zileuton abrogates LPS-induced depressive-like behaviors and neuroinflammation, and enhances CREB/BDNF signaling in the hippocampus, suggesting that zileuton could have potential therapeutic value for depression.

Keywords: 5-lipoxygenase; Depression; Lipopolysaccharide; Neuroinflammation.