Depression-like behaviors and heme oxygenase-1 are regulated by Lycopene in lipopolysaccharide-induced neuroinflammation

Previous studies have demonstrated that lycopene possesses anti-inflammatory properties in the central nervous system. However, the potential role and the molecular mechanisms of lycopene in lipopolysaccharide (LPS)-challenge inflammation and depression-like behaviors has not been clearly investigated. The present study aimed to assess the effects and the potential mechanisms of lycopene on LPS-induced depression-like behaviors. Lycopene was orally administered (60 mg/kg) every day for seven days followed by intraperitoneal LPS injection (1 mg/kg). The Forced swim test and tail suspension test were used to detect changes in the depression-like behaviors. ELISA was used to measure the expression of interleukin-6 (IL-6) and tumor necrosis factor-alpha(TNF-alpha) in the plasma. Immunoblotting was performed to measure the expression of interleukin-1 beta (IL-1 beta) and heme oxygenase-1 (HO-1) in the hippocampus. The results showed that pretreatment with lycopene could ameliorate depression -like behaviors. Moreover, lycopene relieved neuronal cell injury in hippocampal CAl regions. Furthermore, lycopene decreased LPS-induced expression of IL-1 beta and HO-1 in the hippocampus together with decreasing level of IL-6 and TNF-alpha in the plasma. Taken together, these results suggest that lycopene can attenuate LPS-induced inflammation and depression-like behaviors, which may be involved in regulating HO-1 in the hippocampus. (C) 2016 Elsevier B.V. All rights reserved.