Lycopene attenuates LPS-induced liver injury by inactivation of NF-κB/COX-2 signaling

Aim: This study aimed to investigate the effect of lycopene on LPS-induced liver injury in mice and its mechanisms. Methods: Male C57bl/6 mice were randomly assigned to three groups: sham control group (S-C), LPS control group (L-C), lycopene treatment group (L-T). The mice from the L-T were treated with lycopene for 2 weeks, and the remaining mice with solvent. Afterwards, the mice from the L-C and the L-T received an intraperitoneal injection of LPS (20 mg/kg, dissolved in sterile saline), and the S-C mice were injected with sterile saline. Serum levels of alanine transaminase (ALT) and aspartate aminotransferase (AST) were determined for analysis of liver function. Levels of inflammatory cytokines including tumor necrosis factor (TNF)-alpha and interleukin (IL)-6, malondialdehyde (MDA) content, and the activity of superoxide dismutase (SOD), were detected in serum. Liver tissues were operated for morphologic analysis and determination of protein by western blot. Results: Pretreatment with lycopene significantly decreased levels of ALT, AST, and TNF-alpha and IL-6, reduced MDA content, and increased activity of SOD in serum compared with the L-C mice. Lycopene increased expression of nuclear factor-erythroid 2 related factor 2 (Nrf2), and reduced expression of cyclooxygenase (COX)-2, and phosphorylation of nuclear factor-kappa B (NF-kappa B) and extracellular regulated protein kinases 1/2 (ERK1/2). Conclusion: The results showed that lycopene attenuates LPS-induced liver injury by reducing NF-kappa B/COX-2 signaling by upregulation of Nrf2/HO-1 activation.