Phlorofucofuroeckol B suppresses inflammatory responses by down-regulating nuclear factor kappa B activation via Akt, ERK, and JNK in LPS-stimulated microglial cells

Abstract

Microglial activation has been implicated in many neurological disorders for its inflammatory and neurotrophic effects. In this study, we investigated the effects of phlorofucofuroeckol B (PFF-B) isolated from Ecklonia stolonifera, on the production of inflammatory mediators in lipopolysaccharide (LPS)-stimulated microglia. PFF-B decreased secretion of pro-inflammatory cytokines including tumor necrosis factor alpha, interleukin IL-1 beta, and IL-6 and the expression of pro-inflammatory proteins such as cyclooxygenase-2 and inducible nitric oxide synthase in LPS-stimulated BV-2 cells. Profoundly, PFF-B inhibited activation of nuclear factor kappaB (NF-kappa B) by preventing the degradation of inhibitor kappa B-alpha (I kappa B-alpha), which led to prevent the nuclear translocation of p65 NF-kappa B subunit. Moreover, PFF-B inhibited the phosphorylation of Akt, ERIC and JNK These results indicate that the anti-inflammatory effect of PFF-B on LPS-stimulated microglial cells is mainly regulated by the inhibition of I kappa B-alpha/NF-kappa B and Akt/ERK/JNK pathways. Our study suggests that PFF-B can be considered as a therapeutic agent against neuroinflammation by inhibiting microglial activation. (C) 2015 Elsevier B.V. All rights reserved.