An active marine halophenol derivative attenuates lipopolysaccharide-induced acute liver injury in mice by improving M2 macrophage-mediated therapy

2,4 ',5 '-Trihydroxyl-5,2 '-dibromo diphenylmethanone (LM49), an active halophenol derivative synthesized by our group, which exhibits a broad spectrum of therapeutic properties, such as antioxidant and anti-inflammatory activities. In this study, we found LM49 could obviously attenuate acute liver injury induced by lipopolysaccharide (LPS) in mice by polarizing macrophages. The protective effect was described by reducing the hepatic inflammation and improving hepatic function using aspartate transaminase (AST) and alanine transaminase (ALT) assay. Further study revealed that LM49 pretreatment induced the Kupffer cells (KCs) to M2 polarization and decreased the production of inflammatory cytokines. The action mechanism in RAW 264.7 macrophages showed that LM49 could induce the activation of JAK1/STAT6 signaling pathway and the inhibition of TLR-4/ NF-kB axis. Morever, LM49 also upregulated the expression of SOCS1 and FLK-4, which can promote M2 polarization by cooperating with STAT6 and inhibit M1 formation by reducing JAK1/STAT1. Our results suggested that LM49 could protect against LPS-induced acute liver injury in mice via anti-inflammatory signaling pathways and subsequent induction of M2 Kupffer cells. The results provided the first experimental evidence of active halophenols for the anti-inflammatory therapy by targeting M2 macrophages.

Automated summary

LM49, an active halophenol derivative, alleviates acute liver injury induced by LPS in mice by polarizing macrophages, reducing hepatic inflammation and improving hepatic function. This protective effect is achieved through the activation of JAK1/STAT6 signaling pathway and inhibition of TLR-4/NF-kB axis, leading to the induction of M2 Kupffer cells and suppression of inflammatory responses.