Anti-inflammatory effects of grasshopper ketone from Sargassum fulvellum ethanol extract on lipopolysaccharide-induced inflammatory responses in RAW 264.7 cells

Abstract

This study evaluated the anti-inflammatory potential of a grasshopper ketone (GK) isolated from the brown alga Sargassum fulvellum on lipopolysaccharide (LPS)-induced RAW 264.7 murine macrophage cell line. GK was isolated and purified from the n-hexane fraction and its structure was verified on the basis of NMR spectroscopic data. GK up to 100 μg/ml is not cytotoxic to RAW 264.7, and is an effective inhibitor of LPS-induced NO production in RAW 264.7 cells. The production of pro-inflammatory cytokines, including IL-6, IL-1β, and TNF-α was found significantly reduced in 0.1-100 μg/ml dose ranges of GK treatment (p < 0.05). We confirmed the dose-dependent and significant inhibition of iNOS and COX-2 proteins expression. In addition, it has been shown that GK induces anti-inflammatory effects by inhibiting MAPKs (ERK, JNK, and p38) and NF-κB p65 phosphorylation. Our results show that the anti-inflammatory properties of GK may be due to the inhibition of the NF-κB and MAPKs pathways, which are associated with the attenuation of cytokine secretion.