Anti-inflammatory effect of fucoxanthin derivatives isolated from Sargassum siliquastrum in lipopolysaccharide-stimulated RAW 264.7 macrophage

In this study, the anti-inflammatory effect of fucoxanthin (FX) derivatives, which was isolated from Sargassum siliquastrum were evaluated by examining their inhibitory effects on pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated murine macrophage RAW 264.7 cells. The FX derivatives were isolated from activity-guided chloroform fraction using inhibition of nitric oxide (NO) production and identified as 9'-cis-(6'R) fucoxnathin (FXA), and 13-cis and 13'-cis-(6'R) fucoxanthin complex (FXB) on the basis of a comparison of NMR spectroscopic data. Both FXA and FXB significantly inhibited the NO production and showed slightly reduce the PGE2 production. However, FXB exhibited cytotoxicity at the whole tested concentration, therefore, the results of FXA was only illustrate for further experiments. FXA induced dose-dependent reduction in the inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) proteins as well as mRNA expression. In addition, FXA reduced the LPS-stimulated production and mRNA expressions of TNF-α and IL-6 in a dose-dependent manner whereas IL-1β production do not inhibit by addition of FXA. Taken together, these findings indicate that the anti-inflammatory properties of FXA may be due to the inhibition of iNOS/NO pathway which associated with the attenuation of TNF-α and IL-6 formation. Thus FXA may provide a potential therapeutic approach for inflammation related diseases.