Anti-inflammatory effect of fucoxanthinol as bioavailable marine carotenoid on LPS-stimulated RAW264.7 macrophages through iNOS suppression and nitrogen radical-scavenging

Abstract

In this study, the anti-inflammatory effect of marine carotenoid fucoxanthinol (FXOH), a deacetylated metabolite of fucoxanthin (FX) was assessed with nitric oxide (NO) reducing capacity on NO production in LPS stimulated RAW 264.7 macrophages. The compounds reduced the induction of nitrite level as an index of NO in the inflammatory cell at low concentration ranges of 6.25-25 mM, and then the inflammatory gene expression, such as iNOS and COX-2, was suppressed in a dose-dependent manner. In addition, the nitrogen-radical-scavenging capacity of the compounds was evaluated in a NO generating system using a Griess assay and the ESR method. These compounds had a potential nitrogen-radical-scavenging capacity; thus the compounds caused the reduction of the nitrite level in cells through suppression of NO production and nitrogen-radical-scavenging activity. Collectively in the results of the assay, the activity of FXOH was higher than that of the FX suggesting that FXOH will have a high bioavailability in the intestinal tract.