Evaluation of anti-inflammatory effect of fucoxanthin isolated from brown algae in lipopolysaccharide-stimulated RAW 264.7 macrophages

In this study, potential anti-inflammatory effect of fucoxanthin isolated from brown algae was assessed via inhibitory effect of nitric oxide (NO) production in lipopolysaccharide (LPS) induced RAW 264.7 macrophage cells. The Myagropsis myagroides was selected for further experiments due to its profound NO inhibitory effect, and was partitioned with different organic solvents. Highest NO inhibitory effect was detected in the chloroform fraction, and the active compound was identified as fucoxanthin, a kind of carotenoid available in brown algae evidenced high correlation with the inhibitory effect of NO production (r2 = 0.9511). Though, fucoxanthin significantly inhibited the NO production, it slightly reduced the prostaglandin E2 (PGE2) production. The inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) protein expressions were inhibited by fucoxanthin. Further, RT-PCR analysis indicated that the iNOS and COX-2 mRNA expressions were suppressed by fucoxanthin. Moreover, the release of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), and the mRNA expression levels of those cytokines were reduced by the addition of fucoxanthin in a dose-dependent manner. Hence, these results suggest that the use of fucoxanthin may be a useful therapeutic approach for the various inflammatory diseases.