5β-Hydroxypalisadin B isolated from red alga Laurencia snackeyi attenuates inflammatory response in lipopolysaccharide-stimulated RAW 264.7 macrophages

In this study, four compounds isolated from the red alga Laurencia snackeyi were evaluated for their potential antiinflammatory effect in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. These compounds were tested for their inhibitory effects on nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells. Since 5-hydroxypalisadin B showed the best activity it was further tested for the production of prostaglandin-E 2 (PGE 2 ), expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), the release of pro-inflammatory cytokines tumor necrotic factor-alpha (TNF-), interleukin-1 (IL-1), and interleukin-6 (IL-6). 5-Hydroxypalisadin B significantly reduced the PGE 2 release and suppressed the iNOS and COX-2 expression in LPS-stimulated RAW 264.7 cells. It also significantly reduced the release of pro-inflammatory cytokines TNF-, IL-1, and IL-6. These findings provide the first evidence of antiinflammatory potential of 5-hydroxypalisadin B isolated from the red alga L. snackeyi and hence, it could be exploited as an active ingredient in pharmaceutical, nutraceutical and functional food applications.