Sargassum muticum (S. muticum) is a brown edible alga and widely distributed in Korea. This report was designed to evaluate the anti-inflammatory properties of apo-9′-fucoxanthinone (APO-9′) isolated from S. muticum on pro-inflammatory cytokine production. S. muticum extract (SME) exhibited significant inhibitory effects on pro-inflammatory cytokine production in bone marrow-derived macrophages (BMDMs) and dendritic cells (BMDCs). APO-9′ pre-treatment in the CpG DNA-stimulated BMDMs and BMDCs showed a strong dose-dependent inhibitory effect on interleukin (IL)-12 p40, IL-6 and tumor necrosis factor (TNF)-α production with IC₅₀ values ranging from 5.31 to 13.79. It exhibited a strong inhibitory effect on the phosphorylation of ERK1/2 and on activator protein (AP)-1 reporter activity. APO-9′ pre-treatment exhibited significant inhibition of CpG DNA-induced production of inducible nitric oxide synthase. Taken together, these data suggest that SME and APO-9′ have a significant anti-inflammatory property and warrant further studies concerning the potentials of SME and APO-9′ for medicinal use.

This study was intended to assess the anti-inflammatory properties of 4-hydroxy-2,3-dimethyl-2-nonen-4-olide (Comp) isolated from Ulva pertusa Kjellman on production of pro-inflammatory cytokines. Comp revealed remarkable inhibitory effects on production of pro-inflammatory cytokines in bone marrow-derived dendritic cells (BMDCs). Comp pre-treatment in the CpG DNA-stimulated BMDCs exhibited strong inhibition of interleukin (IL)-12 p40 and IL-6 production with IC₅₀ values ranging from 7.57 ± 0.2 to 10.83 ± 0.3, respectively. It revealed an inhibitory effect on the phosphorylation of ERK1/2, JNK1/2, and p38, and on activator protein (AP)-1 reporter activity. Comp displayed noteworthy inhibitory effects on phosphorylation and degradation of IκBα, and on NF-κB reporter activity. In summary, these data propose that Comp has substantial anti-inflammatory properties and warrants further study concerning its potential use as a therapeutic agent for inflammation-associated maladies.