Anti-inflammatory effects of apo-9′-fucoxanthinone from the brown alga, Sargassum muticum

Abstract

Abstract Background The marine environment is a unique source of bioactive natural products, of which Sargassum muticum (Yendo) Fensholt is an important brown algae distributed in Jeju Island, Korea. S. muticum is a traditional Korean food stuff and has pharmacological functions including anti-inflammatory effects. However, the active ingredients from S. muticum have not been characterized. Methods Bioguided fractionation of the ethanolic extract of S. muticum, collected from Jeju island, led to the isolation of a norisoprenoid. Its structure was determined by analysis of the spectroscopic data. In vitro anti-inflammatory activity and mechanisms of action of this compound were examined using lipopolysaccharide (LPS)-stimulated RAW 264.7 cells through ELISA assays and Western blot analysis. Results Apo-9′-fucoxanthinone, belonging to the norisoprenoid family were identified. Apo-9′-fucoxanthinone effectively suppressed LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production. This compound also exerted their anti-inflammatory actions by down-regulating of NF-κB activation via suppression of IκB-α in macrophages. Conclusions This is the first report describing effective anti-inflammatory activity for apo-9’-fucoxanthinone′-fucoxanthnone isolated from S. muticum. Apo-9′-fucoxanthinone may be a good candidate for delaying the progression of human inflammatory diseases and warrants further studies.