In vivo and in vitro Anti-inflammatory activities of sulfated polysaccharide, a fucoidan isolated from Sargassum horneri

Abstract

Sargassum horneri China strain is an edible brown alga that grows in the subtidal zone as an annual species along the coasts of Korea, China and Japan. Recently, an extreme amount of S. horneri was moved into the coasts of Jeju, Korea from east coast of China and need to utilize this large biomass in order to protect environmental stability along the shores of Jeju Island. In addition, recent studies suggest that polysaccharide separated from S. horneri China strain has promising anti-inflammatory activities in vitro conditions. However, underlying mechanisms and or polysaccharide responsible for its anti-inflammatory activities not yet discovered. Therefore, the present study was designed to isolate the polysaccharide responsible for anti-inflammatory activities via enzyme assistance extraction from the brown seaweed S. horneri by using five food-grade enzymes (AMG, Celluclast, Viscozyme, Alcalase and Protamax) and FPLC system. Bioactivity-guided polysaccharide isolation lead to a separate fucose-rich sulfated polysaccharide (SH fucoidan) from cellular enzymatic extraction. The levels of nitric oxide (NO) and pro-inflammatory were measured by Gris sassy and enzyme-linked immunosorbent assay respectively. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), nuclear factor (NF)-κB and mitogen-activated protein kinases (MAPKs) were measured using western blot in LPS-Stimulated RAW 264.7 cells. In addition image analysis software used to quantify cell death, NO and ROS production of LPS-exposed zebrafish embryo by using acridine orange, DFA-FM-DA and DCF-DA respectively. SH fucoidan inhibited the NO production in LPS-stimulated RAW 264.7 cells with the IC50 value: 40.0 μg/m. in addition SH fucoidan down-regulated the LPS-stimulated iNOS and COX-2 protein levels as well as the production of inflammatory cytokine, tumor necrosis factor (TNF)-α in a dose-dependent manner. Furthermore, SH fucoidan inhibited the activation of NF-κB p50, p65 and the phosphorylation of MAPKs, including p38 and extracellular signal-regulated kinase (ERK), in LPS-stimulated RAW 264.7 cells. In addition SH fucoidan also down-regulate the LPS-induced heart beating rate, cell death, NO production and ROS production in the LPS-exposed zebrafish embryo. A Fourier transform infrared spectroscopy (FT-IR) analysis showed that the FT-IR spectrum of SH fucoidan is similar to that of commercial fucoidan. In Conclusion, our results showed that SH fucoidan which is likely a fucoidan has anti-inflammatory activities and is a potential candidate for the formulation of a functional food ingredient or/and drug to treat inflammatory diseases.