Sulfated Laminaria japonica polysaccharides inhibit macrophage foam cell formation

In this work, a purified Laminaria japonica polysaccharide (LJP61A) was chemically modified to obtain three sulfated polysaccharides (SLJP1, SLJP2 and SLJP3) with different degrees of sulfation using the method of chlorosulfonic acid/pyridine. The effects and underlying mechanism of SLJP1, SLJP2 and SLJP3 on the suppression of macrophage foam cell formation were further investigated using the model of oxidized low-density lipoprotein (ox-LDL)-induced foam cell formation. Results exhibited that the macrophage foam cell formation induced by ox-LDL could be significantly alleviated by these sulfated polysaccharides in a dose-dependent manner. Meanwhile, the enhancement of PPAR-γ mRNA expression in ox-LDL induced macrophages was remarkably inhibited by these sulfated polysaccharides. Moreover, the cellular inflammation induced by ox-LDL could also be remarkably mitigated by these sulfated polysaccharides. These results indicated that the sulfated L. japonica polysaccharides could inhibit the conversion of macrophage into foam cell via obstructing PPAR-γ activation and alleviating cellular inflammation.