Protective effect of the polysaccharide kreskin on inhibition of lipopolysaccharide-induced nitric oxide production in macrophages caused by oxidised low-density lipoprotein

Abstract

We studied the inhibition by oxidised low-density lipoprotein (Ox-LDL) of the production of NO and gene expression of NO synthase (NOS) in mouse peritoneal macrophages stimulated by lipopolysaccharide (LPS), and protection by the polysaccharide kreskin (PSK). This was done by measuring nitrite in media and messenger RNA(mRNA) for NOS in macrophages. Exposure of mouse peritoneal macrophages (MPM) to Ox-LDL inhibited NO production stimulated by LPS, but exposure of MPM to native LDL and acetylated LDL did not do so. PSK, injected peritoneally into mice, protected their macrophages from the inhibition of NO production caused by Ox-LDL. Results from slot hybridisation showed that Ox-LDL lowered the content of mRNA for NOS in macrophages induced by LPS, while PSK protected macrophages from the decline of mRNA in macrophages caused by Ox-LDL.