Amelioration of atherosclerosis in ox-LDL induced HUVEC by sulfated polysaccharides from Gelidium crinale with antihypertensive activity

Red algal polysaccharide is a good potential medical resource. Different red algal polysaccharides have different structural characteristics and rich biological activities. Previous studies have identified some structural information of sulfated polysaccharide (GNP, 25.8 kDa) from red algae, Gelidium crinale and found that GNP has excellent anti-inflammatory, antioxidant and anti-tumor activities. On this basis, this study investigated the effect of GNP on atherosclerosis, which is closely related to antioxidant and anti-inflammatory mechanisms and usually coexists and interacts with hypertension. This study investigated the inhibitory activity of GNP on angiotensin-converting enzyme (ACE) and its mechanism on oxidized low-density lipoprotein (ox-LDL)-induced HUVEC atherosclerosis. The results showed that GNP inhibits the up-regulation of cell adhesion molecules and oxidized low-density lipoprotein receptor-1 (LOX-1). GNP can regulate mitogen-activated protein kinases (MAPK), nuclear factor kappa B (NF-κB) and PI3K/AKT signal pathways, inhibit apoptosis, invasion and migration. Meanwhile, GNP (IC50 = 269.2 μg/mL) antagonizes ACE by competitive binding mode, and it can reduce systolic blood pressure (SBP) of spontaneously hypertensive rats (SHR). It provides a theoretical basis for GNP as a potential substance for the prevention and treatment of atherosclerosis.