Abstract 15340: Octacosanol Exerts Anti-Inflammatory Effects on Primary Human Aorta Endothelial Cells (HAEC) Induced With Lipopolysaccharides (LPS)

Abstract

Atherosclerosis is a complex process characterized by chronic systemic inflammation, endothelial dysfunction, retention of lipoproteins, plaque formation in large and medium-sized arteries, and has become one of the most common causes of death in the elderly nowadays. Octacosanol, a very long chain (C28) aliphatic alcohol, is believed to be the main active ingredient in the Policosanol, which is extracted from plants, such as sugar cane and wheat germ. Policosanol has been used as a potential diet supplementary to improve fatigue, obesity and lipid metabolism. Previous animal studies have shown that both Policosanol and Octacosanol can significantly ameliorate formation of atherosclerotic lesion. To further explore the possible mechanism of Octacosanol on the formation of atherosclerosis, we examined the anti-inflammatory effects of Octacosanol on HAEC treated with LPS at 100ng/ml FBS-free cell culture medium. LPS treatment significantly enhanced human monocyte (THP1) adherence to HAEC cells in time-dependent and dose-dependent style, but Octacosanol at 1.25 or 2.5 μM markedly blocked the adhesion of THP1 to HAEC. ELISA showed that LPS can significantly increase the expression of inflammatory cytokines and adhesion molecules by HAEC at 100ng/ml within 4 hours. LPS stimulated more than 3-fold of release of IL-6, IL-8, MCP-1 at 4 hours. By flow cytometry and ELISA, LPS dramatically increase the expression of PE-Selectin and VCAM-1. When HAEC were pretreated with Octacosanol (1.25μM or 2.5μM), it significantly reduced the release of inflammatory cytokines, MCP-1(p<0.01), IL-6 (p<0.001) and IL-8(P<0.001), and inhibited the expression of PE-selectin(p<0.001) and VCAM-1(P<0.001). Confocal imaging analysis of HAEC cells showed Octacosanol considerably reduced the expression of PE-Selectin and VCAM-1 and VE-Cadherin, leading to the maintenance of cell membrane integrity and underlying ECM and the prevention of THP1 cell adherence. By RNAseq analysis, Octacosanol inhibits LPS-induced inflammatory pathways related to NFKB 2 and RAS-related signaling. In summary, the beneficial effects of octacosanol on atherosclerosis appears to be related, at least partially to, is potent anti-inflammatory effects in cytokine-induced cell adherence.