Moringa oleifera Lam. leaf extract and its bio-active compound attenuate TNF-α-induced transendothelial migration of monocytes

Abstract

Abstract Endothelial cells maintain blood fluidity, control regional blood flow and contribute to regulation of blood pressure, inflammation and blood clotting. The purpose of this study was to investigate into the effects of a bioactive compound from moringa leaf on endothelial cell production of inflammatory mediators and on monocyte adhesion and transmigration. EA.hy926 cells were pre-treated with crude Moringa oleifera Lam. leaf extract, the constituent fraction 6 of this extract and the bioactive component 3-HBI followed by stimulation with TNF-α. Endothelial cells incubated with the crude extract, fraction 6 or 3-hydroxy-β-ionone (3-HBI) and stimulated with TNF-α showed significantly lower production of pro-inflammatory mediators including IL-6, IL-8, and MCP-1 compared to untreated but TNF-α stimulated cells. The extract and active compound inhibited phosphorylation of IκB-α and reduced expression of the NF-κB p65, suppressing its nuclear translocation. They also reduced the expression of key adhesion molecules (ICAM-1, VCAM-1 and PECAM-1). Moreover, they decreased adhesion of THP-1 monocytes to EA.hy926 cells and monocyte transmigration through an endothelial cell monolayer. According to these findings, 3-HBI and crude moringa leaf extract have the possibility of preventing the development and progression of vascular diseases like atherosclerosis and neuroinflammation by inhibiting the release of pro-inflammatory cytokines, chemokines, and adhesion molecules.