Olive Oil Phenolic Compounds Inhibit Homocysteine-Induced Endothelial Cell Adhesion Regardless of Their Different Antioxidant Activity

Abstract

In this study, we examine the effect of extra virgin olive oil phenolic compounds on homocysteine-induced endothelial dysfunction and whether the protective effects are related to their different scavenging activities. Structurally related compounds have been assayed for their ability to reduce homocysteine-induced monocyte adhesion as well as the cell surface expression of intercellular adhesion molecule-1 (ICAM-1) in EA.hy.926 cells. As well-known, among the selected phenolic compounds, hydroxytyrosol, homovanillyl alcohol, and the hydroxycinnamic acid derivatives caffeic and ferulic acid display high scavenging activities, while tyrosol and p-coumaric acid are poorly active. All of the tested compounds, approaching potential in vivo concentrations, significantly reduce homocysteine-induced cell adhesion and ICAM-1 expression. Interestingly, we report the first evidence that monophenols tyrosol and p-coumaric acid are selectively protective only in homocysteine-activated cells, while they are ineffective in reducing ICAM-1 expression induced by TNFalpha. Finally, we report the synergistic effect of o-diphenolic and monophenolic compounds.

Tomato extract and the carotenoids lycopene and lutein improve endothelial function and attenuate inflammatory NF-κB signaling in endothelial cells

“…Data concerning effects of different antioxidant phytochemicals [39][40][41][42][43][44][45][46][47][48][49] and plant extracts [44,[50][51][52][53] in cultured endothelial cells appear frequently in the recent literature. However, there are only few publications about the effect of lycopene and lutein [18].…”

Hydroxytyrosol in the Prevention of the Metabolic Syndrome and Related Disorders

“…Several in vitro studies confirmed the anti-inflammatory capacity of HT by reducing VCAM-1, intercellular adhesion protein expressions (0.5 to 75 µM) [22,118,133]. Molecular mechanisms leading to this reduction probably involved the reduction of NF-κB activation (0.5 to 75 µM) [22,23].…”

“…Moreover, it can inhibit superoxide anion burst from macrophages but not from neutrophils where it can only scavenge hydrogen peroxide (1 to 50 µM) [116]. It also protects erythrocytes from hemolysis (50 to 200 µM) [117], endothelial cells from monocytes adhesion (0.5 to 2.5 µM) [118] and hepatocytes (10 to 40 µM) [119], and protects from lipid peroxidation in rat livers (5 to 60 µM) [120] as well as from lipid oxidation (10 µM) [91]. …”

Polyphenols: Benefits to the Cardiovascular System in Health and in Aging

“…The antioxidant effects of olive oil polyphenols are attributed to the inhibition of COX-2 and MMP-9 which are regulated by redox-sensitive signaling pathways and typically promote angiogenesis [260]. Extra virgin olive oil reduced cell surface expression of VCAM-1 and ICAM-1 in an in vitro model of inflammation [261,262]. Oleuropein and hydroxtyrosol reduced monocyte adhesion to the endothelial primarily due to the inhibition of VCAM-1 mRNA and protein expression.…”