Oleacein may intensify the efflux of oxLDL from human macrophages by increasing the expression of the SRB1 receptor, as well as ABCA1 and ABCG1 transporters

Oleacein is a polyphenol and can be found in unfiltered extra virgin olive oil and leaves Ligustrum vulgare L. (Oleaceae). The aim of the present study was to investigate whether oleacein could increase efflux cholesterol from macrophages. Oleacein in dose-dependent manner (OLEA20, OLEA50) significantly reduced lipid deposits in macrophages. The increase of SRB1 expression was found for OLEA50 and OLEA20 compared to oxLDL-induced macrophages. Oleacein significantly up-regulated protein expression of ABCA1 and ABCG1 transporter. Moreover, oleacein increased of HO-1 intracellular secretion, as well as increased activation of Nrf2. Whereas, the level of NF-IcB protein was almost completely inhibited by oleacein at the same concentrations. For OLEA10, no significant changes were observed for the parameters tested. Our study demonstrated that oleacein may reduce foam cell formation. Therefore, we propose a novel explanation for the oleacein, that can be used to develop new therapeutic strategies for the treatment of atherosclerosis.