Methanolic extract of Kigelia africana exhibits antiatherosclerotic effects in endothelial cells by downregulating RAGE and adhesion molecules

Abstract

The Kigelia plant is used in African countries for its medicinal properties. Kigelia africana is an interesting example of a medicinal plant due to its pharmacological activities, including its anti-inflammatory effect. Atherosclerosis, the primary cause of cardiovascular disease, is related to lipoprotein oxidation, inflammation and immune responses involving the vascular endothelium and immune cells. Therefore, in this study we investigated the effects of Kigelia africana (Lam.) extract, focusing particularly on antiatherosclerotic effects in endothelial cells (ECs). The methanolic extract of Kigelia africana (MKA) showed no cytotoxicity on ECs at doses of 10-200 μg/ml. MKA reduced RAGE expression on oxLDL- or TNF-α-stimulated ECs in a dose dependent manner, showing significant inhibition at a concentration of 50 μg/ml. In addition, MKA significantly inhibited the oxLDL- or TNF-α-induced expression of vascular cell adhesion molecule-1 (VCAM-1) in ECs in a dose-dependent manner but did not affect intracellular adhesion molecule-1 (ICAM-1), resulting in downregulation of the migration and adhesion of THP-1 monocytes to ECs. These results suggest that MKA could be used for the treatment of atherosclerosis without cytotoxicity.