Koelreuteria formosana extract impedes in vitro human LDL and prevents oxidised LDL-induced apoptosis in human umbilical vein endothelial cells

Koelreuteria formosana ethanol extract (KFEE) is obtained from natural plants that are endemic in Taiwan. A study showed that KFEE has antioxidant activity in DPPH assay. In the current study, the antioxidative activity of KFEE, which contains polyphenols including gallic acid and caffeic acid, was evaluated. The manner by which KFEE protects human umbilical vein endothelial cells (HUVECs) from oxidised LDL (oxLDL)-mediated dysfunction in vitro was investigated as well. The results indicate that the antioxidative activity of KFEE is defined by the relative electrophoretic mobility of oxLDL, the fragmentation of ApoB, conjugated diene production, and malondialdehyde production through Cu2+-mediated oxidation of LDL. KFEE also inhibited ROS generation as well as the subsequent mitochondrial membrane potential collapse, chromosome condensation, cytochrome C release, and caspase-3 activation induced by oxLDL in HUVECs. Our results also indicate that KFEE may protect LDL oxidation and prevent oxLDL-induced cellular dysfunction in HUVECs.