Inhibition of LDL Oxidation In Vitro and Regulation of Cholesterol Metabolism in Hamsters by Apple Peel Bioactives

Cardiovascular disease (CVD) is a global health burden and a leading cause of mortality. Elevated serum low-density lipoprotein (LDL) has been known as a major risk factor for developing atherosclerosis and CVD. Quercetin-rich (QAE) and triterpene-rich (TAE) apple bioactive extracts were individually tested for in vitro LDL oxidation inhibition and in vivo cholesterol metabolism in a hamster model with diet-induced hypercholesterolemia. More than 80% inhibition of in vitro Cu2+-induced LDL oxidation was exerted by QAE at 0.5 to 10 mg L-1and TAE at 50-200 mg L-1. QAE diet lowered serum total cholesterol (TC) and non-high density lipoprotein cholesterol compared to an atherogenic control diet (AC). In contrast, TAB diet increased serum TC relative to AC. Overall, QAE showed in vitro antioxidant properties and in vivo cholesterol-lowering activity in addition to its antioxidant property. Further studies are required to understand QAE's mode of action on LDL oxidation and cholesterol metabolism.