Apple peel flavonoid- and triterpene-enriched extracts differentially affect cholesterol homeostasis in hamsters

Abstract

Flavonoids and triterpenes are two major groups of bioactive compounds in apple peels. This study determined whether flavonoid-rich (FAE) and triterpene-rich (TAE) apple peel extracts affect cholesterol metabolism in diet-induced hypercholesterolemic male Golden Syrian hamsters. Two groups of hamsters were supplemented with 50 mg bioactives/kg/d of FAE or TAE and the third group was the atherogenic control (AC). After 28 days, FAE reduced (p < 0.05) serum total cholesterol (TC) and non-high density lipoprotein cholesterol (non-HDL) compared to AC. In contrast, TAE increased (p < 0.05) serum TC. Extracts had no effect on serum triacylglycerol and HDL. Both FAE and TAE increased (p < 0.05) cholesterol absorption without any effect on cholesterol biosynthesis. Liver TC, free cholesterol, triacylglycerol, serum and liver oxidative stress biomarkers were not altered by any extract. FAE and TAE differentially affected cholesterol metabolism where FAE effectively lowered serum cholesterol, with the underlying mechanism awaiting further investigation.

Keywords

• Apple peel extracts
• Flavonoids
• Triterpenes
• Hamster
• Cholesterol
• Oxidative stress