Hypocholesterolemic effect of quercetin-rich onion peel extract in C57BL/6J mice fed with high cholesterol diet

Hyun-Ju Kang; Pichiah Balasubramanian Tirupathi Pichiah; Ravichandran Vijaya Abinaya; Hee-Sook Sohn; Youn-Soo Cha

doi:10.1007/s10068-016-0141-4

Hypocholesterolemic effect of quercetin-rich onion peel extract in C57BL/6J mice fed with high cholesterol diet

Food Sci Biotechnol. 2016 Jun 30;25(3):855-860. doi: 10.1007/s10068-016-0141-4. eCollection 2016.

Authors

Hyun-Ju Kang¹, Pichiah Balasubramanian Tirupathi Pichiah¹, Ravichandran Vijaya Abinaya¹, Hee-Sook Sohn¹, Youn-Soo Cha¹

Affiliation

¹ Department of Food Science and Human Nutrition and Research Institute of Human Ecology, Chonbuk National University, Jeonju, Jeonbuk, 54896 Korea.

Abstract

Onion peel (OP) extract is known as a rich source of flavonoids, mainly quercetin. We hypothesized that OP has hypocholesterolemic effects. To investigate the effect of OP, C57BL/6J mice were divided into 4 dietary groups (n=10); normal diet (ND); high cholesterol diet (HC); and high cholesterol diet with 100 or 200 mg OP extract (OP-100 or OP-200, respectively) per kg of body weight. After 12 weeks, lower values of liver weight, serum total cholesterol levels, LDL cholesterol, atherogenic index, cardiac risk factor, hepatic triacylglycerol, and total cholesterol, and higher fecal cholesterol levels were observed in the OP-200 than in the HC group. The hepatic mRNA expression levels of low-density lipoprotein receptors (LDL-R) and cholesterol 7-alpha-monooxygenase (CYP7A1) were high in the OP-200 compared to the HC group. These observations suggest that OP promoted lowering of serum and hepatic cholesterol in mice primarily via fecal excretion.

Keywords: atherosclerosis; cholesterol; cholesterol 7-alpha-monooxygenase; low-density lipoprotein receptor; onion peel.