Onion peel extracts and exercise decrease cardiovascular risk in rats fed a high fat diet

Abstract

Quercetin derivatives in onion peel extracts (OPE) have been regarded as the most important flavonoids to improve lipid profiles. The present study was aimed to examine the effects of OPE and exercise on fat deposition and blood lipid profiles in a diet‐induced obese Sprague‐Dawley rats. Twenty eight male Sprague‐Dawley rats were randomly assigned into four groups: High‐fat diet (HFD, 15% beef tallow + 1% cholesterol + 5% corn oil), HFD with exercise (HFD‐Ex), HFD with 0.15% OPE (HFD‐OPE), and HFD with both exercise and 0.15% OPE (HFD‐Ex‐OPE). After feeding experimental diets for 4 weeks, we weighed epididymal fat and retroperitoneal fat, and examined blood lipid profiles and liver lipid peroxide (TBARS). Epididymal fat and retroperioneal fat weights were remarkably lower in the HFD‐Ex and HFD‐Ex‐OPE group than the HFD group. The liver TBARS was significantly reduced and serum HDL cholesterol was significantly increased in HFD‐Ex, HFD‐OPE, and HFD‐Ex‐OPE. Atherogenic index and cardiovascular risk factor(CRF) were lower in HFD‐Ex, HFD‐OPE, and HFD‐Ex‐OPE than those in HFD group. Our results suggest that OPE and exercise might improve cardiovascular (CVD) risk with reduction of epididymal and retroperioneal fat. These findings provide a basis for the use of OPE with exercise to reduce CVD risk.