The Combination of Green Tea Extract and Eriodictyol Inhibited High-Fat/High-Sucrose Diet-Induced Cholesterol Upregulation Is Accompanied by Suppression of Cholesterol Synthesis Enzymes

Abstract

Western diets induce obesity associated with an increased risk of hypercholesterolaemia. Indeed, obesity-induced hypercholesterolaemia is correlated with increased coronary cardiovascular disease (CVD) risk. Male C57BL/6J mice were fed a normal diet, high-fat and high-sucrose diet (HF/HS), HF/HS with green tea extract powder diet (HF/HS+GT), HF/HS with eriodictyol diet (HF/HS+Eri), or HF/HS with green tea extract powder and eriodictyol diet (HF/HS+GT+Eri) for 8 wk. Body weight was lower in the HF/HS+GT+Eri group than in the HF/HS group (-8.3%, p<0.01). The HF/HS diet elicited an upregulation of total cholesterol levels (-63%, p<0.001), and low-density lipoprotein (LDL) levels (-89%, p<0.001) were significantly suppressed by the GT+Eri diet. Conversely, no change (p>0.05) was observed in the HF/HS+GT and HF/HS+Eri groups. The HF/HS diet-induced hepatic mRNA increase in 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) was ameliorated (-73%) by the oral administration of green tea extract and eriodictyol. Moreover, the GT+Eri diet suppressed HF/HS diet-induced upregulation of 3-hydroxy-3-methylglutaryl-coenzyme A synthase (HMGCS) (-75%, p<0.05). Furthermore, the LDL receptor (LDLR) levels were higher in the HF/HS+GT+Eri group (+50%, p<0.05) than in the HF/HS group. These results suggest that a combination of green tea and eriodictyol decreases cholesterol levels, particularly LDL levels, accompanied by the suppression of HMGCR and HMGCS levels and upregulation of LDLR levels in the liver.