Apigenin and luteolin display differential hypocholesterolemic mechanisms in mice fed a high-fat diet.

Hypercholesterolemia is a major risk factor in the development of atherosclerosis. High blood cholesterol can be the result of increased biosynthesis or reduced elimination of cholesterol in the system. Increased consumption of fruits and vegetables is recommended for patients suffering from hypercholesterolemia. The plant food flavones apigenin and luteolin have previously been shown to suppress the synthesis of cholesterol in human hepatocytes. The effectiveness of these two flavones in controlling blood cholesterol was examined in a mouse model in the present study. Mice were fed a high-fat diet and apigenin or luteolin at 50 and 250 ppm was mixed in the diet. After 8 weeks of treatment, the administration of 250 ppm apigenin or 250 ppm luteolin could modulate the total and serum non-HDL cholesterol. The expressions of srebf-2 mRNA, Srebp-2 protein and Hmgcr protein were decreased in the livers of apigenin-treated mice; meanwhile, AMPK was activated in this group of mice. In contrast, suppressed ncp1l1 and induced abcg-5/8 mRNA expressions were seen in the intestinal mucosa of luteolin-fed animals. Increased fecal cholesterol content was also observed in the luteolin-treated mice. These results revealed that apigenin suppressed the biosynthesis of cholesterol, whereas luteolin promoted the elimination of cholesterol. In summary, this study illustrated that the two flavones could attenuate high-fat feeding-induced hypercholesterolemia in two different mechanisms.