Apple polyphenols inhibit plasma CETP activity and reduce the ratio of non‐HDL to HDL cholesterol

Abstract

Previous reports demonstrated that hypocholesterolemic activity of apple was associated with its pectin and fiber. This report was to investigate the effect of apple polyphenols (AP) on blood cholesterol level and gene expression of cholesterol-regulating enzymes in Golden Syrian hamsters maintained on a 0.1% cholesterol diet. It was found that dietary supplementation of 0.3 or 0.6% of AP did not affect plasma total cholesterol (TC), but it increased HDL cholesterol (HDL-C) and decreased non-HDL-C, thus leading to a lower ratio of non-HDL-C to HDL-C. Plasma total triacylglycerol (TG) level was also significantly reduced when hamsters were fed a diet supplemented with 0.6% AP. Western blot analysis did not find any effect of AP on sterol regulatory element-binding protein 2 (SREBP-2), LDL receptor (LDLR), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), and cholesterol-7alpha-hydroxylase (CYP7A). Most interesting was that supplementation of AP had no effect on protein abundance of plasma cholesteryl ester transport protein (CETP), but it suppressed plasma CETP activity. A series of in vitro assays confirmed that AP inhibited CETP in a dose dependent manner. It was concluded that AP favorably improved distribution of cholesterol in lipoproteins, most likely, by its inhibition on CETP activity.

Protective effect of a litchi (Litchi chinensis Sonn.)-flower-water-extract on cardiovascular health in a high-fat/cholesterol-dietary hamsters

“…Dietary apple phenols exert hypolipidemic and antiatherogenic effects via a promotion of cholesterol catabolism and inhibition of intestinal absorption of cholesterol (Osada et al, 2006), while an improvement of lipid profiles (HDL-C and non-HDL-C/HDL-C) by supplementing apple phenols was reported (Lam et al, 2008). Hence, we tried to use a high-fat/cholesteroldietary-hamster model to investigate the effects of rich-phenol LFWE on serum lipids.…”

“…Dietary apple phenols also exert hypolipidemic and antiatherogenic effects via a promotion of cholesterol catabolism and inhibition of intestinal cholesterol absorption (Osada et al, 2006). Furthermore, an improvement of lipid profiles (HDL-C, non-HDL-C/HDL-C) in a rodent model by supplementing apple phenols into the diet was considered as the inhibition on cholesteryl ester transport protein (Lam et al, 2008).…”

Hypocholesterolemic activity of grape seed proanthocyanidin is mediated by enhancement of bile acid excretion and up-regulation of CYP7A1

“…Three diets were prepared as previously described [11]. The control diet contained the following ingredients in proportion (g/kg diet): cornstarch, 508; casein, 242; lard, 50; sucrose, 119; mineral mix AIN-76, 40; vitamin mix AIN-76A, 20; DL-methionine, 1; cholesterol, 1 ( Table 1).…”

Juices in the diet of a child and an adult: Their significance for health

“…Исследования на животных показали, что по-лифенолы яблок увеличивают выведение желчных кислот с калом [17,23]. Это может быть связано с конъюгацией желчных кислот с полифенолами и по-вышением их экскреции.…”