Cholesteryl ester species differently elevate plasma cholesterol in hamsters

The cholesterol-lowering activity of miracle fruit (Synsepalum dulcificum)

Miracle fruit (Synsepalum dulcificum) is famous for its uniqueness of modifying sour taste to sweetness. However, its cholesterol-lowering activity has not been reported. This study investigated the effect of S. dulcificum on the compositional changes of plasma lipids in hamsters fed a high-cholesterol control diet. Six groups of hamsters were fed either a control diet or one of the five experimental diets containing 2% ethanol extract of leaves, 2% water extract of leaves, 2% ethanolic extract of seeds (ES), 2% water extract of seeds, or 2% dry pulp. Results showed that ES decreased the plasma total cholesterol (TC). Two triterpenoids (lupeol acetate and β-amyrin acetate) were isolated from the ES and they added to a diet could decrease TC by 15%-20% in hamsters. It was concluded that ES showed potent TC-lowering activity and triterpenoid was one of the active components of ES. PRACTICAL APPLICATIONS: In recent years, people are more interested in phytochemicals from functional foods treated for hyperlipidemia because they possessed fewer side effects than the synthetic drugs. The triterpenoids isolated from the miracle fruit may be promising candidates for the development of cholesterol-lowering agent, especially for patients whose blood cholesterol level and body weight are high. Meanwhile, the miracle fruit have a good potential as cholesterol-lowering functional food or a natural source of cholesterol-lowering agent.

6-Gingerol Regulates Hepatic Cholesterol Metabolism by Up-regulation of LDLR and Cholesterol Efflux-Related Genes in HepG2 Cells

Gingerols, the pungent ingredients in ginger, are reported to possess a cholesterol-lowering activity. However, the underlying mechanism remains unclear. The present study was to investigate how 6-gingerol (6-GN), the most abundant gingerol in fresh ginger, regulates hepatic cholesterol metabolism. HepG2 cells were incubated with various concentrations of 6-GN ranging from 50 to 200 μM for 24 h. Results showed that both cellular total cholesterol and free cholesterol decreased in a dose-dependent manner. Besides, 6-GN ranging from 100 to 200 μM increased the LDLR protein and uptake of fluorescent-labeled LDL. Moreover, the mRNA and protein expressions of cholesterol metabolism-related genes were also examined. It was found that 6-GN regulated cholesterol metabolism via up-regulation of LDLR through activation of SREBP2 as well as up-regulation of cholesterol efflux-related genes LXRα and ABCA1.

Wild Lonicera caerulea berry polyphenol extract reduces cholesterol accumulation and enhances antioxidant capacity in vitro and in vivo

The hypocholesterolemic effect of Lonicera caerulea berry extract rich in polyphenols (LCBP) on high cholesterol-induced hypercholesterolemia and lipoprotein metabolite changes was examined in Caco-2 cells and rats. Cyanidin-3-glucoside, catechin, and chlorogenic acid are the major phenolic components of LCBP. The cholesterol-reducing effect and antioxidant capacity of these components were compared in Caco-2 cells. LCBP (80 μg/mL) and cyanidin-3-glucoside, catechin, and chlorogenic acid (50 μM) were found to be effective (p < 0.05). Rats were fed a high cholesterol diet (HCD) with or without LCBP supplementation (75, 150, and 300 mg/kg body weight intragastrically once daily) for 12 weeks. Compared with the HCD control group, LCBP supplementation at 150 and 300 mg/kg decreased the levels of TC, TG, and LDL-C, but increased that of HDL-C. LCBP treatment promoted greater neutral and acidic sterol excretion (p < 0.05) and improved the antioxidant capacity of the colon tissue, colon contents, and blood. Moreover, trimethylamine N-oxide (TMAO) levels were decreased in serum (p < 0.05). NPC1L1, ACAT2, and MTP mRNA and protein expression were reduced and ABCG5/8 expression was increased (p < 0.05) after LCBP treatment. Our results suggest that LCBP could be used as a functional food for the prevention and treatment of diseases related to excessive cholesterol accumulation.