Influence of phytostanol phosphoryl ascorbate (FM-VP4) on insulin resistance, hyperglycemia, plasma lipid levels, and gastrointestinal absorption of exogenous cholesterol in Zucker (fa/fa) fatty and lean rats

Inflammation, Oxidative Stress, and Antioxidants Contribute to Selected Sleep Quality and Cardiometabolic Health Relationships: A Cross-Sectional Study

Sleep is vital for cardiometabolic health, but a societal shift toward poor sleep is a prominent feature of many modern cultures. Concurrently, factors such as diet and lifestyle have also changed and may mediate the relationship between sleep quality and cardiometabolic health. Objectives were to explore (1) the interrelationship and (2) mediating effect of inflammation, oxidative stress, and antioxidants on sleep quality and cardiometabolic health. Cross-sectional data from the US National Health and Nutritional Examination Survey 2005-06 (≥20 y; N = 2,072) was used. Cardiometabolic health was defined as per the Joint Interim Statement; overall sleep quality was determined from six sleep habits and categorized as good, fair, poor, and very poor. Fair quality sleepers had optimal inflammation, oxidative stress, and antioxidant levels. Inflammation was above the current clinical reference range across all sleep quality categories, while oxidative stress was only within the clinical reference range for fair sleep quality. Selected sleep quality-cardiometabolic health relationships were mediated by inflammation, oxidative stress, and antioxidants and were moderated by sex. Our results provide initial evidence of a potential role for inflammation, oxidative stress, and antioxidants in the pathway between poor sleep quality-cardiometabolic decline. Further prospective research is needed to confirm our results.

Disodium ascorbyl phytostanol phosphate (FM-VP4), a modified phytostanol, is a highly active hypocholesterolaemic agent that affects the enterohepatic circulation of both cholesterol and bile acids in mice

Disodium ascorbyl phytostanol phosphate (FM-VP4) is a synthetic compound derived from sitostanol and campestanol that has proved to be efficient as a cholesterol-lowering therapy in mice and human subjects. However, the mechanism of action of FM-VP4 remains unknown. The present study tests the ability of FM-VP4 to alter intestinal and liver cholesterol homeostasis in mice. Female C57BL/6J mice were fed either a control chow or a 2 % FM-VP4-enriched diet for 4 weeks. FM-VP4 reduced the in vivo net intestinal cholesterol absorption and plasma and liver cholesterol concentrations by 2.2-, 1.5- and 1.6-fold, respectively, compared with control mice. Furthermore, FM-VP4 also showed an impact on bile acid homeostasis. In FM-VP4 mice, liver and intestinal bile acid content was increased by 1.3- and 2.3-fold, respectively, whereas faecal bile acid output was 3.3-fold lower. FM-VP4 also increased the intestinal absorption of orally administered [3H]taurocholic acid to small intestine in vivo. Inhibition of intestinal cholesterol absorption by FM-VP4 was not mediated via transcriptional increases in intestine liver X receptor (LXR)-alpha, adenosine triphosphate-binding cassette transporter (ABC)-A1, ABCG5/G8 nor to decreases in intestinal Niemann-Pick C1-like 1 (NPC1L1) expression. In contrast, FM-VP4 up-regulated liver LXRalpha, ABCA1, ABCG5, scavenger receptor class BI (SR-BI) and hydroxymethylglutaryl coenzyme A reductase (HMGCoA-R) gene expression, whereas it down-regulated several farnesoid X receptor (FXR)-target genes such as cytochrome P450 family 7 subfamily A polypeptide 1 (CYP7A1) and Na+/taurocholate co-transporter polypeptide (NTCP). In conclusion, FM-VP4 reduced intestinal cholesterol absorption, plasma and liver cholesterol and affected bile acid homeostasis by inducing bile acid intestinal reabsorption and changed the liver expression of genes that play an essential role in cholesterol homeostasis. This is the first phytosterol or stanol that affects bile acid metabolism and lowers plasma cholesterol levels in normocholesterolaemic mice.

Phytosterols do not change susceptibility to obesity, insulin resistance, and diabetes induced by a high-fat diet in mice

Most studies have focused on the cholesterol-lowering activity of phytosterols; however, other biological actions have also been attributed to these plant compounds. In this study, we investigated whether phytosterols could delay (progression phase) and/or reverse (regression phase) insulin resistance or type 2 diabetes mellitus in an experimental mouse model of diet-induced obesity, insulin resistance, and diabetes. Body mass, plasma lipid levels, insulin resistance, and hyperglycemia were determined. Phytosterol intake did not improve these metabolic parameters. Therefore, we were unable to substantiate any protective effect of phytosterol intake on diabetes development or regression in the mouse model used.

Plant stanol ascorbate esters reduce body weight gain through decreased energy absorption in hamsters

OBJECTIVE

The objective of this study was to determine the effects of disodium ascorbyl phytostanyl phosphate (DAPP), a novel hydrophilic phytostanol analogue, on energy homeostasis, including body weight and intestinal energy absorption, and plasma triglyceride concentrations, in hamsters.

METHODS

Male Golden Syrian hamsters (n = 50) were fed for 5 weeks with experimental diets varying in cholesterol and phytostanol content. Diets included (i) non-cholesterol (semipurified diet without added cholesterol), (ii) cholesterol-control (semipurified diet with 0.25% cholesterol), (iii) stanol (cholesterol-control with 1% free phytostanols), (iv) DAPP 0.7% (cholesterol-control with 0.71% DAPP) or (v) DAPP 1.4% (cholesterol-control with 1.43% DAPP). Fecal samples were collected continuously for 3 days on week 3, and fecal energy output was measured by bomb calorimetry.

RESULTS

Hamsters fed 1.4% DAPP gained less (P<0.05) weight than hamsters fed non-cholesterol and stanol diets. Diets had no effect on total food consumption or gross energy intake after 5 weeks, but lower (P<0.05) weekly food consumptions in hamsters fed 1.4% DAPP were observed at weeks 1 and 2 of the experiment in comparison to animals fed the non-cholesterol diet. In comparison to non-cholesterol and cholesterol-control diets, DAPP 1.4% increased (P<0.01) fecal energy output by 47 and 46%, respectively. In hamsters supplemented with 1.4% DAPP, plasma triglyceride concentrations were 45% lower (P<0.05) than in cholesterol-control fed hamsters. Furthermore, plasma triglyceride levels in the DAPP 1.4% group was 49% lower (P<0.01) than in the stanol group, despite the fact that both diets contained equivalent amounts of phytostanols. The lower concentration of DAPP (0.7%) also reduced plasma triglycerides (P<0.05) compared with the stanol diet.

CONCLUSION

Stanol-ascorbate decreases body weight gain in hamsters, likely due to lower energy absorption at the intestinal level. In addition to its previously observed powerful cholesterol-lowering effect, DAPP has a hypotriglyceridemic function in hamsters.

Cholesterol absorption inhibitors as a therapeutic option for hypercholesterolaemia

The development of cholesterol-lowering drugs (including a variety of statins, bile acid-binding resins and recently discovered inhibitors of cholesterol absorption) has expanded the options for cardiovascular prevention. Recent treatment guidelines emphasise that individuals at substantial risk for atherosclerotic coronary heart disease should meet defined targets for LDL cholesterol concentrations. Combination therapy with drugs that have different or complementary mechanisms of action is often needed to achieve lipid goals. Existing approaches to the treatment of hypercholesterolaemia are still ineffective in halting the progression of coronary artery disease in some patients despite combination therapies. Other patients are resistant to conventional drug treatment and remain at high risk for the development and progression of atherosclerotic cardiovascular disease and alternative approaches are needed. The discovery and development of ezetimibe (a novel, selective and potent cholesterol absorption inhibitor) has advanced the treatment of hypercholesterolaemia. New agents including the phytostanol preparation FM-VP4 and inhibitors of acyl coenzyme A:cholesterol acyltransferase, the apical Na(+)-dependent bile acid transporter and microsomal triglyceride transfer protein may also play a future role in combination therapy. This review focuses on the recent progress in the molecular mechanisms of intestinal cholesterol absorption and transport, and novel therapeutic approaches to inhibit the cholesterol absorption process.

Development and characterization of liposomal disodium ascorbyl phytostanyl phosphates (FM-VP4)

The specific objectives of this project were (1) to develop liposomal disodium ascorbyl phytostanyl phosphate (FM-VP4) formulations, (2) to develop a liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) assay for quantification of FM-VP4 in liposomal formulations and plasma sample, and (3) to characterize liposomal FM-VP4 formulations by finding optimal drug-to-lipid ratios and determining the degradation of FM-VP4 in liposomes. Section 2 describes an LC/MS/MS assay developed for the identification and quantification of FM-VP4 in liposomal formulations to provide estimates of drug concentrations and encapsulation efficiency. The extra step of removing plasma proteins prior to LC/MS/MS assay yields an analysis of FM-VP4 in plasma samples. Section 3 describes experiments designed to find the optimal drug-to-lipid ratio for liposomal FM-VP4 formulations by comparing encapsulation efficiencies and varying the lipid compositions. Additionally, this section details our degradation studies to determine if liposomes have any protective effects on FM-VP4; these studies tested various lipid compositions at 37 degrees C in rabbit plasma. The mechanism of how FM-VP4 lowers low-density lipoprotein (LDL) cholesterol and total cholesterol levels in various animal models is presently unknown. However, before the mechanism of action could be studied, FM-VP4 first had to be delivered efficiently into plasma or cultured cell. The low systemic bioavailability and cellular uptake of FM-VP4 further suggested the importance of finding an efficient delivery vehicle for this drug. This project proposed a framework for such delivery and paves the way for further investigation into how FM-VP4 works in vivo and in vitro.

Development of novel water-soluble phytostanol analogs: disodium ascorbyl phytostanyl phosphates (FM-VP4): preclinical pharmacology, pharmacokinetics and toxicology

FM-VP4 is a novel inhibitor of cholesterol absorption that has lipid lowering and body weight reducing properties. In vitro and in vivo studies were performed to investigate the lipid-lowering effects, mechanism of action, pharmacokinetics, and toxicity of FM-VP4. FM-VP4 decreased cholesterol accumulation in Caco-2 cells by approximately 50%; its activity appeared to be independent of pancreatic lipase, p-glycoprotein, or cholesterol incorporation in micelles. In animal studies, FM-VP4 was added to the diet or drinking water and the following results were obtained. In gerbils 2% FM-VP4 produced mean 56 and 53% reduction in total cholesterol (TC) after 4 and 8 weeks, respectively. This reduction was entirely due to the loss of the low-density lipoprotein (LDL) pool, which was reduced to undetectable levels at either time point. At 8 weeks, high-density lipoprotein (HDL) concentration had risen by a mean of 34% whereas total triglyceride (TG) concentrations had decreased by a mean of 60%. FM-VP4 also had a profound effect on body weight in these animals. At 8 weeks, the mean body weight was in the 4% FM-VP4 treatment group 25% lower than in the control group. No hepatic or renal toxicity was associated with these changes. In Apo E-deficient mice, after 4- and 8-week treatments FM-VP4 caused a significant decrease in both TC and TG concentrations compared to controls. After 12 weeks, the areas of atherosclerotic lesion involvement in the aortic roots were decreased by a mean of 80% in the 0.5, 1, and 2% FM-VP4 treatment groups compared to controls. Taken together, these results suggest that FM-VP4 is a potential new drug with lipid-lowering and weight loss potential, without apparent toxicity.