Triglyceride-Lowering Response to Plant Sterol and Stanol Consumption

Dietary Cholest-4-en-3-one, a Cholesterol Metabolite of Gut Microbiota, Alleviates Hyperlipidemia, Hepatic Cholesterol Accumulation, and Hyperinsulinemia in Obese, Diabetic db/db Mice

Previous studies have shown that dietary cholest-4-en-3-one (4-cholestenone, 4-STN) exerts anti-obesity and lipid-lowering effects in mice. However, its underlying mechanisms are not fully understood. In the present study, we evaluated whether 4-STN supplementation would protect obese diabetic db/db mice from obesity-related metabolic disorders. After four weeks of feeding of a 0.25% 4-STN-containing diet, dietary 4-STN was found to have significantly alleviated hyperlipidemia, hepatic cholesterol accumulation, and hyperinsulinemia; however, the effect was not sufficient to improve hepatic triglyceride accumulation or obesity. Further analysis demonstrated that dietary 4-STN significantly increased the content of free fatty acids and neutral steroids in the feces of db/db mice, indicating that the alleviation of hyperlipidemia by 4-STN was due to an increase in lipid excretion. In addition, dietary 4-STN significantly reduced the levels of desmosterol, a cholesterol precursor, in the plasma but not in the liver, suggesting that normalization of cholesterol metabolism by 4-STN is partly attributable to the suppression of cholesterol synthesis in extrahepatic tissues. In addition, dietary 4-STN increased the plasma and hepatic levels of 4-STN metabolites cholestanol (5α-cholestan-3β-ol) and coprostanol (5β-cholestan-3β-ol). Our results show that dietary 4-STN alleviates obesity-related metabolic disorders, such as hyperlipidemia, hepatic cholesterol accumulation, and hyperinsulinemia, in db/db mice.

Liposomal Phytosterols as LDL-Cholesterol-Lowering Agents in Diet-Induced Hyperlipidemia

The high blood level of low-density lipoprotein cholesterol (LDL-C) is a primary risk factor for cardiovascular disease. Plant sterols, known as phytosterols (PSs), can reduce LDL-C in a range of 8-14%. The extent of LDL-C reduction depends on its formulation. Encapsulation into liposomes is one formulation strategy to enhance the efficiency of PSs. PSs (campesterol, stigmasterol, and β-sitosterol) have frequently been assessed alone or in combination for their LDL-C-lowering ability. However, one naturally abundant PS, brassicasterol, has not yet been tested for its efficacy. We have previously developed a novel liposomal formulation containing the PS mixture present naturally in canola that is composed of brassicasterol, campesterol, and β-sitosterol. In this work, the efficacy of our novel liposomal PS formulation that includes brassicasterol was assessed in a hamster model. Animals were divided into five groups: (i) liposomal PS in orange juice, (ii) liposomal PS in water, (iii) marketed PS in orange juice, (iv) control orange juice, and (v) control water. The animals were fed a high-fat, cholesterol-supplemented (0.5%) diet to induce hypercholesterolemia. The treatment was administered orally once daily for 4 weeks. Fasting blood samples were collected at baseline, week 2, and week 4. The extent of the reduction of total cholesterol, LDL-C, high-density lipoprotein cholesterol (HDL-C), and triglycerides was compared among the groups. Liposomal PSs in both orange juice and water significantly reduced LDL-C compared to their controls. Furthermore, the liposomal PS was as effective as a marketed PS-containing product in reducing LDL-C. Liposomal PSs in both orange juice and water showed similar efficacy in LDL-C reduction, highlighting that these vehicles/food matrices do not affect the efficacy of PSs. The liposomal formulation of a natural PS mixture extracted from canola oil, with brassicasterol as a major component, exhibited a significant LDL-C reduction in a hamster model.

Interaction between APOE, APOA1, and LPL Gene Polymorphisms and Variability in Changes in Lipid and Blood Pressure following Orange Juice Intake: A Pilot Study

SCOPE

Chronic orange juice intake is associated with reduced risk of cardiovascular disease, however, a large inter-individual variability in response to orange juice for lipid profile and blood pressure has been observed. This heterogeneity in responsiveness could be associated with single nucleotide polymorphism (SNP), which has not been previously addressed. This study aims to investigate the influence of SNP in apolipoprotein E (APOE), apolipoprotein A1 (APOA1), mevalonate (MVK), and lipase lipoprotein (LPL) genes in the biological response after chronic orange juice intake.

METHODS AND RESULTS

Forty-six volunteers ingested 500 mL daily for 60 days and blood pressure and biochemical parameters are measured. Also, SNPs in APOE, APOA1, MVK, and LPL genes are genotyped in the volunteers that are medium/high excretors of flavanone metabolites. Genotypes CC (APOA1), AA, and GG (LPL) are associated with positive health effects of orange juice and the CC (APOE), GG (APOA1), GG, and AA (LPL) genotypes are associated with no effects of orange juice consumption (p < 0.05).

CONCLUSION

These results identify for the first-time SNP associated with effects of orange juice on lipid levels and blood pressure, results that may provide bases for future precise nutritional recommendations regarding this flavanone-rich food to lower the risk for cardiovascular disease.

Through regulation of the SIRT1 pathway plant sterol ester of α-linolenic acid inhibits pyroptosis thereby attenuating the development of NASH in mice

Increasing evidence demonstrated that pyroptosis and subsequent inflammation played an important role in the pathological process of non-alcoholic steatohepatitis (NASH). Plant sterol ester of α-linolenic acid (PS-ALA) was beneficial for non-alcoholic fatty liver disease, but the underlying mechanisms are still not fully understood. This study aims to investigate whether PS-ALA can protect against proptosis via regulating SIRT1. Thirty male C57BL/6J mice were fed a normal diet, a high-fat and high-cholesterol diet (HFCD), or a HFCD supplemented with either 1.3%ALA, 2%PS, or 3.3% PS-ALA for 24 weeks. Hepatocytes were treated with oleic acid and cholesterol (OA/Cho) with or without PS-ALA. We found that PS-ALA ameliorated NASH in HFCD-fed mice. In addition, PS-ALA decreased the expression of NLRP3 and ASC and reduced the co-localization of NLRP3 and cleave-Caspase-1. Also, PS-ALA protected against pyroptosis as evidenced by decreased co-localization of GSDMD and propidium iodide (PI) positive cells. Mechanistically, we revealed that the inhibitory action of PS-ALA on the pyroptosis was mediated by SIRT1. This was demonstrated by the fact that silencing SIRT1 with small interfering RNA or inhibition of SIRT1 with its inhibitor abolished the inhibition effect of PS-ALA on the expression of NLRP3 and GSDMD cleavage. Collectively, the data from the present study reveals a novel mechanism that PS-ALA inhibits pyroptosis and it triggered inflammation via stimulating SIRT1, which provides new insights into the beneficial effect of PS-ALA on NASH.

Molecular Mechanism of Crataegi Folium and Alisma Rhizoma in the Treatment of Dyslipidemia Based on Network Pharmacology and Molecular Docking

Background

Dyslipidemia has become a critical global issue for public health, with elevating prevalence and morbidity closely related to many cardiovascular diseases (CVD) with high incidence rates. Crataegi Folium (known as Shanzhaye in China, SZ, the leaves of Crataegus pinnatifida Bge. var. major N.E. Br. or Crataegus pinnatifida Bge) and Alisma rhizoma (known as Zexie in China, ZX, the dried tuber of Alisma orientale (Sam.) Juzep or Alisma plantago-aquatica Linn), a classic combination of herbs, have been widely used to treat dyslipidemia. However, the therapeutic mechanism of this pair still remains unclear. Hence, this study aimed to elucidate the molecular mechanism of the Shanzhaye-Zexie herb pair (SZHP) in the treatment of dyslipidemia with the use of a network pharmacology analysis approach.

Methods

Active compounds, targets of the SZHP, and targets for dyslipidemia were screened based on the public database. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were performed on the database for annotation, visualization, and integrated discovery (DAVID 6.8). The compound-target-disease-pathway network was visualized using the Cytoscape software, and SYBYL was used for molecular docking.

Results

Twelve active compounds in the SZHP were screened out, which were closely connected to 186 dyslipidemia-related targets. The network analysis revealed that sitosterol, stigmasterol, isorhamnetin, kaempferol, and quercetin might be candidate agents and CCND1, CASP3, HIF1A, and ESR1 genes were potential drug targets. GO analysis revealed 856 biological processes (BP), 139 molecular functions (MF), and 89 cellular components (CC). The KEGG pathway enrichment analysis indicated that the lipid level and atherosclerosis might influence the treatment of dyslipidemia. Molecular docking showed that quercetin bound well to CCND1, HIF1A, MYC, AKT1, and EGFR genes. These findings were in accord with the prediction obtained through the network pharmacology approach.

Conclusions

This study revealed the primary pharmacological effects and relevant mechanisms of the SZHP in treating dyslipidemia. Our findings may facilitate the development of the SZHP or its active compounds as an alternative therapy for dyslipidemia. Still, more pharmacological experiments are needed for verification.

An Overview on the Therapeutic Function of Foods Enriched with Plant Sterols in Diabetes Management

Diabetes is one of the most significant health issues across the world. People identified with diabetes are more vulnerable to various infections and are at a greater risk of developing cardiovascular diseases. The plant-based food we consume often contains many sterol-based bioactive compounds. It is well documented that these compounds could effectively manage the processes of insulin metabolism and cholesterol regulation. Insulin resistance followed by hyperglycemia often results in oxidative stress level enhancement and increased reactive oxygen species production. At the molecular level, these changes induce apoptosis in pancreatic cells and hence lead to insulin insufficiency. Studies have proved that plant sterols can lower inflammatory and oxidative stress damage connected with DNA repair mechanisms. The effective forms of phyto compounds are polyphenols, terpenoids, and thiols abundant in vegetables, fruits, nuts, and seeds. The available conventional drug-based therapies for the prevention and management of diabetes are time-consuming, costly, and with life-threatening side effects. Thereby, the therapeutic management of diabetes with plant sterols available in our daily diet is highly welcome as there are no side effects. This review intends to offer an overview of the present scenario of the anti-diabetic compounds from food ingredients towards the therapeutic beneficial against diabetes.

Phytosterols: From Preclinical Evidence to Potential Clinical Applications

Phytosterols (PSs) are plant-originated steroids. Over 250 PSs have been isolated, and each plant species contains a characteristic phytosterol composition. A wide number of studies have reported remarkable pharmacological effects of PSs, acting as chemopreventive, anti-inflammatory, antioxidant, antidiabetic, and antiatherosclerotic agents. However, PS bioavailability is a key issue, as it can be influenced by several factors (type, source, processing, preparation, delivery method, food matrix, dose, time of administration into the body, and genetic factors), and the existence of a close relationship between their chemical structures (e.g., saturation degree and side-chain length) and low absorption rates has been stated. In this sense, the present review intends to provide in-depth data on PS therapeutic potential for human health, also emphasizing their preclinical effects and bioavailability-related issues.

Effects of Daily Consumption of an Aqueous Dispersion of Free-Phytosterols Nanoparticles on Individuals with Metabolic Syndrome: A Randomised, Double-Blind, Placebo-Controlled Clinical Trial

Metabolic syndrome (MS) affects up to 40% of the population and is associated with heart failure, stroke and diabetes. Phytosterols (PS) could help to manage one or more MS criteria. The purpose of this study was to evaluate the therapeutic effect of daily supplementation of an aqueous dispersion of 2 g of free-phytosterols nanoparticles in individuals with MS over six months of intervention, compared with placebo. This double-blind study included 202 participants with MS randomly assigned into phytosterol (n = 102) and placebo (n = 100) groups. Participants were assessed at baseline, 4, 12 and 24 weeks. General health questions, anthropometric measurements and blood parameters were analysed. At week 24, the proportion of participants with high triglycerides (≥150 mg/dL) in the phytosterol group was 15.65% lower than in the placebo group (p-value = 0.023). Similarly, half of the participants in the phytosterol group decreased their waist circumference up to 4 cm compared with 0 cm in the placebo group (p-value = 0.0001). We reported no adverse effects (diarrhoea or vitamin D reduction); nonetheless, almost 70% of participants in the phytosterol group self-reported an improvement in bowel habits. Daily intake of free-PS nanoparticles improved some MS criteria; therefore, it might be a promising adjuvant therapy for individuals with MS (NCT02969720).

Pseudocereal grains: Nutritional value, health benefits and current applications for the development of gluten-free foods

Nowadays, consumers are more conscious of the environmental and nutritional benefits of foods. Pseudocereals grains, edible seeds belonging to dicotyledonous plant species, are becoming a current trend in human diets as gluten-free (GF) grains with excellent nutritional and nutraceutical value. Pseudocereals are a good source of starch, fiber, proteins, minerals, vitamins, and phytochemicals such as saponins, polyphenols, phytosterols, phytosteroids, and betalains with potential health benefits. The present review aims to summarize the nutritional quality and phytochemical profile of the three main pseudocereal grains: quinoa, amaranth and buckwheat. In addition, current evidence about their health benefits in animal models and human studies is also provided in detail. Based on the accumulating research supporting the inclusion of pseudocereals grains in the diet of celiac persons, this review discusses the recent advances in their application for the development of new GF products. Future directions for a wider cultivation and commercial exploitation of these crops are also highlighted.

Potential role of phytochemicals in metabolic syndrome prevention and therapy

Metabolic syndrome (MetS) is a set of cardiovascular risk factors which severely increases the risk of type II diabetes, renal disease and cardiovascular disease. Over the last decades, the role of dietary bioactive substances in features of MetS has been extensively investigated. Due to their multiple properties, these plant-derived natural compounds have demonstrated to provide positive effects in obesity, diabetes, renal and in cardiovascular disease. Catechins of green tea and caffeine reduce body mass index and waist circumference. Catechins, anthocyanins and proanthocyanidins of cocoa reduce blood pressure and blood glucose. Curcumin and silymarin exert hepatoprotective effects. Monacolins of red yeast rice are effective cholesterol-lowering agents. However, inconsistent or conflicting results have been found in clinical trials when other promising compounds in vitro or in animal studies, such as policosanol, curcumin or silymarin, were used. Low oral bioavailability of substances, ineffective dosages, inadequate treatment duration and insufficient statistical approach may explain the lack of effectiveness observed in some human studies. Further clinical studies are needed to better understand the role of bioactive compounds in the prevention and management of MetS.

Intake of stigmasterol and β-sitosterol alters lipid metabolism and alleviates NAFLD in mice fed a high-fat western-style diet

OBJECTIVE

To investigate and compare the effects of two common dietary phytosterols, stigmasterol and β-sitosterol, in altering lipid metabolism and attenuating nonalcoholic fatty liver disease (NAFLD).

METHODS

Stigmasterol and β-sitosterol were administered to mice at 0.4% in a high-fat western-style diet (HFWD) for 17 weeks.

RESULTS

Stigmasterol and β-sitosterol significantly ameliorated HFWD-induced fatty liver and metabolic abnormalities, including elevated levels of hepatic total lipids, triacylglycerols, cholesterol and liver histopathology. Both phytosterols decreased the levels of intestinal bile acids, accompanied by markedly increased fecal lipid levels. In addition, they altered the expression of genes involved in lipid metabolism. β-Sitosterol was less effective in affecting most of these parameters. Lipidomic analysis of liver and serum samples showed that stigmasterol prevented the HFWD-induced elevation of some di- and triacylglycerol species and lowering of some phospholipid species. Stigmasterol also decreased serum levels of ceramides.

CONCLUSION

Stigmasterol and β-sitosterol, at a dose corresponding to that suggested for humans by the FDA for lowering cholesterol levels, are shown to alleviate HFWD-induced NAFLD. Stigmasterol was more effective than β-sitosterol, possibly because of its suppression of hepatic lipogenic gene expression and modulation of circulating ceramide levels.

Plant sterols lower LDL-cholesterol and triglycerides in dyslipidemic individuals with or at risk of developing type 2 diabetes; a randomized, double-blind, placebo-controlled study

Background

Managing cardiovascular disease (CVD) risk factors, e.g., dyslipidemia in type-2 diabetes mellitus (T2DM) is critically important as CVD is the most common cause of death in T2DM patients. This study aimed to investigate the effect of plant sterols (PS) on lowering both elevated low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG).

Methods

In a double-blind, randomized, placebo-controlled, parallel study, 161 individuals at increased risk of and with established T2DM, consumed low-fat spreads without or with added PS (2 g/d) for 6 weeks after a 2-week run-in period. Increased risk of developing T2DM was defined by the Australian T2DM Risk Assessment Tool (AUSDRISK). Fasting serum/plasma total cholesterol (TC), LDL-C, TG, high-density lipoprotein cholesterol (HDL-C), glucose and insulin were measured at baseline and after 6 weeks. Effects on acute and chronic postprandial blood lipids, glucose and insulin were measured over 4-h in 39 individuals with T2DM following a mixed meal challenge without and with added 2 g/d PS at week 6. The study was registered at clinicaltrials.gov (NCT02288585).

Results

Hundred fifty-one individuals completed the study and 138 (57% men, 43% women; 44 with and 94 at risk of T2DM) were included in per protocol analysis. Baseline LDL-C and TG were 3.8 ± 1.0 and 2.5 ± 0.8 mmol/l, respectively. PS intake significantly lowered fasting LDL-C (−4.6%, 95%CI −1.2; −8.0; p = 0.009), TC (−4.2%, 95%CI −1.2; −7.1; p = 0.006) and TG (−8.3%, 95% −1.1, −15.0; p = 0.024) with no significant changes in HDL-C, glucose or insulin. Postprandial lipid (TG, TC, LDL-C, HDL-C, remnant cholesterol), glucose and insulin responses did not differ.

Conclusions

In individuals at risk of and with established T2DM and with elevated TG and LDL-C, 2 g/d of PS results in dual LDL-C plus TG lowering. Postprandial lipid or glycemic responses did not differ between PS and control treatment.

A low-fat spread with added plant sterols and fish omega-3 fatty acids lowers serum triglyceride and LDL-cholesterol concentrations in individuals with modest hypercholesterolaemia and hypertriglyceridaemia

Purpose

The primary and secondary objectives were to investigate the triglyceride (TG) and LDL-cholesterol (LDL-C) lowering effects of a spread with added plant sterols (PS) and fish oil as compared to a placebo spread.

Methods

This study had a randomized, double-blind, placebo-controlled, parallel group design with two intervention arms. Following a 2-week placebo run-in period, 260 healthy individuals with modestly elevated blood TG (≥ 1.4 mmol/L) and LDL-C (≥ 3.4 mmol/L) concentrations consumed either the placebo or intervention spread for 4 weeks. The intervention spread contained 2.0 g/day PS and 1.0 g/day eicosapentaenoic acid (EPA) + docosahexanoic acid (DHA) from fish oil. Fasting serum lipids and apolipoproteins (Apo) (exploratory) were measured at the end of the run-in and intervention phases.

Results

Four-week consumption of the intervention spread resulted in significantly lower TG (− 10.6%, 95% CI − 16.0 to − 4.9%; P < 0.001) and LDL-C concentrations (− 5.2%; 95% CI − 7.8 to − 2.4%) as compared to placebo. Total cholesterol (− 3.9%; 95% CI − 6.1 to − 1.5%), non-HDL-C (− 5.4%; 95% CI − 8.1 to − 2.7%), remnant-cholesterol (− 8.1%; 95% CI − 3.4 to − 12.5%), ApoAII (− 2.9%; 95% CI − 5.5 to − 0.2%), ApoCIII (− 7.7%; 95% CI − 12.1 to − 3.1%) and ApoB (− 3.2%; 95% CI − 5.9 to − 0.4%) concentrations were also significantly lower, as compared to placebo. No significant treatment effects were found for HDL-cholesterol, ApoAI, ApoCII, Apo E or ApoB/ApoAI.

Conclusions

Four-week consumption of the intervention spread led to significant and clinically relevant decreases in serum TG, LDL-C and other blood lipid concentrations. The study was registered at clinicaltrials.gov (NCT 02728583).

Electronic supplementary material

The online version of this article (10.1007/s00394-018-1706-1) contains supplementary material, which is available to authorized users.

Influence of maternal hypercholesterolemia and phytosterol intervention during gestation and lactation on dyslipidemia and hepatic lipid metabolism in offspring of Syrian golden hamsters

SCOPE

Although there is a normal physiological rise in maternal lipids during pregnancy, excessive maternal hyperlipidemia during pregnancy increases cardiovascular disease risk for both the mother and offspring. There are limited safe lipid-lowering treatment options for use during pregnancy, therefore, we evaluated the influence of maternal phytosterol (PS) supplementation on lipid and lipoprotein metabolism in mothers and progeny.

METHODS AND RESULTS

Female Syrian golden hamsters were randomly assigned to three diets throughout prepregnancy, gestation, and lactation (n = 6/group): (i) Chow (Chow), (ii) chow with 0.5% cholesterol (CH), and (iii) chow with 0.5% CH and 2% PS (CH/PS). Compared with newly weaned pups from Chow dams, pups from dams fed the CH-enriched diet demonstrated increases (p < 0.05) in total-C, LDL-C, HDL-C, and total LDL and VLDL particle number. Pups from CH-fed mothers also exhibited higher hepatic CH concentration and differential mRNA expression pattern of CH regulatory genes. Pups from PS-supplemented dams demonstrated reductions (p < 0.05) in serum total-C, non-HDL-C, and LDL-C but also increased triglycerides compared with pups from CH-fed dams. Maternal PS supplementation reduced (p < 0.05) hepatic CH and increased the abundance of HMG-CoAr and LDLr protein in newly weaned pups compared with the CH group.

CONCLUSION

Results suggest that maternal PS supplementation is largely effective in normalizing CH in pups born to mothers with hypercholesterolemia, however, the cause and long-term influence of increased triglyceride is not known.