Phytosterols and vascular disease

Functionalized ZnO-Based Nanocomposites for Diverse Biological Applications: Current Trends and Future Perspectives

The wide array of structures and characteristics found in ZnO-based nanostructures offers them a versatile range of uses. Over the past decade, significant attention has been drawn to the possible applications of these materials in the biomedical field, owing to their distinctive electronic, optical, catalytic, and antimicrobial attributes, alongside their exceptional biocompatibility and surface chemistry. With environmental degradation and an aging population contributing to escalating healthcare needs and costs, particularly in developing nations, there's a growing demand for more effective and affordable biomedical devices with innovative functionalities. This review delves into particular essential facets of different synthetic approaches (chemical and green) that contribute to the production of effective multifunctional nano-ZnO particles for biomedical applications. Outlining the conjugation of ZnO nanoparticles highlights the enhancement of biomedical capacity while lowering toxicity. Additionally, recent progress in the study of ZnO-based nano-biomaterials tailored for biomedical purposes is explored, including biosensing, bioimaging, tissue regeneration, drug delivery, as well as vaccines and immunotherapy. The final section focuses on nano-ZnO particles' toxicity mechanism with special emphasis to their neurotoxic potential, as well as the primary toxicity pathways, providing an overall review of the up-to-date development and future perspectives of nano-ZnO particles in the biomedicine field.

Dietary and Therapeutic Benefits of Edible Insects: A Global Perspective

Edible insects are gaining traction worldwide for research and development. This review synthesizes a large and well-established body of research literature on the high nutritional value and variety of pharmacological properties of edible insects. Positive benefits of insect-derived products include immune enhancement; gastrointestinal protection; antitumor, antioxidant, and anti-inflammatory capacities; antibacterial activities; blood lipid and glucose regulation; lowering of blood pressure; and decreased risk of cardiovascular diseases. However, the pharmacological mechanisms of these active components of edible insects in humans have received limited research attention. In addition, we discuss health risks (safety); application prospects; regulations and policies governing their production and consumption with a view to promote innovations, intraglobal trade, and economic development; and suggestions for future directions for further pharmacological functional studies. The aim is to review the current state of knowledge and research trends on edible insects as functional ingredients beneficial to the nutrition and health of humans and animals (livestock, aquatic species, and pets).

Ultra-High-Resolution Liquid Chromatography Coupled with Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry Analysis of Tessaria absinthioides (Hook. & Arn.) DC. (Asteraceae) and Antioxidant and Hypocholesterolemic Properties

Recently, we reported the chemical profile and the hypocholesterolemic effects of a decoction of Tessaria absinthioides (Hook. & Arn.) DC. (Asteraceae). In this study, we evaluated a methanolic extract (METa) instead. Metabolite profiling was conducted using ultra-high-resolution liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS), identifying thirty compounds, including flavonoids, phenolic acids, fatty acids, and phorbolesters. Antioxidant properties were assessed through 2,2-diphenyl-1-picrylhydrazyl (DPPH), Trolox equivalent antioxidant activity (TEAC), ferric-reducing antioxidant power (FRAP), and inhibition of lipid peroxidation in erythrocytes (ILP) assays, exhibiting robust antioxidant activity. The in vivo impact of METa on serum lipid parameters and liver X receptors (LXRs) was evaluated in a hypercholesterolemic animal model. After 14 days on a high-fat diet, male rats received either a vehicle (V) or METa100, METa200 or METa500 (100; 200 and 500 mg METa/kg animal, respectively) for an additional two weeks. METa500 reduced total cholesterol levels (17.62%; p < 0.05) and all doses increased high-density lipoprotein cholesterol levels (METa100: 86.27%; METa200: 48.37%, and METa500: 29.42%; p < 0.0001). However, METa did not alter LXRs expression. The observed antioxidant and hypocholesterolemic properties of METa may be linked to the presence of six di-caffeoylquinic acids. These findings underscore T. absinthioides as a potential candidate for the treatment of metabolic disease.

Study on the synthesis of pine sterol esters in solvent-free systems catalyzed by Candida rugosa lipase immobilized on hydrophobic macroporous resin

BACKGROUND

Pine sterol ester is a type of novel food source nutrient with great advantages in lowering blood cholesterol levels, inhibiting tumors, preventing prostate enlargement, and regulating immunity. Macroporous resins with large specific surface area, stable structures, and various functional groups (epoxy, amino, and octadecyl groups) have been selected for immobilization of Candida rugosa lipase (CRL) to improve its stability and efficiency in the synthesis of pine sterol esters. A solvent-free strategy using oleic acid (substrate) as an esterification reaction medium is an important alternative for avoiding the use of organic solvents.

RESULTS

The immobilization conditions of CRL immobilized on several types of commercial macroporous resins were optimized. Fortunately, by adsorption (hydrophobic interaction), a high immobilization efficiency of CRL was obtained using macroporous resins with hydrophobic octadecyl groups with an immobilization efficiency of 86.5%, enzyme loading of 138.5 mg g-1 and enzyme activity of 34.7 U g-1 . The results showed that a 95.1% yield could be obtained with a molar ratio of oleic acid to pine sterol of 5:1, an enzyme amount of 6.0 U g-1 (relative to pine sterol mass) at 50 °C for 48 h.

CONCLUSION

The hydrophobic macroporous resin (ECR8806M) with a large specific surface area and abundant functional groups was used to achieve efficient immobilization of CRL. CRL@ECR8806M is an efficient catalyst for the synthesis of phytosterol esters and has the potential for further large-scale applications. Therefore, this simple, green, and low-cost strategy for lipase immobilization provides new possibilities for the high-efficiency production of pine sterol esters and other food source nutrients. © 2023 Society of Chemical Industry.

New Therapeutic Strategies for Obesity and Its Metabolic Sequelae: Brazilian Cerrado as a Unique Biome

Brazil has several important biomes holding impressive fauna and flora biodiversity. Cerrado being one of the richest ones and a significant area in the search for new plant-based products, such as foods, cosmetics, and medicines. The therapeutic potential of Cerrado plants has been described by several studies associating ethnopharmacological knowledge with phytochemical compounds and therapeutic effects. Based on this wide range of options, the Brazilian population has been using these medicinal plants (MP) for centuries for the treatment of various health conditions. Among these, we highlight metabolic diseases, namely obesity and its metabolic alterations from metabolic syndrome to later stages such as type 2 diabetes (T2D). Several studies have shown that adipose tissue (AT) dysfunction leads to proinflammatory cytokine secretion and impaired free fatty acid (FFA) oxidation and oxidative status, creating the basis for insulin resistance and glucose dysmetabolism. In this scenario, the great Brazilian biodiversity and a wide variety of phytochemical compounds make it an important candidate for the identification of pharmacological strategies for the treatment of these conditions. This review aimed to analyze and summarize the current literature on plants from the Brazilian Cerrado that have therapeutic activity against obesity and its metabolic conditions, reducing inflammation and oxidative stress.

TBS-pyrrole as an "universal" reference to quantify artemisinin and structurally-diverse natural products in plants extracts by NMR

The commercial production of artemisinin and other valuable bioactive natural products depends on their plant sources, which may provide variable amounts of the compound depending on plant variety, the period of the year, abiotic stress and other factors. Therefore, it requires a method for large-scale, low-cost natural product quantification. The standard HPLC and UHPLC methods are accurate but the analysis are costly and require different optimization for structurally-diverse products. An alternative method using NMR with TBS-pyrrole as a novel "universal" reference affords a simple, fast method to quantify many different products. The method is shown with antimalarial artemisinin, whose yield using conventional and novel extraction procedures was determined by standard UHPLC-MS procedures and by our NMR protocol, with similar quantification results. The novel reference compound does not interfere with artemisinin or extract signals, only needs a small amount of the extract, is accurate and operationally simple, and a large volume of samples can be processed in little time. Moreover, bioactive terpenes, steroids, alkaloids, aromatic compounds, and quinones, among others, were quantified in a model vegetal extract with this "universal" reference with excellent accuracy.

Beneficial sterols in selected edible insects and their associated antibacterial activities

Edible insects are increasingly gaining popularity as research reveals multiple benefits. However, the rediscovery of natural products from insects as medicinal agents has received limited attention. This study aimed at evaluating the diversity of sterols in extracts of nine edible insects and potential antibacterial activities. Dichloromethane extracts of these insects were analyzed using gas chromatography-mass spectrometry to identify important sterols, followed by evaluation of their anti-bacterial activities. Nineteen sterols were identified with the highest recorded in African fruit beetle [Pachnoda sinuata (47.37%)], crickets [Gryllus bimaculatus (36.84%) and Scapsipedus icipe (31.58%)]. Cholesterol was the most prevalent, except in black soldier fly (Hermetia illucens). Bioactivity revealed S. icipe as the most potent extract against Escherichia coli and Bacillus subtilis whereas G. bimaculatus was highest against Methicillin-susceptible Staphylococcus aureus 25923. These findings unravels the diversity of sterols in edible insects and their possible application in food, pharmaceutical and cosmetic industries.

Phytosterols and Cardiovascular Risk Evaluated against the Background of Phytosterolemia Cases-A German Expert Panel Statement

Phytosterols (PSs) have been proposed as dietary means to lower plasma LDL-C. However, concerns are raised that PSs may exert atherogenic effects, which would offset this benefit. Phytosterolemia was thought to mimic increased plasma PSs observed after the consumption of PS-enriched foods. This expert statement examines the possibility of specific atherogenicity of PSs based on sterol metabolism, experimental, animal, and human data. Observational studies show no evidence that plasma PS concentrations would be associated with an increased risk of atherosclerosis or cardiovascular (CV) events. Since variants of the ABCG5/8 transporter affect the absorption of cholesterol and non-cholesterol sterols, Mendelian randomization studies examining the effects of ABCG5/8 polymorphisms cannot support or refute the potential atherogenic effects of PSs due to pleiotropy. In homozygous patients with phytosterolemia, total PS concentrations are ~4000% higher than under physiological conditions. The prevalence of atherosclerosis in these individuals is variable and may mainly relate to concomitant elevated LDL-C. Consuming PS-enriched foods increases PS concentrations by ~35%. Hence, PSs, on a molar basis, would need to have 20-40 times higher atherogenicity than cholesterol to offset their cholesterol reduction benefit. Based on their LDL-C lowering and absence of adverse safety signals, PSs offer a dietary approach to cholesterol management. However, their clinical benefits have not been established in long-term CV endpoint studies.

Plasma lathosterol measures rates of cholesterol synthesis and efficiency of dietary phytosterols in reducing the plasma cholesterol concentration

OBJECTIVES

Because the plasma campesterol/cholesterol ratio does not differ between groups that absorb different amounts of cholesterol, the authors investigated whether the plasma Phytosterols (PS) relate to the body's cholesterol synthesis rate measured as non-cholesterol sterol precursors (lathosterol).

METHOD

The authors studied 38 non-obese volunteers (58±12 years; Low-Density Lipoprotein Cholesterol ‒ LDL-C ≥ 130 mg/dL) randomly assigned to consume 400 mL/day of soy milk (Control phase) or soy milk + PS (1.6 g/day) for four weeks in a double-blind, cross-over study. PS and lathosterol were measured in plasma by gas chromatography coupled to mass spectrophotometry.

RESULTS

PS treatment reduced plasma total cholesterol concentration (-5.5%, p < 0.001), LDL-C (-7.6%, p < 0.001), triglycerides (-13.6%, p < 0.0085), and apolipoprotein B (apo B) (-6.3%, p < 0.008), without changing high density lipoprotein cholesterol (HDL-C concentration), but plasma lathosterol, campesterol and sitosterol expressed per plasma cholesterol increased.

CONCLUSIONS

The lathosterol-to-cholesterol plasma ratio predicted the plasma cholesterol response to PS feeding. The highest plasma lathosterol concentration during the control phase was associated with a lack of response of plasma cholesterol during the PS treatment period. Consequently, cholesterol synthesis in non-responders to dietary PS being elevated in the control phase indicates these cases resist to further synthesis rise, whereas responders to dietary PS, having in the control phase synthesis values lower than non-responders, expand synthesis on alimentary PS. Responders absorb more PS than non-responders, likely resulting from responders delivering into the intestinal lumen less endogenous cholesterol than non-responders do, thus facilitating greater intestinal absorption of PS shown as increased plasma PS concentration.

Fatty acid profile, minor bioactive constituents and physicochemical properties of insect-based oils: A comprehensive review

Insect-based food or ingredients have received tremendous attention worldwide because of their potential to ensure food and nutrition security, mitigating the reliance on land-dependent agricultural products. Indeed, insect-farming has low environmental impacts with reduced land, water and energy input. More importantly, insects are rich in high quality proteins and fats. They are also excellent sources of minerals, vitamins and bioactive compounds. Insect-based lipids are intriguing because they may contain high levels of unsaturated fatty acids particularly linoleic and α-linolenic acids. Besides, the insect-based lipids also show a considerable amount of bioactive components such as tocols, sterols and carotenoids. However, their fatty acid compositions and the nutritional values may vary depending on species, feed composition, developmental stage, geographical locations, and extraction techniques. Therefore, the present article aims to provide a comprehensive review on the fatty acid composition, the minor bioactive constituents and the physicochemical properties of fats and oils derived from insects of different orders (Coleoptera, Lepidoptera, Hymenoptera, Orthoptera, Hemiptera and Diptera). The various parameters affecting the nutritional compositions of the insect-based lipids will also be highlighted. These information will definitely provide a detailed insight on the potential applications of these fats in various food systems based on their unique properties.

ER-Mitochondria Calcium Flux by β-Sitosterol Promotes Cell Death in Ovarian Cancer

Phytosterols, which are derived from plants, have various beneficial physiological effects, including anti-hypercholesterolemic, anti-inflammatory, and antifungal activities. The anticancer activities of natural products have attracted great attention, being associated with a low risk of side effects and not inducing antineoplastic resistance. β-sitosterol, a phytosterol, has been reported to have anticancer effects against fibrosarcoma and colon, breast, lung, and prostate cancer. However, there are no reports of its activity against ovarian cancer. Therefore, we investigated whether β-sitosterol shows anticancer effects against ovarian cancer using human ovarian cancer cell lines. We confirmed that β-sitosterol induced the apoptosis of ovarian cancer cells and suppressed their proliferation. It triggered pro-apoptosis signals and the loss of mitochondrial membrane potential, enhanced the generation of reactive oxygen species and calcium influx through the endoplasmic reticulum-mitochondria axis, and altered signaling pathways in human ovarian cancer cells. In addition, we observed inhibition of cell aggregation, suppression of cell growth, and decreased cell migration in ovarian cancer cells treated with β-sitosterol. Further, our data obtained using ovarian cancer cells showed that, in combination with standard anti-cancer drugs, β-sitosterol demonstrated synergistic anti-cancer effects. Thus, our study suggests that β-sitosterol may exert anti-cancer effects against ovarian cancer in humans.

Tessaria absinthioides (Hook. & Arn.) DC. (Asteraceae) Decoction Improves the Hypercholesterolemia and Alters the Expression of LXRs in Rat Liver and Hypothalamus

Chronic high-fat diet consumption induces hypercholesterolemia. The effect of Tessaria absinthioides (Hook. & Arn.) DC. (Asteraceae) was studied on the levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), and triglycerides, and on the expression of liver X receptors (LXRs) in a hypercholesterolemic model. Adult male rats received a normal diet (ND) or a high-fat diet (HFD; normal diet + bovine fat + cholesterol). After 14 days, rats received water (W) or a decoction of the aerial parts of T. absinthioides (Ta; 10% w/v) for 2, 4, or 6 weeks. Four and six weeks of Ta improved the levels of TC and HDL-c in HFD. After 6 weeks of Ta, the expression of LXRs in HFD was the same as that in ND in both tissues. The Ta chemical profile was studied with an ultrahigh resolution liquid chromatography Orbitrap MS analysis (UHPLC-PDA-OT-MS/MS). Fifty-one compounds were identified, of which twelve are reported for the first time. Among these compounds, caffeoylquinic acid and its derivatives could modify the lipid profile and the expression of LXRs. This is the first in vivo report of T. absinthioides, which may be a potential candidate against hypercholesterolemia.

Cross-Sectional Study of Plant Sterols Intake as a Basis for Designing Appropriate Plant Sterol-Enriched Food in Indonesia

Coronary heart disease (CHD) is one of the leading causes of mortality in many low-income and middle-income countries, including Indonesia, with elevated blood cholesterol level being one of significant risk factors for this condition. The problem should be addressed by combining healthy lifestyle and diet, where functional foods having a cholesterol-lowering activity could play a significant role. A group of compounds that had been proven to show cholesterol-lowering ability are plant sterols. To develop more suitable functional foods that could substantially contribute to hypercholesterolemia prevention in Indonesian population, up-to-date data about plant sterols dietary intake are required, and were not available until this research was done. This study aimed to estimate daily plant sterols intake and to determine the consumption pattern of foods containing plant sterols in rural and urban area of Bogor, West Java, Indonesia. The research was conducted with a cross-sectional design, with 200 respondents. The study revealed that the level of plant sterols intake in Bogor reached on average 229.76 mg/day and was not significantly different between urban and rural area. Cereals, vegetables, and fruit products were the main food sources of plant sterols in both areas. In addition, a list of several surveyed food items possible to be enriched with plant sterols was developed within the study. These results provide baseline data to develop functional foods fortified with plant sterols suitable for the Indonesian needs and taste. However, further studies are needed to confirm efficacy and safety of introducing such phytosterol-enriched products into a habitual diet, especially considering possible long-term side effects of plant sterol treatment.

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.

Pathophysiology of atherosclerosis: Association of risk factors and treatment strategies using plant-based bioactive compounds

Under physiological conditions, endothelial cells act as protective barrier which prevents direct contact of blood with circulating factors via production of tissue plasminogen activator. Risk factors of metabolic disorders are responsible to induce endothelial dysfunction and may consequently lead to prognosis of atherosclerosis. This article summarizes the process of atherosclerosis which involves number of sequences including formation and interaction of AGE-RAGE, activation of polyol pathway, protein kinase C, and hexosamine-mediated pathway. All these mechanisms can lead to the development of oxidative stress which may further aggravate condition. Different pharmacological interventions are being used to treat atherosclerosis, however, these might be associated with mild to severe side effects. Therefore, plant-based bioactive compounds having potential to combat and prevent atherosclerosis in diabetic patients are attaining recent focus. By understanding process of development and mechanisms involved in atherosclerotic plaque formation, these bioactive compounds can be better option for future therapeutic interventions for atherosclerosis treatment. PRACTICAL APPLICATIONS: Atherosclerosis is one of major underlying disorders of cardiovascular diseases which occur through multiple mechanisms and is associated with metabolic disorders. Conventional therapeutic interventions are not only used to treat atherosclerosis, but are also commonly associated with mild to severe side effects. Therefore, nowadays, bioactive compounds having potential to combat and prevent atherosclerosis in diabetic patients are preferred. By understanding mechanisms involved in atherosclerotic plaque formation, bioactive compounds can be better understood for treatment of atherosclerosis. In this manuscript, we have focused on treatment strategies of atherosclerosis using bioactive compounds notably alkaloids and flavonoids having diverse pharmacological and therapeutic potentials with special focus on the mechanism of action of these bioactive compounds suitable for treatment of atherosclerosis. This manuscript will provide the scientific insights of bioactive compounds to researchers who are working in the area of drug discovery and development to control pathogenesis and development of atherosclerosis and its associated cardiometabolic disorders.

Effects of Phytosterols supplementation on blood glucose, glycosylated hemoglobin (HbA1c) and insulin levels in humans: a systematic review and meta-analysis of randomized controlled trials

Background

In the literature, there are still controversies regarding the effect of phytosterol(PS) supplementation on fasting blood sugar (FBS), insulin levels and glycosylated hemoglobin (HbA1c) in humans. We aimed to assess the impact of PS supplementation on FBS, HbA1c and insulin levels by conducting a systematic review and meta-analysis of the available randomized controlled trials (RCTs).

Methods

A comprehensive search was conducted to identify all RCTs published up to May 2019 in the following databases: PubMed-MEDLINE, Web of Science, Cochrane Library and Scopus. The mean difference with 95% confidence intervals (CIs) was pooled using a random-effects model (DerSimonian-Laird method).

Results

Twenty-six arms from 20 RCTs were included in the present meta-analysis. Our findings show that PS supplementation decreases insulin levels (mean difference [MD]: -6.426 μU/ml, 95% CI: -7.187, -5.665, P- value = 0.000). However, PS supplementation did not have significant effects on FBS and HbA1c levels. Following PS supplementation, significant changes in FBS (mean difference [MD]: -1.942 mg/dl, 95% CI: -3.637, -0.246, P- value = 0.025) and HbA1c (mean difference [MD]: -0.059%, 95% CI: -0.114, -0.004, P- value = 0.035) based on PS dosage (mg/d) were recorded.

Conclusions

In patients with a baseline BMI <25 kg/m², PS consumption significantly increased FBS levels. Patients who consumed 1-2 g/day of PS had a lower FBS and lower HbA1c levels.

Phytosterols in Cancer: From Molecular Mechanisms to Preventive and Therapeutic Potentials

Cancer is the second leading cause of death worldwide. Compelling evidence supports the hypothesis that the manipulation of dietary components, including plant compounds termed as phytochemicals, demonstrates certain important health benefits in humans, including those in cancer. In fact, beyond their well-known cardiovascular applications, phytosterols may also possess anticancer properties, as has been demonstrated by several studies. Although the mechanism of action by which phytosterols (and derivatives) may prevent cancer development is still under investigation, data from multiple experimental studies support the hypothesis that they may modulate proliferation and apoptosis of tumor cells. Phytosterols are generally considered safe for human consumption and may also be added to a broad spectrum of food matrices; further, they could be used in primary and secondary prevention. However, few interventional studies have evaluated the relationship between the efficacy of different types and forms of phytosterols in cancer prevention. In this context, the purpose of this review was to revisit and update the current knowledge on the molecular mechanisms involved in the anticancer action of phytosterols and their potential in cancer prevention or treatment.

Stigmasterol accumulation causes cardiac injury and promotes mortality

Cardiovascular disease is expected to remain the leading cause of death worldwide despite the introduction of proprotein convertase subtilisin/kexin type 9 inhibitors that effectively control cholesterol. Identifying residual risk factors for cardiovascular disease remains an important step for preventing and clinically managing the disease. Here we report cardiac injury and increased mortality occurring despite a 50% reduction in plasma cholesterol in a mouse model of phytosterolemia, a disease characterized by elevated levels of dietary plant sterols in the blood. Our studies show accumulation of stigmasterol, one of phytosterol species, leads to left ventricle dysfunction, cardiac interstitial fibrosis and macrophage infiltration without atherosclerosis, and increased mortality. A pharmacological inhibitor of sterol absorption prevents cardiac fibrogenesis. We propose that the pathological mechanism linking clinical sitosterolemia to the cardiovascular outcomes primarily involves phytosterols-induced cardiac fibrosis rather than cholesterol-driven atherosclerosis. Our studies suggest stigmasterol is a potent and independent risk factor for cardiovascular disease.

Date Palm (Phoenix dactylifera): Novel Findings and Future Directions for Food and Drug Discovery

Phoenix dactylifera is a useful traditional medicinal plant, mainly the fruit is used, which is the edible part of the plant (Ajwa date). It is now considered to be a valuable source of natural medicinal products against various diseases. Phytochemical investigations have shown that the fruit contains anthocyanins, phenolics, sterols, carotenoids, and flavonoids. The fruits are a rich source of carbohydrates, vitamins, and proteins. P. dactylifera is considered as a complete diet because it also contains different fatty acids, amino acids, proteins, and steroidal substances. This review highlights the phytochemical composition, nutritional significance, and potential health benefits of P. dactylifera and discusses its potential as a functional food for disease prevention, management, and treatment.

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.

Recurrent tendosynovitis as a rare manifestation of a lipid disorder

A 33-year-old female had suffered from spontaneously recurrent bursitis and tendosynovitis/enthesitis of the patellar and Achilles tendons for about 10 years. The episodes of immobilization increased. Ultrasound imaging of the swollen and painful tendons showed chronic inflammation with neoangiogenesis within the tendons and hypoechoic lesions. Clinical and laboratory tests did not provide evidence for a rheumatic disease. Low density lipoprotein cholesterol was elevated. Biopsies of skin lesions did not confirm the suspicion of cutaneous xanthomas. Genetic testing for familial hypercholesterolemia was negative. Campesterol and sitosterol were elevated 7- to 12-fold and 20- to 38-fold over the upper limit of normal on two occasions. There was no relevant mutation in ABCG5. In ABCG8, we identified a missense mutation c.1267G>A in exon 9 changing glutamic acid 423 into lysine within the transmembrane domain, and an insertion of adenine (c.1487insA) leading to a frameshift and a premature stop codon (Ile497Aspfs*105). The patient had no clinical evidence of premature atherosclerosis. Therapeutic approaches with nonsteroidal antirheumatic drugs, prednisone, statins, and ezetimibe accompanied by a diet poor in plant sterols led to a relief of symptoms. This case report shows that tendon xanthoma along with tendosynovitis, especially on extensor areas, is suspicious for hypercholesterolemia as the underlying cause. The absence of atherosclerotic plaques in the abdominal aorta and in the carotid arteries on ultrasound may suggest that phytosterolemia is not necessarily accompanied by premature vascular disease.

Bitter Melon (Momordica charantia L) Fruit Decreased Blood Glucose Level and Improved Lipid Profile of Streptozotocin Induced Hyperglycemia Rats

Bitter melon (Momordica charantia, L) is a fruit that traditionally believe has benefits on health. The objective of this study is to identify bitter melon bioactive and nutritional compounds, and their effect on blood glucose level and lipid profile of streptozotocin induced hyperglycemia rats. Rats were divided into three group, those were normal group; hyperglycemia group without bitter melon fruit feeding; and hyperglycemia group with bitter melon fruit administration. Hyperglycemia condition was achieved by STZ induction. The experiment was conducted for 4 weeks. The results showed that fresh bitter melon fruit contains β-sitosterol 348.16+1.66 ppm, stigmasterol 183.08+0.8 ppm, campesterol 130.79+0.4 ppm, diosgenin 16.42+0.06 ppm, soluble dietary fiber 2.99+0.07%, insoluble dietary fiber 0.55+0.01%, and pectin 1.41+0.05%. At week 4 of experiment, bitter melon fruit fed hyperglycemia group showed a decrease of 56% blood glucose level compared to blood glucose level at week 0. Body weight of this group also increased. The improvement of lipid profile of bitter melon fed group was indicated by decreasing blood total cholesterol of 49%, triglyceride of 35%, LDL cholesterol of 42%, and increasing HDL of 133% compared to initial level at week 0. Bitter melon also increased fecal cholesterol secretion and effectively inhibited cholesterol absorption in hyperglycemia rats. Bitter melon fruit is suggested for hyperglycemia management due to its ability to reduce glucose and improve lipid profile simultaneously.

Effect of liver pâté enrichment with flaxseed oil and flaxseed extract on lipid composition and stability

BACKGROUND

There is an increase interest from food technologists in the improvement of the nutritional value of meat products, especially their lipid profile and shelf life. The aim of this study was to determine the effect of animal fat replacement with flaxseed oil (20%) and flaxseed extract addition (0.05%-0.25%) on changes in composition and stability of liver pâté lipid fractions.

RESULTS

Replacement of animal fat with flaxseed oil was observed to lower the saturated and monoenoic fatty acid in the product's fatty acid profile by around 12% and to raise the polyene fatty acid contribution by more than 70% when compared to the control. The replacement also resulted in enriching the pâté with phytosterols (β-sitosterol, campesterol, and cycloartenol). The addition of 0.05% and 0.10% ethanol flaxseed extract significantly slowed down lipid oxidation changes during storage of the pâté.

CONCLUSIONS

The study showed that a storage-stable meat product - liver pâté - characterized by a high nutritional value can be designed through the addition of flax oil rich in unsaturated fatty acids and flaxseed extract. The addition of 0.05% of the extract was found to be sufficient to improve the liver pâté's oxidative stability; it can thus be recommended for this type of product. © 2018 Society of Chemical Industry.

Tissue sterol composition in Atlantic salmon (Salmo salar L.) depends on the dietary cholesterol content and on the dietary phytosterol:cholesterol ratio, but not on the dietary phytosterol content

The aim of the study was to investigate how the dietary sterol composition, including cholesterol, phytosterol:cholesterol ratio and phytosterols, affect the absorption, biliary excretion, retention, tissue storage and distribution of cholesterol and individual phytosterols in Atlantic salmon (Salmo salar L.). A feeding trial was conducted at two different temperatures (6 and 12°C), using nine different diets with varying contents of phytosterols, cholesterol and phytosterol:cholesterol ratio. Cholesterol retention values were clearly dependent on dietary cholesterol, and showed that fish fed cholesterol levels <1000 mg/kg feed produced considerable quantities of cholesterol de novo. Despite this production, cholesterol content increased with increasing dietary cholesterol in liver, plasma, bile, muscle, adipose tissue and whole fish at 12°C, and in plasma, bile and whole fish at 6°C. The tissue sterol composition generally depended on the dietary cholesterol content and on the dietary phytosterol:cholesterol ratio, but not on the dietary phytosterol content in itself. Campesterol and brassicasterol appeared to be the phytosterols with the highest intestinal absorption in Atlantic salmon. There was a high biliary excretion of campesterol, but not of brassicasterol, which accumulated in tissues and particularly in adipose tissue, with 2-fold-higher retention at 12°C compared with 6°C. Campesterol had the second highest retention of the phytosterols in the fish, but with no difference between the two temperatures. Other phytosterols had very low retention. Although brassicasterol retention decreased with increasing dietary phytosterols, campesterol retention decreased with increasing dietary cholesterol, indicating differences in the uptake mechanisms for these two sterols.

Endogenous Cholesterol Excretion Is Negatively Associated With Carotid Intima-Media Thickness in Humans

OBJECTIVE

Epidemiological studies strongly suggest that lipid factors independent of low-density lipoprotein cholesterol contribute significantly to cardiovascular disease risk. Because circulating lipoproteins comprise only a small fraction of total body cholesterol, the mobilization and excretion of cholesterol from plasma and tissue pools may be an important determinant of cardiovascular disease risk. Our hypothesis is that fecal excretion of endogenous cholesterol is protective against atherosclerosis.

APPROACH AND RESULTS

Cholesterol metabolism and carotid intima-media thickness were quantitated in 86 nondiabetic adults. Plasma cholesterol was labeled by intravenous infusion of cholesterol-d₇ solubilized in a lipid emulsion and dietary cholesterol by cholesterol-d₅ and the nonabsorbable stool marker sitostanol-d₄. Plasma and stool samples were collected while subjects consumed a cholesterol- and phytosterol-controlled metabolic kitchen diet and were analyzed by mass spectrometry. Carotid intima-media thickness was negatively correlated with fecal excretion of endogenous cholesterol (r=-0.426; P<0.0001), total cholesterol (r=-0.472; P≤0.0001), and daily percent excretion of cholesterol from the rapidly mixing cholesterol pool (r=-0.343; P=0.0012) and was positively correlated with percent cholesterol absorption (r=+0.279; P=0.0092). In a linear regression model controlling for age, sex, systolic blood pressure, hemoglobin A1c, low-density lipoprotein, high-density lipoprotein cholesterol, and statin drug use, fecal excretion of endogenous cholesterol remained significant (P=0.0008).

CONCLUSIONS

Excretion of endogenous cholesterol is strongly, independently, and negatively associated with carotid intima-media thickness. The reverse cholesterol transport pathway comprising the intestine and the rapidly mixing plasma, and tissue cholesterol pool could be an unrecognized determinant of cardiovascular disease risk not reflected in circulating lipoproteins. Further work is needed to relate measures of reverse cholesterol transport to atherosclerotic disease.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01603758.

Plant sterol enriched functional food and atherosclerosis

Hypercholesterolaemia is a major cardiovascular risk factor. A healthy diet and a healthy lifestyle reduces cardiovascular risk. 'Functional foods' supplemented with phytosterols are recommended for the management of hypercholesterolaemia and have become a widely used non-prescription approach to lower plasma cholesterol levels. Two billion euros are spent world-wide each year on various functional foods, which have regulator-approved health claims for the management of elevated cholesterol levels. While international societies, such as the European Atherosclerosis Society or the National Heart Foundation in Australia, still advise phytosterols as an additional dietary option in the management of hypercholesterolaemia, recently released guidelines such as those from the National Institute of Health and Clinical Excellence in the United Kingdom are more critical of food supplementation with phytosterols and draw attention to significant safety issues. This review challenges whether an intervention with phytosterol supplements is beneficial. We summarize the current evidence from genetic diseases, genetic association studies, clinical trial data and data from animal studies.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.

[Using plant sterols in clinical practice: From the chemistry to the clinic]

This paper describes what are plant sterols, the chemical structure to understand their mechanism of cholesterol-lowering action, and indications and contraindications in clinical practice.

Polyamine derivatives of betulinic acid and β-sitosterol: A comparative investigation

β-Sitosterol and betulinic acid were used in designing their conjugates with selected polyamines bearing either an amide bond, or an ester and an amide bond simultaneously in the target molecule. The synthesized compounds were subjected to basic cytotoxic and antimicrobial tests. The synthetic protocol is described separately for each of the three series of the target amides, because each series of compounds required a different synthetic approach. The cytotoxicity was tested on cells derived from human T-lymphoblastic leukemia, breast adenocarcinoma and cervical cancer, and compared with the tests on normal human fibroblasts. Most of the target compounds (5a-5c, 11a-11c and 16a-16c) showed medium to high cytotoxicity (0.7-7.8 μM), however, in some cases the compounds showed high cytotoxicity even toward normal human fibroblasts (11a-11c). Two compounds of this series (11c and 16c) also displayed antimicrobial activity with high and selective microbe specificity. The compound 11c was potent against Escherichia coli (minimal inhibition concentration (MIC) 6.25 μg mL(-1), i.e. 9.75 nM mL(-1)) and Staphylococcus aureus (MIC 12.5 μg mL(-1), i.e. 19.5 nM mL(-1)), and showed medium activity against Pseudomonas aeruginosa. The compound 16c was highly active against Enterococcus faecalis and S. aureus (both, MIC 3.125 μg mL(-1), i.e. 4.22 nM mL(-1)), both Gram-positive bacteria, however showed only weak activity against E. coli and no activity against P. aeruginosa, both Gram-negative bacteria, which indicates possible microbe specificity of 16c. Comparing β-sitosterol-based series (5a-5c) and betulinic acid series (11a-11c and 16a-16c) of the target compounds, the latter one gave more promising structures. The compounds 11c and 16c showed effects which may be described as multifarious activity (pleiotropic effects).

Potential of the Desert Locust Schistocerca gregaria (Orthoptera: Acrididae) as an Unconventional Source of Dietary and Therapeutic Sterols

Insects are increasingly being recognized not only as a source of food to feed the ever growing world population but also as potential sources of new products and therapeutic agents, among which are sterols. In this study, we sought to profile sterols and their derivatives present in the desert locust, Schistocerca gregaria, focusing on those with potential importance as dietary and therapeutic components for humans. Using coupled gas chromatography-mass spectrometry (GC-MS), we analyzed and compared the quantities of sterols in the different sections of the gut and tissues of the locust. In the gut, we identified 34 sterols which showed a patchy distribution, but with the highest composition in the foregut (55%) followed by midgut (31%) and hindgut (14%). Fed ad libitum on wheat seedlings, five sterols unique to the insect were detected. These sterols were identified as 7-dehydrocholesterol, desmosterol, fucosterol, (3β, 5α) cholesta-8, 14, 24-trien-3-ol, 4, 4-dimethyl, and (3β, 20R) cholesta-5, 24-dien-3, 20-diol with the first three having known health benefits in humans. Incubation of the fore-, mid- and hindgut with cholesterol-[4-¹³C] yielded eight derivatives, three of these were detected in the gut of the desert locust after it had consumed the vegetative diet but were not detected in the diet. Our study shows that the desert locust ingests phytosterols from a vegetative diet and, amplifies and metabolizes them into derivatives with potential salutary benefits and we discuss our findings in this context.

Plant Sterols, Stanols, and Sitosterolemia

Phytosterolemia (sitosterolemia) is a rare autosomal recessive sterol storage disease caused by mutations in either of the adenosine triphosphate (ATP) binding cassette transporter genes; (ABC) G5 or ABCG8, leading to impaired elimination of plant sterols and stanols, with their increased accumulation in the blood and tissues. Thus the disease is characterized by substantially elevated serum plant sterols and stanols, with moderate to high plasma cholesterol levels, and increased risk of premature atherosclerosis. Hematologic abnormalities including macrothrombocytopenia, stomatocytosis and hemolysis are frequently observed in sitosterolemia patients. Currently, ezetimibe, a sterol absorption inhibitor, is used as the routine treatment for sitosterolemia, with reported improvement in plant sterol levels and hemolytic parameters. This review summarizes the research related to the health impact of plant sterols and stanols on sitosterolemia.

Phytochemicals and their potential usefulness in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract with unclear etiology, namely ulcerative colitis and Crohn's disease. Various drug therapies including aminosalicylates and immunomodulators have been approved for use; they have shown to produce diverse side effects. To overcome these limitations of the current therapeutics for IBD, extensive research is underway to identify drugs that are effective and free of undesirable side effects. Recently, various naturally occurring phytochemicals that cover a wide range of chemical entities such as polyphenols, terpeniods, flavonoids, and alkaloids have received attention as alternative candidates for IBD therapy. These phytochemicals act by modulating the immune response, various transcription factors, or reduce cytokine secretion. This review summarizes the findings of recent studies on phytochemicals as therapeutic agents in the management of IBD.

Potential effects of NPC1L1 polymorphisms in protecting against clinical disease in a chinese family with sitosterolaemia

Sitosterolaemia is caused by mutations in either ABCG5 or ABCG8. Chinese and Japanese individuals usually have mutations in ABCG5. We herein report a known and a novel mutation in ABCG8 and their potential interaction with NPC1L1 polymorphisms in a Chinese family with sitosterolaemia. We sequenced ABCG5 and ABCG8 and measured the levels of plasma plant sterols in a 15-year-old Chinese girl with clinical sitosterolaemia (xanthomas with elevated low-density lipoprotein cholesterol (LDL-C) and plant sterols) and her apparently healthy family members. NPC1L1 was sequenced in the genetically affected sibling and other family members. A known mutation, c.490C＞T (p. Arg164(＊)), in exon 4 and a novel mutation, c.1949T＞G (p.Leu650Arg), in exon 13 of ABCG8 were detected in the proband and her sister, who had elevated sterols but low LDL-C levels and no xanthomas. The genetically affected sister, but not the proband, carried two additional heterozygous changes in NPC1L1 (rs2072183 C＞G, rs2301935 A＞C), which were inherited from the mother, who also had a low LDL-C level. In this study, we detected a known and a novel mutation in ABCG8 in a Chinese patient with sitosterolaemia. The same mutations were found in her clinically normal sister, suggesting that the contrasting features with the proband may be related to different variants in NPC1L1 and/or some other undetermined lipid-related genetic factors.

Non-cholesterol sterols and cholesterol metabolism in sitosterolemia

Sitosterolemia (STSL) is a rare autosomal recessive disease, manifested by extremely elevated plant sterols (PS) in plasma and tissue, leading to xanthoma and premature atherosclerotic disease. Therapeutic approaches include limiting PS intake, interrupting enterohepatic circulation of bile acid using bile acid binding resins such as cholestyramine, and/or ileal bypass, and inhibiting intestinal sterol absorption by ezetimibe (EZE). The objective of this review is to evaluate sterol metabolism in STSL and the impact of the currently available treatments on sterol trafficking in this disease. The role of PS in initiation of xanthomas and premature atherosclerosis is also discussed. Blocking sterols absorption with EZE has revolutionized STSL patient treatment as it reduces circulating levels of non-cholesterol sterols in STSL. However, none of the available treatments including EZE have normalized plasma PS concentrations. Future studies are needed to: (i) explore where cholesterol and non-cholesterol sterols accumulate, (ii) assess to what extent these sterols in tissues can be mobilized after blocking their absorption, and (iii) define the factors governing sterol flux.