Efficacy and safety of sitosterol in the management of blood cholesterol levels

Characterization of Silybum marianum and Silybum eburneum seed oils: Phytochemical profiles and antioxidant properties supporting important nutritional interests

Milk thistle seed oil is still not a well-known edible oil. Silybum marianum (milk thistle), is present in several countries and is the only known representative of the genus Silybum. However, Silybum eburneum, which is an endemic plant in Spain, Kenya, Morocco, Algeria, and Tunisia, is considered a marginalized species. The present work is the first report that gives information on the lipid and phenolic profiles of Tunisian S. eburneum seed oil compared to those of Tunisian S. marianum seed oil. In addition, the antioxidant properties of these oils were determined with DPPH, FRAP, and KRL assays, and their ability to prevent oxidative stress was determined on human monocytic THP-1 cells. These oils are characterized by high amounts of unsaturated fatty acids; linoleic acid and oleic acid are the most abundant. Campesterol, sitosterol, stigmasterol, and β-amyrin were the major phytosterols identified. α-tocopherol was the predominant tocopherol found. These oils also contain significant amounts of phenolic compounds. The diversity and richness of Silybum marianum and Silybum eburneum seed oils in unsaturated fatty acids, phenolic compounds, and tocopherols are associated with high antioxidant activities revealed by the DPPH, FRAP, and KRL assays. In addition, on THP-1 cells, these oils powerfully reduced the oxidative stress induced by 7-ketocholesterol and 7β-hydroxycholesterol, two strongly pro-oxidant oxysterols often present at increased levels in patients with age-related diseases. Silybum marianum and Silybum eburneum seed oils are therefore important sources of bioactive molecules with nutritional interest that prevent age-related diseases, the frequency of which is increasing in all countries due to the length of life expectancy.

Cholesterol-metabolism, plant sterols, and long-term cognitive decline in older people - Effects of sex and APOEe4

Neurodegenerative, vascular, and dementia diseases are linked to dysregulations in cholesterol metabolism. Dietary plant sterols, or phytosterols, may interfere to neurodegeneration and cognitive decline, and have cholesterol-lowering, anti-inflammatory, and antioxidant qualities. Here, we investigated the potential associations between circulating cholesterol precursors and metabolites, triglycerides, and phytosterols with cognitive decline in older people by performing multivariate analysis on 246 participants engaged in a population-based prospective study. In our analysis we considered the potential effect of sex and APOEe4. We reveal particular dysregulations of diet-derived phytosterols and endogenous cholesterol synthesis and metabolism, and their variations over time linked to cognitive decline in the general population. These results are significant to the development of interventions to avoid cognitive decline in older adults and suggest that levels of circulating sterols should be taken into account when evaluating risk.

Low density lipoprotein receptor endocytosis in cardiovascular disease and the factors affecting LDL levels

Cardiovascular disease (CVD) is the one of major global health issues with approximately 30% of the mortality reported in the mid-income population. Low-density lipoprotein (LDL) plays a crucial role in development of CVD. High LDL along with others forms a plaque and blocks arteries, resulting in CVD. The present chapter deals with the mechanism of receptor-mediated endocytosis of LDL and its management by drugs such as statins and PCSK9 inhibitors along with dietary supplementation for health improvements.

Production, Characterization, Delivery, and Cholesterol-Lowering Mechanism of Phytosterols: A Review

Phytosterols are natural plant-based bioactive compounds that can lower blood cholesterol levels and help prevent cardiovascular diseases. Consequently, they are being utilized in functional foods, supplements, and pharmaceutical products designed to improve human health. This paper summarizes different approaches to isolate, purify, and characterize phytosterols. It also discusses the hypolipidemic mechanisms of phytosterols and their impact on cholesterol transportation. Phytosterols have a low water-solubility, poor chemical stability, and limited bioavailability, which limits their utilization and efficacy in functional foods. Strategies are therefore being developed to overcome these shortcomings. Colloidal delivery systems, such as emulsions, oleogels, liposomes, and nanoparticles, have been shown to be effective at improving the water-dispersibility, stability, and bioavailability of phytosterols. These delivery systems can be used to incorporate phytosterols into a broader range of cholesterol-lowering functional foods and beverages. We also discuses several issues that need to be addressed before these phytosterol delivery systems can find widespread commercial utilization.

Fatty acid metabolism and colon cancer protection by dietary methyl donor restriction

INTRODUCTION

A methyl donor depleted (MDD) diet dramatically suppresses intestinal tumor development in Apc-mutant mice, but the mechanism of this prevention is not entirely clear.

OBJECTIVES

We sought to gain insight into the mechanisms of cancer suppression by the MDD diet and to identify biomarkers of cancer risk reduction.

METHODS

A plasma metabolomic analysis was performed on Apc^Δ14/+ mice maintained on either a methyl donor sufficient (MDS) diet or the protective MDD diet. A group of MDS animals was also pair-fed with the MDD mice to normalize caloric intake, and another group was shifted from an MDD to MDS diet to determine the durability of the metabolic changes.

RESULTS

In addition to the anticipated changes in folate one-carbon metabolites, plasma metabolites related to fatty acid metabolism were generally decreased by the MDD diet, including carnitine, acylcarnitines, and fatty acids. Some fatty acid selectivity was observed; the levels of cancer-promoting arachidonic acid and 2-hydroxyglutarate were decreased by the MDD diet, whereas eicosapentaenoic acid (EPA) levels were increased. Machine-learning elastic net analysis revealed a positive association between the fatty acid-related compounds azelate and 7-hydroxycholesterol and tumor development, and a negative correlation with succinate and β-sitosterol.

CONCLUSION

Methyl donor restriction causes dramatic changes in systemic fatty acid metabolism. Regulating fatty acid metabolism through methyl donor restriction favorably effects fatty acid profiles to achieve cancer protection.

Wide Spectrum of Active Compounds in Sea Buckthorn (Hippophae rhamnoides) for Disease Prevention and Food Production

Growing demand for value-added products and functional foods is encouraging manufacturers to consider new additives that can enrich their products and help combat lifestyle diseases. The healthy properties of sea buckthorn have been recognized for centuries. This plant has a high content of bioactive compounds, including antioxidants, phytosterols, essential fatty acids, and amino acids, as well as vitamins C, K, and E. It also has a low content of sugar and a wide spectrum of volatiles, which contribute to its unique aroma. Sea buckthorn shows antimicrobial and antiviral properties, and is a potential nutraceutical or cosmeceutical. It was proven to help treat cardiovascular disease, tumors, and diabetes, as well as gastrointestinal and skin problems. The numerous health benefits of sea buckthorn make it a good candidate for incorporation into novel food products.

Investigation of the Potential Mechanism Governing the Effect of the Shen Zhu San on COVID-19 by Network Pharmacology

BACKGROUND

Since December 2019, coronavirus disease 2019 (COVID-19) due to SARS-CoV-2 infection has emerged in Wuhan and rapidly spread throughout China and even to other countries. Combined therapy with modern medicine and traditional Chinese medicine has been proposed, in which Shen Zhu San (SZS) was regarded as one of the basic prescriptions.

METHODS

Network pharmacological approaches along with candidate compound screening, target prediction, target tissue location, protein-protein interaction network, gene ontology (GO), KEGG enrichment analyses, and gene microarray analyses were applied.

RESULTS

A total of 627 targets of the 116 active ingredients of SZS were identified. Targets in immune cells and tissues were much more abundant than those in other tissues. A total of 597 targets were enriched in the GO biological cellular process, while 153 signaling pathways were enriched according to the KEGG analysis. A total of 450 SARS-related targets were integrated and intersected with the targets of SZS to identify 40 common targets that were significantly enriched in five immune function aspects of the immune system process during GO analysis. Several inflammation-related pathways were found to be significantly enriched throughout the study.

CONCLUSIONS

The therapeutic mechanisms of the effects of SZS on COVID-19 potentially involve four effects: suppressing cytokine storms, protecting the pulmonary alveolar-capillary barrier, regulating the immune response, and mediating cell death and survival.

Plants mentioned in the Islamic Scriptures (Holy Qur'ân and Ahadith): Traditional uses and medicinal importance in contemporary times

ETHNOPHARMACOLOGICAL RELEVANCE

Over the past thousand years, Islamic physicians have collected cultural, philosophical, sociological and historical backgrounds for understanding diseases and medications. The Prophet Mohammed (Peace Be Upon Him (PBUH) said: "There is no disease that Allah has created, except that Allah also has created its cure." Therefore, Islamic scholars are encouraged to explore and use both traditional and modern forms of medicine.

AIM OF THE STUDY

(1) To identify some of the medicinal plants mentioned in the Holy Qur'ân and Ahadith textbooks of the period 700-1500 AD; (2) to compare them with presently used traditional medicines; (3) to evaluate their value based on modern research; and (4) to investigate the contributions of Islamic scholars to the development of the scientific branches, particularly medicine.

MATERIALS AND METHODS

A literature search was performed relating to 12 medicinal plants mentioned in the Holy Qur'ân and Ahadith using textbooks, Al-Azhar scholars, published articles, the plant list website (http://www.theplantlist.org/), the medicinal plant names services website (http://mpns.kew.org/mpns-portal/) and web databases (PubMed, Science Direct, and Google Scholar).

RESULTS AND DISCUSSION

The Islamic Golden Age was a step towards modern medicine, with unique insights and multi-disciplinary aspects. Traditional Islamic Medicine has had a significant impact on the development of various medical, scientific and educational activities. Innumerable Muslim and non-Muslim physicians have built on the strong foundation of Traditional Islamic Medicine by translating the described natural remedies and effects. The influences of different ancient cultures on the traditional uses of natural products were also documented in Islamic Scriptures in the last part of the second millennium. The divine teachings of Islam combine natural and practical healing and incorporate inherited science and technology.

CONCLUSION

In this review, we discuss Traditional Islamic Medicine with reference to both medical recommendations mentioned in the Holy Qur'ân and Prophetic Traditional Medicine (al-Tibb al-Nabawi). Although the molecular mechanisms and functions of some of the listed medicinal plants and their derivatives have been intensively studied, some traditional remedies have yet to be translated into clinical applications.

Stigmasterol prevents glucolipotoxicity induced defects in glucose-stimulated insulin secretion

Type 2 diabetes results from defects in both insulin sensitivity and insulin secretion. Elevated cholesterol content within pancreatic β-cells has been shown to reduce β-cell function and increase β-cell apoptosis. Hyperglycemia and dyslipidemia contribute to glucolipotoxicity that leads to type 2 diabetes. Here we examined the capacity of glucolipotoxicity to induce free cholesterol accumulation in human pancreatic islets and the INS-1 insulinoma cell line. Glucolipotoxicity treatment increased free cholesterol in β-cells, which was accompanied by increased reactive oxygen species (ROS) production and decreased insulin secretion. Addition of AAPH, a free radical generator, was able to increase filipin staining indicating a link between ROS production and increased cholesterol in β-cells. We also showed the ability of stigmasterol, a common food-derived phytosterol with anti-atherosclerotic potential, to prevent the increase in both free cholesterol and ROS levels induced by glucolipotoxicity in INS-1 cells. Stigmasterol addition also inhibited early apoptosis, increased total insulin, promoted actin reorganization, and improved insulin secretion in cells exposed to glucolipotoxicity. Overall, these data indicate cholesterol accumulation as an underlying mechanism for glucolipotoxicity-induced defects in insulin secretion and stigmasterol treatment as a potential strategy to protect β-cell function during diabetes progression.

Silkworm pupae oil exerts hypercholesterolemic and antioxidant effects in high-cholesterol diet-fed rats

BACKGROUND

Silkworm pupae is a good resource of edible oil that is especially rich in unsaturated fatty acids and is considered to be an excellent dietary supplement for hyperlipidemia.

RESULTS

Groups fed a high-cholesterol diet (HCD) with silkworm pupae oil (SPO) supplementation (1, 2, or 4 mL kg^-1  day^-1 ) orally had significantly lower levels of serum total cholesterol (P < 0.05) and low-density lipoprotein cholesterol (P < 0.05) compared to the HCD group. With regard to antioxidant parameters, except for levels of glutathione peroxidase (GSH-Px) in the liver, 2 and 4 mL kg^-1  day^-1 of SPO supplementation leaded to higher total antioxidant capacity (P < 0.05), superoxide dismutase (P < 0.05) and GSH-Px levels (P < 0.05), as well as lower malondialdehyde levels (P < 0.05), both in serum and liver compared to the HCD group.

CONCLUSION

The results of the present study indicate that supplementation with SPO can improve lipid profiles and alleviate oxidative stress in high-cholesterol diet-fed rats. © 2016 Society of Chemical Industry.

Ethyl acetate extract of crabapple fruit is the cholesterol-lowering fraction

Hypercholesterolemia is highly associated with cardiovascular diseases (CVDs) such as atherosclerosis.

Effect of Diabetea tea ™ consumption on inflammatory cytokines and metabolic biomarkers in type 2 diabetes patients

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetea tea™ (DT) is an anti-diabetic alternative medicine in some Asian countries. The main constituent of DT is black tea originating from Camellia sinensis that is supplemented by 12 other medicinal plants. Black tea contains a large amount of the flavonoids catechins especially epigallocatechin gallate (EGCG) which has anti-inflammatory and antioxidative capacity. This study was undertaken to evaluate the possible effects of DT intake on inflammatory cytokines, regulatory T cells (Tregs) and metabolic biomarkers in T2DM.

MATERIALS AND METHODS

The study included 50 patients with T2DM. The patients had received 3 cups (600ml) of DT extract or placebo (PL) extract per day during a period of 12 weeks. Intracellular cytokine expression in peripheral blood mononuclear cell (PBMC) as well as the glycemic and lipid profiles were measured at baseline and after the treatment period. The active constituents of the medicinal plants included in DT were investigated by gas chromatography-mass spectrometry (GC/MS).

RESULTS

Ingestion of DT suppressed CD4+ T cell expression of IL-1β and Il-8 (p<0.05) and up-regulated the expression of IL-10 and the Treg/IL-17 ratio (p<0.05) which was not shown in PL. A significant decrease in HbA1c and LDL was observed at the end of the study period (p<0.05) in DT. The GC/MS analyses of DT indicated the presence of lupeol, β-Amyrin and β-sitosterol. Also analyses of individual herbs showed the presence of higher levels of lupeol and β-Amyrin in Nuga Ficus bengalensis and β-sitosterol in the Attikka Ficus racemosa, indicating that the active ingredients of DT are concentrated in these two herbs.

CONCLUSION

The present study provides evidence that DT has hypoglycemic and antihyperlipidemic properties. Interestingly, DT has anti-inflammatory effects. These properties are attributed to the flavonoids, triterpenes and phytosterol contents of the tea. We suggest that DT protects against diabetes complications in the long term.

Impaired hepatic and intestinal ATP-binding cassette transporter G5/8 was associated with high exposure of β-sitosterol and the potential risks to blood-brain barrier integrity in diabetic rats

OBJECTIVES

Plant sterols are thought to treat hypercholesterolemia via inhibiting intestinal cholesterol absorption. The aim of this study was to evaluate the contribution of impaired ATP-binding cassette transporter G5/8 (ABCG5/8) expression by diabetes to the increased β-sitosterol (BS) exposure and impact of increased BS on integrity of blood-brain barrier (BBB).

METHODS

Basal BS level in tissues of streptozotocin-inducted rats and ABCG5/8 protein levels in liver and intestine were investigated; pharmacokinetics of BS was studied following oral dose; and primarily cultured rat brain microvessel endothelial cells (rBMECs) were used to study BS transportation across BBB and effect of BS on BBB integrity.

KEY FINDINGS

Diabetic rats showed greatly upgraded basal levels of BS in plasma, intestine, cerebral and hippocampus, accompanied by impairment of ABCG5/8 protein expression in liver and intestine. Pharmacokinetics studies demonstrated higher AUC0-48 and Cmax , and lower faecal recoveries of BS after oral administration, indicating enhancement of absorption or efflux impairment. In-vitro data showed increased ratio of BS/cholesterol in high levels BS-treated rBMECs was associated with increased BBB permeability of some biomarkers including BS itself.

CONCLUSIONS

Impaired ABCG5/8 protein expression by diabetes led to increase in BS exposure, which may be harmful to BBB function.

Plant polyisoprenoids and control of cholesterol level

The ability of plant polyisoprenoids (polyprenols and polyprenyl phosphates) to diminish the levels of serum cholesterol affecting its biosynthetic pathway are highlighted here. Possible mechanism of such process is discussed. It is also noted that polyisoprenoids can prevent toxic injuries of the liver and restore disturbed hepatic functions. The possibility of polyprenyl phosphates to reveal at the same time anti-inflammatory action suppressing lipoxygenase activity and lowering the levels of proinflammatory cytokines will be illustrated. Attention will be focused on the potential usefulness of plant polyisoprenoids in the course of prevention and treatment of hypercholesterolemia. High efficiency for combined use of polyprenyl phosphate and β-sitosterol, which leads to substantial enhancement of the ability to overcome hypercholesterolemia versus the individual constituents will be demonstrated.

Quantum chemical treatment of beta-sitosterol molecule

Beta-sitosterol is used as a dietary supplement for lowering plasma cholesterol, and has atherosclerosis preventive, anti-inflammatory, antimicrobial, antipyretic, induced apoptosis, and anticancer effects. In order to understand the effect of the molecule we have investigated the molecule theoretically. The structural, vibrational, and electronic properties of the beta-sitosterol molecule have been investigated theoretically by performing molecular mechanics (MM+ force field), semiempirical self-consistent-field molecular-orbital (PM3), and density functional theory (B3LYP) calculations. The geometry of the considered molecule has been optimized; the vibrational dynamics and the electronic properties have been calculated in its ground state in the gas phase. The optimized structure of the molecule is not planar, and its heat of formation is exothermic. The calculated infrared spectrum for beta-sitosterol agrees well qualitatively with the experimentally determined FTIR spectrum. The interfrontier molecular orbitals are localized mainly on the double C-C bond, and the energy difference of the corresponding orbitals is relatively small, which makes the molecule kinetically stable. According to the calculated dipole moment, beta-sitosterol is a polar molecule. The calculated results for the beta-sitosterol molecule in the present study will aid in elucidation of the mechanism of action and may further be used in lipid metabolism drug design studies.

Stearate-enriched plant sterol esters lower serum LDL cholesterol concentration in normo- and hypercholesterolemic adults

Studies in our laboratory have previously demonstrated in hamsters a superior cholesterol-lowering ability of plant sterol (PS) esters enriched in stearate compared with linoleate. We therefore conducted a randomized, double-blind, 2-group parallel, placebo-controlled study to test the cholesterol-lowering properties of stearate-enriched PS esters in normo- and hypercholesterolemic adults. Thirty-two adults, 16 per group with equal number of males and females in each group, participated in the 4-wk study. Participants consumed 3 g/d (1 g three times per day with meals) of either PS esters or placebo delivered in capsules. Serum LDL cholesterol concentration significantly decreased 0.42 mmol/L (11%) and the LDL:HDL cholesterol ratio decreased 10% with PS ester supplementation, whereas LDL particle size and lipoprotein subclass particle concentrations (as measured by NMR) were not affected. The percent change in LDL cholesterol was positively correlated with baseline lathosterol concentration (r = 0.729; P = 0.0014), indicating an association between the magnitude of LDL change and the rate of whole-body cholesterol synthesis. Serum campesterol (but not sitosterol) concentration significantly increased in the PS ester group. Serum tocopherol, retinol, and beta-carotene concentrations were not affected by PS ester supplementation. Thus, our findings demonstrate the usefulness of a novel stearate-enriched PS ester compound in decreasing LDL cholesterol in both normo- and hypercholesterolemic adults. The extent to which PS ester fatty acid composition affects intestinal micelle formation and cholesterol absorption in humans requires further study.

Effects of lactose-beta-sitosterol and beta-sitosterol on ovalbumin-induced lung inflammation in actively sensitized mice

Asthma is a disease marked by chronic lung inflammation and the number of patients suffering from asthma increases annually. Both beta-sitosterol (BS) and beta-sitosterol glucoside exist in a variety of plants and have anti-tumor, anti-microbial, and immunomodulatory activities. However, the precise role of BS and beta-sitosterol glucoside in asthma has not been well understood. The aim of this study was to investigate the inhibitory effects of BS and lactose-BS (L-BS) on the pathophysiological process in ovalbumin-induced asthmatic mice. The total cells and eosinophils in the bronchoalveolar lavage (BAL) fluid markedly decreased (p<0.05) after L-BS or BS administration (1 mg/kg; i.p.), and the ROS production also decreased in comparison to the asthma control. Histopathological features were detected by performing histochemistry, including H&E and alcian blue & P.A.S staining. Both L-BS and BS mitigated the inflammation by eosinophil infiltration and mucus hypersecretion by goblet hyperplasia. These effects of L-BS were superior to those of BS. L-BS and BS inhibited the increased mRNA and protein expression of IL-4 and IL-5 in the lung tissue and BAL fluid, respectively. The IgE concentration in the BAL fluid and serum was measured by performing ELISA and the ovalbumin-specific IgE in the BAL fluid was uniquely inhibited by L-BS (p<0.05). The splenocytes were isolated from the normal and asthmatic mice and incubated in the absence and presence of 100 microg/ml ovalbumin, respectively. L-BS blocked the survival rate of the splenocytes of the mice (p<0.01). This finding indicates the possibility of L-BS and BS as potential therapeutic molecules in asthma and may contribute to the need to improve current therapeutic drugs.