Food Protein Sterylation: Chemical Reactions between Reactive Amino Acids and Sterol Oxidation Products under Food Processing Conditions

Sterols, especially cholesterol and phytosterols, are important components of food lipids. During food processing, such as heating, sterols, like unsaturated fatty acids, can be oxidized. Protein modification by secondary products of lipid peroxidation has recently been demonstrated in food through a process called lipation. Similarly, this study was performed to assess, for the first time, the possibility of reactions between food proteins and sterol oxidation products in conditions relevant for food processing. Therefore, reaction models consisting of oxysterol (cholesterol 5α,6α-epoxide) and reactive amino acids (arginine, lysine, and methionine) were incubated in various conditions of concentration (0–8 mM), time (0–120 min), and temperature (30–180 °C). The identification of lysine adducts through thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) with a diode array detector (DAD), and electrospray ionization (ESI) mass spectrometry (MS) evidenced a reaction with lysine. Moreover, the HPLC-ESI with tandem mass spectrometry (MS/MS) analyses allowed observation of the compound, whose mass to charge ratio m/z 710.5 and fragmentation patterns corresponded to the reaction product [M + H]⁺ between cholesterol-5α,6α-epoxide and the ε-amino-group of N_α-benzoylglycyl-l-lysine. Moreover, kinetic studies between N_α-benzoylglycyl-l-lysine as a model for protein-bound lysine and cholesterol 5α,6α-epoxide were performed, showing that the formation of lysine adducts strongly increases with time, temperature, and oxysterol level. This preliminary study suggests that in conditions commonly reached during food processing, sterol oxidation products could react covalently with protein-bound lysine, causing protein modifications.

Phytosterols: Nutritional Health Players in the Management of Obesity and Its Related Disorders

Obesity and its related disorders, such as diabetes and cardiovascular risk, represent an emerging global health issue. Even though genetic factors seem to be the primary actors in the development and progression of these diseases, dietary choices also appear to be of crucial importance. A healthy diet combined with physical activity have been shown to ameliorate glycaemic levels and insulin sensitivity, reduce body weight and the risk of chronic diseases, and contribute to an overall improvement in quality of life. Among nutrients, phytosterols have become the focus of growing attention as novel functional foods in the management of metabolic disorders. Phytosterols are natural plant compounds belonging to the triterpene family and are structurally similar to cholesterol. They are known for their cholesterol-lowering effects, anti-inflammatory and antioxidant properties, and the benefits they offer to the immune system. The present review aims to provide an overview of these bioactive compounds and their therapeutic potential in the fields of obesity and metabolic disorders, with special attention given to oxidative stress, inflammatory status, and gut dysbiosis, all common features of the aforementioned diseases.

Impact of Quercetin Encapsulation with Added Phytosterols on Bilayer Membrane and Photothermal-Alteration of Novel Mixed Soy Lecithin-Based Liposome

This study used highly lipophilic agents with an aim to increase the oxidant inhibitory activity and enhance photothermal stability of a novel mixed soy lecithin (ML)-based liposome by changing the composition of formulation within the membrane. Specifically, the development and optimization of the liposome intended for improving Trolox equivalent antioxidant capacity (TEAC) value and %TEAC loss was carried out by incorporating a natural antioxidant, quercetin (QU). In this context, a focus was set on QU encapsulation in ML-based liposomes and the concentration-dependent solubility of QU was investigated and calculated as encapsulation efficiency (EE). To explore the combined effects of the incorporation of plant sterols on the integrity and entrapment capacity of mixed phospholipid vesicles, conjugation of two types of phytosterols (PSs), namely β-sitosterol (βS) and stigmasterol (ST), to mixed membranes at different ratios was also performed. The EE measurement revealed that QU could be efficiently encapsulated in the stable ML-based liposome using 0.15 and 0.1 g/100 mL of βS and ST, respectively. The aforementioned liposome complex exhibited a considerable TEAC (197.23%) and enhanced TEAC loss (30.81%) when exposed to ultraviolet (UV) light (280-320 nm) over a 6 h duration. It appeared that the presence and type of PSs affect the membrane-integration characteristics as well as photodamage transformation of the ML-based liposome. The association of QU with either βS or ST in the formulation was justified by their synergistic effects on the enhancement of the EE of liposomes. Parallel to this, it was demonstrated that synergistic PS effects could be in effect in the maintenance of membrane order of the ML-based liposome. The findings presented in this study provided useful information for the development and production of stable QU-loaded ML-based liposomes for food and nutraceutical applications and could serve as a potential mixed lipids-based delivery system in the disease management using antioxidant therapy.

Corn Bioethanol Side Streams: A Potential Sustainable Source of Fat-Soluble Bioactive Molecules for High-Value Applications

This paper reports data from a characterization study conducted on the unsaponifiable lipid fraction of dry-grind corn bioethanol side streams. Phytosterols, squalene, tocopherols, tocotrienols, and carotenoids were quantified by High Performance Liquid Chromatography with Diode-Array Detector (HPLC-DAD) and Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS) in different lots of post-fermentation corn oil and thin stillage collected from a bioethanol plant over a time-span of one year. Fat-soluble bioactives were present at high levels in corn oil, with a prevalence of plant sterols over tocols and squalene. Beta-sitosterol and sitostanol accounted altogether for more than 60% of total sterols. The carotenoid profile was that typical of corn, with lutein and zeaxanthin as the prevalent molecules. The unsaponifiable lipid fraction profile of thin stillage was qualitatively similar to that of post-fermentation corn oil but, in quantitative terms, the amounts of valuable biomolecules were much lower because of the very high dilution of this side stream. Results indicate that post-fermentation corn oil is a promising and sustainable source of health-promoting bioactive molecules. The concomitant presence of a variegate complex of bioactive molecules with high antioxidant potentialities and their potential multifaceted market applications as functional ingredients for food, nutraceutical, and cosmeceutical formulations, make the perspective of their recovery a promising strategy to create new bio-based value chains and maximize the sustainability of corn dry-grind bioethanol biorefineries.

Engineering of Phytosterol-Producing Yeast Platforms for Functional Reconstitution of Downstream Biosynthetic Pathways

As essential structural molecules for plant plasma membranes, phytosterols are key intermediates for the synthesis of many downstream specialized metabolites of pharmaceutical or agricultural significance, such as brassinosteroids and withanolides. Saccharomyces cerevisiae has been widely used as an alternative producer for plant secondary metabolites. Establishment of heterologous sterol pathways in yeast, however, has been challenging due to either low efficiency or structural diversity, likely a result of crosstalk between the heterologous phytosterol and the endogenous ergosterol biosynthesis. For example, in this study, we engineered campesterol production in yeast using plant enzymes; although we were able to enhance the titer of campesterol to ∼40 mg/L by upregulating the mevalonate pathway, no conversion to downstream products was detected upon the introduction of downstream plant enzymes. Further investigations uncovered two interesting observations about sterol engineering in yeast. First, many heterologous sterols tend to be efficiently and intensively esterified in yeast, which drastically impedes the function of downstream enzymes. Second, yeast can overcome the growth deficiency caused by altered sterol metabolism through repeated culture. By employing metabolic engineering, strain evolution, fermentation engineering, and pathway reconstitution, we were able to reconstruct the multienzyme pathways for the synthesis of a set of phytosterols: campesterol (∼7 mg/L), β-sitosterol (∼2 mg/L), 22-hydroxycampesterol (∼1 mg/L), and 22-hydroxycampest-4-en-3-one (∼4 mg/L). This work identified and addressed some of the technical bottlenecks in phytosterol-derived pathway reconstitution in the baker's yeast and opens up opportunities for efficient bioproduction and metabolic pathway elucidation of this group of phytochemicals.

A preliminary investigation into the unsaponifiable fraction of donkey milk: Sterols of animal origin, phytosterols, and tocopherols

We investigated the main sterols, phytosterols, and the α- and γ-tocopherol content in donkey milk during the first 2 mo of lactation. Cholesterol was the main sterol in milk (mean ± standard deviation = 0.97 ± 0.443 g/100 g of fat). Lanosterol was the main minor sterol of animal origin, followed by desmosterol (0.003 ± 0.001 and 0.001 ± 0.001 g/100 g of fat, respectively). Of the phytosterols, β-sitosterol was the main sterol of vegetal origin in donkey milk (0.005 ± 0.002 g/100 g of fat), but lower levels of campesterol, brassicasterol, and stigmasterol were also recorded. Mean levels of α- and γ-tocopherol were 0.01 ± 0.007 and 0.003 ± 0.001 g/100 g of fat, respectively. We observed no significant changes in sterol or tocopherol content during the first 2 mo of lactation. The presence of lanosterol in donkey milk is of particular interest, because lanosterol is a potential drug and has important physiological effects. The presence of phytosterols, which are considered nutraceutical molecules, enhances the nutritional quality of donkey milk fat for consumers.

Chemical and Physical Characterization of the Hackberry (Celtis australis) Seed Oil: Analysis of Tocopherols, Sterols, ECN and Fatty Acid Methyl Esters

For the very first time, the nutritional and physicochemical properties of the oil extracted from hackberry Celtis australis fruit were investigated with the aim of possible applications of such wild fruit oil. The physicochemical properties such as peroxide value, acidity, saponification, iodine value and total fat content of the extracted oil were examined extensively. The obtained results showed that peroxide value, acidity, saponification, iodine value and total fat content of the extracted oil were found to be 4.9 meq O₂/kg fat, 0.9 mg KOH/g fat, 193.6 mg KOH/g fat, 141.52 mg I₂/g fat and ~5%, respectively. The predominant fatty acid found in this wild fruit is linoleic acid which was calculated to be 73.38%±1.24. In addition, gamma-tocopherol (87%) and β-sitosterol (81.2%±1.08) were the major tocopherol and sterol compositions found in Celtis australis seed oil. Moreover, equivalent carbon number (ECN) analysis has indicated that the three linoleic acids are the main composition of the triacylglycerols extracted from Celtis australis. Also, the high value of omega 6 and β-sitosterol make this oil applicable in cosmetics and pharmaceutical applications.

A Randomized, Double-Blinded, Placebo-Controlled, Clinical Study of the Effects of a Nutraceutical Combination (LEVELIP DUO®) on LDL Cholesterol Levels and Lipid Pattern in Subjects with Sub-Optimal Blood Cholesterol Levels (NATCOL Study)

Phytosterols and red yeast rice are largely studied cholesterol-lowering nutraceuticals, respectively inhibiting the bowel absorption and liver synthesis of cholesterol. Our aim was to test the effect of combined nutraceutical-containing phytosterols and red yeast rice vs. a placebo on the lipid profile. We performed a parallel arms, double-blind, placebo-controlled clinical trial, randomizing 88 moderately hypercholesterolemic subjects to treatment with a combined nutraceutical containing phytosterols (800 mg) and red yeast rice, standardized to contain 5 mg of monacolins from Monascus purpureus, with added niacin (27 mg) and policosanols (10 mg) (LEVELIP DUO^®), or placebo. The mean LDL-Cholesterol (LDL-C) change at Week 8 was −32.5 ± 30.2 mg/dL (−19.8%) in the combined nutraceutical group and 2.5 ± 19.4 mg/dL (2.3%) in the placebo group. The estimated between-group difference of −39.2 mg/dL (95% CI: −48.6; −29.8) indicates a statistically significant difference between treatments in favor of the combined nutraceutical (p < 0.0001). Total Cholesterol (TC), non-HDL cholesterol (non-HDL-C), Apolipoprotein B, TC/HDL-C and LDL-C/HDL-C improved in a similar way in the combined nutraceutical group only. No significant changes in other clinical and laboratory parameters were observed. In conclusion, the tested combined nutraceutical was well tolerated, while significantly reducing the plasma levels of LDL-C, TC, non-HDL-C, ApoB, TC/HDL-C and LDL-C/HDL-C ratios in mildly hypercholesterolemic patients. Trial registration (ClinicalTrials.gov): NCT03739242.

Biosynthesis and Industrial Production of Androsteroids

Steroids are a group of organic compounds that include sex hormones, adrenal cortical hormones, sterols, and phytosterols. In mammals, steroid biosynthesis starts from cholesterol via multiple steps to the final steroid and occurs in the gonads, adrenal glands, and placenta. This highly regulated pathway involves several cytochrome P450, as well as different dehydrogenases and reductases. Steroids in mammals have also been associated with drug production. Steroid pharmaceuticals such as testosterone and progesterone represent the second largest category of marketed medical products. There heterologous production through microbial transformation of phytosterols has gained interest in the last couple of decades. Phytosterols being the plants sterols serve as inexpensive substrates for the production of steroid derivatives. Various genes and biochemical pathways involved in phytosterol degradation have been identified in many Rhodococcus and Mycobacterium species. Apart from an early investigation in mammals, presence of steroids such as androsteroids and progesterone has also been demonstrated in plants. Their main role is linked with growth, development, and reproduction. Even though plants share some chemical features with mammals, the biosynthesis is different, with the first C22 hydroxylation as an example. This is performed by CYP11A1 in mammals and CYP90B1 in plants. Moreover, the entire plant steroid biosynthesis is not fully elucidated. Knowing this pathway could provide new processes for the industrial biotechnological production of steroid hormones in plants.

The Role of Specific Components of a Plant-Based Diet in Management of Dyslipidemia and the Impact on Cardiovascular Risk

Convincing evidence supports the intake of specific food components, food groups, or whole dietary patterns to positively influence dyslipidemia and to lower risk of cardiovascular diseases (CVD). Specific macro- and micro-components of a predominantly plant-based dietary pattern are vegetable fats, dietary fibers, and phytonutrients such as phytosterols. This review summarizes the current knowledge regarding effects of these components on lowering blood lipids, i.e., low-density lipoprotein cholesterol (LDL-C) and on reducing CVD risk. The beneficial role of a plant-based diet on cardiovascular (CV) health has increasingly been recognized. Plant-based dietary patterns include a Mediterranean and Nordic diet pattern, the dietary approaches to stop hypertension (DASH), and Portfolio diet, as well as vegetarian- or vegan-type diet patterns. These diets have all been found to lower CVD-related risk factors like blood LDL-C, and observational study evidence supports their role in lowering CVD risk. These diet patterns are not only beneficial for dyslipidemia management and prevention of CVD but further contribute to reducing the impact of food choices on environmental degradation. Hence, the CV health benefits of a predominantly plant-based diet as a healthy and environmentally sustainable eating pattern are today recommended by many food-based dietary as well as clinical practice guidelines.

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).

Plasma Non-cholesterol Sterols as Markers of Cholesterol Synthesis and Intestinal Absorption: A Critical Review

Plasma concentrations of phytosterols and non-cholesterol sterol precursors of cholesterol synthesis have been used as markers of intestinal cholesterol absorption and synthesis in inherited and secondary dyslipidemias and in population-based investigations to evaluate the risk for cardiovascular disease, respectively. The method aims at replacing initial research procedures such as the use of stable isotopes associated with fecal steroid balance, which are limited by the high cost and tedious procedures. However, we show in this review that numerous results obtained with serum sterol measurements are contradictory. In this regard, the following points are discussed: 1) how phytosterols relate to atherosclerosis considering that defects in biliary output or in the transport of phytosterols from the intestinal mucosa back into the intestinal lumen provide increased content of phytosterols and other sterols in plasma and tissues, thus not allowing to conclude that their presence in arteries and atheromas represents the etiology of atherosclerosis; 2) serum non-cholesterol sterols as markers of cholesterol synthesis and absorption, such as cholestanol, present discrepant results, rendering them often inadequate to identify cases of coronary artery disease as well as alterations in the whole body cholesterol metabolism; 3) such methods of measurement of cholesterol metabolism are confounded by factors like diabetes mellitus, body weight and other pathologies including considerable hereditary hyperlipidemias biological variabilities that influence the efficiency of synthesis and intestinal absorption of cholesterol.

Nutraceutical nanodelivery; an insight into the bioaccessibility/bioavailability of different bioactive compounds loaded within nanocarriers

Nanofoods is a current concept that is based on the application of nanotechnologies in the preparation of safe foods, with superior nutritional and sensory characteristics, and capable of providing multiple health benefits. In line with the principles of this concept, food scientists have focused on developing new types of nano biosystems that can contribute to increasing the bioavailability of bioactive compounds used in food fortification. Numerous research teams have investigated the main factors limiting oral bioavailability including: bioaccessibility, absorption and transformation of bioactive compounds and bioactive-loaded nanocarriers. The physicochemical processes involved in the factors limiting oral bioavailability have been extensively studied, such asthe release, solubility and interaction of bioactive compounds and nanocarriers during food digestion, transport mechanisms of bioactive compounds and nanoparticles through intestinal epithelial cells as well as the chemical and biochemical transformations in phase I and phase II reactions. In this comprehensive review, the physicochemical processes involved in the bioaccessibility/bioavailability of different encapsulated bioactive compounds, that play an important role in human health, will be explained including polyphenols, phytosterols, carotenoids, vitamins and minerals. In particular, the mechanisms involved in the cellular uptake of bioactive-loaded nanocarriers including transcellular transport (diffusion, endocytosis, pinocytosis, transcytosis, phagocytosis), paracellular transport (through the "tight junctions" between epithelial cells), and the active transport of bioactive compounds under the action of membrane transporters are highlighted.

The Sterol Carrier Hydroxypropyl-β-Cyclodextrin Enhances the Metabolism of Phytosterols by Mycobacterium neoaurum

Androst-4-ene-3,17-dione (AD) and androst-1,4-diene-3,17-dione (ADD) are valuable steroid pharmaceutical intermediates obtained by soybean phytosterol biotransformation by Mycobacterium Cyclodextrins (CDs) are generally believed to be carriers for phytosterol delivery and can improve the production of AD and ADD due to their effects on steroid solubilization and alteration in cell wall permeability for steroids. To better understand the mechanisms of CD promotion, we performed proteomic quantification of the effects of hydroxypropyl-β-CD (HP-β-CD) on phytosterol metabolism in Mycobacterium neoaurum TCCC 11978 C2. Perturbations are observed in steroid catabolism and glucose metabolism by adding HP-β-CD in a phytosterol bioconversion system. AD and ADD, as metabolic products of phytosterol, are toxic to cells, with inhibited cell growth and biocatalytic activity. Treatment of mycobacteria with HP-β-CD relieves the inhibitory effect of AD(D) on the electron transfer chain and cell growth. These results demonstrate the positive relationship between HP-β-CD and phytosterol metabolism and give insight into the complex functions of CDs as mediators of the regulation of sterol metabolism.IMPORTANCE Phytosterols from soybean are low-cost by-products of soybean oil production and, owing to their good bioavailability in mycobacteria, are preferred as the substrates for steroid drug production via biotransformation by Mycobacterium However, the low level of production of steroid hormone drugs due to the low aqueous solubility (below 0.1 mmol/liter) of phytosterols limits the commercial use of sterol-transformed strains. To improve the bioconversion of steroids, cyclodextrins (CDs) are generally used as an effective carrier for the delivery of hydrophobic steroids to the bacterium. CDs improve the biotransformation of steroids due to their effects on steroid solubilization and alterations in cell wall permeability for steroids. However, studies have rarely reported the effects of CDs on cell metabolic pathways related to sterols. In this study, the effects of hydroxypropyl-β-CD (HP-β-CD) on the expression of enzymes related to steroid catabolic pathways in Mycobacterium neoaurum were systematically investigated. These findings will improve our understanding of the complex functions of CDs in the regulation of sterol metabolism and guide the application of CDs to sterol production.

Profiling of the lipophilic components of seed oils recovered from twelve Japanese quince (Chaenomeles japonica) genotypes

The seeds and oil yield and profile/levels of fatty acids, tocopherols and phytosterols in seed oils of twelve Japanese quince (Chaenomeles japonica) genotypes were studied. The seeds and oil yield ranged from 3.8 to 5.7% w/w fresh fruit, and 10.9 to 14.6% w/w dry weight seeds, respectively. The range of three predominated fatty acids C16:0, C18:1 and C18:2 in the seed oil of twelve Japanese quince genotypes were 8.1-9.8, 37.5-48.1, and 40.1-50.3%, respectively. α-Tocopherol and β-sitosterol were the main minor lipophilic compounds detected in all investigated genotypes. The percentage of predomination of α-tocopherol and β-sitosterol in each investigated genotype was very similar and amounted to 97-99% of total tocopherols and 76-80% of total phytosterols, respectively. The range of total content tocopherols and phytosterols in 12 genotypes of Japanese quince were 91.9-129.3 and 7830-14166 mg/100 g oil, respectively.

Flavonoids and other Non-alkaloidal Constituents of Genus Erythrina: Phytochemical Review

BACKGROUND

Genus Erythrina belongs to family Fabaceae, which is widely distributed in tropical and subtropical areas. It has been used in both traditional herbal medicines and pharmacological applications. Original research articles and publications on the overview of alkaloids related to this genus are available, but a supportive systematic review account which highlighted phytochemical aspects of other types of secondary metabolites is currently insufficient.

OBJECTIVE

With the utilization of data and information from SCI-Finder, Google Scholar, the Web of Science, Scopus, Science Direct, PubMed, Chemical Abstracts, ACS journals, Springer, Taylor Francis, Bentham Science and IOP Science, the reliable material sources of this systematic review paper were obtained from the literature published from the 1980s to now.

CONCLUSION

A vast amount of data showed that the non-alkaloidal secondary metabolites were obtained from genus Erythrina with various classes of chemical structures. Herein, approximately five hundred constituents were isolated, comprising flavonoids, terpenoids, saponins, phytosterols, phenols, arylbenzofurans, coumarins, alcohols, ceramides, mono-sugars and fatty acid derivatives. In agreement with the previous phytochemical reports on the plants of the family Fabaceae, flavonoids reached a high amount in the plants of genus Erythrina. Numerous biological activity investigations such as anti-bacteria, anti-cancer, anti-virus using isolated compounds from Erythrina species suggested that secondary metabolites of Erythrina plants are now becoming the promising agents for drug developments.

Safety of the extension of use of plant sterol esters as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of an extension of use of the novel food 'plant sterol esters' when added to vegetable fat spreads and to liquid vegetable fat-based emulsions for cooking and baking purposes pursuant to Regulation (EU) 2015/2283. Member States expressed concerns in relation to plant sterol oxidation products (POP) and consumption by non-target population groups. The median (0.5%) and P90 (2.28%) value of the oxidation rates of plant sterols determined by a wide range of cooking experiments were used together with exposure estimates for plant sterol when added and cooked with vegetable fat spreads and liquids. The no-observed adverse effect level (NOAEL) of a subchronic rat study and an applied default uncertainty factor of 200 served to derive levels (i.e. 0.64 mg POP/kg body weight (bw) per day) considered safe for humans. This safe level of exposure would be exceeded at the P95 by all age groups when considering the P90 oxidation rate and using EFSA's comprehensive food consumption database for assessing the potential exposure. When considering the median oxidation rate, the safe level of 0.64 mg POP/kg bw per day would be exceeded at the highest P95 intake estimates in children below 9 years of age. When considering an intake of the maximum authorised use level of 3 g plant sterols/person per day and oxidation rates of 0.5% and 2.28%, the resulting daily POP intakes per kg bw by an adult weighing 70 kg would be 0.21 and 0.98 mg/kg bw per day, respectively, the latter value exceeding 0.64 mg/kg bw per day. The Panel concludes that the safety of the intended extension of use of plant sterol esters under the proposed conditions of use has not been established.

Phytosterol, Lipid and Phenolic Composition, and Biological Activities of Guava Seed Oil

Plant seeds have been found to contain bioactive compounds that have potential nutraceutical benefits. Guava seeds (Psidium guajava) are by-products in the beverage and juice industry; however, they can be utilized for a variety of commercial purposes. This study was designed to analyze the phytochemicals of the n-hexane extract of guava seed oil (GSO), to study its free-radical scavenging activity, and to monitor the changes in serum lipids and fatty acid profiles in rats that were fed GSO. The GSO was analyzed for phytochemicals using chromatographic methods. It was also tested for free-radical scavenging activity in hepatoma and neuroblastoma cells, and analyzed in terms of serum lipids and fatty acids. GSO was found to contain phenolic compounds (e.g., chlorogenic acid and its derivatives) and phytosterols (e.g., stimasterol, β-sitosterol and campesterol), and exerted radical-scavenging activity in cell cultures in a concentration-dependent manner. Long-term consumption of GSO did not increase cholesterol and triglyceride levels in rat serum, but it tended to decrease serum fatty acid levels in a concentration-dependent manner. This is the first study to report on the lipid, phytosterol and phenolic compositions, antioxidant activity, and the hepato- and neuro-protection of hydrogen peroxide-induced oxidative stress levels in the GSO extract.

Brassicasterol with Dual Anti-Infective Properties against HSV-1 and Mycobacterium tuberculosis, and Cardiovascular Protective Effect: Nonclinical In Vitro and In Silico Assessments

While few studies have revealed the biological properties of brassicasterol, a phytosterol, against some biological and molecular targets, it is believed that there are still many activities yet to be studied. In this work, brassicasterol exerts a therapeutic utility in an in vitro setting against herpes simplex virus type 1 (HSV-1) and Mycobacterium tuberculosis (Mtb) as well as a considerable inhibitory property against human angiotensin-converting enzyme (ACE) that plays a dynamic role in regulating blood pressure. The antireplicative effect of brassicasterol against HSV-1 is remarkably detected (50% inhibitory concentration (IC₅₀): 1.2 µM; selectivity index (SI): 41.7), while the potency of its effect is ameliorated through the combination with standard acyclovir with proper SI (IC₅₀: 0.7 µM; SI: 71.4). Moreover, the capacity of this compound to induce an adequate level of antituberculosis activity against all Mtb strains examined (minimum inhibitory concentration values ranging from 1.9 to 2.4 µM) is revealed. The anti-ACE effect (12.3 µg/mL; 91.2% inhibition) is also ascertained. Molecular docking analyses propose that the mechanisms by which brassicasterol induces anti-HSV-1 and anti-Mtb might be related to inhibiting vital enzymes involved in HSV-1 replication and Mtb cell wall biosynthesis. In summary, the obtained results suggest that brassicasterol might be promising for future anti-HSV-1, antituberculosis, and anti-ACE drug design.

Phytosterols Supplementation Reduces Endothelin-1 Plasma Concentration in Moderately Hypercholesterolemic Individuals Independently of Their Cholesterol-Lowering Properties

Experimental and clinical studies have demonstrated the effect of phytosterols (PS) on reducing plasma levels of cholesterol and LDL-c, but the effects of plant sterols beyond cholesterol-lowering are still questionable. Since inflammation and endothelial dysfunction are involved in the pathogenesis of atherosclerosis, this study aims to evaluate the effect of PS on biomarkers involved in atherosclerosis progression and whether these effects are independent of alterations in plasma LDL-c levels. Thirty-eight moderately hypercholesterolemic volunteers (58 ± 12 years; LDL-c ≥ 130 mg/dL) were randomly assigned to consume 400 mL/day of soy milk or soy milk + PS (1.6 g/day) for 4 weeks in a double-blind, placebo-controlled, cross-over study. Blood samples were collected and lipid profiles and biomarkers for inflammation and endothelial dysfunction determined. The results showed that PS treatment reduced endothelin-1 plasma concentration by 11% (p = 0.02) independently of variations in plasma levels of LDL-c. No alterations were observed regarding fibrinogen, IL-6, hs-CRP, SAA, TNFα, or VCAM-1 between placebo and PS-treated groups. Furthermore, PS reduced total plasma cholesterol concentration (−5,5%, p < 0.001), LDL-c (−6.4%, p < 0.05), triglycerides (−8.3%, p < 0.05), and apo B (−5.3%, p < 0.05), without changing HDL-c concentration (p > 0.05). Therefore, PS supplementation effectively lowers endothelin-1 independently of the reductions in plasma levels of LDL-c, contributing to the comprehension of the effect of plant sterols on endothelial function and prevention of cardiovascular diseases.

Microencapsulation as a Tool for the Formulation of Functional Foods: The Phytosterols' Case Study

Hypercholesterolemia, which is an increase in total and low-density lipoprotein (LDL) serum cholesterol, is an important risk factor for the development of cardiovascular diseases. Lifestyle modifications underpin any action plan for reducing serum cholesterol. Phytosterols are natural compounds belonging to the triterpenes family. Thanks to their structural analogy with cholesterol, phytosterols have the ability to reduce serum LDL-cholesterol levels. Phytosterols are used to enrich or fortify a broad spectrum of food products. Like unsaturated fatty acids and cholesterol, phytosterols are easily oxidized. Microencapsulation could be a useful tool to overcome this and other drawbacks linked to the use of phytosterols in food fortification. In this review, in addition to explaining the phytosterols’ mechanisms of action, a focus on the use of free and encapsulated phytosterols for the formulation of functional foods, taking also into account both technological and legislative issues, is given.

Himalayan Nettle Girardinia diversifolia as a Candidate Ingredient for Pharmaceutical and Nutraceutical Applications-Phytochemical Analysis and In Vitro Bioassays

Girardinia diversifolia, also known as Himalayan nettle, is a perennial herb used in Nepal to make fiber as well as in traditional medicine for the treatment of several diseases. To date, phytochemical studies and biological assays on this plant are scarce. Thus, in the present work, the G. diversifolia extracts have been evaluated for their potential pharmaceutical, cosmetic and nutraceutical uses. For this purpose, detailed phytochemical analyses were performed, evidencing the presence of phytosterols, fatty acids, carotenoids, polyphenols and saponins. The most abundant secondary metabolites were β- and γ-sitosterol (11 and 9% dw, respectively), and trans syringin (0.5 mg/g) was the most abundant phenolic. Fatty acids with an abundant portion of unsaturated derivatives (linoleic and linolenic acid at 22.0 and 9.7 mg/g respectively), vitamin C (2.9 mg/g) and vitamin B2 (0.12 mg/g) were also present. The antioxidant activity was moderate while a significant ability to inhibit acetylcholinesterase (AChE), butyrilcholinesterase (BuChE), tyrosinase, α-amylase and α-glucosidase was observed. A cytotoxic effect was observed on human ovarian, pancreatic and hepatic cancer cell lines. The effect in hepatocarcinoma cells was associated to a downregulation of the low-density lipoprotein receptor (LDLR), a pivotal regulator of cellular cholesterol homeostasis. These data show the potential usefulness of this species for possible applications in pharmaceuticals, nutraceuticals and cosmetics.

Chemical composition, in vitro antioxidant and antibacterial activities of Centaurea resupinata subsp. dufourii (dostál) greuter

The current study focuses on the chemical composition, and evaluation of antioxidant and antibacterial activity of the aerial parts of Centaurea resupinata subsp. dufourii. Using different chromatographic methods nine compounds 1-9 were isolated. The structural identification of isolated compounds was achieved using several spectroscopic methods NMR techniques (¹H NMR, ¹³C NMR, COSY, HSQC, HMBC) and mass spectroscopy (ESI-MS) and by comparison with literature data. The structures of these compounds were identified as nicotiflorin (1), apigetrin (2), chrysoeriol (3), apigenin (4), chrysin (5), daucosterol (6), β-sitosterol (7), taraxastrerol (8) and lupeol (9). The antibacterial and antioxidant activities of ethyl acetate and n-butanol extracts have been evaluated. The antioxidant activity was assessed in vitro using DPPH radical scavenging method, which showed that ethyl acetate extract possessed an interesting antioxidant potential (IC₅₀ = 36.263 ± 0.005 μg/mL).

The effect of drying on the native tocopherol and phytosterol content of Sinapis alba L. seeds

BACKGROUND

Postharvest processing, including drying, has a significant effect on the processability of oil crop seeds. High drying air temperature may significantly affect the levels of bioactive compounds in plant raw materials. We decided to investigate the subject given the lack of data on the drying of mustard seeds. The aim was to determine the effect of drying temperature on free fatty acid, phytosterol and tocopherol levels in the oil obtained from white mustard seeds. Seeds were dried in a thin layer at 40, 60, 80, 100, 120 and 140 °C. Changes in phytosterol levels were assessed using gas chromatography-mass spectrometry and changes in tocopherol levels by high-performance liquid chromatography.

RESULTS

The analysis showed that, upon completion of air drying at 40-100 °C, losses of sterols did not exceed 5%, while upon completion of drying at 120 °C and 140 °C these losses amounted to 17-50%. Our investigation also showed that during drying of white mustard seed the total tocopherol levels increased, and the higher the drying temperature, the greater the increment. In seeds air-dried at 120 °C and 140 °C, the increase in tocopherol amounted to 7-9%.

CONCLUSION

We also showed that the temperature of the drying agent significantly affects the tocopherol and phytosterol levels. It was found that a maximum temperature of 100 °C provides optimal drying conditions for mustard seeds. Principal component analysis identified two subgroups of oils obtained from seeds dried at 120 °C and 140 °C, which differed considerably from the other samples in terms of their bioactive component contents. © 2019 Society of Chemical Industry.

Cho W, Martins N. Avocado-Soybean Unsaponifiables: A Panoply of Potentialities to Be Exploited

Avocado and soybean unsaponifiables (ASU) constitute vegetable extracts made from fruits and seeds of avocado and soybean oil. Characterized by its potent anti-inflammatory effects, this ASU mixture is recommended to act as an adjuvant treatment for osteoarthritic pain and slow-acting symptomatic treatment of hip and knee osteoarthritis; autoimmune diseases; diffuse scleroderma and scleroderma-like states (e.g., morphea, sclerodactyly, scleroderma in bands). Besides, it was reported that it can improve the mood and quality of life of postmenopausal women in reducing menopause-related symptoms. This article aims to summarize the studies on biological effects of the avocado-soybean unsaponifiable, its chemical composition, pharmacotherapy as well as applications in auto-immune, osteoarticular and menopausal disorders. Finally, we will also discuss on its safety, toxicological and regulatory practices.