Micellar Solubility Of Cholesterol Research Articles

Coffee pulp simulated digestion enhances its in vitro ability to decrease emulsification and digestion of fats, and attenuates lipid accumulation in HepG2 cell model

The coffee industry produces a considerable quantity of coffee pulp (CP), a by-product with high levels of caffeine, phenolic compounds, and dietary fiber, which are reportedly involved in the lipid homeostasis regulation required to maintain human health. This work's objective was to evaluate the hypolipidemic activity of coffee pulp flour (CPF) and aqueous extract (CPE) after static simulated digestion by the assessment of their in vitro capacity to decrease emulsification and digestion of fats, and lipid-lowering capacity in HepG2 cells after the induction of intracellular fat accumulation. The CPF and CPE digested fractions displayed in vitro hypolipidemic properties by preserving the reduction of micellar cholesterol solubility (27–34%) and the secondary bile acid-binding capacity (22–30%), increasing their primary bile acid-binding ability (2.7-fold and 2.4-fold, respectively), and inhibiting the lipase and the HMGCR (77–79% and 36–85%, respectively) activities. Moreover, the hypolipidemic properties of non-digested fractions enhanced the CPF potential to decrease lipid absorption. Both ingredients (CPF and CPE) demonstrated lipid-lowering effects since they effectively counteract the accumulation of intracellular triglycerides and cholesterol triggered by palmitic acid in hepatic cells after the simulated digestion. This study suggests that phenolic compounds, caffeine, and dietary fiber may be responsible for the lipid-lowering properties exhibited by the CP ingredients and their composition differences affect the above-mentioned properties exhibited in the simulated digestion. These results contribute to demonstrating that the CPF and the CPE may act as modulators of pathways involved in hepatic lipid accumulation and could be a key element in its prevention.

Ursolic Acid Inhibited Cholesterol Esterase and Pancreatic Lipase Activities and Decreased Micellar Cholesterol Solubility In Vitro

Ursolic acid (UA) is a natural triterpene carboxylic acid with an underlying anti-hyperlipidemia effect. This study examined the mechanism of interactions of UA with cholesterol esterase (CEase), pancreatic lipase (PL), and micellar cholesterol solubility in vitro. The half-maximal inhibitory concentration (IC50) of CEase, PL, and micellar cholesterol solubility was determined to be 0.07 ± 0.01 mg/mL, 1.81 ± 0.13 mg/mL, and 1.73 ± 0.08 mg/mL, respectively. Multispectral combination revealed that UA changed the secondary structure and quenched the intrinsic fluorescence by static quenching of the two enzymes. The interactions were exothermic reaction as determined by enthalpy. Furthermore, molecular docking confirmed that UA was bound to amino acids of two enzymes at active site through hydrophobic interaction and van der Waals forces. Molecular dynamics (MD) simulation found that CEase and PL rearranged with UA to form stable complexes. The strong inhibition effect of CEase and PL mediated by UA might provide additional insight into understanding the role of UA in the hypolipidemic effect.

Wheat Bran Protein Improves Lipid Metabolism by Downregulating the Amount of HMG-CoA Reductase in the Liver of High-Fat Diet-Fed Rats

Background. The hypolipidemic effects of wheat bran have been widely documented; however, limited research has concurrently revealed the hypolipidemic and antioxidant properties of wheat bran protein (WBP). Objective. This study investigates the impact of WBP (5% daily dietary intake) on antioxidant activity, cholesterol metabolism, and serum/hepatic lipids in high-fat diet-fed rats. Methodology. In our animal experiment, we used 12 male Wistar rats that were 4 weeks old. Biochemical indicators of fecal, serum, intestinal, and liver were tested by kits or chemical techniques. The experiment on cholesterol micellar solubility was also carried out in vitro. Results. After 28 days of feeding, the results revealed that WBP significantly reduced the levels of total cholesterol (P<0.05) in serum and liver, the levels of triglycerides (P<0.05), the levels of MDA (P<0.05), and the levels of very low-density lipoprotein and low-density lipoprotein (P<0.05), and significantly increased the levels of high-density lipoprotein (P<0.05), the levels of glutathione peroxidase, and the level of total antioxidant capability. By downregulating the level of sterol regulatory element-binding protein-2 (P<0.05), WBP also reduced the content of 3-hydroxy-3-methylglutaryl-coenzyme A (P<0.05). Conclusion. In vivo, WBP demonstrated a substantial hypolipidemic and antioxidant impact (P<0.05), while in vitro, it significantly decreased the micellar solubility of cholesterol (P<0.001).

Exploring the Nutritional, Antioxidant, and Lipid-Lowering Properties of Saba Banana (Musa acuminata x balbisiana BBB Group) Peels

This study investigated the nutritional and functional components of ‘saba’ banana peel (SBP) to determine its health-promoting potential for special food applications. SBP has undergone analyses measuring proximate composition, vitamin C, antioxidant activity, phytochemical content, estimated glycemic index (eGI), pancreatic lipase inhibition, and cholesterol micellar solubility inhibition. Data were processed using SPSS v20 and expressed as mean ± SD. Proximate analysis showed that SBP contained 83.83 ± 1.06% moisture, 6.74 ± 0.83% crude fat, 5.58 ± 0.24% crude protein, 9.97 ± 0.04% total ash, 9.91 ± 0.10% crude fiber, and 60.08% nitrogen-free extracts. Vitamin C content was found to be 72.15 ± 2.20 mg vitamin C/100 g fresh sample, whereas its antioxidant activity was 53.75 ± 1.29% DPPH inhibition. The eGI of SBP was 77.88 ± 1.42 and the phytochemical content analyses revealed that SBP contained total phenols at 135.61 ± 2.72 mg GAE, total flavonoids at 18.33 ± 0.65 mg catechin equivalent, and total tannins at 65.64 ± 1.97 mg quercetin equivalent. Finally, its pancreatic lipase inhibition was 35.34 ± 4.34%—almost 50% as effective as lipase inhibitor drug Orlistat. Its cholesterol micellar solubility inhibition was 71.40 ± 2.06%—almost 80% as effective as the cholesterol-lowering drug Cholestyramine. SBP had the highest phenolic content when compared with the published values of other fruit peels and far greater lipid-lowering enzyme inhibition effects than the healthy pigmented red and black rice varieties. These findings showed that SBP, which was considered as agricultural waste, contains nutritional properties and bioactive compounds, and can be utilized as food products and nutraceuticals with potentials in ameliorating obesity and associated disorders, providing banana farmers and processors additional revenue for their crops.

Pentapeptide IIAEK ameliorates cholesterol metabolism via the suppression of intestinal cholesterol absorption in mice.

Dietary protein-derived peptides are effective in improving dyslipidemia and hypercholesterolemia. We previously identified a novel cholesterol-lowering pentapeptide IIAEK from milk beta-lactoglobulin. However, it remains unclear whether IIAEK affects the micellar solubility of cholesterol and the bile acid-binding ability to lower cholesterol. Moreover, there is no direct evidence that IIAEK inhibits intestinal cholesterol absorption and affects hepatic cholesterol and fecal steroid excretion in vivo. Herein, we showed that IIAEK did not affect the micellar solubility of cholesterol and the bile acid-binding ability. However, we found that IIAEK decreased serum and liver cholesterol levels and increased fecal steroid excretion in mice. Interestingly, IIAEK markedly suppressed the intestinal absorption of [3H]-cholesterol in mice. In conclusion, we found that IIAEK ameliorated cholesterol metabolism by suppressing intestinal cholesterol absorption without affecting in vitro micellar solubility of cholesterol and the bile acid-binding ability in mice.

Chemical composition and anti-cholesterol activity of tea (Camellia sinensis) flowers from albino cultivars.

Albino tea cultivars are mutant tea plants with altered metabolisms. Current studies focus on the leaves while little is known about the flowers. To evaluate tea flowers from different albino cultivars, the chemical composition and anti-cholesterol activity of tea flowers from three albino cultivars (i.e., Baiye No.1, Huangjinya, and Yujinxiang) were compared. According to the results, tea flowers from Yujinxiang had more amino acids but less polyphenols than tea flowers from the other two albino cultivars. A reduced content of procyanidins and a high chakasaponins/floratheasaponins ratio were characteristics of tea flowers from Yujinxiang. In vitro anti-cholesterol activity assays revealed that tea flowers from Yujinxiang exhibited stronger activity in decreasing the micellar cholesterol solubility, but not in cholesterol esterase inhibition and bile salt binding. It was noteworthy that there were no specific differences on the chemical composition and anti-cholesterol activity between tea flowers from albino cultivars and from Jiukeng (a non-albino cultivar). These results increase our knowledges on tea flowers from different albino cultivars and help food manufacturers in the cultivar selection of tea flowers for use.

Impact of molecular interactions between hydrophilic phytosterol glycosyl derivatives and bile salts on the micellar solubility of cholesterol

Hydrophilic phytosterol glycosyl derivatives are synthetic phytosterol analogues by coupling with the glycosyl moiety to improve the water solubility and bioaccessibility of free phytosterols. The aim of this study is to clarify the molecular interaction of phytosterol glycosyl derivatives with bile salts and the consequent impact on cholesterol solubilization. Sharp nonlinear decrease in the micellar solubility of cholesterol and accompanying changes in particle size, zeta potential and microtopography of mixed micelles were observed when phytosterol glycosyl derivatives were introduced in cholesterol-loaded bile salt micelles. These results suggested that β-sitosterol glycosyl derivatives molecules indeed participated in the formation of mixed micelles. Further, nuclear magnetic resonance showed that the structural change of mixed micelles was caused by the insertion of β-sitosterol glycosyl derivatives via hydrogen bonds with sodium taurocholate, which resulted in the low cholesterol solubilization. Moreover, the hydrogen-bond interactions were apparently influenced by the glycosyl moiety of β-sitosterol glycosyl derivatives. These molecular mechanisms may contribute to the development of cholesterol-absorption inhibitors.

Effect of Phenolic Compounds from Cymbopogon citratus (DC) Stapf. Leaves on Micellar Solubility of Cholesterol.

Dyslipidemias are one of the risk factors for cardiovascular diseases, the leading cause of death and hospitalization worldwide. One way to control cholesterol levels is to control the exogenous cholesterol intake in the body. Natural polyphenolic compounds, namely theaflavins from plant extracts such as black tea, showed the ability to inhibit the formation of the micellar structure, essential for the absorption of cholesterol in the intestine. There are several methodologies to determine this effect, many of which are expensive and time-consuming. Due to these facts, the main purposes of this work were to optimize an inexpensive colorimetric method to study, in vitro, the micellar solubility of cholesterol and applied it to plant extracts. In this work, Cymbopogon citratus leaf extracts, its phenolic fractions, and flavonoids were evaluated. The non-delipidified infusion (CcI) obtained a maximum percentage of micelle destruction of 59.22% for a concentration of 50 μg/mL and the delipidified infusion (CcdI) obtained a maximum percentage of micelle destruction of 58.01% for a concentration of 200 μg/mL. In the case of the fraction of phenolic acids (CcPAs), 23.85% of maximum micellar destruction was recorded for the concentration of 100 μg/mL, while for the fraction of flavonoids (CcF), the micellar destruction was 92.74% at 1 μg/mL, and for the tannin fraction (CcT) of 99.45% at 25 μg/mL. Luteolin presented a percentage of micelle destruction of 94.83% in the concentration of 1 ng/mL, followed by luteolin-7-O-glucoside with 93.71% and luteo-lin-6-C-glucoside with 91.26% at the concentrations of 25 ng/mL and 50 ng/mL, respectively. These results suggest the capability of polyphenols from Cymbopogon citratus to prevent the cholesterol absorption in the gut by micellar destruction, and its contribution for cholesterol-lowering activity.

Insight into structural characteristics of theabrownin from Pingwu Fuzhuan brick tea and its hypolipidemic activity based on the in vivo zebrafish and in vitro lipid digestion and absorption models

Fuzhuan brick tea (FBT) is a post-fermented dark tea preferred by consumers for its excellent hypolipidemic activity, and theabrownin (TB) is the main bioactive composition in FBT. This work explored the structural and hypolipidemic properties of TB derived from Pingwu FBT, and investigated whether it exerted hypolipidemic activity by inhibiting intestinal lipid absorption. Structural characterization revealed that TB was an amorphous polymerized phenolic compound rich in hydroxyl and carboxyl groups with good thermostability. In vivo, TB and its fractions with different molecular weights (TB-LT3k, TB-3-10k, TB-10-30k, TB-30-100k, TB-GT100k) significantly reduced the lipid levels of hyperlipidemia zebrafish (P < 0.05). Moreover, TB attenuated hyperlipidemia by inhibiting intestinal lipid absorption, as TB effectively bound to bile acids, inhibited enzymatic activity of pancreatic lipase and cholesterol esterase, influenced micelle formation, and decreased micellar cholesterol solubility. Results facilitated research on TB and offered support for its feasibility as a natural alternative to prevent hyperlipidemia.

The Hypolipidemic and Antioxidant Activity of Wheat Germ and Wheat Germ Protein in High-Fat Diet-Induced Rats.

Background: So far, no articles have discussed the hypolipidemic effect of wheat germ protein in in vivo experiments. Objective: In this study, we investigated the effects of wheat germ protein (WGP, 300 mg/kg/day) and wheat germ (WG, 300 mg/kg/day) on cholesterol metabolism, antioxidant activities, and serum and hepatic lipids in rats fed a high-fat diet through gavage. Methodology: We used 4-week-old male Wistar 20 rats in our animal experiment. Biochemical indicators of fecal, serum and liver were tested by kits or chemical methods. We also conducted the cholesterol micellar solubility experiment in vitro. Results: After 28 days of treatment, our results showed that WGP significantly reduced the serum levels of total cholesterol (p < 0.05) and nonhigh-density lipoprotein cholesterol (p < 0.05), improved the enzymatic activities of cholesterol 7-α hydroxylase (p < 0.01) and low-density lipoprotein receptor (p < 0.01) and increased bile acid excretion in feces (p < 0.05). Conclusion: WG did not significantly increase bile acid excretion in feces or decrease serum levels of total cholesterol. Moreover, WGP and WG both presented significant antioxidant activity in vivo (p < 0.05) and caused a significant reduction in cholesterol micellar solubility in vitro (p < 0.001). Therefore, WGP may effectively prevent hyperlipidemia and its complications as WGP treatment enhanced antioxidant activity, decreased the concentration of serum lipids and improved the activity of enzymes involved in cholesterol metabolism.

Mild preheating improves cholesterol-lowering benefits of soy protein via enhancing hydrophobicity of its gastrointestinal digests: An in vitro study

Although the cholesterol-lowering benefits of soy proteins have been well recognized for a long time, the importance of protein structural characteristics to their cholesterol-lowering activities is little understood. In the work, we reported that a mild preheating at 95 °C for 20 min could remarkably improve the cholesterol-lowering activities of soy protein isolate (SPI) after an in vitro simulated pepsin-pancreatin digestion, including cholesterol and bile acids binding capacities (CBC and BBC), and inhibition of micellar cholesterol solubility (MCI), while an extensive preheating at 121 °C contrarily impaired its potential. The improvement of the cholesterol-lowering activities of the pepsin-pancreatin digest by the mild preheating was largely associated with the facilitated formation of digestion-induced peptide aggregates with high surface hydrophobicity (Ho) in the digest. The final pepsin-pancreatin digest of the mildly preheated SPI could be fractionated using a gradient ethanol precipitation technique at ethanol concentrations of 20–80% (v/v). The Ho and cholesterol-lowering activities of peptides in the resultant precipitate or supernatant fractions considerably varied. The ethanol-precipitated fractions at ethanol concentrations of 40–80%, with high Ho but low solubility (in water), largely contributed to the CBC of the digest, while all the precipitates obtained at ethanol concentrations of 20–80% dominated the BBC of the digest. In contrast, the soluble peptides in 80% ethanol were mainly responsible for the high potential of the digest to inhibit micellar cholesterol solubilization. In general, a good positive relationship between the CBC (or BBC) and Ho could be well observed for the pepsin-pancreatin digests of SPI, or their fractions. The MCI of the mildly preheated SPI digest was largely ascribed to the action of soluble peptides in 80% ethanol. The results demonstrated that the choice of preheating conditions (especially temperature) is of vital importance for optimal cholesterol-lowering benefits of soy proteins. The findings are also of interest for understanding the molecular mechanisms of the cholesterol-lowering activities of soy proteins.

Elevated CO2 improves the nutritive value, antibacterial, anti-inflammatory, antioxidant and hypocholestecolemic activities of lemongrass sprouts

Sprouts have been regarded as a big store for bioactive compounds with a wide range of biological activities. Elevated CO2 (eCO2, 620 μmol mol−1)was employed to enhance the nutritive and health promoting values of sprouts of two species of lemongrass, i.e. Cymbopogon citratus and Cymbopogon proximus. eCO2 improved the biomass production of sprouts, and their levels of primary metabolites e.g., amino acids and oils and active secondary metabolites e.g., phenolic compounds. As a result, eCO2 increased total antioxidant capacity, cytotoxicity against several human cancer cell lines, and antibacterial activities of Cymbopogon sprouts. We also recorded a significant increase in hypocholesterolaemic potential and anti-inflammatory activities of eCO2-treated sprouts, as indicated by inhibition of cholesterol micellar solubility and pancreatic lipase activity, as well as lipoxygenase and cyclooxygenase activities, respectively. Thus, the present investigation supports the use of eCO2 as a promising approach to produce lemongrass sprouts with effective phytochemicals and enhanced biological activities.

In vitro lipid-lowering properties of the fruits of two bignay [Antidesma bunius (L.) Spreng] cultivars as affected by maturity stage and thermal processing

Bignay [Antidesma bunius (L). Spreng] fruit contains an array of polyphenols and information on how these bioactive compounds vary with cultivar type, maturity stage, and process treatment are unclear. Also, the effects of these variations on the lipid-lowering potential of this Philippine indigenous berry have not been reported. This study aimed to evaluate the lipid-lowering properties of the fruits of two bignay cultivars as affected by maturity stage and thermal processing. In vitro lipid-lowering assays revealed that both bignay cultivars had appreciable pancreatic lipase inhibitory activity, bile acid binding capacity, and cholesterol micellar solubility inhibition, which were comparable to those of the known lipid-lowering agents used as positive controls in this study. Freeze-dried samples of the freshly harvested fruits of both bignay cultivars [i.e., Common Cultivar (CC) and Kalabaw cultivar (KC)] had the highest bile acid binding activity (41.9–45.5% for CC and 43.4–54.0% for KC) for all the three maturity stages implying the beneficial effects of fresh bignay fruits related to lipid metabolism. Steam-blanched fruits had the highest pancreatic lipase inhibition activity (17.8–37.4% for CC and 29.2–39.0% for KC), regardless of maturity stage, while water-blanched samples exhibited the highest cholesterol micellar solubility inhibition (39.6–42.2% for CC and 40.2–47.6% for KC). Thermal processing tended to lower the lipid-lowering properties of the bignay fruits relative to their freeze-dried fresh fruits. Results of this study showed the potential of Philippine bignay fruit as a functional food that may be helpful in the management of dyslipidemia.

Laser Light Treatment of Seeds for Improving the Biomass Photosynthesis, Chemical Composition and Biological Activities of Lemongrass Sprouts

Compared to seeds and mature plants, sprouts are well characterized based on their nutritive values and biological properties. Moreover, laser light application is known to be a promising approach to improving plant growth, photosynthesis, and nutraceutical values. However, no studies have investigated the phytochemicals and biological activity of lemongrass (Cymbopogon proximus (Hochst. ex A.Rich.) Chiov.) sprouts or the further improvement of their quality by applying laser light treatment. We carried out a preliminary experiment for the optimization of laser treatment conditions, finding that a helium neon (He–Ne) laser at 632 nm and 5 mW for 5 min provided the most favorable conditions. We then investigated fresh weight, photosynthetic reactions, and primary and secondary metabolites, including sugars, amino acids, organic acids, essential oils, and phenolic compounds. Moreover, we studied the effect of laser light-induced changes in chemical compositions on the antioxidant, anti-diabetic, and anti-cholesterol activities of Cymbopogon proximus sprouts grown from laser-treated seeds. Laser light treatment increased the photosynthesis and respiration and hence the fresh weight of Cymbopogon proximus sprouts. Overall, sprouting increased most bioactive primary and secondary metabolites as compared to seeds. Increased photosynthesis by laser light improved carbon allocation and raised non-structural carbohydrates, which in turn led to improved synthesis of amino acids, organic acids, and essential oils, as well as phenolic and flavonoid compounds. As a result, laser light significantly improved the antioxidant capacity in terms of increasing the levels of ferric reducing antioxidant power (FRAP) (from 9.5 to 21 µmole trolox/g fresh weight (FW)), oxygen radical absorbance (ORAC) (from 400 to 1100 µmole trolox/100 g FW), and DPPH (from 5% to 25% of inhibation) and enhanced the hypocholesterolemic and antidiabetic activity through increasing the percentage of cholesterol micellar solubility (CMS) inhibition (from 42% to 62%) and glycemic index (from 33 to 17 µmole/g) over sprouts and seeds. In conclusion, the synergism of seed laser treatment and sprouting induced the health-promoting bioactive compounds in Cymbopogon proximus as compared to seeds, which can be applied at a large scale to improve the biochemical, physiological, and nutraceutical values of medicinal and crop sprouts.

Phenolic compounds from an Algerian medicinal plant (Pallenis spinosa): simulated gastrointestinal digestion, characterization, and biological and enzymatic activities.

Pallenis spinosa is a medicinal plant which is used in folk medicine as curative or preventive remedies for various diseases. Individual phenolic compounds from the methanolic extracts of its flowers, leaves and stem were determined by the high performance liquid chromatography method (HPLC) and total phenolic contents (TPC) were evaluated by Folin-Ciocalteu assay. The stability and bioactivity (antioxidant activity, micellar cholesterol solubility, α-amylase, and angiotensin converting enzymes (ACE) inhibitory effects) of these extracts in the gastrointestinal environment was determined before and after their protection in hydroxypropylmethylcellulose (HPMC) capsules. HPLC analysis revealed the presence of thirteen phenolic compounds with nine flavonoids and four phenolic acids. Except for kaempferol, the twelve other compounds have not been previously detected in the aerial part of the studied plant. Quantification of phenolics by HPLC and Folin Ciocalteu methods revealed that the highest TPC was detected in the flower extracts (104.31 ± 0.80 and 145.73 ± 0.48 mg EGA per g of extract, respectively). Leaf extracts displayed the best antioxidant capacity against the two tested radicals DPPH and ABTS (IC50 = 1.24 ± 0.03 and 0.94 ± 0.02 mg mL-1, respectively), FRAP assay (IC50 = 0.50 ± 0.02 mg mL-1), α-amylase inhibitory (IC50 = 1.25 ± 0.00 mg mL-1) and angiotensin activity with an inhibitory percent of 30.10 ± 0.12%. The best activity shown by stem extracts was against micellar cholesterol solubility (67.57 ± 0.00%). A strong decrease in TPC and their bioactivity was observed after the gastrointestinal digestion (GID) in non encapsulated extracts. These results showed that P. spinosa is a good source of phenolic compounds and GID affects significantly their composition, content and bioactivity.

Phenolic acids from Coffea arabica L. suppress intestinal uptake of glucose and cholesterol.

The This study assessed the hypoglycaemic and hypocholesterolaemic effects of coffee fruit extracts and their active compounds involved in cholesterol and glucose uptake, as well as the inhibitory activity of α-glucosidase and α-amylase, the physiochemical changes of cholesterol micelles, and the uptake of glucose and cholesterol in Caco-2 cells. The results revealed that coffee green dry (CGD) coffee yellow dry (CYD), and coffee red bean dry (CRBD) extracts inhibited α-amylase activity by approximately 49% whereas caffeine and caffeic acid, showed high potency to inhibit α-amylase activity by 94.49% and 93.35%, respectively. In addition, coffee red pulps dry (CRPD) and citric acid inhibited αglucosidase by 29% and 46%, respectively. The extracts (1 mg/mL) and their active compounds (200 µM) inhibited glucose uptake in Caco-2 cells. All coffee fruit extracts inhibited cholesterol uptake in Caco-2 cells by approximately 40%, and they decreased the micellar solubility of cholesterol, except for coffee red fresh (CRF) and coffee red dry (CRD). Moreover, CYD strongly increased the size of cholesterol micelles. These findings demonstrate the potential effect of coffee extracts on anti-diabetic activity and their cholesterol-lowering activity according to the inhibitory activity of α-glucosidase and α-amylase and the uptake of glucose and cholesterol in Caco-2 cells.

Recovery and determination of cholesterol-lowering compounds from Olea europaea seeds employing pressurized liquid extraction and gas chromatography-mass spectrometry

Our previous work demonstrated the presence of compounds with hypocholesterolemic capacity in olive seeds. These compounds were extracted using CO2-expanded ethyl acetate and identified as tyrosol, hydroxytyrosol, and β-sitosterol using GC–MS. This work describes the extraction of these compounds from different olive seeds using pressurized ethyl acetate. Their solubility in ethyl acetate at temperatures ranging from 40–200 °C was theoretically predicted by Hansen solubility parameters. The content of these compounds was estimated by GC–MS, as well as, the reduction of the micellar cholesterol solubility (RMCS) capacity of extracts enabling to establish the optimum extraction temperature at 100 °C. A GC–MS method was developed and validated in terms of its analytical characteristics for a sensitive determination and quantification of tyrosol, hydroxytyrosol, and β-sitosterol in different olive seeds. Within varieties, Manzanilla seeds presented the highest concentration of tyrosol, hydroxytyrosol, and the lowest concentration of β-sitosterol, as well as the highest RMCS capacity.

Novel milk casein–derived peptides decrease cholesterol micellar solubility and cholesterol intestinal absorption in Caco-2 cells

This study sought to assess the cholesterol-lowering activity of peptides obtained from milk casein hydrolyzed with neutrase. The bioactive peptides were separated using a Sephadex G-10 chromatographic column (Amersham Pharmacia Biotech, Uppsala, Sweden) after ultrafiltration using a 1-kDa molecular mass cutoff membrane. Via ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry, we determined that peptides Thr-Asp-Val-Glu-Asn [TDVEN; β-casein f(143-147)], Leu-Gln-Pro-Glu [LQPE; β-casein f(103-106)], Val-Ala-Pro-Phe-Pro-Glu [VAPFPE; αS1-casein f(40-45)], and Val-Leu-Pro-Val-Pro-Gln [VLPVPQ β-casein f(185-190)] reduced micellar cholesterol solubility. After Caco-2 cells were treated with LQPE, VLPVPQ, and VAPFPE, the Niemann-Pick C1-Like 1 (NPC1L1) protein levels decreased by (means ± SEM) 19.33 ± 2.47%, 52.1 ± 3.77%, and 23.09 ± 8.52%, respectively, compared with the control group. Treatment with each peptide induced significant upregulation of ATP binding cassette subfamily G member 8 antibody (ABCG8) mRNA expression by 398.1 ± 23.27%, 86.4 ± 27.07%, and 92.8 ± 8.49%. We found that VLPVPQ and LQPE significantly upregulated ATP-binding cassette transporter A1 (ABCA1) transcription by 203.9 ± 8.44% and 220.8 ± 36.42% respectively, whereas VLPVPQ significantly decreased mRNA expression of acetyl-CoA-acetyltransferase 2 (ACAT2) and microsomal triacylglycerols (MTP). The cholesterol-lowering action of milk-derived peptides may be induced by suppression of micellar cholesterol solubility and affects the expression of cholesterol absorption-related proteins and enzymes in intestinal epithelial cells. This research discovers new milk-derived peptides with decreasing cholesterol micellar solubility and provides a theoretical basis of in vitro cholesterol-lowering effects of peptides.

Use of Plant Sterol and Stanol Fortified Foods in Clinical Practice.

Plant sterols and stanols (PS) are natural, non-nutritive molecules that play a structural role in plant membranes similar to that of cholesterol in animal membranes and abound in seeds and derived oils. PS exert their physical effect of interference with micellar solubilization of cholesterol within the intestinal lumen and are marginally absorbed by enterocytes, with negiglible increases in circulating levels. The physiological role of PS in plants and their natural origin and non-systemic action, together with their cholesterol-lowering effect, make them an attractive option as non-pharmacological agents for the management of hypercholesterolemia. Recent meta-analyses have summarized the results of >100 controlled clinical trials and have firmly established that the consumption of PS-supplemented foods in different formats at doses of 2-3 g per day results in LDL-cholesterol reductions of 9-12%. PS are both effective and safe cholesterol-lowering agents and have many clinical applications: adjuncts to a healthy diet, treatment of common hypercholesterolemia, combination therapy with statins and other lipid-lowering drugs, and treatment of metabolic syndrome and diabetes. The cholesterol-lowering efficacy is similar in all clinical situations. PS are also useful agents for treatment of hypercholesterolemic children who are not yet candidates to statins or receive low-doses of these agents. In the setting of statin treatment, the average LDL-cholesterol reduction obtained with PS is equivalent to up- titrating twice the statin dose. However, information is still scarce on the efficacy of PS as an add-on therapy to ezetimibe, fibrates, omega- 3 fatty acids, or bile acid binding resins. The consistent scientific evidence on the cholesterollowering efficacy and safety of functional foods supplemented with PS has led several national and international scientific societies to endorse their use for the non-pharmacologic treatment of hypercholesterolemia as adjuncts to a healthy diet. There is, however, a lack of clinical trials of PS with outcomes on cardiovascular events.

Studies on Riceberry rice (Oryza sativa L.) extract on the key steps related to carbohydrate and lipid digestion and absorption: A new source of natural bioactive substances

Riceberry rice (Oryza sativa L.), a new cross-breed from Hom Nin rice, a local non-glutinous purple rice, and Khoa Dawk Mali 105. The present study systematically assessed the effect of Riceberry rice extract (RBE) on the inhibition of key steps of carbohydrate and lipid digestion and absorption. The main anthocyanin identified in RBE was cyanidin-3-O-glucoside and peonidin-3-O-glucoside. In the step of carbohydrate digestion and absorption, RBE markedly inhibited intestinal maltase and sucrase. Kinetic analysis demonstrated that RBE was a mix-type competitive inhibitor against intestinal maltase. In Caco-2 cells, RBE had no effect on inhibition of glucose uptake but it could suppress mRNA expression of SGLT1. The results showed that RBE caused the reduction of lipid digestion and absorption by inhibiting pancreatic lipase, decreasing the micellar cholesterol solubility and binding of bile acid. Moreover, RBE showed non-competitive inhibition toward pancreatic lipase activity. In Caco-2 cells, RBE exhibited a significant reduction in cholesterol uptake and suppressed mRNA expression of NPC1L1 transporter. These findings provide important evidence that Riceberry rice may be a potential natural source for inhibiting the key steps of carbohydrate and lipid digestion and absorption.