Sterol bioaccessibility in a plant sterol-enriched beverage using the INFOGEST digestion method: Influence of gastric lipase, bile salts and cholesterol esterase.

This study evaluates the influence of increasing bile salts and the addition of key enzymes of the lipidic metabolism in the INFOGEST digestion method on sterol bioaccessibility from a plant sterol (PS)-enriched beverage. The assayed modifications were increasing concentration of bovine bile salts (10 vs. 17.5 mM), and addition of gastric lipase (GL) (60U/mL), cholesterol esterase (CE) (0.075 or 2U/mL) or both. Compared to the original method (10 mM bile salts without enzymes), the assayed conditions significantly reduced bioaccessibility of individual (from 11.3 to 19.7 to 5.1-16.6%) and total PS (13.7 to 6.9-8.0%), and cholesterol (52.8 to 20.9-26.1%), except only when CE is added not allowing cholesterol quantification. The bioaccessibility achieved when lipolytic enzymes were tested was similar for all sterols. For a more physiological approach to in vivo conditions, incorporation of bile salts (10 mM), GL (60U/mL) and CE (0.075U/mL) to the INFOGEST method is proposed, although it increases the cost compared to the established method.

Hypercholesterolemic patients have higher eryptosis and erythrocyte adhesion to human endothelium independently of statin therapy.

BACKGROUND: Phosphatidylserine (PS) externalization out of the membrane facilitates the eryptotic erythrocytes (EE) binding to endothelial cells (EC), potentially leading to atherosclerosis. Thus, the levels of eryptosis and interactions of EE-EC in hypercholesterolemic patients, either non-medicated or medicated, compared with healthy subjects were studied. METHODS: A total of 56 subjects clustered into three groups: (control (n = 20), hypercholesterolemic non-treated (HCNT) (n = 15), and statin-treated (HCT) (n = 21)) were enrolled in this cross-sectional study. Biochemical parameters were determined with validated and standard methods. PS exposure was estimated from annexin-V-binding, cell volume from forward scatter (FSC), and GSH from CMFDA fluorescence by flow cytometry. The erythrocyte-EC adhesion assay was performed by using the parallel-plate flow chamber technique. RESULTS: Higher PS externalization and adhesion of erythrocytes to EC (P < .05) was found in hypercholesterolemic subjects, regardless of statin treatment, compared with the control group. Although no correlation between FSC and PS externalization with other parameters was found, GSH was inversely correlated with erythrocyte adhesion, which was significantly correlated with total cholesterol, LDL-c, and apolipoprotein B. CONCLUSION: The link between hypercholesterolemia and eryptosis suggests a possible detrimental impact of this binomial on endothelial function with possible further development of atherosclerosis and microcirculation problems in hypercholesterolemic patients, independently of statin therapy.

Bovine plasma hydrolysates' iron chelating capacity and its potentiating effect on ferritin synthesis in Caco-2 cells.

The low bioavailability of iron is one factor that contributes to its deficiency in the human diet. For this reason, it is necessary to find compounds that can form iron chelates so that these can be added to foods that contain iron to improve its bioavailability at the intracellular level. In this study, we assessed the relationship between bovine plasma hydrolysates' iron chelating ability and their degree of hydrolysis. The hydrolysate with the highest chelating capacity was fractionated and each fraction's chelating capacity was subsequently assessed. Each fraction's effect on ferritin synthesis in Caco-2 cells was also determined. The results showed that bovine plasma hydrolysates with a degree of hydrolysis of 19.1% have an iron chelating capacity of 38.5 ± 0.4% and increase the synthesis of ferritin in Caco-2 cells five-fold compared to the control. This may be due to the fact that these hydrolysates contain amino acids such as Leu, Lys, Glu, Ala, Asp, Val, Thr, Cys and Phe, which may be responsible for binding iron to the hydrolysate, increasing its solubility and the consequent uptake by Caco-2 cells.

Optimization of the Red Tilapia (Oreochromis spp.) Viscera Hydrolysis for Obtaining Iron-Binding Peptides and Evaluation of In Vitro Iron Bioavailability.

Iron deficiencies continue to cause significant health problems in vulnerable populations. A good strategy to combat mineral deficiency includes fortification with iron-binding peptides. This research aims to determine the optimal conditions to hydrolyze red tilapia viscera (RTV) using Alcalase 2.4 L and recovery of iron-binding protein hydrolysate. The result showed that under the optimal hydrolysis condition including pH 10, 60 °C, E/S ratio of 0.306 U/g protein, and substrate concentration of 8 g protein/L, the obtained hydrolysate with 42.5% degree of hydrolysis (RTVH-B), displayed the maximal iron-binding capacity of 67.1 ± 1.9%. Peptide fractionation was performed using ultrafiltration and the <1 kDa fraction (FRTVH-V) expressed the highest iron-binding capacity of 95.8 ± 1.5%. Iron content of RTVH-B and its fraction was assessed, whereas iron uptake was measured indirectly as ferritin synthesis in a Caco-2 cell model and the result showed that bioavailability of bound minerals from protein complexes was significantly higher (p < 0.05) than iron salt in its free form, increased 4.7 times for the Fe2+-RTVH-B complex. This research suggests a potential application of RTVH-B as dietary supplements to improve iron absorption.

Antiproliferative Effect of Bioaccessible Fractions of Four Brassicaceae Microgreens on Human Colon Cancer Cells Linked to Their Phytochemical Composition.

The antiproliferative effect of the bioaccessible fractions (BFs) of four hydroponic Brassicaceae microgreens (broccoli, kale, mustard and radish) was evaluated on colon cancer Caco-2 cells vs. normal colon CCD18-Co cells after 24 h treatment with BFs diluted 1:10 v/v in cell culture medium. Their bioactivity was compared with the digestion blank, while the colon cancer chemotherapeutic drug 5-fluorouracil was used as a positive control. Cell viability (mitochondrial enzyme activity assay (MTT test) and Trypan blue test) and mechanisms related to antiproliferative activity (cell cycle, apoptosis/necrosis, mitochondrial membrane potential, reactive oxygen species (ROS) production, Ca2+ and glutathione (GSH) intracellular content) were studied. All microgreen BFs increased ROS and decreased GSH, altering the redox status and causing mitochondrial membrane dissipation followed by a general cell cycle arrest in G2/M and apoptotic cell death via a Ca2+-independent mechanism. As a result, the antioxidant bioactive compounds present in these microgreen species reduced the proliferation of tumoral cells (10 to 12.8% -MTT or 20 to 41.9% -Trypan blue), showing lesser effects with broccoli microgreens, in line with their lower ascorbic acid content and total antioxidant capacity. Therefore, the daily intake of microgreens within a balanced diet could be a preventive nutritional strategy to reduce the burden of chronic degenerative diseases such as colon cancer.

Anti-Inflammatory and Cytoprotective Effect of Plant Sterol and Galactooligosaccharides-Enriched Beverages in Caco-2 Cells.

Plant sterol (PS) (1 g/100 mL) enriched milk-based fruit beverages with or without galactooligosaccharides (GOS) (1.8 g/100 mL) were used in differentiated Caco-2 cells. Their potential cytopreventive effect against oxidative stress induced by cholesterol oxidation products (COPs) and their anti-inflammatory properties were evaluated. Preincubation (24 h) with bioaccessible fractions from beverages without and with GOS (MfB and MfB-G) completely prevented the COPs (60 µM/4 h) induced oxidative stress independent to GOS presence with exception to calcium influx and GSH content, where a partial protective effect was observed. Besides, MfB produced a significant (p < 0.05) reduction of IL-8 (40%) and IL-6 (50%) after IL-1ß-induction (1 ng/mL/24 h) through the inhibition of NF-κB p65 translocation into the nucleus (16%) compared to control cells, while GOS presence compromised their anti-inflammatory effect. Therefore, PS-enriched milk-based fruit beverage could be an interesting strategy to prevent intestinal injury produced by COPs and to attenuate the pro-inflammatory process in intestinal human diseases. GOS addition had no extra beneficial antioxidant effect and even reduced their anti-inflammatory properties.

Evaluation of the Bioaccessibility of Antioxidant Bioactive Compounds and Minerals of Four Genotypes of Brassicaceae Microgreens.

Microgreens constitute an emerging class of fresh, healthy foods due to their nutritional composition. In this study the content of minerals and antioxidant bioactive compounds, and for the first time bioaccessibility, were evaluated in broccoli (Brassica oleracea L. var. italica Plenck), green curly kale (Brassica oleracea var. sabellica L.), red mustard (Brassica juncea (L.) Czern.) and radish (Raphanus sativus L.) hydroponic microgreens. Macro- (K, Ca, Mg) and oligo-elements (Fe, Zn), ascorbic acid, total soluble polyphenols, total carotenoids, total anthocyanins, total isothiocyanates and total antioxidant capacity (Trolox Equivalent Antioxidant Capacity and Oxygen Radical Absorbance Capacity) were determined before and after the standardized simulated gastrointestinal digestion process. All microgreens provided relevant amounts of vitamin C (31-56 mg/100 g fresh weight) and total carotenoids (162-224 mg ß-carotene/100 g dry weight). Mineral content was comparable to that normally found in hydroponic microgreens and the low potassium levels observed would allow their dietetic recommendation for patients with impaired kidney function. Both total soluble polyphenols and total isothiocyanates were the greatest contributors to the total antioxidant capacity after digestion (43-70% and 31-63% bioaccessibility, respectively) while macroelements showed an important bioaccessibility (34-90%). In general, radish and mustard presented the highest bioaccessibility of bioactive compounds and minerals. Overall, the four hydroponic Brassicaceae microgreens present a wide array of antioxidant bioactive compounds.

In-vitro antioxidant capacity and cytoprotective/cytotoxic effects upon Caco-2 cells of red tilapia (Oreochromis spp.) viscera hydrolysates.

The antioxidant capacity of red tilapia viscera hydrolysates (RTVH) with different degrees of hydrolysis (DH) as well as their ultrafiltration membrane fractions, were analyzed using different chemical assays. Their protective effects against oxidative stress were evaluated using H2O2-stressed human intestinal differentiated Caco-2. The highest antioxidant capacity was obtained with a DH of 42.5% (RTVH-A) and its <1 kDa fraction (FRTVH-V). RTVH-A and FRTVH-V did not show cytotoxic effects at a concentration of ≤0.5 mg/mL,prevented the decrease in cell viability, and suppressed intracellular reactive oxygen species (ROS) accumulation induced by H2O2. However, pretreatment with RTVH-A after adding H2O2, showed a greater decrease in glutathione levels. Moreover, FRTVH-V allowed for a recovery close to that of control levels of cell proportions in the G1 and G2/M cell cycle phases; and a decrease in the cell proportion in late apoptosis. These results suggest that RTVH-A and FRTVH-V can be beneficial ingredients with antioxidant properties and can have protective effects against ROS-mediated intestinal injuries.

Effect of a Milk-Based Fruit Beverage Enriched with Plant Sterols and/or Galactooligosaccharides in a Murine Chronic Colitis Model.

The potential anti-inflammatory effect of plant sterols (PS) enriched milk-based fruit beverages (PS, 1 g/100 mL) (MfB) with/without galactooligosaccharides (GOS, 2 g/100 mL) (MfB-G) in an experimental mice model of chronic ulcerative colitis was evaluated. Beverages were orally administered to mice every day by gavage to achieve PS and GOS doses of 35 and 90 mg/kg, respectively, and experimental colitis was induced by giving mice drinking water ad libitum containing 2% (w/v) dextran sulphate sodium (DSS) for 7 days, alternating with periods without DSS up to the end of the study (56 days). MfB beverage showed significant reduction of symptoms associated to ulcerative colitis and improved the colon shortening and mucosal colonic damage, but it was not able to reduce the increase of myeloperoxidase levels produced by DSS. MfB-G showed higher incidence of bloody feces and loss of stool consistency than MfB, as well as high levels of immune cells infiltration in colon tissue and myeloperoxidase. Therefore, PS-enriched milk-based fruit beverage could be an interesting healthy food to extend the remission periods of the diseases and the need to evaluate, in a pre-clinical model, the anti-inflammatory effect of the combination of bioactive compounds in the context of a whole food matrix.

The impact of galactooligosaccharides on the bioaccessibility of sterols in a plant sterol-enriched beverage: adaptation of the harmonized INFOGEST digestion method.

The effect of the addition of galactooligosaccharides (GOS) on sterol bioaccessibility in three plant sterol (PS)-enriched milk-based fruit beverages (without GOS addition (MfB) and with 2.5 g (MfB-G2) and 5.0 g (MfB-G5) GOS per 250 mL) was evaluated after micellar gastrointestinal digestion. Cholesterol bioaccessibility was very similar among beverages, though a slight significant increase (from 80% to 85%) was observed by the addition of 5.0 g GOS. The addition of GOS did not affect total PS bioaccessibility (≈37%). Based on the results obtained after micellar digestion, it has been demonstrated that these beverages could be a suitable food matrix for simultaneous enrichment with PS and GOS. The harmonized in vitro digestion model INFOGEST was applied to the MfB beverage, but the cholesterol content could not be quantified due to its contribution of bile salts. Hence, it was proposed: (i) a change in porcine bile salt concentration from 10 mM to 1.4 mM (in order to compare with micellar digestion); or (ii) a change of bile salt origin (bovine instead of porcine), maintaining physiological concentration (10 mM, INFOGEST condition). Both options allowed cholesterol quantification, with bioaccessibilities of 62% (reduction of bile salts) and 38% (replacement of the bile salt source), whereas plant sterol bioaccessibilities were 22% and 14%, respectively. Therefore, the change of bile salt origin maintaining INFOGEST concentration is proposed as a method to evaluate sterol (cholesterol and PS) bioaccessibility in these beverages, demonstrating the need for the selection of appropriate conditions of the INFOGEST harmonized method according to the food matrix and compounds to be determined.

Effects of Plant Sterols or ß-Cryptoxanthin at Physiological Serum Concentrations on Suicidal Erythrocyte Death.

The eryptotic and hemolytic effects of a phytosterol (PS) mixture (ß-sitosterol, campesterol, stigmasterol) or ß-cryptoxanthin (ß-Cx) at physiological serum concentration and their effect against oxidative stress induced by tert-butylhydroperoxide (tBOOH) (75 and 300 µM) were evaluated. ß-Cryptoxanthin produced an increase in eryptotic cells, cell volume, hemolysis, and glutathione depletion (GSH) without ROS overproduction and intracellular Ca2+ influx. Co-incubation of both bioactive compounds protected against ß-Cx-induced eryptosis. Under tBOOH stress, PS prevented eryptosis, reducing Ca2+ influx, ROS overproduction and GSH depletion at 75 µM, and hemolysis at both tBOOH concentrations. ß-Cryptoxanthin showed no cytoprotective effect. Co-incubation with both bioactive compounds completely prevented hemolysis and partially prevented eryptosis as well as GSH depletion induced by ß-Cx plus tBOOH. Phytosterols at physiological serum concentrations help to prevent pro-eryptotic and hemolytic effects and are promising candidate compounds for ameliorating eryptosis-associated diseases.