Search results for "Sterols"
showing 10 items of 174 documents
Antiproliferative effect of plant sterols at colonic concentrations on Caco-2 cells
2017
Abstract Plant sterols (PS) have been incorporated to foods due to their cholesterol-lowering effect. Because of their low intestinal absorption (0.5–2%), they can reach the colon and exert local actions. The aim of this study was to evaluate the antiproliferative effect of individual (β-sitosterol, campesterol and stigmasterol) and combined PS in colon cancer cells (Caco-2) at human colonic concentrations after simulated gastrointestinal digestion of a PS enriched milk-based fruit beverage. β-Sitosterol, campesterol and stigmasterol induced significant cell viability reduction (13–59% vs control), but only stigmasterol produced an overproduction of reactive oxygen species (92% vs control).…
Physiological concentrations of phytosterols enhance the apoptotic effects of 5-fluorouracil in colon cancer cells
2018
Abstract Combining natural products as co-adjuvants in 5-fluorouracil (5-FU) chemotherapy might enhance the effectiveness of 5-FU by avoiding a high dosage and/or reducing treatment times. We explored the anticancer efficacy of the phytosterols (PS) at concentrations achievable in the human colon, as well as their potential as sensitizing agents of human colon cancer cells (Caco-2 and HT-29) to 5-FU treatment. Cells proliferation, combination index, cell cycle, apoptosis, caspases activation, ROS production, and ΔΨm were determined. Co-treatment (PS+5-FU) had an antiproliferative additive effect, and moreover, in general a significantly improved efficacy was observed on cell cycle arrest at…
Sterols in infant formulas: validation of a gas chromatographic method.
2017
AbstractSterols are components present in the fat fraction of infant formulas (IFs). Their characterization is therefore of interest, though there are no official reference methods for their analysis in these matrices.Aim: To validate a gas chromatographic method with flame ionization detection for the determination of animal (cholesterol and desmosterol) and plant sterols (brassicasterol, campesterol, stigmasterol, β-sitosterol and sitostanol) found in IFs.All correlation coefficients obtained for the calibration curves of sterols studied were >0.99. Limits of detection (<1 μg/100 mL) and quantification (<4 μg/100 mL) are suitable for sterols determination in IFs. The within-assay precisio…
Apoptotic effect of a phytosterol-ingredient and its main phytosterol (β-sitosterol) in human cancer cell lines
2018
Dietary interventions may effectively control cancer development, with phytosterols (PS) being a class of cancer chemopreventive dietary phytochemicals. The present study, for the first time, evaluates the antiproliferative effects of a PS-ingredient used for the enrichment of several foods and its main PS, β-sitosterol, at physiological serum levels, in the most prevalent cancer cells in women (breast (MCF-7), colon (HCT116) and cervical (HeLa)). In all three cell lines, these compounds induced significant cell viability reduction without a clear time- and dose-dependent response. Moreover, all treatments produced apoptotic cell death with the induction of DNA fragmentation through the app…
Bioaccessibility study of plant sterol-enriched fermented milks.
2015
The bioaccessibility (BA) of total and individual plant sterols (PS) of four commercial PS-enriched fermented milk beverages (designated as A to D) was evaluated using in vitro gastrointestinal digestion including the formation of mixed micelles. The fat content of the samples ranged from 1.1 to 2.2% (w/w), and PS enrichment was between 1.5 and 2.9% (w/w). β-Sitosterol, contained in all samples, was higher in samples A and B (around 80% of total PS). The campesterol content was C (22%) > A (7%) > B (5%). Sitostanol was the most abundant in sample D (85%). Stigmasterol was only present in sample C (33%). The greatest BA percentage for total PS corresponded to samples A and B (16–17%), follow…
EBI2 – Sensor for dihydroxycholesterol gradients in neuroinflammation
2018
Dihydroxycholesterols such as 7α,25-dihydroxysterols (7α,25-OHC) and 7α,27-OHC are generated from cholesterol by the enzymes CH25H, CYP7B1 and CYP27A1 in steady state but also in the context of inflammation. The G-protein coupled receptor (GPCR) Epstein-Barr virus-induced gene 2 (EBI2), also known as GPR183, senses these oxysterols and induces chemotactic migration of immune cells towards higher concentrations of these ligands. We recently showed that these ligands are upregulated in the CNS in experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis and that EBI2 enhanced early infiltration of encephalitogenic T cells into the CNS. In this short-review we dis…
First international descriptive and interventional survey for cholesterol and non-cholesterol sterol determination by gas- and liquid-chromatography–…
2019
International audience; Serum concentrations of lathosterol, the plant sterols campesterol and sitosterol and the cholesterol metabolite 5alpha-cholestanol are widely used as surrogate markers of cholesterol synthesis and absorption, respectively. Increasing numbers of laboratories utilize a broad spectrum of well-established and recently developed methods for the determination of cholesterol and non-cholesterol sterols (NCS). In order to evaluate the quality of these measurements and to identify possible sources of analytical errors our group initiated the first international survey for cholesterol and NCS. The cholesterol and NCS survey was structured as a two-part survey which took place…
7-Keto-Cholesterol and Cholestan-3beta, 5alpha, 6beta-Triol Induce Eryptosis through Distinct Pathways Leading to NADPH Oxidase and Nitric Oxide Synt…
2019
Background/aims We showed that patho-physiological concentrations of either 7-keto-cholesterol (7-KC), or cholestane-3beta, 5alpha, 6beta-triol (TRIOL) caused the eryptotic death of human red blood cells (RBC), strictly dependent on the early production of reactive oxygen species (ROS). The goal of the current study was to assess the contribution of the erythrocyte ROS-generating enzymes, NADPH oxidase (RBC-NOX), nitric oxide synthase (RBC-NOS) and xanthine oxido-reductase (XOR) to the oxysterol-dependent eryptosis and pertinent activation pathways. Methods Phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, reactive oxygen/nitrogen species (RONS) and nitri…
Effects of Plant Sterols or β-Cryptoxanthin at Physiological Serum Concentrations on Suicidal Erythrocyte Death.
2018
The eryptotic and hemolytic effects of a phytosterol (PS) mixture (β-sitosterol, campesterol, stigmasterol) or β-cryptoxanthin (β-Cx) at physiological serum concentration and their effect against oxidative stress induced by tert-butylhydroperoxide (tBOOH) (75 and 300 μM) were evaluated. β-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 β-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. β…
Plant sterols and human gut microbiota relationship: An in vitro colonic fermentation study
2018
Abstract Due to the preventive effect that plant sterols could have in relation to colon cancer and the scarce information available on plant sterols-gut microbiota interaction, we evaluate the sterols influence upon gut microbiota and viceversa. In vitro colonic fermentation using a residue from the in vitro digestion of a plant sterol-enriched beverage were used. Faecal sterols by GC–MS, and gut microbiota using DNA sequencing were determined. A higher plant sterols metabolism and lower for cholesterol in presence of plant sterols was occurred. Neutral plant sterols decreased and its metabolites increased during fermentation times. The global changes in microbial communities were associat…