Search results for "Sterols"
showing 10 items of 174 documents
Eutrophication and browning influence Daphnia nutritional ecology
2019
Climate change and land-use practices can enhance lake eutrophication and browning, which influence phytoplankton composition by decreasing the availability of food high in nutritional quality (algae) and increasing the abundance of low-quality food (terrestrial detritus, bacteria) for herbivorous zooplankton. Nutritionally valuable algae for zooplankton are rich in essential biomolecules such as amino acids, polyunsaturated fatty acids (PUFAs), sterols, and phosphorus. We performed laboratory experiments and showed a stronger positive relationship between zooplankton (Daphnia) cumulative offspring number and availability of high-quality algae (Cryptophytes: Rhodomonas/Cryptomonas; and Chry…
Generation of oxysterols formed by free radicals and enzymes by electrochemical oxidation
2016
International audience; It is commonly accepted that cholesterol oxide derivatives, also named oxysterols, are 27 carbon-atom molecules deriving either from enzymatic and non-enzymatic oxidation of cholesterol. Most of these compounds can be synthesized by more or less difficult and time consuming chemical reactions, and some of them have been discovered before the identification of the enzymes [mainly cytochrome P450 enzymes (CYP enzymes)] involved in their biosynthesis. A wide range of biological activities depends on oxysterols. Some oxysterols are also involved in the synthesis of cholesterol metabolites which have various properties. The paper by Weber et al. in this issue of European …
Impact of colonic fermentation on sterols after the intake of a plant sterol-enriched beverage: A randomized, double-blind crossover trial
2017
Summary Background Cholesterol microbial transformation has been widely studied using in vitro fermentation assays, but less information is available on the biotransformation of plant sterols (PS). The excretion percentage of animal sterols (AS) (67–73%) is considerably greater than that of PS (27–33%) in feces from healthy humans following a Western diet. However, a lower content of AS in feces from subjects following a vegetarian, vegan or low-fat animal diet has been seen when compared to omnivorous subjects. Although only one human study has reported fecal sterol excretion after the consumption of PS-enriched food (8.6 g PS/day), it was found that the target group showed an increase in …
Sterols in human milk during lactation: bioaccessibility and estimated intakes.
2018
Human milk (HM) is the exclusive food during the first 4–6 months of an infant's life. Breastfeeding has been related to significant health benefits for infants, and hence it is of interest to study the bioactive compounds present in HM, such as sterols (cholesterol being the most abundant). The aim of this study was to determine the contents of sterols (cholesterol, desmosterol, lathosterol, lanosterol, campesterol, stigmasterol and β-sitosterol) in 10 pools of colostrum, transitional milk, and 1, 3 and 6 month HM obtained from Spanish volunteers from two different geographical areas (coastal and central) and to estimate the intake and bioaccessibility (BA) of sterols in order to ascertain…
Cholesterol Content in Human Milk during Lactation: A Comparative Study of Enzymatic and Chromatographic Methods.
2018
This study validates a gas chromatography (GC) method for determining the sterol profile of human milk (HM) and compares it with an enzymatic-spectrophotometric (E-S) method. Good linearity ( r > 0.97) and low limits of detection and quantification were obtained with the GC method (<1.8 and <6 μg/100 g of HM, respectively). Suitable intra- and interassay precisions (all <18%) and satisfactory recovery percentages (80-109%) were obtained for both methods. In addition, both methodologies were used to assess cholesterol evolution in HM during lactation, showing a 50% decrease at 6 months versus colostrum. The E-S method overestimated cholesterol content by <20% versus the GC method. The result…
Dietary phytochemicals in the protection against oxysterol-induced damage.
2017
The intake of fruits and vegetables is associated with reduced incidence of many chronic diseases. These foods contain phytochemicals that often possess antioxidant and free radical scavenging capacity and show anti-inflammatory action, which are also the basis of other bioactivities and health benefits, such as anticancer, anti-aging, and protective action for cardiovascular diseases, diabetes mellitus, obesity and neurodegenerative disorders. Many factors can be included in the etiopathogenesis of all of these multifactorial diseases that involve oxidative stress, inflammation and/or cell death processes, oxysterols, i.e. cholesterol oxidation products (COPs) as well as phytosterol oxidat…
Profile of Fatty Acids, Tocopherols, Phytosterols and Polyphenols in Mediterranean Oils (Argan Oils, Olive Oils, Milk Thistle Seed Oils and Nigella S…
2019
Background: The effects of vegetable oils on human health depend on their components. Therefore, their profiles of lipid nutrients and polyphenols were determined. Objective: To establish and compare the fatty acid, tocopherol, phytosterol and polyphenol profiles of Mediterranean oils: cosmetic and dietary argan oils (AO; Morocco: Agadir, Berkane); olive oils (OO; Morocco, Spain, Tunisia); milk thistle seed oils (MTSO; Tunisia: Bizerte, Sousse, Zaghouane); nigella seed oil (NSO). Methods: The biochemical profiles were determined by gas chromatography-flame ionization, high performance liquid chromatography and gas chromatography, coupled with mass spectrometry as required. The antioxidant …
Impact of plant sterols enrichment dose on gut microbiota from lean and obese subjects using TIM-2 in vitro fermentation model
2019
There are scarce data on plant sterols (PS) and gut microbiota relationship. The purpose of this study is to compare the interaction between PS and gut microbiota through in vitro colonic fermentation studies using a validated system (TIM-2) with a PS-enriched dose (similar to 2 g/day) from two sources (food PS-source ingredient and commercial standard) using microbiota from lean and obese populations. Fecal sterols, short chain fatty acids (SCFA) and microbiota composition were determined by GC/MS, IEC, and 16S-sequencing, respectively.PS-feeding decreased coprostanol and ethylcoprostanol concentration and increased the production of acetate and butyrate (mainly with lean microbiota). In a…
Sterols in Infant Formulas: A Bioaccessibility Study.
2018
The design of infant formulas (IFs) seeks to resemble human milk (HM) composition and functionality. The fat sources used usually comprise vegetable oil blends to mimic the fatty acid composition of HM and introduce changes in the animal/plant sterol ratio. In contrast, the use of milk fat globule membrane (MFGM)-rich ingredients could improve this aspect by increasing the ratio. The present study evaluates the bioaccessibility (BA) of sterols (cholesterol, desmosterol, brassicasterol, campesterol, stigmasterol, and β-sitosterol) in three IFs (with or without MFGM) using an in vitro digestion method simulating infant conditions. Analytical parameters confirmed the suitability of the method …
A positive impact on the serum lipid profile and cytokines after the consumption of a plant sterol-enriched beverage with a milk fat globule membrane…
2018
The hypocholesterolemic effect and the modification of serum biomarkers of a dietary plant sterol (PS) intake, cholesterol precursors and cytokines after the consumption of milk-based fruit beverages with a milk fat globule membrane were evaluated by a randomized, double-blind, crossover, multiple dose bioavailability study. Postmenopausal women (n = 38) consumed daily 250 mL of a beverage with or without 2 g of PS added during 6 weeks in each of the study periods. With the intake of the PS-added beverage, significant decreases (mg dL-1) in serum total cholesterol (pre-treatment: 220.0 ± 27.8 vs. post-treatment: 212.9 ± 25.8; p < 0.05) and LDL-cholesterol (129.4 ± 28.5 vs. 121.7 ± 24.4; p <…