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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). Individual PS induced reversible arrest in phase G 0 /G 1 of the cell cycle, suggesting that they act as cytostatic agents. Combined PS showed a greater effect than individual PS, inducing also cell necrosis and irreversible cell cycle arrest (G 0 /G 1 phase). The consumption of PS-enriched foods therefore could exert a potential preventive effect against colon cancer. [ABSTRACT FROM AUTHOR]

Sterol oxidation products (SOPs) have shown cytotoxic effect in human intestinal cells; however, their effect within a food matrix has not been assayed yet. This study evaluated the possible cytotoxic effect of SOPs within bioaccessible fractions (BFs) of two milk-based fruit beverages with (BFA)/without (BFB) plant sterols in differentiated Caco-2 cells and if the BFs counteracted the cytotoxic effect induced by COPs mixture (30 and 60 μM). BFs did not evoke cytotoxic effect in any of the tests carried out and they protected against the loss of intestinal cohesion, mitochondrial depolarization and necrosis induced by COPs mixture. Moreover, BFB sample protected from cell cycle arrest, lessened lysosomal injury and overproduction of ROS at 30 μM. Therefore, the formation of SOPs within milk-based fruit beverages with/without plant sterols does not contribute to intestinal epithelium damage and these types of food matrices confer additional protection against COPs at dietary concentrations. [ABSTRACT FROM AUTHOR]

• Inclusion of lipidic enzymes provides a more physiological in vitro digestion scenario. • Sterols provided by bile salts and pancreatin must be subtracted from digested samples. • Increasing concentration of bile salts decreased plant sterol bioaccessibility. • Gastric lipase and cholesterol esterase reduced plant sterol bioaccessibility. • Cholesterol cannot be quantified when only cholesterol esterase is used. 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. [ABSTRACT FROM AUTHOR]

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 H 2 O 2 -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 H 2 O 2. However, pretreatment with RTVH-A after adding H 2 O 2 , 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. Unlabelled Image • The most antioxidant hydrolysate from red tilapia viscera was generated with DH of 42.5% (RTVH-A). • RTVH-A purification showed low molecular mass peptides had higher antioxidant activity. • RTVH-A and its <1-kDa fraction preserve Caco-2 viability and decrease ROS production. • <1-kDa fraction peptides protect Caco-2 cells from H 2 O 2 -induced oxidative stress. [ABSTRACT FROM AUTHOR]