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Summary: The aim of this study was to evaluate the antiproliferative activity of bioaccessible fractions (BFs) obtained by the internationally standardized INFOGEST static digestion method to Sicilian honeys of three distinct floral origins (Sulla, Thistle and Dill) and the Manuka honey (gold standard), and to compare their effects based on total polyphenol content (TPC). Differentiated CaCo‐2 cells (intestinal‐like) and non‐differentiated CaCo‐2 and HCT‐116 colonic tumour‐like cells were incubated for 24 h with BFs of honeys to test viability, apoptosis, mitochondrial membrane potential (MMP), ROS and cell cycle. TPC after digestion ranked in the following order: Dill > Thistle > Sulla > Manuka. No decrease in cell viability in differentiated CaCo‐2 cells was observed, while a reduction to 25–85% (CaCo‐2) and 20–80% (HCT‐116) of viability was obtained. This descent in viability was caused by a cell cycle block with an increase in apoptosis through dissipation of MMP and raise in ROS levels, being Thistle and Dill the most effective honeys followed by Sulla and finally Manuka, in agreement with TPC after digestion. [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]