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This study investigates the gut anti-inflammatory activity of a plant sterol (PS) food supplement (PS-FS), alongside PS-enriched milk-based fruit beverage and PS-enriched rye bread. A co-culture model based on a dual-chamber system with differentiated intestinal-like Caco-2 cells (apical) and RAW264.7 macrophages (basolateral) was used. The bioaccessible fractions (BF) of the samples were obtained after INFOGEST 2.0 simulated gastrointestinal digestion. The BF were added to the apical part (diluted 1/20 v/v with culture medium to avoid cytotoxicity) for 90 min, followed by stimulation with lipopolysaccharide (LPS) (1 μg mL -1 , 24 h) on the basolateral side. The pharmacological interaction between samples and budesonide (1 μM, 90 min) was evaluated. Results indicate that PS-FS significantly attenuated LPS-induced secretion of IL-8 (28%) by Caco-2 cells, and TNF-α (9%) and IL-6 (54%) by RAW264.7 macrophages, whereas PS-enriched beverage and bread did not exhibit protective effects. Additionally, PS-FS demonstrated an improvement in oxidative status in Caco-2 cells, evidenced by reduced levels of reactive oxygen species (47%), iNOS protein expression (27%), and nitrite/nitrate secretion (27%). Mechanistically, PS-FS inhibited the NF-κB-COX-2-PGE 2 signaling pathway in macrophages, resulting in decreased NF-κB p65 nuclear translocation (39%), COX-2 protein expression (32%), and PGE 2 production (27%). Co-treatment with budesonide and PS-FS displayed an antagonistic effect (combination index 0.38-0.63). This study demonstrates the potent intestinal anti-inflammatory activity of a PS-FS, positioning it as a promising nutraceutical product for the management of inflammatory bowel diseases. However, the food matrix of the milk-based fruit beverage and rye bread appear to interfere with the anti-inflammatory activity of PS.

A physiological mechanism of programmed cell death called eryptosis occurs in aged or damaged red blood cells (RBCs). Dysregulated eryptosis contributes to abnormal microcirculation and prothrombotic risk. Cigarette smoke extract (CSE) induces a p38 MAPK-initiated, Fas-mediated eryptosis, activating the death-inducing signaling complex (DISC). Indicaxanthin (Ind) from cactus pear fruits, is a bioavailable dietary phytochemical in humans and it is able to incorporate into RBCs enhancing their defense against numerous stimuli. This in vitro work shows that Ind, at concentrations that mimic plasma concentrations after a fruit meal, protects erythrocytes from CSE-induced eryptosis. CSE from commercial cigarettes was prepared in aqueous solution using an impinger air sampler and nicotine content was determined. RBCs were treated with CSE for 3 h in the absence or presence of increasing concentrations of Ind (from 1 to 5 μM). Cytofluorimetric measurements indicated that Ind reduced CSE-induced phosphatidylserine externalization and ceramide formation in a concentration-dependent manner. Confocal microscopy visualization and coimmunoprecipitation experiments revealed that Ind prevented both CSE-triggered Fas aggregation and FasL/FADD/caspase 8 recruitment in the membrane, indicating inhibition of DISC assembly. Ind inhibited the phosphorylation of p38 MAPK, caspase-8/caspase-3 cleavage, and caspase-3 activity induced by CSE. Finally, Ind reduced CSE-induced ATP depletion and restored aminophospholipid translocase activity impaired by CSE treatment. In conclusion, Ind concentrations comparable to nutritionally relevant plasma concentrations, can prevent Fas-mediated RBC death signaling induced by CSE, which suggests that dietary intake of cactus pear fruits may limit the deleterious effects of cigarette smoking., (© 2024 International Union of Biochemistry and Molecular Biology.)