in vitro antioxidant properties of digests of hydrolyzed casein and caseinophosphopeptide preparations in cell models of human intestine and osteoblasts

Abstract Three commercial samples consisting of enriched calcium-free caseinophosphopeptides (CPP), enriched calcium-bound caseinophosphopeptides (Ca-CPP) and an enzymatically hydrolyzed casein (hCN) were in vitro digested according to COST-Infogest protocol. As assessed by UPLC-HR-MS/MS, the digests contained 207–235 unique caseinophosphopeptides, and the species presenting the cluster sssEE were more abundant in CPP digest. The antioxidant activity at three different doses of each digest was firstly evaluated on human intestinal Caco-2/HT-29 70/30 co-culture. In presence of AAPH, hCN and CPP digests displayed a dose-dependent antioxidant activity equal or even greater than Vitamin C. In presence of Fe2+, the digests exerted an antioxidant activity mainly at the highest dose. Antioxidant activities of the intestinal metabolized digests was then evaluated on human osteoblast (Saos-2) cells. The digests exerted an antioxidant activity in presence of AAPH, but not in presence of Fe2+. These results highlight milk-derived peptides as potential dietary supplements for gut and bone health

Bovine whey peptides transit the intestinal barrier to reduce oxidative stress in muscle cells

peer-reviewedHealth benefits are routinely attributed to whey proteins, their hydrolysates and peptides based on in vitro chemical and cellular assays. The objective of this study was to track the fate of whey proteins through the upper gastrointestinal tract, their uptake across the intestinal barrier and then assess the physiological impact to downstream target cells. Simulated gastrointestinal digestion (SGID) released a selection of whey peptides some of which were transported across a Caco-2/HT-29 intestinal barrier, inhibited free radical formation in muscle and liver cells. In addition, SGID of β-lactoglobulin resulted in the highest concentration of free amino acids (176 nM) arriving on the basolateral side of the co-culture with notable levels of branched chain and sulphur-containing amino acids. In vitro results indicate that consumption of whey proteins will deliver bioactive peptides to target cells

Mediterranean Diet Food Components as Possible Adjuvant Therapies to Counteract Breast and Prostate Cancer Progression to Bone Metastasis

Bone metastasis is a serious and often lethal complication of particularly frequent carcinomas, such as breast and prostate cancers, which not only reduces survival but also worsens the patients’ quality of life. Therefore, it is important to find new and/or additional therapeutic possibilities that can counteract the colonization of bone tissue. High adherence to the Mediterranean diet (MD) is effective in the prevention of cancer and improves cancer patients’ health, thus, here, we considered its impact on bone metastasis. We highlighted some molecular events relevant for the development of a metastatic phenotype in cancer cells and the alterations of physiological bone remodeling, which occur during skeleton colonization. We then considered those natural compounds present in MD foods with a recognized role to inhibit or reverse the metastatic process both in in vivo and in vitro systems, and we reported the identified mechanisms of action. The knowledge of this bioactivity by the dietary components of the MD, together with its wide access to all people, could help not only to maintain healthy status but also to improve the quality of life of patients with bone metastases

Dynamics of glycolipid domains in the plasma membrane of living cultured neurons, following protein kinase C activation: A study performed by excimer-formation imaging

Dynamic changes of glycolipid domains within the plasma membranes of cultured rat cerebellar granule cells have been investigated. For this purpose, a pyrene-labelled derivative of G(M1) ganglioside has been incorporated in the cell plasma membrane, and the rate of excimer formation, directly related to the formation of domains, has been studied by a fluorescence imaging technique (excimer-formation imaging). Fluorescence imaging showed that upon addition of 100 μM glutamate, indirectly inducing the activation of protein kinase C (PKC), glycolipid concentration within domains increases in cell bodies. Comparable effects were exerted by the addition of PMA, directly inducing the activation of PKC. On the contrary, the phorbol ester was not effective in the presence of the specific PKC inhibitor, bisindolylmaleimide. These results suggest that glycolipid-enriched domains are dynamic supramolecular structures affected by membrane-associated events, such as PKC activation. Dynamic changes of domains could be important in modulating their postulated participation in a series of functions, including signal transduction and lipid/protein sorting

Sphingosine Kinase 2 and Ceramide Transport as Key Targets of the Natural Flavonoid Luteolin to Induce Apoptosis in Colon Cancer Cells.

The plant flavonoid luteolin exhibits different biological effects, including anticancer properties. Little is known on the molecular mechanisms underlying its actions in colorectal cancer (CRC). Here we investigated the effects of luteolin on colon cancer cells, focusing on the balance between ceramide and sphingosine-1-phosphate (S1P), two sphingoid mediators with opposite roles on cell fate. Using cultured cells, we found that physiological concentrations of luteolin induce the elevation of ceramide, followed by apoptotic death of colon cancer cells, but not of differentiated enterocytes. Pulse studies revealed that luteolin inhibits ceramide anabolism to complex sphingolipids. Further experiments led us to demonstrate that luteolin induces an alteration of the endoplasmic reticulum (ER)-Golgi flow of ceramide, pivotal to its metabolic processing to complex sphingolipids. We report that luteolin exerts its action by inhibiting both Akt activation, and sphingosine kinase (SphK) 2, with the consequent reduction of S1P, an Akt stimulator. S1P administration protected colon cancer cells from luteolin-induced apoptosis, most likely by an intracellular, receptor-independent mechanism. Overall this study reveals for the first time that the dietary flavonoid luteolin exerts toxic effects on colon cancer cells by inhibiting both S1P biosynthesis and ceramide traffic, suggesting its dietary introduction/supplementation as a potential strategy to improve existing treatments in CRC

Calcium bioaccessibility and uptake by human intestinal like cells following in vitro digestion of casein phosphopeptide-calcium aggregates

Casein phosphopeptides (CPPs), derived by casein proteolysis, can bind calcium ions and keep them in solution. In vitro studies have demonstrated CPP-induced cell calcium uptake, depending on the formation of (CPP + calcium) complexes and on the degree of differentiation of the intestinal cells. With the present study, we address the persistence of the complexes and of the CPP-induced calcium uptake in intestinal like cells after the digestion process, thus examining their eligibility to serve as nutraceuticals. A calcium-preloaded CPP preparation of commercial origin (Ca-CPPs) was subjected to in vitro digestion. The evolution of the supramolecular structure of the Ca-CPP complexes was studied using laser-light and X-ray scattering. The bioactivity of the pre- and post-digestion Ca-CPPs was determined in differentiated Caco2 and HT-29 cells by video imaging experiments using Fura-2. We found that Ca-CPP aggregates keep a complex supramolecular organization upon digestion, despite getting smaller in size and increasing internal calcium dispersion. Concomitantly and most interestingly, digested Ca-CPPs clearly enhance the uptake of calcium ions, especially in Caco2 cells. In contrast, digestion depletes the ability of post-loaded decalcified-CPPs (Ca-dekCPPs), with a weaker internal structure, to induce calcium uptake. The enhanced bioactivity reached upon digestion strongly suggests a recognized role of Ca-CPPs, in the form used here, as nutraceuticals