Peptides from water buffalo cheese whey induced senescence cell death via ceramide secretion in human colon adenocarcinoma cell line

Scope: Milk proteins are a source of bioactive peptides. Recent studies have indicated that protein‐derived peptides released in buffalo cheese acid whey exert a cytomodulatory effect in human epithelial colon cancer (CaCo2) cells. The aim of the present study was to explain the molecular mechanism involved in the response of CaCo2 cells to oxidative stress in the presence of peptide fractions of buffalo cheese whey, purified and characterized by mass spectrometry. Methods and results: We demonstrated that treatment of CaCo2 treated with H₂O₂ (H‐CaCo2) cells with a partially purified peptide sub‐fraction (f3) from buffalo cheese acid whey induced a reduction of mitochondrial superoxide anion with subsequent decrease in heat shock protein 70 and 90 expression. Moreover, we observed a 5‐fold decrease in cyclin A expression and cell cycle arrest in G1/G0 phases. These responses were associated with increased activity of alkaline phosphatase and beta‐galactosidase, markers of differentiation and senescence respectively. Conclusions: The structural characterization of the active peptide fraction and the elucidation of the effects induced by its treatment on H‐CaCo2 cells in vitro demonstrated an activity of this peptide sub‐fraction in the modulation of cell cycle, thus suggesting potential application for the development of nutraceuticals as well as health‐promoting functional foods.     

Contamination of some foodstuffs marketed in Italy by fatty acid esters of monochloropropanediols and glycidol

ABSTRACT

Fatty acid esters of 3-monochloropropanediol (3-MCPD), 2-MCPD and glycidol (Gly) are food-processing contaminants that cause concerns about possible adverse health effects. The present study evaluates the contamination levels of the three ester classes in 130 samples of foodstuffs marketed in Italy covering 10 food categories, namely margarines, oils, roasted coffee, breakfast cereals, salted crackers, cookies, infant biscuits, rusks, breads and potato crisps. The analytical method employed is a so-called indirect method that entails MCPD/glycidol cleavage from their esterified forms, cleanup, derivatisation and GC-MS analysis. The MCPDs and glycidol concentrations (from esters) were found to be equal or a little higher than the levels reported in previous studies conducted in other European countries and described in the literature. 3-MCPD was the predominant compound in all foodstuffs analysed with the exception for rusks where Gly levels were slightly higher. Considering the sum of MCPD and Gly esters, the most contaminated foodstuffs were seed oils, followed by margarines and cookies, whereas roasted coffee, bread, rusks, cornflakes and infant biscuits were less contaminated with MCPDs and Gly concentrations often below LOQ or LOD values. Refined olive oil, potato chips and salted crackers showed contamination levels intermediate between the two above groups. The results of this study also confirm that the use of palm oil as an ingredient or frying medium is an important cause of increase of the levels of MCPD and Gly esters, especially in salted crackers, rusks and potato crisps. Finally, the Italian intake of 3-MCPD due to the various foods analysed has been calculated and related to TDI. The MoE for Gly was also estimated.     

α–ω Alkenyl-bis-S-Guanidine Thiourea Dihydrobromide Affects HeLa Cell Growth Hampering Tubulin Polymerization

Cancer is going to be the first cause of mortality worldwide in the 21th century. It is considered a multifactorial disease that results from the combined influence of many genetic aberrations, leading to abnormal cell proliferation. As microtubules are strongly implicated in cellular growth, they represent an important target for cancer treatment. The well-known microtubule-targeting agents (MTAs) including paclitaxel, colchicine and vinca alkaloids are commonly used in the treatment of various cancers. However, adverse effects and drug resistance are major limitations in their clinical use. To find new candidates able to induce microtubule alteration with reduced toxic effects or drug resistance, we studied a small new series of derivatives that present imidazolinic, guanidinic, thioureidic and hydrazinic groups ( 1 – 9 ). All the compounds were tested for their antitumor activity against a panel of six tumoral cell models. In particular, compound 8 (nonane-1,9-diyl-bis-S-amidinothiourea dihydrobromide) showed the lowest IC₅₀ value against HeLa cells, together with a low cytotoxicity for normal cells. This compound was able to induce the apoptotic mitochondrial pathway and inhibited tubulin polymerization with a similar efficacy to vinblastine and nocodazole. Taken together, these promising biological properties make compound 8 useful for the development of novel therapeutic approaches in cancer treatment.     

Nanostructured Silicon Oxide–Nickel Oxide Sol–Gel Films with Enhanced Optical Carbon Monoxide Gas Sensitivity

Sol–gel derived silica (SiO₂) films doped with nickel oxide (NiO) nanocrystals were fabricated. A bifunctional ligand was used, bearing amine groups capable of coordinating the nickel ions and hydrolysable siloxane groups for anchoring the metal complex moiety to the silicate matrix. Nickel oxide nanocrystals precipitated at 500°C while the film was still porous. The nanocomposite films showed a reversible change in the optical transmittance in the VIS-NIR range when exposed to carbon monoxide gas. The effects of residual porosity, testing temperature, and carbon monoxide gas concentration on optical transmittance were studied.