Simulated gastrointestinal digestion, intestinal permeation and plasma protein interaction of white, green, and black tea polyphenols

The gastrointestinal digestion, intestinal permeation, and plasma protein interaction of polyphenols from a single tea cultivar at different stages of processing (white, green, and black teas) were simulated. The salivary phase contained 74.8-99.5% of native polyphenols, suggesting potential bioavailability of significant amounts of antioxidants through the oral mucosal epithelium that might be gastric sensitive and/or poorly absorbed in the intestine. White tea had the highest content and provided the best intestinal bioaccessibility and bioavailability for catechins. Since most of native catechins were not absorbed, they were expected to accumulate in the intestinal lumen where a potential inhibition capacity of cellular glucose and cholesterol uptake was assumed. The permeated catechins (approximately, 2-15% of intestinal levels) significantly bound (about 37%) to plasma HDLs, suggesting a major role in cholesterol metabolism. White tea and its potential nutraceuticals could be effective in the regulation of plasma glucose and cholesterol levels

Urantide Conformation and Interaction with the Urotensin-II Receptor

Urotensin II (U-II) is a disulfide bridged peptide hormone identified as the ligand of a G protein-coupled receptor. Human U-II (H-Glu-Thr-Pro-Asp-c[Cys-Phe-Trp-Lys-Tyr-Cys]-Val-OH) has been described as the most potent vasoconstrictor compound identified to date. We have previously identified the compound termed urantide (H-Asp-c[Pen-Phe-DTrp-Orn-Tyr-Cys]-Val-OH), which is the most potent UT receptor (UTR) antagonist described to date. Urantide may have potential clinical value in the treatment of atherosclerosis. In the present study, we studied the conformational preferences of urantide in DPC micelles and developed a urantide/UTR interaction model. This model can help the design of novel peptides and small molecules as UTR antagonists

Citrus sinensis and Vitis vinifera Protect Cardiomyocytes from Doxorubicin-Induced Oxidative Stress: Evaluation of Onconutraceutical Potential of Vegetable Smoothies

The interest towards nutraceuticals able to counteract drug side effects is continuously growing in current chemotherapeutic protocols. In the present study, we demonstrated that smoothies containing mixtures of Citrus sinensis and Vitis vinifera L. cv. Aglianico N, two typical fruits of the Mediterranean diet, possess bioactive polyphenols that protect cardiomyocytes against doxorubicin-induced oxidative stress. The polyphenolic extracts isolated from Citrus sinensis- and Vitis vinifera-based functional smoothies were deeply characterized by Liquid Chromatography-Mass Spectrometry methods. Subsequently, the functional smoothies and relative mixtures were tested to verify their ability to affect cellular viability and oxidative stress parameters in embryonic cardiomyocyte cells (H9c2), and human breast adenocarcinoma cell line (MCF-7) exposed to doxorubicin. Interestingly, we found that the mix resulting from Citrus sinensis and Vitis vinifera association in ratio 1:1 was able to reduce cardiomyocytes damage induced by anthracyclines, without significantly interfering with the pro-apoptotic activity of the drug on breast cancer cells. These results point out the potential use of vegetable smoothies as adjuvants functional foods for chemotherapeutic anticancer protocols

N-4 Alkyl Cytosine Derivatives Synthesis: A New Approach

The selective N-4 alkylation of cytosine plays a critical role in the synthesis of biologically active molecules. This work focuses on the development of practical reaction conditions toward a regioselective synthesis of N-4-alkyl cytosine derivatives. The sequence includes a direct and selective sulfonylation at the N-1 site of the cytosine, followed by the alkylation of the amino siteusing KHMDS in CH2Cl2/THF mixture, providing a fast and efficient approach consistent withpyrimidine-based drug design

Therapeutic potential of TRPM8 antagonists in prostate cancer.

Transient receptor potential melastatin-8 (TRPM8) represents an emerging target in prostate cancer, although its mechanism of action remains unclear. Here, we have characterized and investigated the effects of TRPM8 modulators in prostate cancer aggressiveness disclosing the molecular mechanism underlying their biological activity. Patch-clamp and calcium fluorometric assays were used to characterize the synthesized compounds. Androgen-stimulated prostate cancer-derived cells were challenged with the compounds and the DNA synthesis was investigated in a preliminary screening. The most effective compounds were then employed to inhibit the pro-metastatic behavior of in various PC-derived cells, at different degree of malignancy. The effect of the compounds was then assayed in prostate cancer cell-derived 3D model and the molecular targets of selected compounds were lastly identified using transcriptional and non-transcriptional reporter assays. TRPM8 antagonists inhibit the androgen-dependent prostate cancer cell proliferation, migration and invasiveness. They are highly effective in reverting the androgen-induced increase in prostate cancer cell spheroid size. The compounds also revert the proliferation of castrate-resistant prostate cancer cells, provided they express the androgen receptor. In contrast, no effects were recorded in prostate cancer cells devoid of the receptor. Selected antagonists interfere in non-genomic androgen action and abolish the androgen-induced androgen receptor/TRPM8 complex assembly as well as the increase in intracellular calcium levels in prostate cancer cells. Our results shed light in the processes controlling prostate cancer progression and make the transient receptor potential melastatin-8 as a ‘druggable’ target in the androgen receptor-expressing prostate cancers

Comparison of Content in Phenolic Compounds and Antioxidant Capacity in Grains of White, Red, and Black Sorghum Varieties Grown in the Mediterranean Area

orghum (Sorghum bicolor L.) is a gluten-free cereal with many varieties containing greater amounts of bioactive compounds than other grains. In this work, the phenolic composition and antioxidant capacity were compared in three sorghum varieties grown in the Mediterranean, consisting of different pericarp colors: white, red, and black. The qualitative and quantitative profiles of acidified aqueous methanol extracts of whole grain sorghum flours were elucidated through ultrahigh performance liquid chromatography (UHPLC) coupled to photodiode array (PDA) and ion trap time-of-flight (IT-TOF) mass spectrometry. The investigated sorghum varieties contained polyamines, such as spermidines, and polyphenolic compounds belonging to different classes: hydroxycinnamic acids, flavanols, flavones, and flavanones. Pyrano-flavanone-flavanols were detected only in the black sorghum. Precolumn and postcolumn 2,2′-diphenyl-1-picrylhydrazyl (DPPH)· radical scavenging assays to determine the main antioxidant compounds isolated from sorghum were developed. These results will further help develop sorghum varieties containing polyphenols relevant to the potential prevention of human diseases

Integrating GRK2 and NFkappaB in the Pathophysiology of Cardiac Hypertrophy

G protein coupled receptor kinase type 2 (GRK2) plays an important role in the development and maintenance of cardiac hypertrophy and heart failure even if its exact role is still unknown. In this study, we assessed the effect of GRK2 on the regulation of cardiac hypertrophy. In H9C2 cells, GRK2 overexpression increased atrial natriuretic factor (ANF) activity and enhanced phenylephrine-induced ANF response, and this is associated with an increase of NFκB transcriptional activity. The kinase dead mutant and a synthetic inhibitor of GRK2 activity exerted the opposite effect, suggesting that GRK2 regulates hypertrophy through upregulation of NFκB activity in a phosphorylation-dependent manner. In two different in vivo models of left ventricle hypertrophy (LVH), the selective inhibition of GRK2 activity prevented hypertrophy and reduced NFκB transcription activity. Our results suggest a previously undisclosed role for GRK2 in the regulation of hypertrophic responses and propose GRK2 as potential therapeutic target for limiting LVH

Combined inhibition of AKT/mTOR and MDM2 enhances Glioblastoma Multiforme cell apoptosis and differentiation of cancer stem cells

The poor prognosis of Glioblastoma Multiforme (GBM) is due to a high resistance to conventional treatments and to the presence of a subpopulation of glioma stem cells (GSCs). Combination therapies targeting survival/self-renewal signals of GBM and GSCs are emerging as useful tools to improve GBM treatment. In this context, the hyperactivated AKT/mammalian target of the rapamycin (AKT/mTOR) and the inhibited wild-type p53 appear to be good candidates. Herein, the interaction between these pathways was investigated, using the novel AKT/mTOR inhibitor FC85 and ISA27, which re-activates p53 functionality by blocking its endogenous inhibitor murine double minute 2 homologue (MDM2). In GBM cells, FC85 efficiently inhibited AKT/mTOR signalling and reactivated p53 functionality, triggering cellular apoptosis. The combined therapy with ISA27 produced a synergic effect on the inhibition of cell viability and on the reactivation of p53 pathway. Most importantly, FC85 and ISA27 blocked proliferation and promoted the differentiation of GSCs. The simultaneous use of these compounds significantly enhanced GSC differentiation/apoptosis. These findings suggest that FC85 actively enhances the downstream p53 signalling and that a combination strategy aimed at inhibiting the AKT/mTOR pathway and re-activating p53 signalling is potentially effective in GBM and in GSCs

Detailed peptide profiling of “Scotta”: from a dairy waste to a source of potential health-promoting compound

“Scotta” is a liquid waste deriving from Ricotta cheese production, which is wrongly considered only a dairy by-product. In this work, with the aim to elucidate the presence of valuable bioactive compounds in Buffalo’s Scotta, a peptide fraction under 3000 Da was isolated by ultra-filtration, purified by solid-phase extraction, and,subsequently, characterized in detail by liquid chromatography coupled to Orbitrap mass spectrometry. Analytical results revealed a complex profile, leading to the identification of 226 peptides, belonging to alpha, beta, and kappa caseins. A database-driven search approach was used to assess the biological effects of some of the identified peptides. A wide range of healthy properties was ascribed to the encrypted peptides, comprising antihypertensive, antimicrobial, immunomodulating, opioid, antioxidant, and antithrombotic. The peptidomic profile of Scotta was highlighted in depth for the first time, and the results revealed that this matrix should not be considered only a mere by-product, but a source of potential health-promoting peptides, which can be recovered and employed in nutraceuticals and functional foods

A Novel Vasoactive Peptide “PG1” from Buffalo Ice-Cream Protects from Angiotensin-Evoked High Blood Pressure

Arterial hypertension is the most important risk factor for cardiovascular diseases, myocardial infarction, heart failure, renal failure and peripheral vascular disease. In the last decade, milk-derived bioactive peptides have attracted attention for their beneficial cardiovascular properties. Methods: Here, we combined in vitro chemical assay such as LC-MS/MS analysis of buffalo ice cream, ex vivo vascular studies evaluating endothelial and smooth muscle responses using pressure myograph, and translational assay testing in vivo the vascular actions of PG1 administration in murine models. Results: We demonstrate that a novel buffalo ice-cream-derived pentapeptide “QKEPM”, namely PG1, is a stable peptide that can be obtained at higher concentration after gastro-intestinal digestions (GID) of buffalo ice-cream (BIC). It owns potent vascular effect in counteract the effects of angiotensin II-evoked vasoconstriction and high blood pressure levels. Its effects are mediated by the inhibitory effect on AT1 receptor leading to a downregulation of p-ERK½/Rac1-GTP and consequent reduction of oxidative stress. Conclusions: These results strongly candidate PG1, as a novel bioactive peptide for the prevention and management of hypertension, thus expanding the armamentarium of preventive strategies aimed at reducing the incidence and progression of hypertension and its related cardiovascular complication