Lipomatrix: A Novel Ascorbyl Palmitate-Based Lipid Matrix to Enhancing Enteric Absorption of Serenoa Repens Oil.

The class of lipophilic compounds coming from vegetal source represents a perspective in the adjuvant treatment of several human diseases, despite their poor bioavailability in humans. These compounds are generally soluble in fats and poorly soluble in water. The major reason for the poor bioavailability of lipophilic natural compounds after oral uptake in humans is related to their reduced solubility in enteric water-based fluids, leading to an ineffective contact with absorbing epithelium. The main goal to ensure efficacy of such compounds is then creating technological conditions to deliver them into the first enteric tract as hydro-dispersible forms to maximize epithelial absorption. The present work describes and characterizes a new technological matrix (Lipomatrix, Labomar Research, Istrana, TV, Italy) based on a molten fats core in which Ascorbyl Palmitate is embedded, able to deliver lipophilic compounds in a well-dispersed and emulsified form once exposed to duodenal fluids. Authors describe and quantify Lipomatrix delivery of Serenoa repens oil through an innovative in vitro model of human gastro-enteric digestion, reporting results of its improved bioaccessibility, enteric absorption and efficacy compared with not formulated Serenoa repens oil-containing commercial products using in vitro models of human intestine and prostatic tissue.

In Absence of the Cellular Prion Protein, Alterations in Copper Metabolism and Copper-Dependent Oxidase Activity Affect Iron Distribution.

Essential elements as copper and iron modulate a wide range of physiological functions. Their metabolism is strictly regulated by cellular pathways, since dysregulation of metal homeostasis is responsible for many detrimental effects. Neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and prion diseases are characterized by alterations of metal ions. These neurodegenerative maladies involve proteins that bind metals and mediate their metabolism through not well-defined mechanisms. Prion protein, for instance, interacts with divalent cations via multiple metal-binding sites and it modulates several metal-dependent physiological functions, such as S-nitrosylation of NMDA receptors. In this work we focused on the effect of prion protein absence on copper and iron metabolism during development and adulthood. In particular, we investigated copper and iron functional values in serum and several organs such as liver, spleen, total brain and isolated hippocampus. Our results show that iron content is diminished in prion protein-null mouse serum, while it accumulates in liver and spleen. Our data suggest that these alterations can be due to impairments in copper-dependent cerulopalsmin activity which is known to affect iron mobilization. In prion protein-null mouse total brain and hippocampus, metal ion content shows a fluctuating trend, suggesting the presence of homeostatic compensatory mechanisms. However, copper and iron functional values are likely altered also in these two organs, as indicated by the modulation of metal-binding protein expression levels. Altogether, these results reveal that the absence of the cellular prion protein impairs copper metabolism and copper-dependent oxidase activity, with ensuing alteration of iron mobilization from cellular storage compartments.

Prion protein and copper cooperatively protect neurons by modulating NMDA receptor through S-nitrosylation.

AIMS: Several neurodegenerative disorders show alterations in glutamatergic synapses and increased susceptibility to excitotoxicity. Mounting evidence suggests a central role for the cellular prion protein (PrP(C)) in neuroprotection. Therefore, the loss of PrP(C) function occurring in prion disorders may contribute to the disease progression and neurodegeneration. Indeed, PrP(C) modulates N-methyl-d-aspartate receptors (NMDAR), thus preventing cell death. In this study, we show that PrP(C) and copper cooperatively inhibit NMDAR through S-nitrosylation, a post-translational modification resulting from the chemical reaction of nitric oxide (NO) with cysteines. RESULTS: Comparing wild-type Prnp (Prnp(+/+)) and PrP(C) knockout (Prnp(0/0)) mouse hippocampi, we found that GluN1 and GluN2A S-nitrosylation decrease in Prnp(0/0). Using organotypic hippocampal cultures, we found that copper chelation decreases NMDAR S-nitrosylation in Prnp(+/+) but not in Prnp(0/0). This suggests that PrP(C) requires copper to support the chemical reaction between NO and thiols. We explored PrP(C)-Cu neuroprotective role by evaluating neuron susceptibility to excitotoxicity in Prnp(+/+) and Prnp(0/0) cultures. We found that (i) PrP(C)-Cu modulates GluN2A-containing NMDAR, those inhibited by S-nitrosylation; (ii) PrP(C) and copper are interdependent to protect neurons from insults; (iii) neuronal NO synthase inhibition affects susceptibility in wild-type but not in Prnp(0/0), while (iv) the addition of a NO donor enhances Prnp(0/0) neurons survival. INNOVATION AND CONCLUSIONS: Our results show that PrP(C) and copper support NMDAR S-nitrosylation and cooperatively exert neuroprotection. In addition to NMDAR, PrP(C) may also favor the S-nitrosylation of other proteins. Therefore, this mechanism may be investigated in the context of the different cellular processes in which PrP(C) is involved.