Allergenic Lipid Transfer Proteins from Plant-Derived Foods Do Not Immunologically and Clinically Behave Homogeneously: The Kiwifruit LTP as a Model

BACKGROUND: Food allergy is increasingly common worldwide. Tools for allergy diagnosis measuring IgE improved much since allergenic molecules and microarrays started to be used. IgE response toward allergens belonging to the same group of molecules has not been comprehensively explored using such approach yet. OBJECTIVE: Using the model of lipid transfer proteins (LTPs) from plants as allergens, including two new structures, we sought to define how heterogeneous is the behavior of homologous proteins. METHODS: Two new allergenic LTPs, Act d 10 and Act c 10, have been identified in green (Actinidia deliciosa) and gold (Actinidia chinensis) kiwifruit (KF), respectively, using clinically characterized allergic patients, and their biochemical features comparatively evaluated by means of amino acid sequence alignments. Along with other five LTPs from peach, mulberry, hazelnut, peanut, mugwort, KF LTPs, preliminary tested positive for IgE, have been immobilized on a microarray, used for IgE testing 1,003 allergic subjects. Comparative analysis has been carried out. RESULTS: Alignment of Act d 10 primary structure with the other allergenic LTPs shows amino acid identities to be in a narrow range between 40 and 55%, with a number of substitutions making the sequences quite different from each other. Although peach LTP dominates the IgE immune response in terms of prevalence, epitope recognition driven by sequence heterogeneity has been recorded to be distributed in a wide range of behaviors. KF LTPs IgE positive results were obtained in a patient subset IgE positive for the peach LTP. Anyhow, the negative results on homologous molecules allowed us to reintroduce KF in patients' diet. CONCLUSION: The biochemical nature of allergenic molecule belonging to a group of homologous ones should not be taken as proof of immunological recognition as well. The availability of panels of homologous molecules to be tested using microarrays is valuable to address the therapeutic intervention

Natural Antioxidant Polyphenols On Inflammation Management: Anti-glycation Activity Vs Metalloproteinases Inhibition.

The diet polyphenols are a secondary metabolites of plants able to act on inflammation process. Their anti-inflammatory activity is articulated through several mechanisms that are related to their antioxidative and radical scavengers properties. Our work is focused on a novel approach to inflammatory disease management, based on anti-glycative and matrix metalloproteinases (MMPs) inhibition effects, as a connected phenomena. To better understand these correlation, polyphenols Structure-Activity Relationship (SAR) studies were also reported. The antioxidant polyphenols inhibit the AGEs at different levels of the glycation process in the following ways: 1) prevention of Amadori adduct oxidation; 2) trapping reactive dycarbonyl compounds; 3) attenuation of receptor for AGEs (RAGE) expression. Moreover, several flavonoids with radical scavenging property showed also MMPs inhibition interact directly with MMPs or indirectly via radical scavengers and AGEs reduction. The essential polyphenols features involved in these mechanisms are C2-C3 double bond and number and position of hydroxyl, glycosyl and O-methyl groups. These factors induce a change in molecular planarity interfering with the hydrogen bond formation, electron delocalization and metal ion chelation. In particular, C2-C3 double bond improve the antioxidant and MMPs inhibition, while the hydroxylation, glycosylation and methylation induce a positive and negative correlation respectively

Dynamic Olfactometry: evaluation of odour intensity and stability of Citronella Oil loaded Solid Lipid Nanoparticles

The Dynamic Olfactometry is a satisfactory method to determine objectively the odour concentration of volatile samples, using a human selected panel. The essential oils (EOs) are composed by lipophilic and highly volatile secondary plant metabolites, including terpenoids, phenol-derived aromatic and aliphatic components. The terpenoids are volatile organic compounds (VOCs) that undergo to oxidative and isomerizzation processes due to the air, light, moisture and high temperatures. Moreover, as a consequence of the high vapour tension of VOCs, the efficacy of EOs are very limited in the time. The Citronella Oil (C.O.) is used extensively as a source of perfumery chemicals or repellent substances, as citronellolal, citronellol and geraniol, that are responsible to their instability. The nanoencapsulation in drug delivery systems represents an efficient strategy to improve the stability and efficacy of EOs-based formulations. In this work the C.O. is formulated in solid lipid nanoparticles (SLNs), by ultrasonication method. The mean diameter (MD), polidispersity index (PDI) and zeta potential (PZ) of C.O. loaded SLN are determined immediately and after one month from production, showing a good long term stability. The aim of the work is the evaluation of odour concentration of C.O. free and loaded in SLN, in order to understand how the formulation can influence volatility, stability and release in SLN formulation. The Dynamic Olfactometry is performed, according to the regulation UNI EN 13725:2004. The results are expressed in OUE/m3 (European Odour Unit, OUE for m3), that represents the amount of odorant, evaporated in 1 m3 of neutral gas, inducing a physiological response, equal to a reference gas used, n-butanol, on a panel. The figure 1 and 2 showed the relationship between the odour intensity (OUE/m3) of the free oil and loaded in SLN, at 2.5% and 0.25%, respectively. The odour intensity is followed for 96 hours. After 24 hours, the odour intensity of free oil is not perceptible at both concentrations used. On the contrary, the odour intensity of C.O. loaded in SLN at 96 hours is 580 OUE/m3, at 2.5%, and 250 OUE/m3, at 0.25%. The obtained results for C.O. loaded in SLN at 2.5% and 0.25%, confirmed a prolonged and concentration-dependent effect of C.O. formulations

Development and In Vitro Evaluation of an Innovative “Dietary Flavonoid Supplement” on Osteoarthritis Process

The aim of this study was to evaluate the antidegenerative effect in osteoarthritis damage of eriocitrin alone and eriocitrin formulated as innovative “dietary flavonoid supplement.” A complexation between eriocitrin and hydroxypropyl β-cyclodextrin by solubilization/freeze-drying method was performed. The complex in solution was evaluated by phase solubility studies and the optimal 1 : 2 flavanone/cyclodextrin molar ratio was selected. Hydroxypropyl β-cyclodextrin was able to complex eriocitrin as confirmed by UV-Vis absorption, DSC, and FTIR studies. The complex formed increased the eriocitrin water solubility (from 4.1±0.2 g·L−1 to 11.0±0.1 g·L−1) and dissolution rate (from 37.0% to 100%) in 30 min. The in vitro studies exhibit the notion that eriocitrin and its complex inhibit AGEs in a similar manner because hydroxypropyl β-cyclodextrin does not interfere with the flavanone intrinsic property. Instead, the presence of cyclodextrin improves eriocitrin antioxidant stability maintaining a high fluorescence value until 8 hours with respect to the pure materials. Moreover, hydroxypropyl β-cyclodextrin showed moderate GAGs restoration acting synergistically with the complexed compound to maintain the structural chondrocytes integrity. The results point out that ERT/HP-betaCD complex possesses technological and biological characteristics able to obtain an easily soluble nutraceutical product, which reduces the degenerative and oxidative damage which occurs in osteoarthritis, and improve the patient compliance

Encapsulation of a citrus by-product extract: Development, characterization and stability studies of a nutraceutical with antioxidant and metalloproteinases inhibitory activity

Spray-dried aqueous extract from citrus by-product (“pastazzo”, ExO) was studied to evaluate the polyphenols content, the antioxidant properties and the inhibition of metalloproteinases over-expressed in dysmetabolic disease. During shelf life studies, ExO changes polyphenols content and decreases the antioxidant properties. Furthermore, Citrus flavonoids are unstable in gastric environment and ExO showed an incomplete in vitro dissolution rate in simulated biological fluids, probably due to their low solubility. For these reasons, formulation studies have been performed to develop spray-dried gastroresistant microsystems for oral administration. Our studies revealed that all the prepared gastroresistant microsystems preserved the polyphenols content, prolonged the shelf-life and the antioxidant efficiency of ExO and maintaining its inhibitory effects on metalloproteinases

Nanostructured Lipid Carriers (NLC) as Vehicles for Topical Administration of Sesamol: In Vitro Percutaneous Absorption Study and Evaluation of Antioxidant Activity

Sesamol is a natural phenolic compound extracted from Sesamum indicum seed oil. Sesamol is endowed with several beneficial effects, but its use as a topical agent is strongly compromised by unfavorable chemical-physical properties. Therefore, to improve its characteristics, the aim of the present work was the formulation of nanostructured lipid carriers as drug delivery systems for topical administration of sesamol. Two different nanostructured lipid carrier systems have been produced based on the same solid lipid (Compritol® 888 ATO) but in a mixture with two different kinds of oil phase such as Miglyol® 812 (nanostructured lipid carrier-M) and sesame oil (nanostructured lipid carrier-PLUS). Morphology and dimensional distribution of nanostructured lipid carriers have been characterized by differential scanning calorimetry and photon correlation spectroscopy, respectively. The release pattern of sesamol from nanostructured lipid carriers was evaluated in vitro determining drug percutaneous absorption through excised human skin. Furthermore, an oxygen radical absorbance capacity assay was used to determine their antioxidant activity. From the results obtained, the method used to formulate nanostructured lipid carriers led to a homogeneous dispersion of particles in a nanometric range. Sesamol has been encapsulated efficiently in both nanostructured lipid carriers, with higher encapsulation efficiency values (> 90?%) when sesame oil was used as the oil phase (nanostructured lipid carrier-PLUS). In vitro evidences show that nanostructured lipid carrier dispersions were able to control the rate of sesamol diffusion through the skin, with respect to the reference formulations. Furthermore, the oxygen radical absorbance capacity assay pointed out an interesting and prolonged antioxidant activity of sesamol, especially when vehiculated by nanostructured lipid carrier-PLUS

An Alginate/Cyclodextrin Spray Drying Matrix to Improve Shelf Life and Antioxidant Efficiency of a Blood Orange By-Product Extract Rich in Polyphenols: MMPs Inhibition and Antiglycation Activity in Dysmetabolic Diseases

Alginate and β-cyclodextrin were used to produce easily dosable and spray-dried microsystems of a dried blood orange extract with antidysmetabolic properties, obtained from a by-product fluid extract. The spray-dried applied conditions were able to obtain a concentrate dried extract without the loss of AOA and with TPC and TMA values of 35–40% higher than that of the starting material. They were also effective in producing microparticles with 80–100% of encapsulation efficiency. The 2% sodium alginate was capable of improving the extract shelf life, while the beta-cyclodextrin (1 : 1 molar ratio with dried extract) prolonged the extract antioxidant efficiency by 6 hours. The good inhibition effect of the dried extract on the AGE formation and the MMP-2 and MMP-9 activity is presumably due to a synergic effect exerted by both anthocyanin and bioflavonoid extract compounds and was improved by the use of alginate and cyclodextrin