Cretan tea (Origanum dictamnus L.) as a functional beverage: an investigation on antiglycative and carbonyl trapping activities

Accumulation of advanced glycation end products (AGEs) in vivo is associated with many chronic disorders such as diabetes, renal failure, aging, and Alzheimer’s disease. The aim of this study was to expand the knowledge about the functional properties of Origanum dictamnus L. beverage (Cretan tea) by an investigation about the inhibitory effects on the formation of AGEs and the capacity to trap dicarbonyl compounds. Dittany infusion was characterized for its polyphenolic composition by RP-HPLC-DAD-ESI/MSn and twenty compounds were detected. Its antiglycative property was evaluated by in vitro BSA-sugar (glucose, fructose, and ribose) and BSA-methylglyoxal (MGO) assays, tests for the formation of Amadori products and dicarbonyl compounds, and the direct glyoxal (GO) and MGO trapping capacity. The infusion showed the highest inhibitory effect on the formation of dicarbonyl compounds and AGEs (activity values range from 72–100%) and only a weak effect on the formation of Amadori products, indicating that the antiglycative action occurred primarily during the last two phases of the non-enzymatic glycation reaction. These activities are partially correlated with the antioxidant/antiradical activity, as demonstrated by the scavenger capacity against the ABTS cation and DPPH stable radicals, and the reducing power. The registered high anti-AGE capacity could probably be ascribed to the dittany polyphenolic composition particularly rich in flavone derivatives. These findings support further investigations to study the feasibility of dittany as an antiglycative agent in food or cosmetic preparation

Hydrophilic interaction chromatography in food matrices analysis: an updated review

This review focuses on the most recent papers (from 2011 to submission date in 2017) dealing with the analysis of different organic components in foods (i.e. nucleobases, nucleosides, nucleotides, uric acid, and creatinine, amino acids and related compounds, choline-related compounds and phospholipids, carbohydrates, artificial sweeteners and polyphenolic compounds), using hydrophilic interaction liquid chromatography (HILIC) combined with different detection techniques. For each compound class, the investigated food matrices are grouped per: foods of animal origin, vegetables, fruits and related products, baby food, and other matrices such as drinks and mushrooms/fungi. Furthermore, the main advantages of HILIC chromatography respect to the other commonly used techniques are discussed

Polyphenolic profile of green/red spotted Italian Cichorium intybus salads by RP-HPLC-PDA-ESI-MSn

Today the consumption of fresh vegetables is highly recommended not only for the intake of nutrients, but also for the healthy properties of secondary metabolites involved in the prevention of many disorders. In the present work, phenolic acids and flavonoids extracted from four green (Cichorium intybus var. sativus and var. foliosum) and a red spotted (a cross between C. intybus var. silvestre cv “Treviso” and C. endivia var. foliosum) salads were characterized by high-performance liquid chromatography–electrospray ionization/mass spectrometry. Among the 76 compounds detected in this work, five organic acids (two malic acid derivatives, two pyroglutamic hexoside isomers, and cis-aconitic acid), ten hydroxycinnamic acid derivatives (ferulic, malonyl caffeoylquinic, and caffeoylmethylglutaroylquinic acids, cinnamoyl- and caffeoyl-malate, coumaroyl, sinapoyl, feruloyl, and coumaroylcaffeoyl glycosides, dicaffeoyl lactone, 3-O-caffeoyl-4-O-(3-hydroxyglutaroylquinic acid), four flavonols (quercetin-di-O-glucoside, quercetin-3-O-malonylhexosyl-7-O-hexoside, myricetin-3-O-glucoside, and isorhamnetin-3-O-glucoside), and cyanidin-3-O-glucuronyl-5-O-hexoside have been identified in chicory salads for the first time. These data, together with the results obtained in our previous investigations on Cichorium genus Italian salads, provide a contribution to a more exhaustive identification of the secondary metabolites profile of each considered plant, that could be also useful in building/selecting hybrids with agronomic and peculiar healthy features, even using traditional methods of cultivation

Artichoke (Cynara cardunculus L. var. scolymus) waste as a natural source of carbonyl trapping and antiglycative agents

The role of polyphenolic compounds extractable from artichoke solid wastes in the formation of advanced glycation end products (AGEs) was studied. Outer bracts and stems were extracted using different water-ethanol mixtures and HPLC-DAD analyses indicated aqueous and hydro-alcoholic 20:80 stem extracts as the richest in polyphenols. The samples were characterized in their phenolic composition (using mass spectrometry) and antioxidant capacity. Antiglycative capacity was evaluated by in vitro BSA-sugars (glucose, fructose, and ribose) and BSA-methylglyoxal (MGO) tests, formation of Amadori products assay, direct glyoxal (GO) and MGO trapping capacity. Results indicated both extracts as effective inhibitors of fructosamine formation and antiglycative agents. In particular, aqueous extract showed the best activity in the systems containing glucose and fructose, differently from ethanolic extract, that was demonstrated able to better inhibit AGEs formation when ribose or MGO act as precursors. Ethanolic extract was also shown to be able to trap MGO and GO, with efficiency increasing after 24 hours of incubation time. These activities are partially correlated with the antioxidant effect of the extract, as demonstrated by the scavenger capacity against ABTS cation and DPPH stable radicals; this relationship is evident when the model system, containing protein incubated with ribose or MGO, is considered. The different activities of the tested extracts could probably be ascribed to the different composition in chlorogenic acids (CQAs), being aqueous extract richer in 1-CQA, 3-CQA, and 1,3-di-CQA, and ethanolic extract in 5-CQA, caffeic acid, 1,5-di-CQA. These findings support further investigations to study the stability of the different CQAs in simil-physiological conditions and the feasibility of artichoke waste as antiglycative agents in food or pharmacological preparations

I. Technological approaches to improve the dissolution behavior of nateglinide, a lipophilic insoluble drug: Nanoparticles and co-mixing.

Nateglinide is a non-sulphonylurea insulinotropic oral antidiabetic agent. The main problem in formulating an oral dosage form is its low solubility in aqueous media. This problem is particularly critical for an anti-diabetic drug because it should be administered just before the meals and be quickly bioavailable to cover the post-prandial glycemic peak. In this work, some technological approaches have been studied to improve the dissolution rate of nateglinide. Furthermore, two different polymorphs of nateglinide (H and B) have been tested to evaluate the influence of the crystal habitus on the dissolution behavior of the drug. The results have clearly demonstrated that wettability plays a key role in the dissolution behavior of nateglinide. As a matter of fact the physical dispersion of the drug with colloidal silica or hydrophilic swellable polymers strongly enhances the dissolution rate of nateglinide. The two polymorphs tested did not show significant differences in terms of dissolution behavior

II. Technological approaches to improve the dissolution behavior of nateglinide, a lipophilic insoluble drug: Co-milling.

Nateglinide is an oral antidiabetic agent that should be administered 10-30min before the meal, but it shows low and pH-dependent solubility that may reduce its oral bioavailability. To improve nateglinide dissolution rate, the active was co-milled with three different super-disintegrants or with some hydrophilic excipients, in 1:1, 1:2, and 1:4 drug to carrier ratio (w:w). The three super-disintegrants were crosslinked polyvinylpyrrolidone (PVPC), sodium starch glycolate (SSG) and crosslinked carboxymethyl cellulose (CMCC). The three hydrophilic excipient were amorphous silica (AS), mannitol (M) and Poloxamer (PO). A strong enhancement of drug dissolution rate was obtained from the nateglinide:super-disintegrant co-milled systems in 1:4 ratio, which can be explained by a combination of several factors: an increase in wettability, due to the hydrophilic nature of the carriers, a possible reduction of particle size and a more intimate dispersion of the drug onto the carrier, as a result of the mechanical treatment

Compatibility of paroxetine hydrochloride and GW597599B. A physico-chemical approach

In this study, we present a full thermal characterization of antidepressant paroxetine and summarize the results for another drug which treats depression: GW597599B. The main aim is to analyze how the thermodynamic and structural properties of these compounds are modified when the two drugs are mixed in the solid state. We begin by putting into evidence how dehydration and melting concur in shaping the calorimetric curves of paroxetine under different experimental conditions. Equipped with this knowledge, we are able to interpret the thermal response of the physical mixtures paroxetine:GW597599B, in terms of partial eutectic formation and simple superposition of contribution from the two compounds

Preparation and physico-chemical characterization of acyclovir co-crystals with improved dissolution properties.

Acyclovir is a well-known antiviral agent. It can be administered in very high doses (from 200 to 1000 mg even three–four times daily). It has absorption problems mainly due to its poor solubility in water (about 0.2 g/100 mL at 25◦C) and its oral bioavailability is approximately 15%–20% with a half-life of about 3 h. To improve acyclovir solubility and/or its dissolution properties, two cocrystals of this drug were successfully produced with glutaric acid (AGA1:1) and fumaric acid (AFA1:1) as conformers, using a cogrinding method. Their effective formation was investigated by a broad range of techniques: thermal analysis, Fourier transform infrared spectroscopy, X- ray powder diffraction, solid state nuclear magnetic resonance, and scanning electron microscopy coupled with energy dispersive X-ray spectrometry. The water solubility of the AGA1:1 cocrystal was not improved in comparison to acyclovir, while AFA1:1 showed a slight increased solubility at equilibrium. The main difference was detected in terms of intrinsic dissolution rates (IDR). The IDR of the new phases were much faster compared with acyclovir, particularly at neutral pH. AFA1:1 showed the most rapid dissolution behavior in water; within 10 min, the drug was released completely, while just 60% of acyclovir was dissolved in 1 h

Preparation and characterization of carprofen co-crystals

Carprofen co-crystals with selected co-formers were prepared by solvent evaporation and wet/dry grinding methods. Their effective formation was investigated by thermal analysis, FT-IR, X-ray single crystal and powder diffraction and SEM-EDS. This last technique has been applied for the first time to co-crystals since it provides unambiguous confirmation of co-crystal formation. Among the investigated co-formers we studied, only 4,40-dipyridyl yields co-crystals. Two different crystal structures are obtained when the molar ratio of carprofen : 4,40-dipyridyl is 2 : 1 (triclinic cell) and 1 : 1.5 (monoclinic cell). The asymmetric triclinic cell (Z ¼ 2) contains two carprofen and two half 4,40-dipyridyl moieties while the monoclinic cell (Z ¼ 4) contains a single carprofen, and one and a half 4,40-dipyridyl moieties. Several hydrogen-bond supramolecular synthons can be identified in the solid state. For both the 2 : 1 and 1 : 1.5 co-crystals, the main hydrogen-bond interaction consists of an O–H/N heterosynthon involving, as a donor, the COOH group of carprofen and, as a H-acceptor, the nitrogen of a 4,40-dipyridyl molecule. The two co-crystals have characteristic FT-IR spectra and slightly different melting temperatures. X-Ray powder diffraction patterns of the 1 : 1 and 1 : 2 compositions reveal a mixture of phases, whose amount is quantified with Rietveld analysis