Lucia Crascì

Heteroarylimino-4-thiazolidinones as inhibitors of cartilage degradation.

2-Benzo[d]thiazolyl- and 2-benzo[d]isothiazolyl-imino-5-benzylidene-4-thiazolidinone derivatives were investigated as potential metalloproteinases (MMPs) inhibitors and evaluated for their antidegenerative activity on human chondrocyte cultures stimulated by IL-1β, using an experimental model that reproduces the mechanisms involved in osteoarthritic (OA) diseases. Cell viability, the amount of glycosaminoglycans (GAGs) and the production of nitric oxide (NO) were measured. The most potent compound, 5-(4-methoxy-benzylidene)-2-(benzo[d]isothiazol-3-ylimino)-thiazolidin-4-one (4b), a MMP-13 inhibitor at nanomolar concentration (IC(50)=0.036 μM), could be considered as a lead compound for the development of novel clinical agents, inhibitors of cartilage degradation, for the treatment of OA.

Antioxidant activity of idebenone-loaded neutral and cationic solid–lipid nanoparticles

Abstract Idebenone (IDE) is a lipophilic benzoquinone electron carrier synthetic analogue of coenzyme Q10, which behaves as an antioxidant and free radical scavenging molecule. Recently, the therapeutic application of IDE in Leber’s hereditary optic neuropathy has been discussed. This work was aimed at evaluating the encapsulation of IDE in solid–lipid nanoparticles (SLN). In particular, we tested the possibility of adapting the quasi-emulsion solvent diffusion technique, already proposed to produce polymeric nanoparticles, to prepare positively charged SLN with different compositions. Such a charge, due to the addition of a cationic lipid, would facilitate the interaction with the negatively charged eye surface epithelium, with a consequent longer pre-corneal residence time of the colloidal systems. In a preliminary evaluation of the produced IDE-loaded SLN, the antioxidant activity of the drug was demonstrated using an oxygen radical absorbance capacity assay. Encapsulation of the drug in the nanocarrier systems seems able to protect IDE from degradation and prolong its antioxidant potential.

Benzisothiazolyliminothiazolidin-4-ones with Chondroprotective Properties: Searching for Potent and Selective Inhibitors of MMP-13

Matrix metalloproteinase-13 (MMP-13) plays a key role in the degradation of type II collagen in cartilage and bone in osteoarthritis. Nonselective inhibition of different MMPs by the early inhibitors appears to be the reason for their toxicity and limited efficacy. Recent findings suggest that selective inhibition of MMP-13 could avoid toxicity and that non-zinc-chelating MMP inhibitors appear to be the most promising agents toward achieving selectivity, since the allosteric binding sites are not shared by different MMPs. Biochemical, histological and clinical models support this findings. [1b,3] Therefore, effective MMP-13 inhibition would be a novel, disease-modifying therapy for the treatment of osteoarthritis. Our recent efforts in the search for new agents with antidegenerative activity, as evaluated in human chondrocyte cultures stimulated by IL-1b, have resulted in the discovery of a series of heteroarylimino-4-thiazolidinones that significantly inhibit MMPs and other inflammatory mediators. Among these, a potent and selective MMP-13 inhibitor has been identified (MMP-13, IC50 = 0.036 mm ; MMP-3, IC50 >100 mm) based upon a 2-(benzo[d]isothiazol-3-ylimino)-5-(4-methoxybenzylidene)thiazolidin-4-one scaffold (1; Figure 1). The presence of the elec-

Natural antioxidant polyphenols on inflammation management: Anti-glycation activity vs metalloproteinases inhibition

ABSTRACT 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.

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.

2-Benzisothiazolylimino-5-benzylidene-4-thiazolidinones as protective agents against cartilage destruction

We report the synthesis, the antioxidant and the inhibitory activity (IC50) on metalloproteinases (MMPs) 3 and 13 of 2-benzo[d]isothiazolylimino-5-benzylidene-4-thiazolidinones. Their potential as protective agents in osteoarthritis (OA) was evaluated by biological assays on chondrocytes cultures, stimulated by IL-1β. The chondroprotective capability, related both to antioxidant activity and to inhibition of MMPs, was studied in vitro, by determining nitric oxide production and glycosaminoglycans release. Moreover, selected derivatives 1h and 1g was studied for nuclear factor kappaB (NF-κB) inhibition by Western Blot analysis and for MMP-3 protein release using ELISA test. The structure-activity relationship of tested compounds demonstrates a favorable effect of the para substitution on the 5-benzilydene ring. Compound 1g shows a potent and selective activity on MMP-3 versus MMP-13. Accordingly, 1g possesses high antioxidant effect, NO lowering and GAGs restoring capability and also reduces the production of MMPs and NF-κB expression. Thus 1g can be considered as new potential chondroprotective agents.

5-Arylidene-4-Thiazolidinone Derivatives Active as Antidegenerative Agents on Human Chondrocyte Cultures

5-Arylidene-2-oxo-4-thiazolidinones and 2-phenylimino analogues were evaluated for their antidegenerative activity on human chondrocyte cultures stimulated by IL-1β and for their inhibitory capability against matrix metalloproteinase- 13. Our results indicated that 5-arylidene-4-thiazolidinone derivatives 1-9 exhibit antidegenerative activity and could block multiple cartilage destruction during the osteoarthritic process. Out of the selected compounds, (5-arylidene- 2,4-dioxothiazolidin-3-yl)acetic acids 7-9 showed significant effectiveness in reducing NO release and restoring normal levels of GAGs in chondrocytes treated with IL-1β. Moreover, benzoic acids 1, 5 and 6 proved to be effective MMP-13 inhibitors and were able to restore normal levels of GAGs.

Nanostructured lipid dispersions for topical administration of crocin, a potent antioxidant from saffron (Crocus sativus L.)

Crocin, a potent antioxidant obtained from saffron, shows anticancer activity in in vivo models. Unfortunately unfavorable physicochemical features compromise its use in topical therapy. The present study describes the preparation and characterization of nanostructured lipid dispersions as drug delivery systems for topical administration of crocin and the evaluation of antioxidant and antiproliferative effects of crocin once encapsulated into nanostructured lipid dispersions. Nanostructured lipid dispersions based on monoolein in mixture with sodium cholate and sodium caseinate have been characterized by cryo-TEM and PCS. Crocin permeation was evaluated in vitro by Franz cells, while the oxygen radical absorbance capacity assay was used to evaluate the antioxidant activity. Furthermore, the antiproliferative activity was tested in vitro by the MTT test using a human melanoma cell line. The emulsification of monoolein with sodium cholate and sodium caseinate led to dispersions of cubosomes, hexasomes, sponge systems and vesicles, depending on the employed emulsifiers. Permeation and shelf life studies demonstrated that nanostructured lipid dispersions enabled to control both rate of crocin diffusion through the skin and crocin degradation. The oxygen radical absorbance capacity assay pointed out an interesting and prolonged antioxidant activity of crocin while the MTT test showed an increase of crocin cytotoxic effect after incorporation in nanostructured lipid dispersions. This work has highlighted that nanostructured lipid dispersions can protect the labile molecule crocin from degradation, control its skin diffusion and prolong antioxidant activity, therefore suggesting the suitability of nanostructured lipid dispersions for crocin topical administration.

Evaluation of the anti-inflammatory/chondroprotective activity of aldose reductase inhibitors in human chondrocyte cultures

(5-Arylidene-4-oxo-2-thioxothiazolidin-3-yl)acetic acids (6) and 5-arylidene-4-oxo-2-thioxothiazolidines (7), which we recently synthesised and assayed as aldose reductase inhibitors, were evaluated as anti-inflammatory/antidegenerative agents in cultures of human chondrocytes stimulated by IL-1β. In this screening, most of the tested compounds were able to control key components of the IL-1β-induced inflammatory signalling, by reducing the levels of NF-kB, ICAM-1, and NO as well as increasing the production of glycosaminoglycans by chondrocytes. Moreover, these 4-thiazolidinone derivatives exhibited antioxidant properties and were shown to inhibit MMP-3 and MMP-13 at micromolar concentrations, with a generally marked preference toward MMP-13 which plays a major role in cartilage degeneration. Thus, on the whole, compounds 6 and 7 were shown to be capable of both counteracting inflammatory events and contributing to restore normal levels of cartilage components. This anti-inflammatory/antidegenerative profile makes them interesting cell-permeable molecules that can be assumed as lead compounds in the search for novel anti-inflammatory agents.

Antioxidant capability and phytochemicals content of Sicilian prickly fruits

Abstract The aim of the present study is to compare three cultivars of prickly pear fruits (“Sanguigna” red, “Sulfarina” yellow and “Muscaredda” white) regarding the quality parameters of antioxidant activity, phenolic compounds, betalains and ascorbic acid (vitamin C). Depending on the crop operation, these cultivars are represented by “Agostane” and “Bastardoni” and are located at an altitude between 150 and 750 m, above sea level. Their antioxidant activity was evaluated by ORAC assay. Total phenolic compounds, betalains and ascorbic acid recovered from pulp juice, were determined by a spectrophotometric analysis. The results indicate that the different cultivars of prickly pear possess antioxidant activity in function of the type of the adopted practice. These fruits were derived from the practice of scozzolatura, by dropping the berries to encourage a second bloom of the plant. Among the “Bastardoni”, the “Sulfarina” possesses the highest antioxidant activity.