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Several clinical studies have shown that exposure of skin to solar ultraviolet (UV) radiation causes adverse effects, such as inflammation, oxidative stress and DNA damage. As a result, different skin disorders can arise, among which are skin cancer, including non-melanoma skin cancer (NMSC) and melanoma (MM). Phenolic compounds are plant-derived secondary metabolites with a well-known antioxidant activity, able to counteract the negative effects of UV radiation. In this review, we discuss the effects of some selected phenols on NMSC and MM, demonstrating that they can be useful in the prevention and in the treatment of these types of tumors. Moreover, we report the mechanisms by which these phenols carry out their antitumor action. In vitro and in vivo studies have highlighted that many phenols are capable of inducing photoprotection, apoptosis and autophagy. They can also reduce DNA methylation, tumorigenesis, tumor incidence and proliferation. Moreover, we describe some examples of plant extracts, whose anticancer activity appears to be better than that of single phenols. A great concordance of results emerged, despite the differences in experimental methods. Therefore, the knowledge compiled here could provide the basis for conducting some well-organized clinical trials to validate the chemopreventive and the therapeutic potential of some phenolic compounds in patients with NMSC and MM.

Polyhydroxyalkanoates (PHAs) are a family of biopolyesters synthesized by various microorganisms. Due to their biocompatibility and biodegradation, PHAs have been proposed for biomedical applications, including tissue engineering scaffolds. Olive leaf extract (OLE) can be obtained from agri-food biowaste and is a source of polyphenols with remarkable antioxidant properties. This study aimed at incorporating OLE inside poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV) fibers via electrospinning to obtain bioactive bio-based blends that are useful in wound healing. PHBHV/OLE electrospun fibers with a size of 1.29 ± 0.34 µm were obtained. Fourier transform infrared chemical analysis showed a uniform surface distribution of hydrophilic -OH groups, confirming the presence of OLE in the electrospun fibers. The main OLE phenols were released from the fibers within 6 days. The biodegradation of the scaffolds in phosphate buffered saline was investigated, demonstrating an adequate stability in the presence of metalloproteinase 9 (MMP-9), an enzyme produced in chronic wounds. The scaffolds were preliminarily tested in vitro with HFFF2 fibroblasts and HaCaT keratinocytes, suggesting adequate cytocompatibility. PHBHV/OLE fiber meshes hold promising features for wound healing, including the treatment of ulcers, due to the long period of durability in an inflamed tissue environment and adequate cytocompatibility.

A growing body of evidence underlines the crucial role of GPR55 in physiological and pathological conditions. In fact, GPR55 has recently emerged as a therapeutic target for several diseases, including cancer and neurodegenerative and metabolic disorders. Several lines of evidence highlight GPR55′s involvement in the regulation of microglia-mediated neuroinflammation, although the exact molecular mechanism has not been yet elucidated. Nevertheless, there are only a limited number of selective GPR55 ligands reported in the literature. In this work, we designed and synthesized a series of novel GPR55 ligands based on the 3-benzylquinolin-2(1H)-one scaffold, some of which showed excellent binding properties (with Ki values in the low nanomolar range) and almost complete selectivity over cannabinoid receptors. The full agonist profile of all the new derivatives was assessed using the p-ERK activation assay and a computational study was conducted to predict the key interactions with the binding site of the receptor. Our data outline a preliminary structure–activity relationship (SAR) for this class of molecules at GPR55. Some of our compounds are among the most potent GPR55 agonists developed to date and could be useful as tools to validate this receptor as a therapeutic target.

We previously reported the 2-oxopyridine-3-carboxamide derivative EC21a as the first small synthetic CB2R positive allosteric modulator which displayed antinociceptive activity in vivo in an experimental mouse model of neuropathic pain. Herein, we extended the structure-activity relationships of EC21a through structural modifications regarding the p-fluoro benzyl moiety at position 1 and the amide group in position 3 of the central core. The characterization in vitro was assessed through radioligand binding experiments and functional assays (GTPγS, cAMP, βarrestin2). Among the new compounds, the derivatives A1 (SV-10a) and A5 (SB-13a) characterized respectively by fluorine atom or by chlorine atom in ortho position of the benzylic group at position 1 and by a cycloheptane-carboxamide at position 3 of the central core, showed positive allosteric behavior on CB2R. They enhanced the efficacy of CP55,940 in [35S]GTPγS assay, and modulated CP55,940-dependent βarrestin2 recruitment and cAMP inhibition. The obtained results extend our knowledge of the structural requirements for interaction with the allosteric site of CB2R.

Multiple sclerosis is a chronic inflammatory demyelinating disorder of the central nervous system that eventually leads to progressive neurodegeneration and disability. Recent findings highlighted the emerging role of each target of the endocannabinoid system in controlling the symptoms and disease progression of multiple sclerosis. Therefore, multi-target modulators of the endocannabinoid system could provide a more effective pharmacological strategy as compared to the single target modulation. In this work, N-cycloheptyl-1,2-dihydro-5-bromo-1-(4-fluorobenzyl)-6-methyl-2-oxo-pyridine-3-carboxamide (B2) was identified as the most promising compound with dual agonism at cannabinoid receptors type-1 and cannabinoid receptors type-2 and good drug-like properties. In in vitro assays, B2 reduced glutamate release from rat synaptosomes through interaction with cannabinoid receptors type-1 and modulated the production of the pro- and anti-inflammatory cytokines (interleukins IL-1β and IL-6 and interleukin IL-10 respectively) via cannabinoid receptors type-2 activation. Furthermore, B2 demonstrated antinociceptive effects in an animal model of neuropathic pain and efficacy in an experimental autoimmune encephalomyelitis model of multiple sclerosis.

The direct activation of cannabinoid receptors (CBRs) results in several beneficial effects; therefore several CBRs ligands have been synthesized and tested in vitro and in vivo. However, none of them reached an advanced phase of clinical development due mainly to side effects on the CNS. Medicinal chemistry approaches are now engaged to develop allosteric modulators that might offer a novel therapeutic approach to achieve potential therapeutic benefits avoiding inherent side effects of orthosteric ligands. Here we identify the first ever synthesized positive allosteric modulator (PAM) that targets CB2Rs. The evidence for this was obtained using [3H]CP55940 and [35S]GTPγS binding assays. This finding will be useful for the characterization of allosteric binding site(s) on CB2Rs which will be essential for the further development of CB2R allosteric modulators. Moreover, the new CB2R PAM displayed antinociceptive activity in vivo in an experimental mouse model of neuropathic pain, raising the possibility th...

In this work, we explored the molecular framework of the known CB1R allosteric modulator PSNCBAM-1 with the aim to generate new bioactive analogs and to deepen the structure-activity relationships of this type of compounds. In particular, the introduction of a NH group between the pyridine ring and the phenyl nucleus generated the amino-phenyl-urea derivative SN15b that behaved as a positive allosteric modulator (PAM), increasing the CB1R binding affinity of the orthosteric ligand CP55,940. The functional activity was evaluated using serum response element (SRE) assay, which assesses the CB1R-dependent activation of the MAPK/ERK signaling pathway. SN15b and the biphenyl-urea analog SC4a significantly inhibited the response produced by CP55,940 in the low µM range, thus behaving as negative allosteric modulators (NAMs). The new derivatives presented here provide further insights about the modulation of CB1R binding and functional activity by allosteric ligands.

A novel series of variously substituted N-[3-(9H-carbazol-9-yl)-2-hydroxypropyl]-arylsulfonamides has been synthesized and assayed for β-Secretase (BACE1) inhibitory activity. BACE1 is a widely recognized drug target for the prevention and treatment of Alzheimer's Disease (AD). The introduction of benzyl substituents on the nitrogen atom of the arylsulfonamide moiety has so far led to the best results, with three derivatives showing IC50 values ranging from 1.6 to 1.9 μM. Therefore, a significant improvement over the previously reported series of N-carboxamides (displaying IC50’s ≥ 2.5 μM) has been achieved, thus suggesting an active role of the sulfonamido-portion in the inhibition process. Preliminary molecular modeling studies have been carried out to rationalize the observed structure-activity relationships.

Several preclinical evidence indicate that the modulation of the endocannabinoid system (ECS) represents a promising therapeutic approach for different diseases. However, only few modulators of this system have reached so far an advanced stage of clinical development, mainly due to limited efficacy and CB1 receptor-dependent side effects. Those limitations might be overcome by multi-target compounds that exert pro-cannabinoid activities through the modulation of two or more targets in the ECS. This approach can offer a safer and more effective pharmacological strategy as compared to the modulation of a single target. In this work, we report the synthesis and biological characterization of new 6-aryl-1,2-dihydro-2-oxo-pyridine-3-carboxamide derivatives. Our results identified several compounds exhibiting interesting multi-target profiles within the ECS. In particular, compound B1 showed moderate-to-high affinity for cannabinoid receptors (Ki CB1R = 304 nM, partial agonist, Ki CB2R = 3.1 nM, inverse agonist) and a potent inhibition of AEA uptake (IC50 = 62 nM) with moderate inhibition of FAAH (IC50 = 2.9 μM). The corresponding 2-alkoxypyridine analogue B14 exhibited significant inhibitor activity on both FAAH (IC50 = 69 nM) and AEA uptake (IC50 = 76 nM) without significantly binding to both cannabinoid receptor subtypes. Molecular docking analysis was carried out on the three-dimensional structures of CB1R and CB2R and of FAAH to rationalize the structure-activity relationships of this series of compounds.

Allosteric modulators of cannabinoid receptors hold great therapeutic potential, as they do not possess intrinsic efficacy, but instead enhance or diminish the receptor's response of orthosteric ligands allowing for the tempering of cannabinoid receptor signaling without the desensitization, tolerance and dependence. Allosteric modulators of cannabinoid receptors have numerous advantages over the orthosteric ligands such as higher receptor type selectivity, probe dependence and biased signaling, so they have a great potential to separate the therapeutic benefits from side effects own of orthosteric ligands. This review aims to give an overview of the CB1 and CB2 receptor allosteric modulators highlighting the structure–activity relationship and pharmacological profile of each classes, and their future promise.

‘Compound A’ (4ı-(N-(4-acetamidobenzyl))-2,2-dimethyl-2,3-dihydro-5ıH-spiro[chromene-4,2ı-[1,4]oxazinan]-5ı-one) is a new spiro-cyclic benzopyran activator of the mitochondrial ATP-dependent potassium channels (mitoKATP). We researched the effect of compound A on ischemia/reperfusion (I/R)-induced ventricular arrhythmias. We also tested the hypothesis that the application of the activation of mitoKATP in combination with the inhibition of sarcolemmal ATP-dependent potassium channels (sarcKATP) may produce a stronger antiarrhythmic effect. In anesthetized rats, myocardial ischemia was performed by ligating the left main coronary artery followed by reperfusion. At a dose of 10 mg/kg, compound A significantly decreased arrhythmia scores and the total length of arrhythmias, whereas this was found to be ineffective at a dose of 3 mg/kg. Pre-treatment with 5-HD, a selective mitoKATP blocker, abolished the antiarrhythmic effect of compound A. Both diazoxide, a selective mitoKATP opener and HMR 1098, a selective sarcKATP blocker, significantly decreased the total length of arrhythmias. However, the combination of neither diazoxide nor compound A with HMR 1098 showed no additional therapeutic benefit. These results reveal that compound A may have a dose-dependent antiarrythmic effect, which is more pronounced than the antiarrhythmic effect of diazoxide. The antiarrhythmic effect of compound A may possibly depend on mitoKATP activation. © 2016, The Pharmaceutical Society of Korea.

Aggressive behavior and diffuse infiltrative growth are the main features of Glioblastoma multiforme (GBM), together with the high degree of resistance and recurrence. Evidence indicate that GBM-derived stem cells (GSCs), endowed with unlimited proliferative potential, play a critical role in tumor development and maintenance. Among the many signaling pathways involved in maintaining GSC stemness, tumorigenic potential, and anti-apoptotic properties, the PDK1/Akt pathway is a challenging target to develop new potential agents able to affect GBM resistance to chemotherapy. In an effort to find new PDK1/Akt inhibitors, we rationally designed and synthesized a small family of 2-oxindole derivatives. Among them, compound 3 inhibited PDK1 kinase and downstream effectors such as CHK1, GS3Kα and GS3Kβ, which contribute to GCS survival. Compound 3 appeared to be a good tool for studying the role of the PDK1/Akt pathway in GCS self-renewal and tumorigenicity, and might represent the starting point for the development of more potent and focused multi-target therapies for GBM.

Allosteric modulation of the CB1Rs could represent an alternative strategy for the treatment of diseases in which these receptors are involved, without the undesirable effects associated with their orthosteric stimulation. PSNCBAM-1 is a reference diaryl urea derivative that positively affects the binding affinity of orthosteric ligands (PAM) and negatively affects the functional activity of orthosteric ligands (NAM) at CB1Rs. In this work we reported the design, synthesis and biological evaluation of three different series of compounds, derived from structural modifications of PSNCBAM-1 and its analogs reported in the recent literature. Almost all the new compounds increased the percentage of binding affinity of CP55940 at CB1Rs, showing a PAM profile. When tested alone in the [35S]GTPγS functional assay, only a few derivatives lacked detectable activity, so were tested in the same functional assay in the presence of CP55940. Among these, compounds 11 and 18 proved to be functional NAMs at CB1Rs, dampening the orthosteric agonist-induced receptor functionality by approximately 30%. The structural features presented in this work provide new CB1R-allosteric modulators (with a profile similar to the reference compound PSNCBAM-1) and an extension of the structure-activity relationships for this type of molecule at CB1Rs.

The endocannabinoid system (ECS) represents one of the major neuromodulatory systems involved in different physiological and pathological processes. Multi-target compounds exert their activities by acting via multiple mechanisms of action and represent a promising pharmacological modulation of the ECS. In this work we report 4-substituted and 4,5-disubstituted 1,2-dihydro-2-oxo-pyridine-3-carboxamide derivatives with a broad spectrum of affinity and functional activity towards both cannabinoid receptors and additional effects on the main components of the ECS. In particular compound B3 showed high affinity for CB1R (Ki = 23.1 nM, partial agonist) and CB2R (Ki = 6.9 nM, inverse agonist) and also significant inhibitory activity (IC50 = 70 nM) on FAAH with moderate inhibition of ABHD12 (IC50 = 2.5 μΜ). Compounds B4, B5 and B6 that act as full agonists at CB1R and as partial agonists (B5 and B6) or antagonist (B4) at CB2R, exhibited an additional multi-target property by inhibiting anandamide uptake with sub-micromolar IC50 values (0.28–0.62 μΜ). The best derivatives showed cytotoxic activity on U937 lymphoblastoid cells. Finally, molecular docking analysis carried out on the three-dimensional structures of CB1R and CB2R and of FAAH allowed to rationalize the structure-activity relationships of this series of compounds.

Alzheimer Diseases (AD) is a multifactorial pathology characterized by a complex etiology. The hallmarks of AD, such as Aβ deposits in senile plaque and Neurofibrillary Tangles (NFT), are strongly intertwined with Reactive Oxygen Species (ROS) production and oxidative stress (OS), which are considered the common effectors of the cascade of degenerative events. An increasing body of evidence reveals that both mitochondrial abnormalities and metal accumulations synergistically act as major producers of ROS, thus contributing to neuronal toxicity. Consequently, the detrimental role of ROS production together with the neurodegenerative events involved in AD has been widely investigated as new potential therapeutic strategies. This review will concisely summarize the link between OS and the hallmarks of AD, emphasizing on their strong correlation with neurodegenerative events and elucidating the pivotal role of ROS in AD pathology. Furthermore, through this review, we will provide a short account of some of the efforts, challenges and opportunities in developing multitarget drugs by addressing ROS production, metal accumulation and protein depositions.

In the present work, we report the synthesis of new aryliodonium salts used as precursors of single-stage nucleophilic 18 F radiofluorination. The corresponding unlabelled fluorinated derivatives showed to be CB2 cannabinoid receptor specific ligands, with K i values in the low nanomolar range and high CB2/CB1 selectivity. The radiolabelled compound [ 18 F] CB91 , was successfully formulated for in vivo administration, and its preliminary biodistribution was assessed with microPET/CT. This tracer presented a reasonable in vivo stability and a preferential extraction in the tissues that constitutionally express CB2 cannabinoid receptor. The results obtained indicate [ 18 F] CB91 as a possible candidate marker of CB2 cannabinoid receptor distribution. This study would open the way to further validation of this tracer for assessing pathologies for which the expression of this receptor is modified.

A novel series of tacrine derivatives were designed and synthesized by combining caffeic acid (CA), ferulic acid (FA) and lipoic acid (LA) with tacrine. The antioxidant study revealed that all the hybrids have much more antioxidant capacities compared to CA. Among these compounds, 1b possessed a good ability to inhibit the β-amyloid protein (Aβ) self-aggregation, sub-micromole acetylcholinesterase (AChE)/butyrylcholinesterase (BuChE) inhibitory, modest BACE1 inhibitory. Moreover, compound 1b also was a DPPH radical scavenger and copper chelatory as well as had potent neuroprotective effects against glutamate-induced cell death with low toxicity in HT22 cells. Our findings suggest that the compound 1b might be a promising lead multi-targeted ligand and worthy of further developing for the therapy of Alzheimer's disease.

Although there is a significant effort in the discovery of effective therapies to contrast both the pathological endocrine and metabolic aspects of diabetes and the endothelial dysfunction associated with this disease, no hypoglycemic drug has been proven to defeat the cardiovascular complications associated with type II diabetes. The aim of this research was to design new compounds exhibiting a double profile of hypoglycemic agents/NO-donors. The synthesis of molecules obtained by the conjunction of NO-donor moieties with two oral insulin-secretagogue drugs (repaglinide and nateglinide) was reported. NO-mediated vasorelaxing effects of the synthesized compounds were evaluated by functional tests on isolated endothelium-denuded rat aortic rings. The most potent molecule (4) was tested to evaluate the hypoglycemic and the anti-ischemic cardioprotective activities. This study indicates that 4 should represent a new insulin-secretagogue/NO-donor prodrug with an enhanced cardiovascular activity, which may contrast the pathological aspects of diabetes and endowed of cardioprotective activity.

Starting from nature as original source, new potential agents with pleiotropic activities have been synthesized and evaluated as neuroprotective agents. In this work, novel nature-based hybrids, combining antioxidant motifs with rivastigmine, have been designed and synthesized. The biological results revealed that the new compounds inhibit both AChE and BuChE. In particular, lipoic acid hybrids LA1, LA2, LA3 resulted to be the most potent inhibitors of BuChE showing IC50 values ranging from 340 to 378 nM. Analogously, all the compounds were able to inhibit the self β-amyloid1-42 aggregation. The gallic acid hybrid GA2 as well as the 2-chromonecarboxylic acid hybrids CA1 and CA2 prevented the self-mediated Aβ aggregation with percentages of inhibition ranging from 53% to 59%. Finally, some of them also show potent neuroprotective effects against glutamate-induced cell death and low toxicity in HT22 cells.

A series of rivastigmine-caffeic acid and rivastigmine-ferulic acid hybrids were designed, synthesized, and evaluated as multifunctional agents for Alzheimer's disease (AD) in vitro. The new compounds exerted antioxidant neuroprotective properties and good cholinesterases (ChE) inhibitory activities. Some of them also inhibited amyloid protein (Aβ) aggregation. In particular, compound 5 emerged as promising drug candidates endowed with neuroprotective potential, ChE inhibitory, Aβ self-aggregation inhibitory and copper chelation properties. These data suggest that compound 5 offers an attractive starting point for further lead optimization in the drug-discovery process against AD.

In this work, we reported the application and validation of an improved high-performance liquid chromatography method coupled with a fluorimetric detector (HPLC-FL) to screen the activity of two heterocyclic derivatives reported as serine palmitoyl transferase (SPT) inhibitors. The analytical conditions were optimized in terms of the derivatization procedure, chromatographic condition, extraction procedure, and method validation according to EMEA guidelines. Once fully optimized, the method was applied to assess the SPT-inhibitory activity of the above-mentioned derivatives and of the reference inhibitor myriocin. The obtained results, expressed as a percentage of residual SPT activity, were compared to those obtained with the reference radio immune assay (RIA). The good correlation between the two types of assay demonstrated that the improved HPLC-FL method is suitable for a preliminary and rapid screening of potential SPT-inhibitors.

Background: Aldose reductase, the first enzyme of the polyol pathway, is the key determinant for the pathogenesis of long term diabetic complications. Accordingly, its inhibition represents the major therapeutic strategy to treat this kind of pathologies. Objectives: In this work we describe the synthesis and the functional evaluation of a number of spiro-oxazolidinone and spiro-morpholinone acetic acid derivatives, and their benzyloxy analogs, developed as aldose reductase inhibitors. Results: Most of them proved to inhibit the target enzyme, showing IC50 values in the micromolar/low micromolar range. SARs observed among the three different series allowed to highlight their key pharmacophoric elements, thus creating sound basis for the design of novel and more effective inhibitors. Conclusion: Although further substitution patterns are needed, the novel compounds here proposed represent a good starting point for the development of novel and effective ARIs.

Starting from the previously developed P-gp ligands 1a and 1b (EC50 = 0.25 μM and 0.65 μM, respectively), new arylmethyloxyphenyl derivatives have been synthesized as P-gp modulators in order to investigate: (i) the effect of small electron-donor groups (OMe) (5–11), (ii) the effect of the replacement of methoxy groups with an electron-withdrawal substituent (Cl) on C-ring (13) (iii) the effect induced by the replacement of C-ring with heteroaromatic cycles such as thiophene and pyrimidine (13, 15, 16), (iv) the effect induced by molecular constriction on C ring (14, 17, 18) on P-gp modulating activity. The results demonstrated that P-gp inhibition potency is strongly correlated to the number of methoxy groups in the A-ring whereas the methoxylation of C-ring seems to poorly affect P-gp activity. The best result was found for compound 10 that displays a nanomolar affinity (EC50 = 7.1 nM) towards P-gp pump and, in the meantime lacks of activity against MRP1 pump.

In this work, hybrid compounds 1&ndash, 4 obtained by conjugation of the non-steroidal anti-inflammatory drug diclofenac, with natural molecules endowed with antioxidant and antiproliferative activity were prepared. The antiproliferative activity of these hybrids was evaluated on immortalized human keratinocyte (HaCaT) cells stimulated with epidermal growth factor (EGF), an actinic keratosis (AK) model, and on human squamous cell carcinoma (SCC) cells (A431). Hybrid 1 presented the best activity in both cell models. Self-assembling surfactant nanomicelles have been chosen as the carrier to drive the hybrid 1 into the skin, the in vitro permeation through and penetration into pig ear skin have been evaluated. Among the nanostructured formulations tested, Nano3Hybrid20 showed a higher tendency of the hybrid 1 to be retained in the skin rather than permeating it, with a desirable topical and non-systemic action. On these bases, hybrid 1 may represent an attractive lead scaffold for the development of new treatments for AK and SCC.

The phosphoinositide-dependent kinase-1 (PDK1) is one of the main components of the PI3K/Akt pathway. Also named the “master kinase” of the AGC family, PDK1 plays a critical role in tumorigenesis, by enhancing cell proliferation and inhibiting apoptosis, as well as in cell invasion and metastasis formation. Although there have been done huge efforts in discovering specific compounds targeting PDK1, nowadays no PDK1 inhibitor has yet entered the clinic. With the aim to pick out novel and potent PDK1 inhibitors, herein we report the design and synthesis of a new class of molecules obtained by merging the 2-oxo-indole nucleus with the 2-oxo-pyridonyl fragment, two moieties with high affinity for the PDK1 hinge region and its DFG-out binding site, respectively. To this purpose, a small series of compounds were synthesised and a tandem application of docking and Molecular Dynamic (MD) was employed to get insight into their mode of binding. The OXID-pyridonyl hybrid 8, possessing the lower IC50 (IC50 = 112 nM), was also tested against recombinant kinases involved in the PI3K/PDK1/Akt pathway and was subjected to vitro studies to evaluate the cytotoxicity and the inhibition of tumour cell migration. All together the results let us to consider 8, as a lead compound of a new generation of PDK1 inhibitors and encourage us to further studies in this direction.

Heart mitochondrial ATP-sensitive potassium channel (mito-K ATP channels) are deeply implicated in the self-defense mechanism of ischemic preconditioning. Therefore, exogenous molecules activating these channels are considered as a promising pharmacological tool to reduce the myocardial injury deriving from ischemia/reperfusion events. In our laboratory, a series of 4-spiro-substituted benzopyran derivatives were earlier synthesized and some of them exhibited anti-ischemic properties. In this study, the above compounds are exploited in order to develop QSAR models, based on classification approaches, capable of discriminating between the ones acting as cardioprotective agents and those that are unable to elicit such a property. Molecules belonging to the whole dataset were subjected to CODESSA and E-Dragon calculations in order to compute a large number of molecular descriptors enabling the construction of classification models. Based on the two program packages used, two different experiments were carried out, with the aim of identify batteries of models to be exploited for designing new cardioprotective agents from libraries of new chemical entities. Both model batteries satisfy the rigorous criteria adopted for the validation, either when tested on the training and test set, according to the most straightforward protocol, and when tested on an additional prediction set. They were proven to ensure successful applications in the field of cardioprotective agent design.

Trace amine associated receptor 1 (TAAR1) is a G protein coupled receptor (GPCR) expressed in brain and periphery activated by a wide spectrum of agonists that include, but are not limited to, trace amines (TAs), amphetamine-like psychostimulants, and endogenous thyronamines such as thyronamine (T0AM) and 3-iodothyronamine (T1AM). Such polypharmacology has made it challenging to understand the role and the biology of TAAR1. In an effort to understand the molecular basis of TAAR1 activation, we rationally designed and synthesized a small family of thyronamine derivatives. Among them, compounds 2 and 3 appeared to be a good mimic of the parent endogenous thyronamine, T0AM and T1AM, respectively, both in vitro and in vivo. Thus, these compounds offer suitable tools for studying the physiological roles of mouse TAAR1 and could represent the starting point for the development of more potent and selective TAAR1 ligands.

In a preliminary work, we reported two NO-sartans, possessing the characteristics of an AT(1) antagonist and a "slow NO donor", obtained by adding NO-donor side chains to losartan 1. The NO release from an NO-sartan should be modulated in order to strengthen the antihypertensive activity of the native drug and to ensure additional effects, such as the antiplatelet and anti-ischemic ones. To obtain a collection of prototypical NO-sartans, showing different rates of NO release, new NO-donor moieties have been linked to 1 or its active metabolite 2 (EXP 3174). Almost all the synthesized compounds exhibited both AT(1)-antagonist and NO-mediated vasorelaxing properties, with a wide range of NO-releasing rates. Further pharmacological investigation on compound 4a showed that it possessed antihypertensive and cardiac antihypertrophic effects similar to those of the reference AT(1)-blocking or ACE-inhibiting drugs. Furthermore, the additional anti-ischemic cardio-protective properties and antiplatelet effects of 4a have been preliminarily investigated.

Several nimesulide preparations (i.e., tablet form, gels) have been marketed, but no parenteral solution has achieved the market because of their low wettability and unsatisfactory chemical-physical properties required for parenteral use. In this paper we describe the synthesis of the nimesulide prodrug 1 and its anti-inflammatory and antihyperalgesic properties. Pharmacological studies, carried out to evaluate the in vivo anti-inflammatory and analgesic activities of compound 1 and nimesulide, showed that sodium sulfamate 1 is an effective nimesulide prodrug that can be administered by parenteral route, undergoing a satisfactory absorption and an extensive transformation into the active nimesulide compound. Moreover, the evaluation of the plasma concentrations of nimesulide after rat treatment with compound 1 showed an increased and dose-dependent release of nimesulide. In contrast, the plasma concentrations of nimesulide, after "native" drug administration, still remain substantially unchanged. These preliminary results prompt further investigations on this prodrug as a possible candidate for parenteral use.

Aldose reductase (ARL2) is the first enzyme in the polyol pathway which catalyzes the NADPH-dependent reduction of glucose to sorbitol. Its involvement on diabetic complications makes this enzyme a challenge therapeutic target widely investigated to limit and/or prevent them. On this basis, a limited series of 4-spiro-oxazolidinone-benzopyran derivatives (1-7) were synthesized to evaluate them as potential ARL2 inhibitors. The activity was determined spectrophotometrically by monitoring the oxidation of NADPH catalyzed by ALR2. Within the series of compounds, the 4-methoxy derivative 1b showed to be the most active compound, exhibiting inhibitory levels in the submicromolar range. In addition, the activity against the aldehyde reductase isoform (ARL1) was also evaluated. Unlike sorbinil (reference drug) that lack of selectivity towards the two enzyme all the tested compounds resulted to be devoid of ARL1 inhibitory activity (IC(50) > 10 µM), thus proving to be selective.

The activation of ATP-sensitive potassium channels (K(ATP)), play a key role in an endogenous "self-defence" mechanism, known as ischemic preconditioning (IPC), which is fundamentally involved in the protection of the heart against the ischemia/reperfusion injury. Presently, it is widely accepted that IPC is mainly (albeit not exclusively) mediated by the activation of K(ATP) channels expressed in the mitochondrial inner membrane (mito-K(ATP)) rather than the sarcoplasmatic ones (sarc-K(ATP)). Consistently, exogenous activation of K(ATP) channels by pharmacological tools can be viewed as one of the most promising strategies for the therapy of myocardial ischemia. As part of our research program devoted to the synthesis and the evaluation of new cardioprotective agents, we extensively studied several six-membered spiro-heterocycle-benzopyran compounds endowed of a significant anti-ischemic activity. The positive results obtained, prompted us to further explore the influence on the biopharmacological effects, of the spiro-substitution at C4 benzopyran nucleus by replacing the six-membered spirocycle of the most active compounds with 5-membered-one. The preliminary evaluation of the new compounds on cultured H9c2 cardiomyoblasts exposed to anoxia/reperfusion and on Langendorff-perfused rat hearts submitted to ischemia/reperfusion cycles, showed that some of them can exert a cardioprotective effect. This anti-ischemic activity was antagonized by 5-hydroxydecanoic acid, a selective blocker of mito-K(ATP) channels, confirming the involvement of this channel in the cardioprotective activity.

The non-steroidal anti-inflammatory drug (NSAID) sulindac exhibits cyclooxygenase (COX)-dependent and COX-independent chemopreventive properties in human cancer. The present study was aimed at investigating whether the hydroxamic acid substitution for the carboxylic acid group could enhance the in vitro antitumor and antiangiogenic activities of sulindac. Characterization tools used on this study included analyses of cell viability, caspase 3/7 induction, DNA fragmentation, and gene expression. Our findings demonstrate that the newly synthesized hydroxamic acid derivative of sulindac and its sulfone and sulfide metabolites were characterized by a good anticancer activity on human pancreatic and colon cancer cells, both in terms of potency (IC(50) mean values from 6 ± 1.1 μM to 64 ± 1.1 μM) and efficacy (E(max) of ∼100%). Hydroxamic acid derivatives trigger a higher degree of apoptosis than carboxylic acid counterparts, increase bax/bcl-2 expression ratio and induce caspase 3/7 activation. Most notably, these compounds significantly inhibit proangiogenic growth factor-stimulated proliferation of vascular endothelial cell (HUVEC) at sub-micromolar concentrations. Our data also provide evidence that the COX-active metabolite of sulindac hydroxamic acid were the most active of the series and selective inhibition of COX-1 but not COX-2 can mimic its effects, suggesting that COX inhibition could only play a partial role in the mechanism of compound action. In conclusion, these data demonstrate that substitution of the carboxylic acid group with the hydroxamic acid moiety enhances in vitro antiproliferative, proapoptotic and antiangiogenic properties of sulindac, therefore increasing the therapeutic potential of this drug.

This paper describes an overview of recent insights concerning some socially relevant neurodegenerative diseases such as Alzheimer's (AD), Parkinson's (PD), Huntington's (HD) and Creutzfeldt-Jakob's (CJD) diseases, amyotrophic lateral sclerosis (ALS) and epilepsy. For each pathological state, the direct and/or indirect involvement of P-glycoprotein (P-gp) efflux transport is underlined. On this basis, P-gp still represents an innovative target which can offer new tools for the development of more effective and preventive therapeutic strategies for neurodegenerative disorders. For each of them, therefore, a possible use of drugs affecting P-gp transport activity has been suggested.

This work aimed to determine the enantioselectivity in cardioprotection induced by the racemic mixture of the "archetype" 1a of a new class of spirocyclic-benzopyran derivatives. The racemate was resolved by HPLC and the absolute configuration was accomplished by a combined strategy based on single-crystal X-ray diffraction and circular dichroism methods. The (S)-(-)-1a enantiomer, evaluated for its anti-ischemic activity, showed significant cardioprotective effects, whereas the (R)-(+)-1a enantiomer was completely lacking in anti-ischemic effects.

Heart mitochondrial ATP-sensitive potassium channels (mito-K ATP channels) are deeply implicated in the self-defense mechanism of ischemic preconditioning. Therefore, exogenous molecules activating these channels are considered as a promising pharmacological tool to reduce the myocardial injury deriving from ischemia/reperfusion events. This paper reports the synthesis and pharmacological evaluation of original spiromorpholine- and spiromorpholone-benzopyran derivatives, with the aim to obtain selective activators of mito-K ATP channels. Some compounds of this series showed appreciable cardioprotective effects on rat isolated and perfused hearts, submitted to ischemia/reperfusion cycles. The selective mito-K ATP channel blocker 5-hydroxydecanoic acid antagonized the anti-ischemic activity, indicating a clear implication of this pharmacological target. Furthermore, these effects were not associated with significant hypotensive and vasorelaxing properties, which represent one of the main limiting factors for the clinical use of nonselective K ATP-openers against myocardial ischemia.

Starting from lead compounds 12b and 28b, previously characterized as P-glycoprotein (P-gp) modulating agents, two series of new compounds were investigated. Compounds 14a, b and 15a, b displayed high P-gp modulating activity in the submicromolar range (EC 50 values from 0.25 to 0.80 microM). Moreover, amino derivatives 23- 27 showed EC 50 values ranging from 0.085 to 0.90 microM. In the pyridyl series, the best result has been obtained for 4-pyridyl derivative 17b (EC 50 = 0.85 microM). The best P-gp modulating agents 14a, b, 15a, b, and 23- 27 also have been studied for determining their breast cancer resistance protein (BCRP) inhibition activity. The results demonstrated that only the amino derivatives 23- 27 displayed moderate BCRP inhibition activity.

Recently, 2-[(3-methoxyphenylethyl)phenoxy]-moiety has been selected for the design and synthesis of new small ABCB1 inhibitors. In the present paper, this moiety has been linked through a spacer of 2-5 carbon atoms to the nitrogen of three different basic nuclei such as: (i) N-4-arylpiperazine, (ii) N-4-methylpiperazine, and (iii) 6,7-dimethoxytetrahydroisoquinoline. The results demonstrated that all the selected basic nuclei were well tolerated and that, globally, the best inhibitory activity for each series was obtained when the spacer between the 2-[(3-methoxyphenylethyl)phenoxy] moiety and the basic nucleus consisted of a four-carbon chain. Among the synthesized compounds, N-4-methylpiperazine- 10c (IC(50) = 0.15 microM) and tetrahydroisoquinoline-derivatives 11c (IC(50) = 0.08 microM) with the spacer n = 4 for both series, displayed the best potency to inhibit ABCB1 activity. Moreover, for each compound, the ABCB1 interacting mechanism has been evaluated by three combined biological assays. N-4-methylpiperazine- (10a-d) and tetrahydroisoquinoline- (11a-d) derivatives were Cyclosporin A-like ABCB1 nontransported substrates.

Biphenylic ester derivatives, designed by using a ‘soft-drug’ approach, proved to possess good binding properties toward cannabinoid CB1 and CB2 receptors and, at the same time, their metabolically labile ester portion would promote a rapid systemic inactivation. This may constitute a possible solution to the psychotropic side effects encountered when cannabinoids are therapeutically employed as local analgesic or antiglaucoma agents.

Some arylmethyloxyphenyl derivatives were prepared as simplified structures of analogous arylpiperazines with high affinity toward dopaminergic D(2) and serotonergic 5-HT(1A) receptors and inhibiting P-glycoprotein (P-gp). The compounds 5b and 8b displayed good P-gp inhibition activity measured as [(3)H]vinblastine transport inhibition in the Caco-2 cell monolayer and intracellular doxorubicin accumulation in MCF7/Adr cells by flow cytometry. Compounds 5b and 8b also inhibited, dose-dependently, ATP-ase activation induced by P-gp substrate vinblastine.