The possibility of replacing raltegravir or elvitegravir with dolutegravir in heavily treatment-experienced patients failing on raltegravir/elvitegravir has been evaluated in VIKING trials. All ...studied patients failed by the most common pathways, Y143, Q148 and N155, and dolutegravir demonstrated efficacy except for Q148 viruses. The aim of this study was to explore, in the same way, the behaviour of dolutegravir in comparison with raltegravir and elvitegravir against the atypical resistance integrase profiles, G118R and F121Y, described in HIV-1 patients failing on raltegravir therapy.
The behaviour of integrases with mutations G118R and F121Y towards raltegravir, elvitegravir and dolutegravir was analysed by evaluating phenotypic susceptibility and by means of in silico techniques (investigating binding affinities and the stabilization of the inhibitors in terms of their hydrogen bond network).
The phenotypic analysis of G118R and F121Y showed high resistance to raltegravir, elvitegravir and dolutegravir with a fold change >100 when the clinically derived integrase was used, and resistance was also seen when mutations were tested alone in an NL43 backbone, but more often with a lower fold change. In silico, results showed that G118R and F121Y enzymes were associated with reduced binding affinities to each of the inhibitors and with a decreased number of hydrogen bonds compared with the wild-type complexes.
This study showed that G118R and F121Y mutations, rarely described in patients failing on raltegravir, induced broad cross-resistance to all currently used integrase inhibitors. These results are in accordance with our thermodynamic and geometric analysis indicating decreased stability compared with the wild-type complexes.
Dolutegravir, an integrase strand-transfer inhibitor (STI), shows a high genetic barrier to resistance. Dolutegravir is reported to be effective against viruses resistant to raltegravir and ...elvitegravir. In this study, we report the case of a patient treated with dolutegravir monotherapy. Failure of dolutegravir treatment was observed concomitant with the appearance of N155H-K211R-E212T mutations in the integrase (IN) gene in addition to the polymorphic K156N mutation that was present at baseline in this patient.
The impact of N155H-K156N-K211R-E212T mutations was studied in cell-free, culture-based assays and by molecular modelling.
Cell-free and culture-based assays confirm that selected mutations in the patient, in the context of the polymorphic mutation K156N present at the baseline, lead to high resistance to dolutegravir requiring that the analysis be done at timepoints longer than usual to properly reveal the results. Interestingly, the association of only N155H and K156N is sufficient for significant resistance to dolutegravir. Modelling studies showed that dolutegravir is less stable in IN/DNA complexes with respect to the WT sequence.
Our results indicate that the stability of STI IN/DNA complexes is an important parameter that must be taken into account when evaluating dolutegravir resistance. This study confirms that a pathway including N155H can be selected in patients treated with dolutegravir with the help of the polymorphic K156N that acts as a secondary mutation that enhances the resistance to dolutegravir.
Naturally occurring flavonoids display a plethora of different biological activities, but emerging evidence suggests that this class of compounds may also act as antidepressant agents endowed with ...multiple mechanisms of action in the central nervous system, increasing central neurotransmission, limiting the reabsorption of bioamines by synaptosomes, and modulating the neuroendocrine and GABAA systems. Due to their presence in foods, food-derived products, and nutraceuticals, we established their role and structure–activity relationships as reversible and competitive human monoamine oxidase (MAO) inhibitors. In addition, molecular modeling studies, which evaluated their modes of MAO inhibition, are presented. These findings could provide pivotal implications in the quest of novel drug-like compounds and for the establishment of harmful drug–dietary supplement interactions commonly reported in the therapy with antidepressant agents.
Proteasome malfunction parallels abnormal amyloid accumulation in Alzheimer's Disease (AD). Here we scrutinize a small library of pyrazolones by assaying their ability to enhance proteasome activity ...and protect neuronal cells from amyloid toxicity. Tube tests evidenced that aminopyrine and nifenazone behave as 20S proteasome activators. Enzyme assays carried out on an “open gate” mutant (α3ΔN) proteasome demonstrated that aminopyrine activates proteasome through binding the α‐ring surfaces and influencing gating dynamics. Docking studies coupled with STD‐NMR experiments showed that H‐bonds and π‐π stacking interactions between pyrazolones and the enzyme play a key role in bridging α1 to α2 and, alternatively, α5 to α6 subunits of the outer α‐ring. Aminopyrine and nifenazone exhibit neurotrophic properties and protect differentiated human neuroblastoma SH‐SY5Y cells from β‐amyloid (Aβ) toxicity. ESI‐MS studies confirmed that aminopyrine enhances Aβ degradation by proteasome in a dose‐dependent manner. Our results suggest that some pyrazolones and, in particular, aminopyrine are promising compounds for the development of proteasome activators for AD treatment.
Drugs redirected: Inspired by recent reports showing that some outdated painkillers may rescue proteasome activity in mice and attracted by the possibility to repurpose “old” medicines and thus de‐risk the drug development process, we scrutinized a small library of pyrazolones by assaying their ability to augment proteasome activity and protect neurons from amyloid toxicity.
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•A new set of powerful steroidal aromatase inhibitors was found.•A new reaction for the preparation of a new 3,4-steroidal dioxene was discovered.•New SAR were established revealing ...some 5β-steroids as aromatase inhibitors.•New chemical features to increase planarity were disclosed.•C-ring modified androstenedione present aromatase inhibitory activity.
In this work, new potent steroidal aromatase inhibitors both in microsomes and in breast cancer cells have been found. The synthesis of the 3,4-(ethylenedioxy)androsta-3,5-dien-17-one (12), a new steroid containing a heterocycle dioxene fused in the A-ring, led to the discovery of a new reaction for which a mechanism is proposed. New structure–activity relationships were established. Some 5β-steroids, such as compound 4β,5β-epoxyandrostan-17-one (9), showed aromatase inhibitory activity, because they adopt a similar A-ring conformation as those of androstenedione, the natural substrate of aromatase. Moreover, new chemical features to increase planarity were disclosed, specifically the 3α,4α-cyclopropane ring, as in 3α,4α-methylen-5α-androstan-17-one (5) (IC50=0.11μM), and the Δ9–11 double bond in the C-ring, as in androsta-4,9(11)-diene-3,17-dione (13) (IC50=0.25μM). In addition, induced-fit docking (IFD) simulations and site of metabolism (SoM) predictions helped to explain the recognition of new potent steroidal aromatase inhibitors within the enzyme. These insights can be valuable tools for the understanding of the molecular recognition process by the aromatase and for the future design of new steroidal inhibitors.
Although science and technology have progressed rapidly, de novo drug development has been a costly and time-consuming process over the past decades. In this scenario, drug repurposing has appeared ...as an alternative tool to accelerate the drug development process. Herein, we applied such an approach to the highly popular human Carbonic Anhydrase (hCA) VA drug target, that is involved in ureagenesis, gluconeogenesis, lipogenesis, and in the metabolism regulation. Albeit several hCA inhibitors have been designed and are currently in clinical use, serious drug interactions have been reported due to their poor selectivity. In this perspective, the drug repurposing approach could be a useful tool for investigating the drug promiscuity/polypharmacology profile. In this chapter, we describe a combination of virtual screening techniques and in vitro assays aimed to identify novel selective hCA VA inhibitors and to repurpose drugs known for other clinical indications.
Coronaviridae is a peculiar viral family, with a very large RNA genome and characteristic appearance, endowed with remarkable tendency to transfer from animals to humans. Since the beginning of the ...21st century, three highly transmissible and pathogenic coronaviruses have crossed the species barrier and caused deadly pneumonia, inflicting severe outbreaks and causing human health emergencies of inconceivable magnitude. Indeed, in the past two decades, two human coronaviruses emerged causing serious respiratory illness: severe acute respiratory syndrome coronavirus (SARS-CoV-1) and Middle Eastern respiratory syndrome coronavirus (MERS-CoV), causing more than 10,000 cumulative cases, with mortality rates of 10 % for SARS-CoV-1 and 34.4 % for MERS-CoV. More recently, the severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) has emerged in China and has been identified as the etiological agent of the recent COVID-19 pandemic outbreak. It has rapidly spread throughout the world, causing nearly 22 million cases and ∼ 770,000 deaths worldwide, with an estimated mortality rate of ∼3.6 %, hence posing serious challenges for adequate and effective prevention and treatment. Currently, with the exception of the nucleotide analogue prodrug remdesivir, and despite several efforts, there is no known specific, proven, pharmacological treatment capable of efficiently and rapidly inducing viral containment and clearance of SARS-CoV-2 infection as well as no broad-spectrum drug for other human pathogenic coronaviruses. Another confounding factor is the paucity of molecular information regarding the tendency of coronaviruses to acquire drug resistance, a gap that should be filled in order to optimize the efficacy of antiviral drugs.
In this light, the present review provides a systematic update on the current knowledge of the marked global efforts towards the development of antiviral strategies aimed at coping with the infection sustained by SARS-CoV-2 and other human pathogenic coronaviruses, displaying drug resistance profiles. The attention has been focused on antiviral drugs mainly targeting viral protease, RNA polymerase and spike glycoprotein, that have been tested in vitro and/or in clinical trials as well as on promising compounds proven to be active against coronaviruses by an in silico drug repurposing approach. In this respect, novel insights on compounds, identified by structure-based virtual screening on the DrugBank database endowed by multi-targeting profile, are also reported. We specifically identified 14 promising compounds characterized by a good in silico binding affinity towards, at least, two of the four studied targets (viral and host proteins). Among which, ceftolozane and NADH showed the best multi-targeting profile, thus potentially reducing the emergence of resistant virus strains. We also focused on potentially novel pharmacological targets for the development of compounds with anti-pan coronavirus activity. Through the analysis of a large set of viral genomic sequences, the current review provides a comprehensive and specific map of conserved regions across human coronavirus proteins which are essential for virus replication and thus with no or very limited tendency to mutate. Hence, these represent key druggable targets for novel compounds against this virus family. In this respect, the identification of highly effective and innovative pharmacological strategies is of paramount importance for the treatment and/or prophylaxis of the current pandemic but potentially also for future and unavoidable outbreaks of human pathogenic coronaviruses.
Compartmentation is a key strategy enacted by plants for the storage of specialized metabolites. The saffron spice owes its red color to crocins, a complex mixture of apocarotenoid glycosides that ...accumulate in intracellular vacuoles and reach up to 10% of the spice dry weight. We developed a general approach, based on coexpression analysis, heterologous expression in yeast (
), and in vitro transportomic assays using yeast microsomes and total plant metabolite extracts, for the identification of putative vacuolar metabolite transporters, and we used it to identify
transporters mediating vacuolar crocin accumulation in stigmas. Three transporters, belonging to both the multidrug and toxic compound extrusion and ATP binding cassette C (ABCC) families, were coexpressed with crocins and/or with the gene encoding the first dedicated enzyme in the crocin biosynthetic pathway, CsCCD2. Two of these, belonging to the ABCC family, were able to mediate transport of several crocins when expressed in yeast microsomes. CsABCC4a was selectively expressed in
stigmas, was predominantly tonoplast localized, transported crocins in vitro in a stereospecific and cooperative way, and was able to enhance crocin accumulation when expressed in
leaves.plantcell;31/11/2789/FX1F1fx1.
The SARS-CoV-2 main protease (Mpro) is a crucial enzyme for viral replication and has been considered an attractive drug target for the treatment of COVID-19. In this study, virtual screening ...techniques and in vitro assays were combined to identify novel Mpro inhibitors starting from around 8000 FDA-approved drugs. The docking analysis highlighted 17 promising best hits, biologically characterized in terms of their Mpro inhibitory activity. Among them, 7 cephalosporins and the oral anticoagulant betrixaban were able to block the enzyme activity in the micromolar range with no cytotoxic effect at the highest concentration tested. After the evaluation of the degree of conservation of Mpro residues involved in the binding with the studied ligands, the ligands’ activity on SARS-CoV-2 replication was assessed. The ability of betrixaban to affect SARS-CoV-2 replication associated to its antithrombotic effect could pave the way for its possible use in the treatment of hospitalized COVID-19 patients.
Alteration of nutritional habits play an essential role on the risk of developing Metabolic Syndrome (MetS). Several epidemiological studies have shown that assuming diets rich of foods included in ...the Mediterranean diet (MetDiet) pattern like, such as olive oil, nuts, fruit, fiber, vegetables, wine and grain cereals has protective effects on the different risk factors characterizing the MetS. The beneficial effects of the MetDiet in the MetS are mainly due to the antioxidant and anti-inflammatory properties of the most abundant phytochemical components of such foods as polyphenols like resveratrol and oleuropein, allyl sulfides, ellagic acid, mono- and poly-unsaturated fatty acids (MUFA and PUFA), tocopherols and flavonoids like quercetin, which have shown positive results in the prevention of cardiovascular diseases (CVDs), with related risk factors, like hypertension, hypercholesterolemia and obesity. In this review, we highlighted the multi-target activities of the bioactive components contained in some foods typical of the Mediterranean area like olive oil, onion, liquorice, rosemary, oregano, hazelnut, pistachio, “Melannurca” apple, red wine, hot pepper, Citrus sp. fruits, saffron and garlic, with particular focus on their impact on health outcomes in relation to MetS main key factors, such as insulin resistance (IR) and type 2 diabetes mellitus (T2DM), endothelial dysfunctions, inflammatory response, oxidative stress and dyslipidaemic and hypercholesterolemic effects.
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•Metabolic syndrome (MetS) increases the risk of heart diseases and type 2 diabetes.•Beneficial effects of Mediterranean diet (MetDiet) products were proved against MetS.•This review focuses on the MetDiet phytochemicals targeting multiple MetS pathways.•MetDiet products could represent a resource in the treatment and prevention of MetS.
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