Identification of New GSK3ß Inhibitors through a Consensus Machine Learning-Based Virtual Screening.

Glycogen synthase kinase-3 beta (GSK3ß) is a serine/threonine kinase that plays key roles in glycogen metabolism, Wnt/ß-catenin signaling cascade, synaptic modulation, and multiple autophagy-related signaling pathways. GSK3ß is an attractive target for drug discovery since its aberrant activity is involved in the development of neurodegenerative diseases such as Alzheimer's and Parkinson's disease. In the present study, multiple machine learning models aimed at identifying novel GSK3ß inhibitors were developed and evaluated for their predictive reliability. The most powerful models were combined in a consensus approach, which was used to screen about 2 million commercial compounds. Our consensus machine learning-based virtual screening led to the identification of compounds G1 and G4, which showed inhibitory activity against GSK3ß in the low-micromolar and sub-micromolar range, respectively. These results demonstrated the reliability of our virtual screening approach. Moreover, docking and molecular dynamics simulation studies were employed for predicting reliable binding modes for G1 and G4, which represent two valuable starting points for future hit-to-lead and lead optimization studies.

Insights into the Antioxidant/Antiradical Effects and In Vitro Intestinal Permeation of Oleocanthal and Its Metabolites Tyrosol and Oleocanthalic Acid.

(1) Background: In recent years, numerous studies have highlighted the beneficial effects of extra virgin olive oil (EVOO) as an active ingredient against chronic diseases. The properties of EVOO are due to its peculiar composition, mainly to its rich content of polyphenols. In fact, polyphenols may contribute to counteract oxidative stress, which often accompanies chronic diseases. In this work, the antioxidant effects of high-value polyphenol oleocanthal (OC) and its main metabolites, tyrosol (Tyr) and oleocanthalic acid (OA), respectively, have been investigated along with their impact on cell viability. (2) Methods: OC, Tyr, and OA have been evaluated regarding antiradical properties in term of scavenging capacity towards biologically relevant reactive species, including O2●-, HOCl, and ROO●, as well as their antioxidant/antiradical capacity (FRAP, DPPH●, ABTS●+). Moreover, the ability to permeate the intestinal membrane was assessed by an intestinal co-culture model composed by Caco-2 and HT29-MTX cell lines. (3) Results: The capacity of OC and Tyr as radical oxygen species (ROS) scavengers, particularly regarding HOCl and O2●-, was clearly demonstrated. Furthermore, the ability to permeate the intestinal co-culture model was plainly proved by the good permeations (>50%) achieved by all compounds. (4) Conclusions: OC, OA, and Tyr revealed promising properties against oxidative diseases.

Machine Learning-Based Virtual Screening for the Identification of Cdk5 Inhibitors.

Cyclin-dependent kinase 5 (Cdk5) is an atypical proline-directed serine/threonine protein kinase well-characterized for its role in the central nervous system rather than in the cell cycle. Indeed, its dysregulation has been strongly implicated in the progression of synaptic dysfunction and neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD), and also in the development and progression of a variety of cancers. For this reason, Cdk5 is considered as a promising target for drug design, and the discovery of novel small-molecule Cdk5 inhibitors is of great interest in the medicinal chemistry field. In this context, we employed a machine learning-based virtual screening protocol with subsequent molecular docking, molecular dynamics simulations and binding free energy evaluations. Our virtual screening studies resulted in the identification of two novel Cdk5 inhibitors, highlighting an experimental hit rate of 50% and thus validating the reliability of the in silico workflow. Both identified ligands, compounds CPD1 and CPD4, showed a promising enzyme inhibitory activity and CPD1 also demonstrated a remarkable antiproliferative activity in ovarian and colon cancer cells. These ligands represent a valuable starting point for structure-based hit-optimization studies aimed at identifying new potent Cdk5 inhibitors.

Medicinal Chemistry approach, pharmacology and neuroprotective benefits of CB2R modulators in neurodegenerative diseases.

In the last decades, cannabinoid receptor 2 (CB2R) has continued to receive attention as a key therapeutic target in neuroprotection. Indeed, several findings highlight the neuroprotective effects of CB2R through suppression of both neuronal excitability and reactive microglia. Additionally, CB2R seems to be a more promising target than cannabinoid receptor 1 (CB1R) thanks to the lack of central side effects, its lower expression levels in the central nervous system (CNS), and its inducibility, since its expression enhances quickly in the brain following pathological conditions. This review aims to provide a thorough overview of the main natural and synthetic selective CB2R modulators, their chemical classification and their potential therapeutic usefulness in neuroprotection, a crucial aspect for the treatment of neurodegenerative diseases.

Cannabinoid-Based Medicines and Multiple Sclerosis.

The emerging role of the endocannabinoid system (ECS) in the control of symptoms and disease progression in multiple sclerosis (MS) has been highlighted by recent studies. MS is a chronic, immune-mediated, and demyelinating disorder of the central nervous system with no cure so far. It is widely reported that cannabinoids might be used to control MS symptoms and that they also might exert neuroprotective effects and slow down disease progression. The aim of this chapter is to give an overview of the main endogenous and synthetic cannabinoids used for the symptomatic amelioration of MS and their beneficial outcomes, providing new possible perspectives for the treatment of this disease.

Heavy Metals Content in Great Shearwater (Ardenna Gravis): Accumulation, Distribution and Biomarkers of Effect in Different Tissues.

The purpose of this study was to explore the usefulness of Great Shearwater (Ardenna gravis) as a bioindicator for biomonitoring programs for metal pollution. Three different metals were analysed in liver, kidney, and feathers, including cadmium, lead, and zinc. Glutathione-S-transferase, malondialdehyde, reduced glutathione, and catalase were assessed as oxidative stress biomarkers. Sex-related trends in metal accumulation also were evaluated. In liver and kidney, the mean concentrations of Zn (146.1 ± 5.14 and 108 ± 2.70 mg/kg, respectively) and Pb (0.19 ± 0.01 and 0.13 ± 0.01 mg/kg, respectively) in A. gravis were generally comparable to values reported in other studies. However, animals presented slightly higher concentrations of Cd (9.67 ± 0.65 in liver and 17.41 ± 0.84 mg/kg in kidney) than those reported in the same species sampled in Southern Atlantic waters. The slightly higher levels of Cd found in this study compared with other studies are probably affected by the location in Northern Atlantic waters (with different diet intake). In feathers, levels of Zn (70.70 ± 1.76 mg/kg) were lower than in other Ardenna shearwaters, whereas higher levels were found for Cd (0.16 ± 0.01 mg/kg) and Pb (0.84 ± 0.06 mg/kg). The lack of differences found between males and females could be influenced by the migration status, because both sexes stay in similar physiological conditions, with no laying eggs. Levels found in the feathers of the present study were related to concentrations in internal tissues below those which cause adverse effects in birds. Thus, feathers would appear as a potential noninvasive tool for metals biomonitoring in seabirds, because it is possible to quantify them. Baseline data of oxidative stress levels have been reported, both in liver and kidney, presenting no correlations with the levels of metals in these tissues. The low internal metal levels and the lack of correlations between oxidative stress metrics suggest a low risk of the environmental concentrations for seabirds.

Evaluation of Oxidative Stress in Blood of Domestic Chickens and Eurasian Magpies (Pica pica).

A physiological equilibrium exists between pro- and antioxidant factors. When the oxidant factors exceed the capacity of their removal or inactivation, oxidative stress (OS) occurs. The OS levels were assayed in plasma obtained from 2 bird species. Blood samples were collected from 20 healthy domestic chicken hens, 10 living in an intensive farming environment and 10 free-range, and from 18 healthy Eurasian magpies (Pica pica; 7 females and 11 males, with an estimated age of >1 year of age). For OS biomarker assessment, the determinable reactive oxygen metabolites (d-ROMs) were measured, and the plasmatic antioxidant test (PAT) was performed; the OS index (OSI) was then calculated (d-ROMs/PAT × 1000) as a parameter of overall oxidative stress. Moreover, lipid peroxidation was assessed by measuring plasmatic malondialdehyde (MDA) levels. A hematological evaluation was also performed on each bird with a hemocytometer, on which a blood sample was placed to obtain both a total and differential white blood cell (WBC) count. In hens, OSI and MDA levels were significantly higher (P = .04, and P = .004) in subjects from intensive farming (14.7 ± 7.1 and 27.2 ± 10.4 nmol/mL) than in those bred in rural conditions (5.6 ± 10.3 and 8.2 ± 13.3 nmol/mL). In magpies, a positive correlation between the total WBC count and OS was found, and both d-ROMs and OSI were significantly higher (P = .03) in subjects with a total WBC count greater than the median value (20.4 × 103 cells/µL) with respect to those with a total WBC count less than the median value. The results generated from this study indicate that higher OS levels occurred in hens bred in an intensive indoor farm environment compared with outdoor free-range conditions. Possibly the higher OS levels could be related to the higher stocking density and dust levels found in the indoor facility. Additionally, the correlation between OS biomarker levels in magpies and total WBC count suggests that OS level is influenced by immune response, in agreement with previous studies. Collectively, present data seem to be promising for the application of OS measurement in avian medicine for health and animal welfare monitoring.

Modification on the 1,2-dihydro-2-oxo-pyridine-3-carboxamide core to obtain multi-target modulators of endocannabinoid system.

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.

O-Functionalised NHC Ligands for Efficient Nickel-catalysed C-O Hydrosilylation.

A series of C,O-bidentate chelating mesoionic carbene nickel(ii) complexes [Ni(NHC^PhO)2] (NHC = imidazolylidene or triazolylidene) were applied for hydrosilylation of carbonyl groups. The catalytic system is selective towards aldehyde reduction and tolerant to electron-donating and -withdrawing group substituents. Stoichiometric experiments in the presence of different silanes lends support to a metal-ligand cooperative activation of the Si-H bond. Catalytic performance of the nickel complexes is dependent on the triazolylidene substituents. Butyl-substituted triazolylidene ligands impart turnover numbers up to 7,400 and turnover frequencies of almost 30,000 h-1, identifying this complex as one of the best-performing nickel catalysts for hydrosilylation and demonstrating the outstanding potential of O-functionalised NHC ligands in combination with first-row transition metals.

A Diiron Hydrogenase Mimic Featuring a 1,2,3-Triazolylidene.

A novel complex featuring a mesoionic carbene [Fe2(CO)5(trz)(µ-pdt)] (1) (trz = 1-phenyl-l,3-methyl,4-butyl-1,2,3-triazol-5-ylidene), was synthesized and spectroscopically and structurally characterized. The reductive behaviour of this compound in the presence and in the absence of acid (CH3CO2H) was examined by cyclic voltammetry (CV) that revealed the lack of efficient activity towards proton reduction.

Sulfonamido-derivatives of unsubstituted carbazoles as BACE1 inhibitors.

A novel series of variously substituted N-[3-(9H-carbazol-9-yl)-2-hydroxypropyl]-arylsulfonamides has been synthesized and assayed for ß-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.

Novel analogs of PSNCBAM-1 as allosteric modulators of cannabinoid CB1 receptor.

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.

Application of An Improved HPLC-FL Method to Screen Serine Palmitoyl Transferase Inhibitors.

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.

Cytotoxic Activity of Oleocanthal Isolated from Virgin Olive Oil on Human Melanoma Cells.

Oleocanthal is one of the phenolic compounds of extra virgin olive oil with important anti-inflammatory properties. Although its potential anticancer activity has been reported, only limited evidence has been provided in cutaneous malignant melanoma. The present study is aimed at investigating the selective in vitro antiproliferative activity of oleocanthal against human malignant melanoma cells. Since oleocanthal is not commercially available, it was obtained as a pure standard by direct extraction and purification from extra virgin olive oil. Cell viability experiments carried out by WST-1 assay demonstrated that oleocanthal had a remarkable and selective activity for human melanoma cells versus normal dermal fibroblasts with IC50s in the low micromolar range of concentrations. Such an effect was paralleled by a significant inhibition of ERK1/2 and AKT phosphorylation and downregulation of Bcl-2 expression. These findings may suggest that extra virgin olive oil phenolic extract enriched in oleocanthal deserves further investigation in skin cancer.

Rifaximin is an effective alternative to metronidazole for the treatment of chronic enteropathy in dogs: a randomised trial.

BACKGROUND: A clinical trial was conducted in order to assess the efficacy of rifaximin, a broad-spectrum antibiotic with negligible gastrointestinal absorption, in comparison with metronidazole, a commonly employed antimicrobial drug, in dogs with chronic enteropathy. Twenty-four pet dogs were randomly enrolled into two different groups: MET group (10 dogs) and RIF group (14 dogs). Dogs of MET group received metronidazole 15 mg/kg q12h for 21 days by oral route, whereas dogs of RIF group, were given rifaximin 25 mg/kg q12h for 21 days by oral route. Clinical signs of disease were evaluated the day before the beginning of drug administration (D0), and at the end of treatment (D21), by means of Canine IBD Activity Index (CIBDAI). Blood levels of C-reactive protein (CRP) at D0 and D21 were also measured, as another parameter of treatment efficacy. The primary outcome measure of efficacy was the complete remission at D21, defined as a 75 % or greater decrease of CIBDAI; secondary outcome measures were the variation of mean CIBDAI scores, of mean CRP serum levels, and any observed adverse effect from D0 to D21. RESULTS: Treatment with metronidazole or rifaximin greatly improved the clinical signs of disease in each group: in MET group the complete remission was achieved in 8 of 10 dogs (80.0 %), and partial remission in 2 subjects (20.0 %). In RIF group, 12 of 14 dogs showed complete remission (85.7 %), and the remaining 2 dogs were in partial remission (14.3 %). There were also significant decreases of CIBDAI scores (P = 0.002 and P = 0.0002 for MET and RIF, respectively), and CRP levels (P = 0.002 and P = 0.0001 for MET and RIF, respectively) compared to pre-treatment values in both groups. No significant difference, however, was found when comparing MET and RIF groups. No relevant side-effect was reported during the trial with either drugs. CONCLUSIONS: The present study showed, for the first time, that oral rifaximin could represent an effective alternative to metronidazole for the induction of clinical remission in dogs with chronic enteropathy.

Design, synthesis and preliminary evaluation of (18)F-labelled 1,8-naphthyridin- and quinolin-2-one-3-carboxamide derivatives for PET imaging of CB2 cannabinoid receptor.

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 Ki 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.

Soil properties discriminating Araucaria forests with different disturbance levels.

Soil biological, chemical, and physical properties can be important for monitoring soil quality under one of the most spectacular vegetation formation on Atlantic Forest Biome, the Araucaria Forest. Our aim was to identify a set of soil variables capable of discriminating between disturbed, reforested, and native Araucaria forest soils such that these variables could be used to monitor forest recovery and maintenance. Soil samples were collected at dry and rainy season under the three forest types in two state parks at São Paulo State, Brazil. Soil biological, chemical, and physical properties were evaluated to verify their potential to differentiate the forest types, and discriminant analysis was performed to identify the variables that most contribute to the differentiation. Most of physical and chemical variables were sensitive to forest disturbance level, but few biological variables were significantly different when comparing native, reforested, and disturbed forests. Despite more than 20 years following reforestation, the reforested soils were chemically and biologically distinct from native and disturbed forest soils, mainly because of the greater acidity and Al3+ content of reforested soil. Disturbed soils, in contrast, were coarser in texture and contained greater concentrations of extractable P. Although biological properties are generally highly sensitive to disturbance and amelioration efforts, the most important soil variables to discriminate forest types in both seasons included Al3+, Mg2+, P, and sand, and only one microbial attribute: the NO2- oxidizers. Therefore, these five variables were the best candidates, of the variables we employed, for monitoring Araucaria forest disturbance and recovery.

1-Acetoxypinoresinol, a Lignan from Olives: Insight into Its Characterization, Identification, and Nutraceutical Properties.

Extra virgin olive oil (EVOO) is a symbol of the Mediterranean diet, constituting its primary source of fat. The beneficial effect of EVOO is strictly related to the presence of fatty acids and polyphenols, bioactive compounds endowed with nutraceutical properties. Among EVOO polyphenols, lignans possess a steroid-like chemical structure and are part of the phytoestrogen family, which is renowned for its health properties. The natural lignans (+)-pinoresinol and 1-acetoxypinoresinol (1-AP) are commonly present in olives and in EVOO. Although (+)-pinoresinol is found in different edible plants, such as flaxseed, beans, whole-grain cereals, sesame seeds, and certain vegetables and fruit, 1-AP was exclusively identified in olives in 2000. So far, the scientific literature has extensively covered different aspects of (+)-pinoresinol, including its isolation and nutraceutical properties. In contrast, less is known about the olive lignan 1-AP. Therefore, this review aimed to comprehensively evaluate the more important aspects of 1-AP, collecting all the literature from 2016 to the present, exploring its distribution in different cultivars, analytical isolation and purification, and nutraceutical properties.

Fecal microbiota characterization of an Italian local horse breed.

The Bardigiano horse is a traditional native Italian breed with a rich history and peculiar characteristics. Local breeds are proven to have unique genetic traits developed over generations to adapt to defined geographical regions and/or conditions. The specific microbial communities that coexist within these animals are unraveled by studying their microbiota, which permits a further step in the characterization of local heritage. This work aimed to characterize Bardigiano horse fecal microbiota composition. The data obtained were then compared with published data of a mix of athlete breeds to evaluate potential differences among local and specialized breeds. The study involved 11 Bardigiano mares between 3 and 4 years of age, from which stool was sampled for the study. Samples were processed for 16S rRNA sequencing. Data obtained were analyzed and plotted using R, RStudio, and FastTree software. The samples analyzed were similar to what literature has reported on horses of other breeds and attitudes at higher taxonomic levels (from phylum to genera). While at lower taxonomic levels, the difference was more marked highlighting specific families found in the Bardigiano breed only. Weight, province of origin, and breeding sites significantly affected microbiota composition (p-value ≤0.02, p-value ≤0.04, and p-value ≤0.05, respectively). The comparison with athlete breed showed a significant difference confirming that animal and environmental factors are crucial in determining fecal microbiota composition (p-value <0.001). Understanding the microbiota composition in local breeds like the Bardigiano horse is crucial for preserving biodiversity, managing animal health, and promoting sustainable farming practices.

The porcine corpus luteum as a model for studying the effects of nanoplastics.

Nanoplastics (NPs) affect fertility. We evaluated the effects of NPs treatment on luteal and endothelial cells. We examined crucial markers of growth and redox status. NPs treatment did not induce changes in ATP levels in luteal cells, while it increased (p< 0.05) their proliferation. In endothelial cells, no change in proliferation was detected, while an increase (p<0.05) in ATP levels was observed. The increase of reactive oxygen species, superoxide anion (p<0.05) and nitric oxide (p<0.001) was detected in both cell types, which also showed changes in superoxide dismutase enzyme activity as well as an increase of non-enzymatic antioxidant power (p<0.05). A decrease (p<0.05) in progesterone production as well as an increase of vascular endothelial growth factor A levels were detected (p<0.05). In addition, a dose-dependent accumulation of NPs in endothelial cells was shown, that likely occurred through adhesion and internalization. Results underline potential risk of NPs for corpus luteum functionality.