Novel 8-(furan-2-yl)-3-benzyl thiazolo [5,4-e][1,2,4] triazolo [1,5-c] pyrimidine-2(3H)-thione as selective adenosine A(2A) receptor antagonist

Discovery of novel A2AR antagonist via 3D-QSAR pharmacophore modeling: neuroprotective effects in 6-OHDA-induced SH-SY5Y cells and haloperidol-induced Parkinsonism in C57 bl/6 mice

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder which is caused by abrupt degeneration of dopaminergic neuronal cells in the substantia nigra pars compacta (SNPc) area of the midbrain. Adenosine A2A receptors have become promising therapeutic targets for PD; however, many A2A receptor antagonists face challenges, such as limited accessibility or failure in clinical trials due to poor selectivity and bioavailability. To identify novel A2A receptor antagonists, a 3D-QSAR-pharmacophore modeling approach was employed, involving virtual screening of ZINC, NCI, and MayBridge databases. The virtual hits were filtered via ADMET criteria to select compounds with favorable bioavailability and solubility profiles. From the MayBridge database, a potent monocyclic A2A receptor antagonist, AW00032 (N-(furan-2-ylmethyl)-5-methylthiazole-4-yl) thiophene-2-sulfonamide, was identified. AW00032 possessed key pharmacophoric features: two lipophilic hydrogen bond acceptors, one hydrophobic aliphatic/aromatic group, and one aromatic ring. Docking analysis revealed AW00032 had a strong binding affinity for A2A receptors (1.23 nM, ∆G - 10.49 kcal/mol), and its ADMET profile indicated good bioavailability. In 6-OHDA induced SH-SY5Y cells, AW00032 increased dopamine levels and tyrosine hydroxylase (TH) expression, demonstrating its potential as an A2A receptor antagonist. AW00032, discovered through 3D-QSAR pharmacophore modeling, also reduced reactive oxygen species (ROS) levels and showed depletion in mitochondrial dysfunction in 6-OHDA-induced SH-SY5Y cells. It exhibited A2A receptor antagonist activity comparable to the standard antagonist ZM241385, partially restoring dopamine and TH levels. Furthermore, AW00032 improved behavioral symptoms in haloperidol-induced C-57 bl/6 mice.

Multitarget action of Benzothiazole-piperazine small hybrid molecule against Alzheimer's disease: In silico, In vitro, and In vivo investigation

A novel small molecule based on benzothiazole-piperazine has been identified as an effective multi-target-directed ligand (MTDL) against Alzheimer's disease (AD). Employing a medicinal chemistry approach, combined with molecular docking, MD simulation, and binding free energy estimation, compound 1 emerged as a potent MTDL against AD. Notably, compound 1 demonstrated efficient binding to both AChE and Aβ1-42, involving crucial molecular interactions within their active sites. It displayed a binding free energy (ΔGbind) -18.64± 0.16 and -16.10 ± 0.18 kcal/mol against AChE and Aβ1-42, respectively. In-silico findings were substantiated through rigorous in vitro and in vivo studies. In vitro analysis confirmed compound 1 (IC50=0.42 μM) as an effective, mixed-type, and selective AChE inhibitor, binding at both the enzyme's catalytic and peripheral anionic sites. Furthermore, compound 1 demonstrated a remarkable ability to reduce the aggregation propensity of Aβ, as evidenced by Confocal laser scanning microscopy and TEM studies. Remarkably, in vivo studies exhibited the promising therapeutic potential of compound 1. In a scopolamine-induced memory deficit mouse model of AD, compound 1 showed significantly improved spatial memory and cognition. These findings collectively underscore the potential of compound 1 as a promising therapeutic candidate for the treatment of AD.

Exploration of chalcones and related heterocycle compounds as ligands of adenosine receptors: therapeutics development

Adenosine receptors (ARs) are ubiquitously distributed throughout the mammalian body where they are involved in an extensive list of physiological and pathological processes that scientists have only begun to decipher. Resultantly, AR agonists and antagonists have been the focus of multiple drug design and development programmes within the past few decades. Considered to be a privileged scaffold in medicinal chemistry, the chalcone framework has attracted a substantial amount of interest in this regard. Due to the potential liabilities associated with its structure, however, it has become necessary to explore other potentially promising compounds, such as heterocycles, which have successfully been obtained from chalcone precursors in the past. This review aims to summarise the emerging therapeutic importance of adenosine receptors and their ligands, especially in the central nervous system (CNS), while highlighting chalcone and heterocyclic derivatives as promising AR ligand lead compounds.

Haloperidol-induced catalepsy as an animal model for parkinsonism: A systematic review of experimental studies

Several useful animal models for parkinsonism have been developed so far. Haloperidol-induced catalepsy is often used as a rodent model for the study of motor impairments observed in Parkinson's disease and related disorders and for the screening of potential antiparkinsonian compounds. The objective of this systematic review is to identify publications that used the haloperidol-induced catalepsy model for parkinsonism and to explore the methodological characteristics and the main questions addressed in these studies. A careful systematic search of the literature was carried out by accessing articles in three different databases: Web of Science, PubMed and SCOPUS. The selection and inclusion of studies were performed based on the abstract and, subsequently, on full-text analysis. Data extraction included the objective of the study, study design and outcome of interest. Two hundred and fifty-five articles were included in the review. Publication years ranged from 1981 to 2020. Most studies used the model to explore the effects of potential treatments for parkinsonism. Although the methodological characteristics used are quite varied, most studies used Wistar rats as experimental subjects. The most frequent dose of haloperidol used was 1.0 mg/kg, and the horizontal bar test was the most used to assess catalepsy. The data presented here provide a framework for an evidence-based approach to the design of preclinical research on parkinsonism using the haloperidol-induced catalepsy model. This model has been used routinely and successfully and is likely to continue to play a critical role in the ongoing search for the next generation of therapeutic interventions for parkinsonism.

Anti-inflammatory Effects of S. cumini Seed Extract on Gelatinase-B (MMP-9) Regulation against Hyperglycemic Cardiomyocyte Stress

Black berry (Syzygium cumini) fruit is useful in curing diabetic complications; however, its role in diabetes-induced cardiomyopathy is not yet known. In this study, we investigated the regulation of gelatinase-B (MMP-9) by S. cumini methanol seed extract (MSE) in diabetic cardiomyopathy using real-time PCR, RT-PCR, immunocytochemistry, gel diffusion assay, and substrate zymography. The regulatory effects of MSE on NF-κB, TNF-α, and IL-6 were also examined. Identification and estimation of polyphenol constituents present in S. cumini extract were carried out using reverse-phase HPLC. Further, in silico docking studies of identified polyphenols with gelatinase-B were performed to elucidate molecular level interaction in the active site of gelatinase-B. Docking studies showed strong interaction of S. cumini polyphenols with gelatinase-B. Our findings indicate that MSE significantly suppresses gelatinase-B expression and activity in high-glucose- (HG-) stimulated cardiomyopathy. Further, HG-induced activation of NF-κB, TNF-α, and IL-6 was also remarkably reduced by MSE. Our results suggest that S. cumini MSE may be useful as an effective functional food and dietary supplement to regulate HG-induced cardiac stress through gelatinase.

Discovery of 7-(Prolinol-N-yl)-2-phenylamino-thiazolo[5,4-d]pyrimidines as Novel Non-Nucleoside Partial Agonists for the A2A Adenosine Receptor: Prediction from Molecular Modeling

We describe the identification of 7-(prolinol-N-yl)-2-phenylamino-thiazolo[5,4-d]pyrimidines as a novel chemotype of non-nucleoside partial agonists for the A2A adenosine receptor (A2AAR). Molecular-modeling indicated that the (S)-2-hydroxymethylene-pyrrolidine could mimic the interactions of agonists' ribose, suggesting that this class of compounds could have agonistic properties. This was confirmed by functional assays on the A2AAR, where their efficacy could be associated with the presence of the 2-hydroxymethylene moiety. Additionally, the best compound displays promising affinity, selectivity profile, and physicochemical properties.

Thiazole: a promising heterocycle for the development of potent CNS active agents

Thiazole is a valuable scaffold in the field of medicinal chemistry and has accounted to display a variety of biological activities. Thiazole and its derivatives have attracted continuing interest to design various novel CNS active agents. In the past few decades, thiazoles have been widely used to develop a variety of therapeutic agents against numerous CNS targets. Thiazole containing drug molecules are currently being used in treatment of various CNS disorders and a number of thiazole derivatives are also presently in clinical trials. A lot of research has been carried out on thiazole and their analogues, which has proved their efficacy to overcome several CNS disorders in rodent as well as primate models. The aim of present review is to highlights diverse CNS activities displayed by thiazole and their derivatives. SAR of this nucleus has also been well discussed. This review covers the recent updates present in literature and will surely provide a greater insight for the designing and development of potent thiazole based CNS active agents in future.

8-(Furan-2-yl)-3-phenethylthiazolo[5,4-e][1,2,4]triazolo[1,5-c]pyrimidine-2(3H)-thione as novel, selective and potent adenosine A(2A) receptor antagonist

Antagonism of the human A2A receptor has been implicated to alleviate the symptoms associated with Parkinson's disease. The present finding reveals the potential of PTTP (8-(furan-2-yl)-3-phenethylthiazolo[1,2,4]triazolo[1,5-c]pyrimidine-2(3H)-thione) as novel and potent A2AR antagonist. In radioligand binding assay, PTTP showed significantly high binding affinity (Ki 6.3 nM) and selectivity with A2AR (A1R/A2AR=4603) which was comparable to the results of docking analysis (Ki=1.6 nM, ΔG=-14.52 Kcal/mol). PTTP antagonized (0.46 pmol/ml) the effect of NECA-induced increase in cAMP concentration (0.65 pmol/ml) better than SCH58261 (0.55 pmol/ml) in HEK293T cells. Haloperidol and NECA-induced mice pre-treated with PTTP at 10mg/kg showed attenuation in catalepsy and akinesia without significant neurotoxicity in rotarod test at 20mg/kg. Essentially, novel compound demonstrated remarkable potential as A2AR antagonist in the therapy of PD.

Design and synthesis of (4E)-4-(4-substitutedbenzylideneamino)-3-substituted-2,3-dihydro-2-thioxothiazole-5-carbonitrile as novel A2A receptor antagonists

Novel 2-thioxothiazole derivatives (6-19) as potential adenosine A2A receptor (A2AR) antagonists were synthesized. The strong interaction of the compounds (6-19) with A2AR in docking study was confirmed by high binding affinity with human A2AR expressed in HEK293T cells using radioligand-binding assay. The compound 19 demonstrated very high selectivity for A2AR as compared to standard A2AR antagonist SCH58261. Decrease in A2AR-coupled release of endogenous cAMP in treated HEK293T cells demonstrated in vitro A2AR antagonist potential of the compound 19. Attenuation in haloperidol-induced impairment (catalepsy) in Swiss albino male mice pre-treated with compound 19 is evocative to explore its prospective in therapy of PD.