4-Hydroxy-N-[3,5-bis(trifluoromethyl)phenyl]-1,2,5-thiadiazole-3-carboxamide: a novel inhibitor of the canonical NF-κB cascade

Chronic Treatment with Nigella sativa Oil Exerts Antimanic Properties and Reduces Brain Inflammation in Rats

Nigella sativa (NS) is a native herb consumed habitually in several countries worldwide, possessing manifold therapeutic properties. Among them, anti-inflammatory features have been reported, presumably relating to mechanisms involved in the nuclear factor kappa-B pathway, among others. Given the observed association between neuroimmune factors and mental illness, the primary aim of the present study was to examine the effects of chronic NS use on manic-like behavior in rats, as well as analyze levels of brain inflammatory mediators following NS intake. Using male and female rats, baseline tests were performed; thereafter, rats were fed either regular food (control) or NS-containing food (treatment) for four weeks. Following intervention, behavioral tests were induced (an open field test, sucrose consumption test, three-chamber sociality test, and amphetamine-induced hyperactivity test). Subsequently, brain samples were extracted, and inflammatory mediators were evaluated, including interleukin-6, leukotriene B4, prostaglandin E2, tumor necrosis factor-α, and nuclear phosphorylated-p65. Our findings show NS to result in a marked antimanic-like effect, in tandem with a positive modulation of select inflammatory mediators among male and female rats. The findings reinforce the proposed therapeutic advantages relating to NS ingestion.

Sodium Danshensu stabilizes atherosclerotic vulnerable plaques by targeting IKKβ mediated inflammation in macrophages

BACKGROUND

The primary cause of acute cardiovascular events with high mortality is the rupture of atherosclerotic plaque followed by thrombosis. Sodium Danshensu (SDSS) has shown potential in inhibiting the inflammatory response in macrophages and preventing early plaque formation in atherosclerotic mice. However, the specific targets and detailed mechanism of action of SDSS are still unclear.

OBJECTIVE

This study aims to investigate the efficacy and mechanism of SDSS in inhibiting inflammation in macrophages and stabilizing vulnerable plaques in atherosclerosis (AS).

MATERIALS AND METHODS

The efficacy of SDSS in stabilizing vulnerable plaques was demonstrated using various techniques such as ultrasound, Oil Red O staining, HE staining, Masson staining, immunohistochemistry, and lipid analysis in ApoE-/- mice. Subsequently, IKKβ was identified as a potential target of SDSS through protein microarray, network pharmacology analysis, and molecular docking. Additionally, ELISA, RT-qPCR, Western blotting, and immunofluorescence were employed to measure the levels of inflammatory cytokines, IKKβ, and NF-κB pathway-related targets, thereby confirming the mechanism of SDSS in treating AS both in vivo and in vitro. Finally, the impact of SDSS was observed in the presence of an IKKβ-specific inhibitor.

RESULTS

Initially, the administration of SDSS led to a decrease in the formation and area of aortic plaque, while also stabilizing vulnerable plaques in ApoE-/- mice. Furthermore, it was identified that IKKβ serves as the primary binding target of SDSS. Additionally, both in vivo and in vitro experiments demonstrated that SDSS effectively inhibits the NF-κB pathway by targeting IKKβ. Lastly, the combined use of the IKKβ-specific inhibitor IMD-0354 further enhanced the beneficial effects of SDSS.

CONCLUSIONS

SDSS stabilized vulnerable plaques and suppressed inflammatory responses by inhibiting the NF-κB pathway through its targeting of IKKβ.

A New NF-κB Inhibitor, MEDS-23, Reduces the Severity of Adverse Post-Ischemic Stroke Outcomes in Rats

Aim: Nuclear factor kappa B (NF-κB) is known to play an important role in the inflammatory process which takes place after ischemic stroke. The major objective of the present study was to examine the effects of MEDS-23, a potent inhibitor of NF-κB, on clinical outcomes and brain inflammatory markers in post-ischemic stroke rats. Main methods: Initially, a Toxicity Experiment was performed to determine the appropriate dose of MEDS-23 for use in animals, as MEDS-23 was analyzed in vivo for the first time. We used the middle cerebral artery occlusion (MCAO) model for inducing ischemic stroke in rats. The effects of MEDS-23 (at 10 mg/kg, ip) on post-stroke outcomes (brain inflammation, fever, neurological deficits, mortality, and depression- and anxiety-like behaviours) was tested in several efficacy experiments. Key findings: MEDS-23 was found to be safe and significantly reduced the severity of some adverse post-stroke outcomes such as fever and neurological deficits. Moreover, MEDS-23 significantly decreased prostaglandin E2 levels in the hypothalamus and hippocampus of post-stroke rats, but did not prominently alter the levels of interleukin-6 and tumor necrosis factor-α. Significance: These results suggest that NF-κB inhibition is a potential therapeutic strategy for the treatment of ischemic stroke.

1,2,5-Thiadiazole Scaffold: A review on recent progress in biological activities

BACKGROUND

Thiadiazoles can be considered as the privileged scaffold having diverse pharmacological potentials such as antihypertensive, anti-HIV, antimicrobials, antileishmanial agents, etc. In particular, 1,2,5-thiadiazoles and their fused analogues are subjects of fast-growing interest due to their higher significance in the fields of biomedicine and material sciences.

OBJECTIVE

This study aims to collect detailed medicinal information about aspects of 1,2,5-thiadiazole.

METHODS

A systemic search has been carried out using PubMed, Google Scholar, CNKI, etc., for relevant studies having the keyword, '1,2,5-thiadiazole'.

RESULTS AND CONCLUSION

In this mini-review, we have covered known procedures of the synthesis and explored in detail all known advancements of this scaffold concerning to its biological activities.

Targeting Acute Myelogenous Leukemia Using Potent Human Dihydroorotate Dehydrogenase Inhibitors Based on the 2-Hydroxypyrazolo[1,5-a]pyridine Scaffold: SAR of the Biphenyl Moiety

The connection with acute myelogenous leukemia (AML) of dihydroorotate dehydrogenase (hDHODH), a key enzyme in pyrimidine biosynthesis, has attracted significant interest from pharma as a possible AML therapeutic target. We recently discovered compound 1, a potent hDHODH inhibitor (IC50 = 1.2 nM), able to induce myeloid differentiation in AML cell lines (THP1) in the low nM range (EC50 = 32.8 nM) superior to brequinar's phase I/II clinical trial (EC50 = 265 nM). Herein, we investigate the 1 drug-like properties observing good metabolic stability and no toxic profile when administered at doses of 10 and 25 mg/kg every 3 days for 5 weeks (Balb/c mice). Moreover, in order to identify a backup compound, we investigate the SAR of this class of compounds. Inside the series, 17 is characterized by higher potency in inducing myeloid differentiation (EC50 = 17.3 nM), strong proapoptotic properties (EC50 = 20.2 nM), and low cytotoxicity toward non-AML cells (EC30(Jurkat) > 100 μM).

Kinetic isotope effects and synthetic strategies for deuterated carbon-11 and fluorine-18 labelled PET radiopharmaceuticals

The deuterium labelling of pharmaceuticals is a useful strategy for altering pharmacokinetic properties, particularly for improving metabolic resistance. The pharmacological effects of such metabolites are often assumed to be negligible during standard drug discovery and are factored in later at the clinical phases of development, where the risks and benefits of the treatment and side-effects can be wholly assessed. This paradigm does not translate to the discovery of radiopharmaceuticals, however, as the confounding effects of radiometabolites can inevitably show in preliminary positron emission tomography (PET) scans and thus complicate interpretation. Consequently, the formation of radiometabolites is crucial to take into consideration, compared to non-radioactive metabolites, and the application of deuterium labelling is a particularly attractive approach to minimise radiometabolite formation. Herein, we provide a comprehensive overview of the deuterated carbon-11 and fluorine-18 radiopharmaceuticals employed in PET imaging experiments. Specifically, we explore six categories of deuterated radiopharmaceuticals used to investigate the activities of monoamine oxygenase (MAO), choline, translocator protein (TSPO), vesicular monoamine transporter 2 (VMAT2), neurotransmission and the diagnosis of Alzheimer's disease; from which we derive four prominent deuteration strategies giving rise to a kinetic isotope effect (KIE) for reducing the rate of metabolism. Synthetic approaches for over thirty of these deuterated radiopharmaceuticals are discussed from the perspective of deuterium and radioisotope incorporation, alongside an evaluation of the deuterium labelling and radiolabelling efficacies across these independent studies. Clinical and manufacturing implications are also discussed to provide a more comprehensive overview of how deuterated radiopharmaceuticals may be introduced to routine practice.

Discovery and Structure Relationships of Salicylanilide Derivatives as Potent, Non-acidic P2X1 Receptor Antagonists

Antagonists for the ATP-gated ion channel receptor P2X1 have potential as antithrombotics and for treating hyperactive bladder and inflammation. In this study, salicylanilide derivatives were synthesized based on a screening hit. P2X1 antagonistic potency was assessed in 1321N1 astrocytoma cells stably transfected with the human P2X1 receptor by measuring inhibition of the ATP-induced calcium influx. Structure-activity relationships were analyzed, and selectivity versus other P2X receptor subtypes was assessed. The most potent compounds, N-[3,5-bis(trifluoromethyl)phenyl]-5-chloro-2-hydroxybenzamide (1, IC₅₀ 0.0192 μM) and N-[3,5-bis(trifluoromethyl)phenyl]-4-chloro-2-hydroxybenzamide (14, IC₅₀ 0.0231 μM), displayed >500-fold selectivity versus P2X2 and P2X3, and 10-fold selectivity versus P2X4 and P2X7 receptors, and inhibited collagen-induced platelet aggregation. They behaved as negative allosteric modulators, and molecular modeling studies suggested an extracellular binding site. Besides selective P2X1 antagonists, compounds with ancillary P2X4 and/or P2X7 receptor inhibition were discovered. These compounds represent the first potent, non-acidic, allosteric P2X1 receptor antagonists reported to date.

Dihydroorotate dehydrogenase inhibitors in anti-infective drug research

Pyrimidines are essential for the cell survival and proliferation of living parasitic organisms, such as Helicobacter pylori, Plasmodium falciparum and Schistosoma mansoni, that are able to impact upon human health. Pyrimidine building blocks, in human cells, are synthesised via both de novo biosynthesis and salvage pathways, the latter of which is an effective way of recycling pre-existing nucleotides. As many parasitic organisms lack pyrimidine salvage pathways for pyrimidine nucleotides, blocking de novo biosynthesis is seen as an effective therapeutic means to selectively target the parasite without effecting the human host. Dihydroorotate dehydrogenase (DHODH), which is involved in the de novo biosynthesis of pyrimidines, is a validated target for anti-infective drug research. Recent advances in the DHODH microorganism field are discussed herein, as is the potential for the development of DHODH-targeted therapeutics.

Design and optimize N-substituted EF24 as effective and low toxicity NF-κB inhibitor for lung cancer therapy via apoptosis-to-pyroptosis switch

As NF-κB signaling pathway is constitutively activated in lung cancer, targeting NF-κB has a potential for the treatment. EF24 has been proved to be a NF-κB inhibitor with good antitumor activity, while whose toxicity possibly became one of the obstacles to enter into clinical application. In order to find high efficiency and low toxicity NF-κB inhibitors, EF24 was modified and 13d was screened out. It was proved that 13d possessed an effective combination of inhibiting NF-κB pathway and showing lower cytotoxicity on normal cells as well as less toxicity in acute toxicity experiment compared with the lead compound of EF24. In addition, 13d was found to inhibit cell vitality, arrest cell cycle in G2/M phase, promote cell apoptosis, and suppress the xenograft tumor growth. Furthermore, 13d was elucidated to induce pyroptosis developing from apoptosis, which was associated with the inhibition of NF-κB. Taken together, it was suggested that 13d was a potent antitumor agent.

Use of the 4-Hydroxytriazole Moiety as a Bioisosteric Tool in the Development of Ionotropic Glutamate Receptor Ligands

We report a series of glutamate and aspartate analogues designed using the hydroxy-1,2,3-triazole moiety as a bioisostere for the distal carboxylic acid. Compound 6b showed unprecedented selectivity among ( S)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptor subtypes, confirmed also by an unusual binding mode observed for the crystal structures in complex with the AMPA receptor GluA2 agonist-binding domain. Here, a methionine (Met729) was highly disordered compared to previous agonist-bound structures. This observation provides a possible explanation for the pharmacological profile. In the structure with 7a, an unusual organization of water molecules around the bioisostere arises compared to previous structures of ligands with other bioisosteres. Aspartate analogue 8 with the hydroxy-1,2,3-triazole moiety directly attached to glycine was unexpectedly able to activate both the glutamate and glycine agonist-binding sites of the N-methyl-d-aspartic acid receptor. These observations demonstrate novel features that arise when employing a hydroxytriazole moiety as a bioisostere for the distal carboxylic acid in glutamate receptor agonists.

Targeting IKKβ in Cancer: Challenges and Opportunities for the Therapeutic Utilisation of IKKβ Inhibitors

Deregulated NF-κB signalling is implicated in the pathogenesis of numerous human inflammatory disorders and malignancies. Consequently, the NF-κB pathway has attracted attention as an attractive therapeutic target for drug discovery. As the primary, druggable mediator of canonical NF-κB signalling the IKKβ protein kinase has been the historical focus of drug development pipelines. Thousands of compounds with activity against IKKβ have been characterised, with many demonstrating promising efficacy in pre-clinical models of cancer and inflammatory disease. However, severe on-target toxicities and other safety concerns associated with systemic IKKβ inhibition have thus far prevented the clinical approval of any IKKβ inhibitors. This review will discuss the potential reasons for the lack of clinical success of IKKβ inhibitors to date, the challenges associated with their therapeutic use, realistic opportunities for their future utilisation, and the alternative strategies to inhibit NF-κB signalling that may overcome some of the limitations associated with IKKβ inhibition.

N-Acetyl-3-aminopyrazoles block the non-canonical NF-kB cascade by selectively inhibiting NIK

NF-κB-inducing kinase (NIK), an oncogenic drug target that is associated with various cancers, is a central signalling component of the non-canonical pathway. A blind screening process, which established that amino pyrazole related scaffolds have an effect on IKKbeta, led to a hit-to-lead optimization process that identified the aminopyrazole 3a as a low μM selective NIK inhibitor. Compound 3a effectively inhibited the NIK-dependent activation of the NF-κB pathway in tumour cells, confirming its selective inhibitory profile.