Design, synthesis and neuropharmacological evaluation of new 2,4-disubstituted-1,5-benzodiazepines as CNS active agents

Synthesis, In vivo, and In silico Evaluation of New Pyrazoline-Benzothiazole Conjugates as Antiepileptic Agents

New 2-(4-benzothiazol-2-yl-phenoxy)-1-(3,5-diphenyl-4,5-dihydro-pyrazol-1-yl)-ethanones (9a-o) have been designed and synthesized. All the synthesized compounds were characterized by thin layer chromatography and spectral analysis. The antiepileptic potential of the synthesized compounds has been tested by following standard animal screening models, including maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) models. The neurotoxic and antidepression effects of the synthesized compounds were checked by utilizing rotarod apparatus, and motor impairment test (by actophotometer) respectively. The study concluded that compounds 9c, 9d, 9f, 9i, 9n, and 9o possessed good antiepileptic potential compared to standard drugs like carbamazepine and phenytoin. The results of the rotarod performance test also established them without any neurotoxicity. The motor impairment test revealed that the synthesized compounds are also good antidepressants. In-silico studies have been performed for calculation of pharmacophore pattern, prediction of pharmacokinetic properties which determine the eligibility of synthesized compounds as orally administered molecules and interactions with the target proteins. The result of in-silico studies reinforced results obtained by in vivo study of the synthesized compounds and their possible mechanism of antiepileptic action i. e. via inhibiting voltage-gated sodium channels (VGSCs) and gamma-aminobutyric acid-A receptor.

3,5-Disubstituted-thiazolidine-2,4-dione hybrids as antidiabetic agents: Design, synthesis, in-vitro and In vivo evaluation

Diabetes is one of the fastest-growing metabolic disorders, nearly doubling the number of patients each year. There are different treatment approaches available for the management of diabetes, which lacks due to their side effects. The inhibition of enzymes involved in the metabolism of complex polysaccharides to monosaccharides has proven beneficial in patients with type 2 diabetes mellitus. Two enzymes, α-amylase and α-glucosidase, have emerged as potential drug targets and are widely explored for drug development against type 2 diabetes mellitus. In this context, thiazolidine-2,4-diones (TZDs) have emerged as potential drug candidates for developing newer molecules against α-amylase and α-glucosidase. Nineteen TZD-hybrids were synthesized and evaluated in vitro α-amylase and α-glucosidase inhibitory activity. The compounds 7i, 7k, and 7p have emerged as the best dual inhibitors with IC50 of 10.33 ± 0.11-20.94 ± 0.76 μM and 10.19 ± 0.25-24.07 ± 1.56 μM against α-glucosidase and α-amylase, respectively. The derivatives had good anti-oxidant activity, displaying IC50 = 14.95 ± 0.65-23.27 ± 0.99 μM. The compounds 7k and 7p showed the best inhibition of reactive oxygen species in the PNAC-1 cells. The molecules exhibit good binding within the active site of α-amylase (PDB id: 1B2Y) and α-glucosidase (PDB id: 3W37), displaying binding energies of -7.5 to -10.7 kcal/mol and -7.4 to -10.3 kcal/mol, respectively. Further, the compounds were nontoxic (LD50 = 500-1311 mg/kg) and possessed good GI absorption. The compounds 7i, 7k, and 7p were evaluated in vivo antidiabetic activity in an STZ-induced diabetic model in Wistar rats. The compound 7p emerged as the best compound in the in vivo studies; however, the activity was lesser than that of the standard drug pioglitazone.

Discovery of thiazolidinedione-based pancreatic lipase inhibitors as anti-obesity agents: synthesis, in silico studies and pharmacological investigations

A series of new 2,5-disubstituted arylidene derivatives of thiazolidinedione (16a-e, 17a-d, 18a-c) designed using molecular hybridization approach were synthesized, structurally characterized, and explored for their anti-obesity potential via inhibition of Pancreatic Lipase (PL). Compound 18a presented the most potent PL inhibitory activity with IC50 = 2.71 ± 0.31 µM, as compared to the standard drug, Orlistat (IC50 = 0.99 µM). Kinetic study revealed reversible competitive mode of enzyme inhibition by compound 18a with an inhibitory constant value of 1.19 µM. The most promising compound 18a revealed satisfactory binding mode within the active site of the target protein (human PL, PDB ID: 1LPB). Also, MM/PBSA binding free energy and molecular dynamics (MD) simulation analysis were performed for the most promising compound 18a, which showed potent inhibition according to the results of in vitro studies. Furthermore, a stable conformation of the 1LPB-ligand suggested the stability of this compound in the dynamic environment. The ADME and toxicity analysis of the compounds were examined using web-based online platforms. Results of in vivo studies confirmed the anti-obesity efficacy of compound 18a, wherein oral treatment with compound 18a (30 mg/kg) resulted in a significant reduction in the body weight, BMI, Lee index, feed intake (in Kcal), body fat depots and serum triglycerides. Compound 18a significantly decreased the levels of serum total cholesterol (TC) to 128.6 ± 0.59 mg/dl and serum total triglycerides (TG) to 95.73 ± 0.67 mg/dl as compared to the HFD control group. The present study identified disubstituted TZD derivatives as a new promising class of anti-obesity agents.Communicated by Ramaswamy H. Sarma.

Anticonvulsant Classes and Possible Mechanism of Actions

Epilepsy is considered one of the most common neurological disorders worldwide; it needs long-term or life-long treatment. Despite the presence of several novel antiepileptic drugs, approximately 30% patients still suffer from drug-resistant epilepsy. Subsequently, searching for new anticonvulsants with lower toxicity and better efficacy is still in paramount demand. Using target-based studies in the discovery of novel antiepileptics is uncommon owing to the insufficient information on the molecular pathway of epilepsy and complex mode of action for most of known antiepileptic drugs. In this review, we investigated the properties of anticonvulsants, types of epileptic seizures, and mechanism of action for anticonvulsants.

Acupuncture-adjuvant therapies for treating perimenopausal depression: A network meta-analysis

BACKGROUND

The issues related to the treatment of perimenopausal depression (PMD) are the side effects of antidepressants and hormone replacement therapy. The aim of this study was to assess the efficiency and safety of acupuncture and moxibustion in PMD patients.

METHODS

Databases, namely PubMed, Cochrane Library, Web of Science, EMBASE, CNKI, CBM, VIP, and WanFang, were reviewed for related randomized controlled trials dated between database inception and November 22, 2022. The primary outcomes were the efficacy rate and the Hamilton Depression Scale score. The secondary outcomes were the levels of follicle-stimulating hormone, luteinizing hormone, and estradiol and the Kupperman score. Odds ratios (ORs) were generated as the effect size for dichotomous outcomes, while the standard mean difference (SMD) ± standard deviation was used for continuous outcomes. Matrices were developed to demonstrate pairwise comparisons of regimens related to each endpoint. Utilizing Review Manager (RevMan) 5.3, Stata 16.0 and SPSS 21, data were analyzed.

RESULTS

In total, 27 studies involving 2269 PMD patients and 8 therapeutic measures were incorporated into the network meta-analysis (NMA). The NMA showed that warm acupuncture (OR = 1.55, 95% CI: 1.00-2.44), electroacupuncture (OR = 1.34, 95% CI: 1.00-1.8), abdominal acupuncture (OR = 1.19, 95% CI: 0.73-1.96), and common acupuncture (OR = 1.4, 95% CI: 0.9-2.17) were more effective than fluoxetine + menopausal hormone treatment in the treatment of PMD. The NMA also showed that, based on the Hamilton Depression Scale score, warm acupuncture was more effective than the other 4 acupuncture-related treatments, i.e., electroacupuncture (SMD = -1.22, 95% CI: -2.34 to -0.09), thread embedding (SMD = -1.31, 95% CI: -2.21 to -0.40), abdominal acupuncture (SMD = -1.33, 95% CI: -2.42 to -0.24), and common acupuncture (SMD = -1.46, 95% CI: -2.26 to -0.66). The cumulative ranking probability (SUCRA) showed that warm acupuncture (99.6%) was the best treatment method.

CONCLUSIONS

The findings of this network meta-analysis may help patients and therapists choose the best acupuncture therapy for treating perimenopausal depression patients and furnish reliable evidence for guidelines.

Targeting GABA receptors with chalcone derivative compounds, what is the evidence?

INTRODUCTION

In medicinal chemistry, privileged structures have been frequently exploited as a successful template for drug discovery. Common simple scaffolds like chalcone are present in a wide range of naturally occurring chemicals. Chalcone exhibits extensive biological activity and has drawn attention in this context due to its function in the GABA receptor. Epilepsy and GABA receptors are related. It is a chronic neurological condition that affects globally.

AREAS COVERED

Numerous neurological disorders, including anxiety and epilepsy, have been related to GABA, the brain's most prevalent inhibitory neurotransmitter. We go through the role of GABA receptors in anxiety and epilepsy in this review. The structure-activity relationship of chalcone and its derivatives on the GABA receptor is covered in our final section.

EXPERT OPINION

GABA is a potential therapeutic target for issues associated with the nervous system. We talk about the potential effects of chalcone as a treatment for epilepsy and anxiety on the GABA receptor. Therefore, thorough research is necessary in this regard; the value of in silico tools in developing and enhancing GABA agonists is significant.

Design, Synthesis and Biological Evaluation of Imidazole-Substituted/Fused Aryl Derivatives Targeting Tubulin Polymerization as Anticancer Agents

The development of new pharmacologically active molecules targeting tubulin polymerization has recently attracted great interest in research groups. In efforts to develop new potent anticancer compounds, imidazole-tethered/fused pharmacologically active aryl derivatives possessing different substitution patterns targeting tubulin polymerization have been rationally designed and synthesized. The target molecules (P1-5 and KG1-5) were synthesized by multistep syntheses involving the reaction of intermediate 2-aminophenyl-tethered imidazoles with appropriate reactants in the presence of p-TsOH under different conditions. The synthesized compounds displayed moderate to good cytotoxicity, comparable to that of colchicine, against four cancer cell lines (MCF-7, MD-MBA-231, A549, and HCT-116). Compounds P2 and P5, with an imidazoloquinoxaline moiety, emerged as potential leads with cytotoxicity profiles against these cell lines similar to colchicine. Compounds P2 and P5 arrested cell division at the G2/M phase and prevented cancerous cell growth through induced apoptosis. These results favored the hypothesis that the compounds might act by binding to the colchicine binding site, which was further confirmed with the help of a tubulin polymerization inhibition assay. The results encourage the further exploration of imidazoloquinoxalines as promising leads that deserve advanced clinical investigation.

Design Strategies, Chemistry and Therapeutic Insights of Multi-target Directed Ligands as Antidepressant Agents

Depression is one of the major disorders of the central nervous system worldwide and causes disability and functional impairment. According to the World Health Organization, around 265 million people worldwide are affected by depression. Currently marketed antidepressant drugs take weeks or even months to show anticipated clinical efficacy but remain ineffective in treating suicidal thoughts and cognitive impairment. Due to the multifactorial complexity of the disease, single-target drugs do not always produce satisfactory results and lack the desired level of therapeutic efficacy. Recent literature reports have revealed improved therapeutic potential of multi-target directed ligands due to their synergistic potency and better safety. Medicinal chemists have gone to great extents to design multitarget ligands by generating structural hybrids of different key pharmacophores with improved binding affinities and potency towards different receptors or enzymes. This article has compiled the design strategies of recently published multi-target directed ligands as antidepressant agents. Their biological evaluation, structural-activity relationships, mechanistic and in silico studies have also been described. This article will prove to be highly useful for the researchers to design and develop multi-target ligands as antidepressants with high potency and therapeutic efficacy.

GABAkines - Advances in the discovery, development, and commercialization of positive allosteric modulators of GABAA receptors

Positive allosteric modulators of γ-aminobutyric acid-A (GABA_A) receptors or GABAkines have been widely used medicines for over 70 years for anxiety, epilepsy, sleep, and other disorders. Traditional GABAkines like diazepam have safety and tolerability concerns that include sedation, motor-impairment, respiratory depression, tolerance and dependence. Multiple GABAkines have entered clinical development but the issue of side-effects has not been fully solved. The compounds that are presently being developed and commercialized include several neuroactive steroids (an allopregnanolone formulation (brexanolone), an allopregnanolone prodrug (LYT-300), Sage-324, zuranolone, and ganaxolone), the α2/3-preferring GABAkine, KRM-II-81, and the α2/3/5-preferring GABAkine PF-06372865 (darigabat). The neuroactive steroids are in clinical development for post-partum depression, intractable epilepsy, tremor, status epilepticus, and genetic epilepsy disorders. Darigabat is in development for epilepsy and anxiety. The imidazodiazepine, KRM-II-81 is efficacious in animal models for the treatment of epilepsy and post-traumatic epilepsy, acute and chronic pain, as well as anxiety and depression. The efficacy of KRM-II-81 in models of pharmacoresistant epilepsy, preventing the development of seizure sensitization, and in brain tissue of intractable epileptic patients bodes well for improved therapeutics. Medicinal chemistry efforts are also ongoing to identify novel and improved GABAkines. The data document gaps in our understanding of the molecular pharmacology of GABAkines that drive differential pharmacological profiles, but emphasize advancements in the ability to successfully utilize GABA_A receptor potentiation for therapeutic gain in neurology and psychiatry.

Neuropharmacological and Antidiabetic Potential of Lannea coromandelica (Houtt.) Merr. Leaves Extract: An Experimental Analysis

The present study examines the neuropharmacological and antidiabetic properties of methanol leaves extract of Lannea coromandelica in animal models. This study is carried out by elevated plus-maze apparatus, motor coordination, thiopental sodium has an induction role in sleeping time, hole board, hole cross, open field, antidiabetic studies. Mice were treated doses of 100, 150, and 200 mg/kg body weight in elevated plus-maze apparatus and motor coordination; 100 and 200 mg/kg body weight in sleeping time, hole cross, hole board, and open field tests; and 200 and 400 mg/kg body weight in the antidiabetic activity test. Extraction specifies a significantly decreased time duration and sleeping time in a thiopental sodium-induced sleeping time test. The experimental extract decreased locomotor and exploratory behaviors of mice in the open-field and hole-cross tests compared to the effects of the control. Furthermore, the extract increased sleeping time with a dose-dependent onset of action. The hole-board test extract also demonstrated a reduced number of head dips. The findings showed that L. coromandelica has potential neuropharmacological effects. In addition, in alloxan-induced diabetic mice, leaves extract at 200 and 400 mg/kg body weight revealed significant antidiabetic properties and could be used to manage blood glucose levels with more research.

Effect of alpha-mangostin in the prevention of behavioral and neurochemical defects in methylmercury-induced neurotoxicity in experimental rats

Methylmercury (MeHg+) is a known neurotoxin that causes progressive motor neuron degeneration in the central nervous system. Axonal degeneration, oligodendrocyte degeneration, and myelin basic protein (MBP) deficits are among the neuropathological abnormalities caused by MeHg+ in amyotrophic lateral sclerosis (ALS). This results in demyelination and motor neuron death in both humans and animals. Previous experimental studies have confirmed that overexpression of the extracellular signalling regulated kinase (ERK1/2) signalling contributes to glutamate excitotoxicity, inflammatory response of microglial cells, and oligodendrocyte (OL) dysfunction that promotes myelin loss. Alpha-mangostin (AMG), an active ingredient obtained from the tree "Garcinia mangostana Linn," has been used in experimental animals to treat a variety of brain disorders, including Parkinson's and Huntington's disease memory impairment, Alzheimer's disease, and schizophrenia, including Parkinson's disease and Huntington's disease memory impairment, Alzheimer's disease, and schizophrenia. AMG has traditionally been used as an antioxidant, anti-inflammatory, and neuroprotective agent.Accordingly, we investigated the therapeutic potential of AMG (100 and 200 mg/kg) in experimental rats with methylmercury (MeHg+)-induced neurotoxicity. The neuroprotective effect of AMG on behavioural, cellular, molecular, and other gross pathological changes, such as histopathological alterations in MeHg+ -treated rat brains, is presented. The neurological behaviour of experimental rats was evaluated using a Morris water maze (MWM), open field test (OFT), grip strength test (GST), and force swim test (FST). In addition, we investigate AMG's neuroprotective effect by restoring MBP levels in cerebral spinal fluid and whole rat brain homogenate. The apoptotic, pro-inflammatory, and oxidative stress markers were measured in rat blood plasma samples and brain homogenate. According to the findings of this study, AMG decreases ERK-1/2 levels and modulates neurochemical alterations in rat brains, minimising MeHg+ -induced neurotoxicity.

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Chronic methylmercury (MeHg+) exposure was used to cause motor neuron degeneration in rats.

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In MeHg-treated rats, oral administration of alpha-mangostin (AMG) improved behavioural, and neurochemical alterations.

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Effect of AMG related to anti-apoptotic, anti-inflammatory, and antioxidant properties via reducing ERK1/2 protein levels.

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AMG improved rat brain remyelination and enhancing MBP levels in rat brain homogenate, blood plasma, and CSF samples.

Design and synthesis of benzodiazepines as brain penetrating PARP-1 inhibitors

The poly (ADP-ribose) polymerase (PARP) inhibitors play a crucial role in cancer therapy. However, most approved PARP inhibitors cannot cross the blood-brain barrier, thus limiting their application in the central nervous system. Here, 55 benzodiazepines were designed and synthesised to screen brain penetrating PARP-1 inhibitors. All target compounds were evaluated for their PARP-1 inhibition activity, and compounds with better activity were selected for further assays in vitro. Among them, compounds H34, H42, H48, and H52 displayed acceptable inhibition effects on breast cancer cells. Also, computational prediction together with the permeability assays in vitro and in vivo proved that the benzodiazepine PARP-1 inhibitors we synthesised were brain permeable. Compound H52 exhibited a B/P ratio of 40 times higher than that of Rucaparib and would be selected to develop its potential use in neurodegenerative diseases. Our study provided potential lead compounds and design strategies for the development of brain penetrating PARP-1 inhibitors.

HIGHLIGHTS

Structural fusion was used to screen brain penetrating PARP-1 inhibitors.

55 benzodiazepines were evaluated for their PARP-1 inhibition activity.

Four compounds displayed acceptable inhibition effects on breast cancer cells.

The benzodiazepine PARP-1 inhibitors were proved to be brain permeable.

Reactive metabolites of the anticonvulsant drugs and approaches to minimize the adverse drug reaction

Several generations of antiepileptic drugs (AEDs) are available in the market for the treatment of seizures, but these are amalgamated with acute to chronic side effects. The most common side effects of AEDs are dose-related, but some are idiosyncratic adverse drug reactions (ADRs) that transpire due to the formation of reactive metabolite (RM) after the bioactivation process. Because of the adverse reactions patients usually discontinue the medication in between the treatment. The AEDs such as valproic acid, lamotrigine, phenytoin etc., can be categorized under such types because they form the RM which may prevail with life-threatening adverse effects or immune-mediated reactions. Hepatotoxicity, teratogenicity, cutaneous hypersensitivity, dizziness, addiction, serum sickness reaction, renal calculi, metabolic acidosis are associated with the metabolites of drugs such as arene oxide, N-desmethyldiazepam, 2-(1-hydroxyethyl)-2-methylsuccinimide, 2-(sulphamoy1acetyl)-phenol, E-2-en-VPA and 4-en-VPA and carbamazepine-10,11-epoxide, etc. The major toxicities are associated with the moieties that are either capable of forming RM or the functional groups may itself be too reactive prior to the metabolism. These functional groups or fragment structures are typically known as structural alerts or toxicophores. Therefore, minimizing the bioactivation potential of lead structures in the early phases of drug discovery by a modification to low-risk drug molecules is a priority for the pharmaceutical companies. Additionally, excellent potency and pharmacokinetic (PK) behaviour help in ensuring that appropriate (low dose) candidate drugs progress into the development phase. The current review discusses about RMs in the anticonvulsant drugs along with their mechanism vis-a-vis research efforts that have been taken to minimize the toxic effects of AEDs therapy.

Efficient Construction of 5H-1,4-Benzodiazepine Derivatives by a Catalyst-Free Direct Aerobic Oxidative Annulation Strategy

A catalyst-free direct aerobic oxidative annulation reaction of 2-aminobenzylic amines and α-hydroxy ketones efficiently afforded versatile 5H-1,4-benzodiazepine derivatives by employing air as economic and green oxidant under mild conditions. Interestingly, solvent was found to be crucial to the reaction, so that by using acetic acid as the best solvent an efficient and practical method could be achieved, requiring no catalysts or additives at all. This method tolerates a wide range of 2-aminobenzylic amines and α-hydroxy ketones and could be scaled up to multigram synthesis and directly applied in one-step synthesis of the pharmaceutically active N-desmethylmedazepam derivatives, revealing the potential of this new method in the synthesis of 5H-1,4-benzodiazepine skeleton-based pharmaceuticals and chemicals.

Isobornylchalcones as Scaffold for the Synthesis of Diarylpyrazolines with Antioxidant Activity

The pyrazoline ring is defined as a "privileged structure" in medicinal chemistry. A variety of pharmacological properties of pyrazolines is associated with the nature and position of various substituents, which is especially evident in diarylpyrazolines. Compounds with a chalcone fragment show a wide range of biological properties as well as high reactivity which is primarily due to the presence of an α, β-unsaturated carbonyl system. At the same time, bicyclic monoterpenoids deserve special attention as a source of a key structural block or as one of the pharmacophore components of biologically active molecules. A series of new diarylpyrazoline derivatives based on isobornylchalcones with different substitutes (MeO, Hal, NO2, N(Me)2) was synthesized. Antioxidant properties of the obtained compounds were comparatively evaluated using in vitro model Fe2+/ascorbate-initiated lipid peroxidation in the substrate containing brain lipids of laboratory mice. It was demonstrated that the combination of the electron-donating group in the para-position of ring B and OH-group in the ring A in the structure of chalcone fragment provides significant antioxidant activity of synthesized diarylpyrazoline derivatives.