Design, Synthesis and Anticonvulsant Activity of Cinnamoyl Derivatives of 3,4,6,7,8,9-hexahydrodibenzo[b,d]furan-1-(2H)-one Oxime.

BACKGROUND: Epilepsy continues to be a significant global health problem and the search for new drugs for its treatment remains an urgent task. 5-HT2 and GABAA-receptors are among promising biotargets for the search for new anticonvulsants. METHODS: New potential 5-HT2 and GABAA ligands in the series of substituted cinnamoyl derivatives of 3,4,6,7,8,9-hexahydrodibenzo[b,d]furan-1-(2H)-one oxime were designed using pharmacophore model and molecular docking analysis. The synthesis of new compounds was carried out from 3,4,6,7,8,9-hexahydrodibenzo[b,d]furan-1(2H)-one oxime and substituted cinnamoyl chlorides. The anticonvulsant activity of new substances has been established using the maximal electroshock seizure test. RESULTS: Several synthesized substituted cinnamoyl derivatives of 3,4,6,7,8,9-hexahydrodibenzo [b,d]furan-1-(2H)-one oxime significantly reduced the severity of convulsive manifestations and completely prevented the death of animals after MES. The structure-activity relationship was investigated. The most effective compound was found to be GIZH-348 (1g) (3,4,6,7,8,9-hexahydrodibenzo[ b,d]furan-1(2Н)-one О-(4-chlorophenyl)acryloyl)oxime) at the doses of 10-20 mg/kg. CONCLUSION: Molecular and pharmacophore modelling methods allowed us to create a new group of substituted cinnamoyl derivatives of 3,4,6,7,8,9-hexahydrodibenzo[b,d]furan-1-(2H)-one oxime with anticonvulsant activity.

Pharmacological Analysis of GABAA Receptor and Sigma1R Chaperone Interaction: Research Report I-Investigation of the Anxiolytic, Anticonvulsant and Hypnotic Effects of Allosteric GABAA Receptors' Ligands.

Two groups of facts have been established in previous drug development studies of the non-benzodiazepine anxiolytic fabomotizole. First, fabomotizole prevents stress-induced decrease in binding ability of the GABAA receptor's benzodiazepine site. Second, fabomotizole is a Sigma1R chaperone agonist, and exposure to Sigma1R antagonists blocks its anxiolytic effect. To prove our main hypothesis of Sigma1R involvement in GABAA receptor-dependent pharmacological effects, we performed a series of experiments on BALB/c and ICR mice using Sigma1R ligands to study anxiolytic effects of benzodiazepine tranquilizers diazepam (1 mg/kg i.p.) and phenazepam (0.1 mg/kg i.p.) in the elevated plus maze test, the anticonvulsant effects of diazepam (1 mg/kg i.p.) in the pentylenetetrazole-induced seizure model, and the hypnotic effects of pentobarbital (50 mg/kg i.p.). Sigma1R antagonists BD-1047 (1, 10, and 20 mg/kg i.p.), NE-100 (1 and 3 mg/kg i.p.), and Sigma1R agonist PRE-084 (1, 5, and 20 mg/kg i.p.) were used in the experiments. Sigma1R antagonists have been found to attenuate while Sigma1R agonists can enhance GABAARs-dependent pharmacological effects.

Rodent Models of Audiogenic Epilepsy: Genetic Aspects, Advantages, Current Problems and Perspectives.

Animal models of epilepsy are of great importance in epileptology. They are used to study the mechanisms of epileptogenesis, and search for new genes and regulatory pathways involved in the development of epilepsy as well as screening new antiepileptic drugs. Today, many methods of modeling epilepsy in animals are used, including electroconvulsive, pharmacological in intact animals, and genetic, with the predisposition for spontaneous or refractory epileptic seizures. Due to the simplicity of manipulation and universality, genetic models of audiogenic epilepsy in rodents stand out among this diversity. We tried to combine data on the genetics of audiogenic epilepsy in rodents, the relevance of various models of audiogenic epilepsy to certain epileptic syndromes in humans, and the advantages of using of rodent strains predisposed to audiogenic epilepsy in current epileptology.

Transcriptome of the Krushinsky-Molodkina Audiogenic Rat Strain and Identification of Possible Audiogenic Epilepsy-Associated Genes.

Audiogenic epilepsy (AE), inherent to several rodent strains is widely studied as a model of generalized convulsive epilepsy. The molecular mechanisms that determine the manifestation of AE are not well understood. In the present work, we compared transcriptomes from the corpora quadrigemina in the midbrain zone, which are crucial for AE development, to identify genes associated with the AE phenotype. Three rat strains without sound exposure were compared: Krushinsky-Molodkina (KM) strain (100% AE-prone); Wistar outbred rat strain (non-AE prone) and "0" strain (partially AE-prone), selected from F2 KM × Wistar hybrids for their lack of AE. The findings showed that the KM strain gene expression profile exhibited a number of characteristics that differed from those of the Wistar and "0" strain profiles. In particular, the KM rats showed increased expression of a number of genes involved in the positive regulation of the MAPK signaling cascade and genes involved in the positive regulation of apoptotic processes. Another characteristic of the KM strain which differed from that of the Wistar and "0" rats was a multi-fold increase in the expression level of the Ttr gene and a significant decrease in the expression of the Msh3 gene. Decreased expression of a number of oxidative phosphorylation-related genes and a few other genes was also identified in the KM strain. Our data confirm the complex multigenic nature of AE inheritance in rodents. A comparison with data obtained from other independently selected AE-prone rodent strains suggests some common causes for the formation of the audiogenic phenotype.

ERK1/2 kinases and dopamine D2 receptors participate in the anticonvulsant effects of a new derivative of benzoylpyridine oxime and valproic acid.

Inhibition of the activity of extracellular signal-regulated kinases (ERK1/2) induced by the activation of the dopamine D2 receptor signalling cascade may be a promising pharmacological target. The aim of this work was to study the involvement of ERK1/2 and dopamine D2 receptor in the mechanism of the anticonvulsant action of valproic acid (VA) and a new benzoylpyridine oxime derivative (GIZH-298), which showed antiepileptic activity in different models of epilepsy. We showed that subchronic exposure to maximal electroshock seizures (MES) for 5 days reduced the density of dopamine D2 receptors in the striatum of mice. GIZH-298 counteracted the decrease in the number of dopamine D2 receptors associated with MES and increased the number of ligand binding sites of dopamine D2 receptors in mice without MES. The affinity of dopamine D2 receptors to the ligand was not changed by GIZH-298. MES caused an increase in ERK1/2 and synapsin I phosphorylation in the striatum while GIZH-298, similar to VA, reduced the levels of both phospho-ERK1/2 and phosphosynapsin I after MES, which correlated with the decrease in the intensity of seizure in mice. In addition, GIZH-298 suppressed ERK1/2 phosphorylation in SH-SY5Y human neuroblastoma cells at therapeutic concentrations, while VA inhibited ERK1/2 phosphorylation in vivo but not in vitro. The data obtained expand the understanding of the mechanisms of action of VA and GIZH-298, which involve regulating the activity of ERK1/2 kinases, probably by modulating dopamine D2 receptors in limbic structures, as well as (in the case of GIZH-298) directly inhibiting of the ERK1/2 cascade.

Levetiracetam effect and electrophysiological mechanism of action in rats with cobalt-induced chronic epilepsy.

Levetiracetam was initially developed as a nootropic drug, although since 2002 it has been used as anticonvulsant for the treatment of partial and generalized epilepsy syndromes. The purpose of the research was to investigate anti-paroxysmal activity of levetiracetam (LEV) on the model of cobalt-induced chronic epilepsy caused by the application of cobalt to the sensorimotor area of the rat cortex to evaluate LEV impact on the different stages of epileptogenesis. LEV effects were studied at the initial stage of the epileptogenesis (2nd day after the cobalt application) and at the stage of generalized paroxysmal activity (6th day after the cobalt application). The research showed that levetiracetam administration (dosages 50 mg/kg and 200 mg/kg) at the early stage of the epileptogenesis had no statistically significant effect on the development of paroxysmal activity in both primary and secondary epileptic areas: in the ipsi- and contralateral cortex, hypothalamus and hippocampus. LEV administration on 6th day (dosage 50 mg/kg) did not have statistical effect on the epileptogenesis, while at a dosage of 200 mg/kg on 6th day LEV significantly suppressed paroxysmal activity in the studied structures of rats with cobalt epilepsy. The strongest anti-paroxysmal effect was detected in hippocampus and was expressed as the normalization of bioelectrical activity and the appearance of a regular theta rhythm. Thus, LEV effects are mostly directed to the hippocampal area of epileptiform activity and, to a lesser extent, to the cortical area.