Synthesis, Spectral Characterization and Anticonvulsant Studies of the Novel Triazolothiadiazoles Bearing Benzoxazole Moiety

In this study, new fused triazolo-thiadiazoles (4a-o) were synthesized viamethyl 2-[bromo(phenyl)methyl]-1,3-benzoxazole-5-carboxylate. The structure of novel derivatives was recognized on the basis of spectral data results and screened their anticonvulsant action by means of maximal electroshock seizure (MES) and subcutaneous pentylenetetrazol (scPTZ) procedures. Minimal motor studies were completed by a rotarod method. Compounds 4e, 4g, 4j, 4l, 4m and 4n showing better anticonvulsant action corresponding to hydrophobicity. Other molecules remained fewer lipophilic and have less effectiveness. Most of the compounds positively tolerable the rotarod test deprived of motor deficiency. In conclusion, the prepared derivatives with distal aryl moiety exhibited higher lipophilic character and lead to improved pharmacological achievement, which can be a forthcoming promise.

Anticonvulsant effect of pterostilbene and its influence on the anxiety- and depression-like behavior in the pentetrazol-kindled mice: behavioral, biochemical, and molecular studies

Rationale Pterostilbene is the 3,5-dimethoxy derivative of resveratrol with numerous beneficial effects including neuroprotective properties. Experimental studies revealed its anticonvulsant action in the acute seizure tests. Objectives The purpose of the present study was to evaluate the effect of pterostilbene in the pentetrazol (PTZ)–induced kindling model of epilepsy in mice as well as to assess some possible mechanisms of its anticonvulsant action in this model. Methods Mice were repeatedly treated with pterostilbene (50–200 mg/kg) and its effect on the development of seizure activity in the PTZ kindling was estimated. Influence of pterostilbene on the locomotor activity and anxiety- and depression-like behavior in the PTZ-kindled mice was also assessed. To understand the possible mechanisms of anticonvulsant activity of pterostilbene, γ-aminobutyric acid (GABA) and glutamate concentrations in the prefrontal cortex and hippocampus of the PTZ-kindled mice were measured using LC–MS/MS method. Moreover, mRNA expression of BDNF, TNF-α, IL-1β, IL-6, GABRA1A, and GRIN2B was determined by RT-qPCR technique. Results We found that pterostilbene at a dose of 200 mg/kg considerably reduced seizure activity but did not influence the locomotor activity and depression- and anxiety-like behavior in the PTZ-kindled mice. In the prefrontal cortex and hippocampus, pterostilbene reversed the kindling-induced decrease of GABA concentration. Neither in the prefrontal cortex nor hippocampus pterostilbene affected mRNA expression of IL-1β, IL-6, GABRA1A, and GRIN2B augmented by PTZ kindling. Pterostilbene at a dose of 100 mg/kg significantly decreased BDNF and TNF-α mRNA expression in the hippocampus of the PTZ-kindled mice. Conclusions Although further studies are necessary to understand the mechanism of anticonvulsant properties of pterostilbene, our findings suggest that it might be considered a candidate for a new antiseizure drug.

Anticonvulsive potential of cardiac glycosides under conditions of pentilentetrazole-induced seizures in mice: comparative study

Aim. The research provides a comparative analysis of the possible anticonvulsant action of different cardiac glycosides, namely: digoxin, lanatoside C, strophanthin G and corglycone. In addition, it detrmines the leading medication among the abovementioned ones by dose-dependence of its anticonvulsant action. Material and Methods. The research was performed on 66 random-bred albino male mice. The anticonvulsant effect of cardiac glycosides was studied in a baseline model of pentylenetetrazole-induced seizures. The first series of experiment evaluated the effect of cardiac glycosides on the course of model seizures in comparable doses of approximately 1/10 LD50 for the corresponding drug: digoxin, lanatoside C and strophanthin G - at a dose of 0.8 mg/kg; corglycone - at a dose of 1 mg/kg. The second series of experiments used the drug-leader, which was digoxin, in a wide dose range from 0.2 to 1.6 mg/kg. Digoxin, strophanthin G and corglycone were administered subcutaneously for 15 minutes, lanatoside C - intragastrically for 30 minutes before the induction of experimental seizures. Convulsive agent - pentylenetetrazole in the form of an aqueous solution was administered to animals subcutaneously at a dose of 80 mg/kg. Results and Discussion. Digoxin at a dose of 0.8 mg/kg under conditions of pentylenetetrazole-induced seizures shows a pronounced anticonvulsant activity: it is the only one among the studied cardiac glycosides that probably reduces lethality. In addition, digoxin prolongs the latency period of the first attacks, and reduces the number of clonic-tonic paroxysms in 1 mouse. Moderate anticonvulsant properties of lanatoside C were found both by a statistically significant decrease in the number of clonic-tonic seizures in 1 mouse, and by a significant reduction in the duration of the convulsive period. Although strophanthin G is unlikely to affect lethality, it moderately reduces the severity of pentylenetetrazole-induced seizures in mice, as evidenced by a statistically significant prolongation of the latency period of the first seizures, as well as a decrease in the number of clonic-tonic seizures in 1 mouse and the duration of seizures. Prophylactic administration of corglycone only prolongs the latency period of seizures and significantly reduces the number of clonic-tonic seizures in 1 mouse. The results of the dose-dependence study of digoxin anticonvulsant action show a clear anticonvulsant potential of this cardiac glycoside in a wide range of doses - from 0.2 to 1.6 mg/kg - with a maximum effect at a dose of 0.8 mg/kg. Conclusions. It was found that cardiac glycosides have a different severity of anticonvulsant effect: the most powerful anticonvulsant effect is due to digoxin, lanatoside C and strophanthin G have moderate properties, and the least pronounced effect is characteristic to corglycone. In addition, it was determined that digoxin exhibits anticonvulsant properties in a wide range of doses, and has the most pronounced anticonvulsant effect at a dose of 0.8 mg/kg. The obtained results substantiate the expediency of further in-depth study of digoxin as an anticonvulsant medicine.

Anticonvulsant Action of GluN2A-Preferring Antagonist PEAQX in Developing Rats

The GluN2A subunit of N-methyl-D-aspartate (NMDA) receptors becomes dominant during postnatal development, overgrowing the originally dominant GluN2B subunit. The aim of our study was to show changes of anticonvulsant action of the GluN2A subunit-preferring antagonist during postnatal development of rats. Possible anticonvulsant action of GluN2A-preferring antagonist of NMDA receptors P = [[[(1S)-1-(4-bromophenyl)ethyl]amino](1,2,3,4-tetrahydro-2,3-dioxo-5-quinoxalinyl)methyl]phosphonic acid tetrasodium salt (PEAQX) (5, 10, 20 mg/kg s.c.) was tested in 12-, 18-, and 25-day-old rats in three models of convulsive seizures. Pentylenetetrazol-induced generalized seizures with a loss of righting reflexes generated in the brainstem were suppressed in all three age groups in a dose-dependent manner. Minimal clonic seizures with preserved righting ability exhibited only moderately prolonged latency after the highest dose of PEAQX. Anticonvulsant action of all three doses of PEAQX against cortical epileptic afterdischarges (generated in the forebrain) was found in the 25-day-old animals. The highest dose (20 mg/kg) was efficient also in the two younger groups, which might be due to lower specificity of PEAQX and its partial affinity to the GluN2B subunit. Our results are in agreement with the postero-anterior maturation gradient of subunit composition of NMDA receptors (i.e., an increase of GluN2A representation). In spite of the lower selectivity of PEAQX, our data demonstrate, for the first time, developmental differences in comparison with an antagonist of NMDA receptors with a dominant GluN2B subunit.

How Antidepressant Drugs Affect the Antielectroshock Action of Antiseizure Drugs in Mice: A Critical Review

Depression coexists with epilepsy, worsening its course. Treatment of the two diseases enables the possibility of interactions between antidepressant and antiepileptic drugs. The aim of this review was to analyze such interactions in one animal seizure model—the maximal electroshock (MES) in mice. Although numerous antidepressants showed an anticonvulsant action, mianserin exhibited a proconvulsant effect against electroconvulsions. In most cases, antidepressants potentiated or remained ineffective in relation to the antielectroshock action of classical antiepileptic drugs. However, mianserin and trazodone reduced the action of valproate, phenytoin, and carbamazepine against the MES test. Antiseizure drug effects were potentiated by all groups of antidepressants independently of their mechanisms of action. Therefore, other factors, including brain-derived neurotrophic factor (BDNF) and glial-derived neurotrophic factor (GDNF) modulation, should be considered as the background for the effect of drug combinations.

Prevalence of Gingival Hyperplasia Induced by Anticonvulsants: A Systematic Review

Objective: Gingival hyperplasia (GH) is one of the side effects of anticonvulsant drugs. The aim of this study was to verify the prevalence of GH associated with the use of anticonvulsant, through a systematic review. Material and Methods: Systematic search was done at databases Pubmed and Embase between January 1984 and March of 2020 for identification of articles addressing the prevalence of GH associated with the use of anticonvulsant drugs. The methodological index for non-randomized studies (MINORS) was independently assessed for quality in the selected papers. Results: The search identified 4.471 references. Nine articles were selected and evaluated 632 participants. All of the studies included in the systematic review showed a low risk of bias. The anticonvulsants used by patients were carbamazepine, ethosuximide, phenytoin, primidone, phenobarbital, sodium valproate. The studies showed a correlation between different types of anticonvulsants and GH prevalence, with a range from 0% to 73%. Among the anticonvulsants used, phenytoin showed the greatest incidence of GH, varying between 15.61% and 73% in patients. Conclusion: In the analysis of the results obtained in the literature, it is possible to notice that the great majority of studies presented incidence of GH associated with anticonvulsant use. However, further studies are necessary to understand the anticonvulsant action mechanism inducing GH, as well as the prevention forms, given that GH is a significant side effect. KEYWORDS Anticonvulsants; Gingival hyperplasia; Prevalence.