Recent progress of 1,3,4-oxadiazoles as anticonvulsants: Future horizons.

Epilepsy is the most common neurological disorder, which affects more than 50 million people worldwide. Despite the development and use of several antiepileptic drugs (AEDs), attempted seizure control fails in almost 30% of the individuals treated. Other patients benefit from seizure control by drug therapy at the expense of dose-related toxicity and side effects. These drawbacks with conventional AEDs demand the need for developing more effective and safer antiseizure agents. As a result, extensive efforts are devoted to design and develop new effective molecules as antiepileptics. This area of research to find more effective and safer AEDs is important and challenging. This review describes the future perspective of various 1,3,4-oxadiazole derivatives as anticonvulsant agents and focuses on the design and development of the new effective molecule.

Design, synthesis, and evaluation of anticonvulsant activities of benzoxazole derivatives containing the 1,2,4-triazolone moiety.

A novel series of benzoxazole derivatives containing 1,2,4-triazolone (5a-m) was designed. These compounds were synthesized in order to screen their anticonvulsant activities by the maximal electroshock seizure (MES) model and the subcutaneous pentylenetetrazole (sc-PTZ) seizure model in mice. The rotarod test was used to evaluate their neurotoxicities. Most of the compounds showed anti-MES activities at 100 and 300 mg/kg. Compound 5f, which showed potential anticonvulsant activity in the MES model with ED50 values of 22.0 mg/kg, was considered as the most promising one in this study. It exhibited greater safety than that of carbamazepine and valproate regarding neurotoxicity. The efficacy of compound 5f in inhibiting the tonic seizures and death induced by the convulsants 3-mercaptopropionic acid and BIC was also verified. In an enzyme-linked immunosorbent assay, compound 5f and the positive drug phenytoin significantly increased the γ-aminobutyric acid (GABA) level in the mouse brain. Further, pretreatment with an inhibitor of the GABA synthesizing enzyme dramatically raised the ED50 value of 5f in the MES model. These results confirmed that the compound 5f plays its anticonvulsive action via regulating the GABA function in the brain. Also, a docking study of the compound 5f in the benzodiazepine (BZD) binding site of the GABAA receptor confirmed possible binding of the compound 5f with BZD receptors.

Recent developments on triazole nucleus in anticonvulsant compounds: a review.

Epilepsy is one of the common diseases seriously threatening life and health of human. More than 50 million people are suffering from this condition and anticonvulsant agents are the main treatment. However, side effects and intolerance, and a lack of efficacy limit the application of the current anticonvulsant agents. The search for new anticonvulsant agents with higher efficacy and lower toxicity continues to be the focus and task in medicinal chemistry. Numbers of triazole derivatives as clinical drugs or candidates have been frequently employed for the treatment of various types of diseases, which have proved the importance of this heterocyclic nucleus in drug design and discovery. Recently many endeavours were made to involve the triazole into the anticonvulsants design, which have brought lots of active compounds. This work is an attempt to systematically review the research of triazole derivatives in the design and development of anticonvulsant agents during the past two decades.

Design, graph theoretical analysis, density functionality theories, Insilico modeling, synthesis, characterization and biological activities of novel thiazole fused quinazolinone derivatives.

Hit, Lead & Candidate Discovery A series of 2-(2-substituted benzylidenehydrazinyl-2-oxopropyl)-3-(4-[4-oxo-2-phenylthiazolo din-3-yl]phenyl)quinazolin-4(3H)-one 7a-7l were synthesized and characterized by IR, 1 H-NMR, 13 C-NMR, mass spectroscopy and elemental analyses. In this present study, the density functionality theory was performed to identify drug stability. Further we introduced graph theoretical analysis by utilised Kyoto Encyclopedia of Genes and Genomes (KEGG) database and Cytoscape software to identify drug target. Based on the observed drug target insilico modeling was executed to know effective drug. The antiepileptic effects of title compounds were evaluated by using MES and subcutaneous pentylenetetrazole (scPTZ) test. Acute neurological toxicity of title compounds was studied by using standardized rotorod test. After 0.5 hr of period many of the compounds showed anticonvulsant activity at MES or scPTZ test. Comparison of the biological activity of test compounds with its chemical structures indicates that, compounds possessing electron donating group exhibited superior activity than the analogs having electron withdrawing moieties. Among the electron donating group tested, amino derivative exhibited good activity than rest of derivatives. From the study it was concluded that, the compound 7j was established as very potent compared with rest of the compounds and standard drugs subjected to biological studies. Thus the compound 2-(2-[4-aminobenzylidene]hydrazinyl-2-oxopropyl)-3-(4-[4-oxo-2-phenylthiazolidin-3-yl]phenyl) quinazolin-4(3H)-one (7j) came out as pilot derivative without any neurotoxicity with a wide spectrum of antiepileptic activity. HIGHLIGHTS: The performed work is having great significance in terms of Graph theoretical analysis used to identify drug target In silico modeling used to identify designed drug interaction with identify target Density functionality studies used to identify synthesized compound energy band gap which is correlate with enhancement of its biological activity Antiepileptic effects of entire synthesized quinazolinone scaffolds were evaluated by MES and scPTZ test 2-(2-[4-aminobenzylidene]hydrazinyl-2-oxopropyl)-3-(4-[4-oxo-2-phenylthiazolidin-3-yl]phenyl) quinazolin-4(3H)-one (7j) was established as very potent compared to the rest of the compounds and standard drugs which were subjected to biological studies.

Structure-anticonvulsant activity studies in the group of (E)-N-cinnamoyl aminoalkanols derivatives monosubstituted in phenyl ring with 4-Cl, 4-CH3 or 2-CH3.

A series of twenty two (E)-N-cinnamoyl aminoalkanols derivatives monosubstituted in phenyl ring with 4-Cl, 4-CH3 or 2-CH3 was designed, synthesized and evaluated for anticonvulsant activity in rodent models of seizures: maximal electroshock (MES) test, subcutaneous pentylenetetrazole (scPTZ) test, and 6-Hz test. There were identified three most active compounds: S-(2E)-N-(1-hydroxypropan-2-yl)-3-(2-methylphenyl)prop-2-enamide (5) (ED50 MES=42.56, ED50 scPTZ=58.38, ED50 6-Hz 44mA=42.27mg/kg tested in mice after intraperitoneal (i.p.) administration); R,S-(2E)-3-(4-chlorophenyl)-N-(1-hydroxybutan-2-yl)prop-2-enamide (6) (ED50 MES=53.76, ED50 scPTZ=90.31, ED50 6-Hz 44mA=92.86mg/kg mice, i.p.); and R,S-(2E)-3-(4-chlorophenyl)-N-(2-hydroxypropyl)prop-2-enamide (11) (ED50 MES=55.58, ED50 scPTZ=102.15, ED50 6-Hz 44mA=51.27mg/kg mice, i.p.). Their structures and configurations were confirmed by crystal X-ray diffraction method. The structure-activity studies among the tested series showed that chlorine atom in position para or methyl group in position ortho of phenyl ring were beneficial for anticonvulsant activity. Methyl group in position para of phenyl ring decreased anticonvulsant activity in reported series of cinnamamide derivatives.

New hybrid molecules with anticonvulsant and antinociceptive activity derived from 3-methyl- or 3,3-dimethyl-1-[1-oxo-1-(4-phenylpiperazin-1-yl)propan-2-yl]pyrrolidine-2,5-diones.

The purpose of this study was to synthetize the focused library of 34 new piperazinamides of 3-methyl- and 3,3-dimethyl-(2,5-dioxopyrrolidin-1-yl)propanoic or butanoic acids as potential new hybrid anticonvulsants. These hybrid molecules join the chemical fragments of well-known antiepileptic drugs (AEDs) such as ethosuximide, levetiracetam, and lacosamide. Compounds 5-38 were prepared in a coupling reaction of the 3-methyl- or 3,3-dimethyl-2-(2,5-dioxopyrrolidin-1-yl)propanoic (1, 2) or butanoic acids (3, 4) with the appropriately substituted secondary amines in the presence of the N,N-carbonyldiimidazole reagent. The initial anticonvulsant screening was performed in mice (ip) using the 'classical' maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) tests as well as in the six-Hertz (6Hz) model of pharmacoresistant limbic seizures. The acute neurological toxicity was determined applying the chimney test. The broad spectra of activity across the preclinical seizure models in mice ip displayed compounds 7, 15, and 36. The most favorable anticonvulsant properties demonstrated 15 (ED50 MES=74.8mg/kg, ED50scPTZ=51.6mg/kg, ED50 6Hz=16.8mg/kg) which showed TD50=213.3mg/kg in the chimney test that yielded satisfying protective indexes (PI MES=2.85, PI scPTZ=4.13, PI 6Hz=12.70) at time point of 0.5h. As a result, compound 15 displayed comparable or better safety profile than clinically relevant AEDs: ethosuximide, lacosamide or valproic acid. In the in vitro assays compound 15 was observed as relatively effective binder to the neuronal voltage-sensitive sodium and L-type calcium channels. Beyond the anticonvulsant properties, 6 compounds diminished the pain responses in the formalin model of tonic pain in mice.

Design, Synthesis, and Biological Evaluation of 6-(2-Amino-substituted phenyl)-4-(substituted phenyl)-1,2,4-triazine-3,5(2H,4H)-dione Derivatives as Anticonvulsant Agents.

As per structural requirement essential for anticonvulsant activity, a series of new 6-(2-amino-substituted phenyl)-4-(substituted phenyl)-1,2,4-triazine-3,5-dione derivatives were designed and synthesized. All the synthesized title derivatives were assessed for in vivo anticonvulsant screening by the two most employed standard animal seizure models, maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ)-induced seizures, along with minimal motor impairment screening by rotarod test. Among all the synthesized compounds, the compound 4r showed excellent anticonvulsant activity with neither signs of neurotoxicity in the minimal motor impairment test nor signs of hepatotoxicity in the serum enzyme activity assay. The in silico studies of these title compounds were carried out for estimation of a pharmacophore pattern and the prediction of pharmacokinetic properties. To know the exact mechanism of our title compounds, a molecular docking study was carried out on the homology model of sodium ion (Na(+) ) channel and GABAA receptors. The results of the docking study as well as the in vitro study on both the receptors showed that our target compounds best act through the GABAA receptor rather than the Na(+) channel receptors. Additionally, GABA enzyme estimation was performed for further confirmation of the mechanism involved in its anticonvulsant activity. Conclusively, the compound 4r presents a novel scaffold in the search for safer and efficient anticonvulsants having neuroprotective as well as GABAergic effects.

Synthesis and Anticonvulsant Activity Evaluation of 4-Phenyl-[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one and Its Derivatives.

A series of 4-(substituted-phenyl)-[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-ones (6a-x) with triazole and other heterocyclic substituents (7-14) were synthesized and the compounds were evaluated for their anticonvulsant activity and neurotoxicity by maximal electroshock (MES) and rotarod neurotoxicity tests. Among the compounds studied, 6o and 6q showed wide margins of safety with protective indices (PIs) that were much higher than those of currently used drugs (PI6o > 25.5, PI6q > 26.0). Compounds 6o and 6q showed significant oral activity against MES-induced seizures in mice, with ED50 values of 88.02 and 94.6 mg/kg, respectively. The two compounds were also found to have potent activity against seizures that were induced by pentylenetetrazole and bicuculline.

Synthesis and Pharmacological Evaluation of Novel Benzenesulfonamide Derivatives as Potential Anticonvulsant Agents.

A novel series of benzenesulfonamide derivatives containing 4-aminobenzenesul-fonamide and α-amides branched valproic acid or 2,2-dimethylcyclopropanecarboxylic acid moieties were synthesized and screened for their anticonvulsant activities in mice maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) test. The activity experimental study showed that 2,2-dipropyl-N¹-(4-sulfamoylphenyl)malonamide (18b) had the lowest median effective dose (ED50) of 16.36 mg/kg in MES test, and 2,2-dimethyl-N-(4-sulfamoylphenyl)cyclopropane-1,1-dicarboxamide (12c) had the lowest ED50 of 22.50 mg/kg in scPTZ test, which resulted in the protective indexe (PI) of 24.8 and 20.4, respectively. These promising data suggest the new compounds have good potential as new class of anticonvulsant agents with high effectiveness and low toxicity for the treatment of epilepsy.

Synthesis and pharmacological evaluation of novel 1'-[2-(difluoromethoxy)benzyl]-2'H,5'H-spiro[8-azabicyclo[3.2.1]octane-3,4'-imidazolidine]-2',5'-diones and their derivatives.

A series of novel 1'-[2-(difluoromethoxy)benzyl]-2'H,5'H-spiro[8-azabicyclo[3.2.1]octane-3,4'-imidazolidine]-2',5'-dione substituted hydantoins (5-32) were synthesized using an appropriate synthetic route and characterized by elemental analysis and spectral data. The novel molecules were screened for anticonvulsant activity in mice by maximal electroshock (MES) and subcutaneous pentylenetetrazol (ScPTZ)-induced seizure tests. The neurotoxicity was assessed using the rotarod method. Compounds 9, 10, 18, 30, and 31 exhibited anticonvulsant potency against MES seizure and in the ScPTZ model, with lesser neurotoxicity. Some title compounds showed lesser central nervous system depression compared to phenytoin.

Screening of Some Novel 4, 5 Disubstituted 1, 2, 4-Triazole-3-thiones for Anticonvulsant Activity.

OBJECTIVE: In the present study, we synthesized fifteen 4, 5-disubstituted 1, 2, 4-triazol- 3-thione derivatives and evaluated for anticonvulsant activity with neurotoxicity determination. METHODS: The synthesized compounds were characterized using FTIR, 1H-NMR and MS. The molecular docking study was also performed to study the interactions of compounds with LYS329 residue of gamma amino butyric acid aminotransferase (GABA-AT) using Autodock 4.2 software. The anticonvulsant activity was assessed by maximal electroshock (MES) test and subcutaneous pentylenetetrazol (scPTZ) tests. The neurotoxicity was assessed by rotarod ataxia test. RESULTS: In MES test, compounds 5a, 8a and 9a were found active at 100 mg/kg and five compounds were found active at 300 mg/kg dose after 1 hr of administration. After 4 hr of drug administration, only two compounds 8a and 9a exhibited protection at 100 mg/kg. In scPTZ test, three compounds 2a, 6a and 8a were found active at 100 mg/kg and 7a was active at 300 mg/kg after 1 hr of test drug administration. Most of the compounds were found active in MES test with 8a and 9a being the most active among all. In docking study, 2a was found to be best compound based on the binding energy of -6.5 kcal/mol and estimated inhibition constant of 17.2 µM. CONCLUSION: Majority of synthesized compounds were found active in MES test, whereas only few were found to possess anti scPTZ activity. Among all compounds, only 14a caused motor coordination impairment in rotarod ataxia test at 300 mg/kg 1 hr duration.

Synthesis of 1,3,4-oxadiazole derivatives with anticonvulsant activity and their binding to the GABAA receptor.

In this study, a series of 1,3,4-oxadiazole derivatives (5a-s, 10a-s, and 16a-d) were designed and synthesized using maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) models, to test the anticonvulsant activity of the target compounds in vivo. The neurotoxicity (NT) of the target compounds was measured using the rotating rod (ROT) method. Seven compounds with potential activity were selected to test the 50% effective dose (ED50) and 50% toxic dose (TD50). Pharmacological experiments revealed that 6-((5-(pentylthio)-1,3,4-oxadiazol-2-yl)methoxy)-3,4-dihydroquinolin-2(1H)-one (5b) showed the best anticonvulsant activity (MES, ED50 = 8.9 mg/kg; scPTZ, ED50 = 10.2 mg/kg), which was greater than the activities of carbamazepine and ethosuximide. Compound 5b exhibited the most potent binding affinity toward the GABAA receptor (IC50 = 0.11 µM) in the in vitro binding experiments. Compound 5b displayed significant anxiolytic activity at a low dose (1 mg/kg) in the elevated plus maze (EPM) test. The GABA content in rat brains was also investigated, and the results showed that compound 5b might have affected the GABA system. In our molecular docking experiment, compound 5b showed significant interactions with residues present at the benzodiazepine binding site on the GABAA receptor. The structure and physicochemical and pharmacokinetic properties of the target compound were predicted using Discovery Studio 2019 and ChemBioDraw Ultra 14.0. Finally we demonstrated that compound 5b mainly acted on GABAA receptor. Thus the present study has provided potential candidates for further investigation in epilepsy.

Design, Synthesis and Biological Activity of Some 4, 5-Disubstituted-2, 4- Dihydro-3H-1, 2, 4- Triazole-3-Thione Derivatives.

BACKGROUND: In the present study, 4, 5-disubstituted triazol-3-thione derivatives were synthesized and evaluated for anticonvulsant activity along with neurotoxicity determination. MATERIALS AND METHODS: The synthesized compounds were characterized using FTIR, 1H-NMR and MS. The anticonvulsant activity was assessed by Maximal Electroshock (MES) test and subcutaneous Pentylenetetrazole (scPTZ) tests and neurotoxicity was assessed by rotarod test. Docking was also performed to study the interactions of compounds with LYS329 residue of gamma amino butyric acid aminotransferase (GABA-AT) using Autodock 4.2 software. RESULTS: The compounds 7a and 9a with significant pharmacological activity were also found to interact with LYS329 residue of GABA-AT by H-bond with a docking score of -5.92 kcal/mol (Ki = 41.99 µM) and -5.87 kcal/mol (Ki = 49.83 µM) respectively. CONCLUSION: Most of the compounds were found to be active in MES test but only seven showed protection in scPTZ test.

ISATIN: New Hope Against Convulsion.

BACKGROUND: Epilepsy is one in every of the foremost important chronic neurological disorders with high incidence worldwide. Several epileptic patients don't seem to be fully treated with currently available marketed medicines likewise so many drugs have shown unfavorable side effect and drug interaction. Therefore, there are continuing interests to seek out new anticonvulsant drugs. METHODS: Literature search was carried out to indentify isatin containing derivatives as anticonvulsant drugs. RESULTS: Common synthetic schemes were studied to design and develop isatin derives anticonvulsant agents. Various structural features essential for the design of isatin compounds were reported. Anticonvulsant activity is evaluated by different tests were identified and their results can be considered for the design of novel isatin derivatives as anticonvulsants. CONCLUSION: In outline, isatin has been proved to be an excellent hybrid building the molecule with interesting biological activities. Among the prospect of derivatizing the N1, C2 and C3 positions, along with substitution on the aromatic ring, the synthetic modification for isatin is almost endless. Despite the fact that isatin derivatives are well-studied compounds, new derivatives are continually being discovered on the basis of known AEDs, isatin has been fused with other bioactive drug fragments and subsequently investigated as hybrid/dual action drugs and selectively targeted against convulsion.

Discovery of novel Methylsulfonyl phenyl derivatives as potent human Cyclooxygenase-2 inhibitors with effective anticonvulsant action: Design, synthesis, in-silico, in-vitro and in-vivo evaluation.

A novel series of methylsulfonyl phenyl derivatives has been designed and synthesized to evaluate their COX-2 inhibitory activity along with anti-convulsant potential. In-vitro evaluation revealed that two compounds MTL-1 and MTL-2 appeared as most potent and selective COX-2 inhibitors in the entire series. Anti-convulsant activity of both potent COX-2 inhibitors was assessed in sc-PTZ induced seizure test and MTL-1 excellently protected animals against PTZ induced seizure at the dose of 30 mg/kg. MTL-1 also indicates long duration of action in time course study and displayed significant seizure protection up to 6 h of drug administration. Further, the anti-epileptogenic effect of MTL-1 has been examined in PTZ induced chronic model of epilepsy. The results indicated that MTL-1 had a significant anti-epileptogenic effect in PTZ kindled rats as compared to Etoricoxib (ETX) and PTZ alone treated group. Additionally, MTL-1 successfully improved cognition deficit in PTZ kindled rats, which was confirmed by social recognition, novel object recognition and light-dark chamber tests. Moreover, molecular docking and molecular simulation (MD simulation) studies were also performed to elucidate the interaction of MTL-1 with the active site of COX-2 and results showed that MTL-1 suitably binds within active site of COX-2. To investigate the safety profile of MTL-1, a sub-acute toxicity study was also performed and MTL-1 emerged as a new non-toxic chemical entity. Thus, the present investigation discovered a potent and safe COX-2 inhibitor, which is endowed with an effective anti-epileptic action.

Discovery of potent anti-convulsant carbonic anhydrase inhibitors: Design, synthesis, in vitro and in vivo appraisal.

We report the design, synthesis and pharmacological assessment of novel benzenesulfonamide derivatives acting as effective carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. All the synthesized compounds were screened for their CA inhibitory action against four isoforms of human origin (h), i.e. hCA I, hCA II, hCA VII and hCA IX. In-vitro carbonic anhydrase inhibition studies have shown that first series, 4-(2-(4-(4-substitutedpiperazin-1-yl)benzylidene)hydrazinyl)benzenesulfonamides (4a- 4i) bestowed low nanomolar range to medium nanomolar range inhibitors against hCA II and hCA VII, effectively involved in epileptogenesis. Furthermore, compounds belonging to the second series, 4-(2-(4-(4-substitutedpiperazin-yl)benzylidene)hydrazinecarbonyl)benzenesulfonamides (8a-8k) showed effective inhibition against hCA VII, being less effective against other hCA isoforms. Inspiring with obtained CA inhibition results, we have chosen some of the potent hCA II and hCA VII inhibitors (4g, 4i and 8d) to test their anti-convulsant efficacy in MES and sc-PTZ seizure tests in Swiss Albino male mice. In result, these compounds significantly attenuated both electrical (MES) as well as chemical (sc-PTZ) induced seizures. Next, in advance anticonvulsant tests, compound 8d displayed long duration of action in time course study and successfully attenuated MES induced seizure in mice up to 6 h after drug administration without showing neurotoxicity in rotarod test. Moreover, this compound was also found to be orally active and effectively abolished generalized tonic-clonic seizures in male Wistar rats upon oral administration, being non-toxic in sub acute toxicity studies.

Synthesis, Molecular Docking and Evaluation of 3-{4-[2-amino-4-(substitutedphenyl)-2H-[1, 3] oxazin/thiazin-6-yl} 2-phenyl-3H-quinazolin-4-one Derivatives for their Anticonvulsant Activity.

BACKGROUND: According to the WHO, around 50 million people worldwide are suffering from epilepsy. It is due to the repeated occurring of seizures. These seizures are caused by sudden which may vary from a brief lapse of attention or muscle jerks, to severe and prolonged convulsions. OBJECTIVES: The aim of the present work was to synthesize 2-phenyl substituted quinazolinone derivatives and to evaluate them for anticonvulsant and neurotoxic activity. METHODS: A series of novel 3-{4-[2-amino-4-(substitutedphenyl)-2H-[1.3] oxazin/thiazin-6-yl} 2- phenyl-3H-quinazolin-4-one derivatives were synthesized and evaluated for their anticonvulsant activity. The structures of the compound have been confirmed by spectral analysis. The molecular docking was performed for all the synthesized compounds to assess their binding mode to Gamma- aminobutyric acid type A (GABAA) receptor in order to rationalize their anticonvulsant activities in a qualitative way. Anticonvulsant activities of compounds were screened by using (Maximal electroshock) MES induced seizures and subcutaneous pentylenetetrazole (scPTZ) induced seizure models in Wistar rats of either sex. None of the compounds demonstrated any sign of neurotoxicity. RESULT: Compounds 3-{4-[2-amino-4-(4-nitro-phenyl)-2H-[1, 3] oxazin-6-yl} 2-phenyl-3H-quinazolin- 4-one (5a) have shown significant activity against tonic seizure by the MES model and 3-{4-[2-amino- 4-(4-nitro-phenyl)-2H-[1, 3] thiazin-6-yl} 2-phenyl-3H-quinazolin-4-one (5d) against clonic seizure by scPTZ induced seizure model. CONCLUSION: All the newly synthesized compounds had significant anticonvulsant activity. The same two compounds 5a and 5d showed promising activity, while the other compounds have moderate activity. The proposed work is to effort towards the development and identification of novel molecules as anticonvulsant agents by the synthesis of some novel quinazolinone derivatives with improved biological activity.

Pharmacological characterization of the cannabinoid receptor 2 agonist, ß-caryophyllene on seizure models in mice.

PURPOSE: Activation of CB1 receptors, produces anticonvulsant effect accompanied by memory disturbance both in animal seizure tests and in patients with epilepsy. Few reports considered the role of CB2 receptor on seizure susceptibility and cognitive functions. The aim of the present study was to explore the effect of a selective CB2 receptor agonist ß-caryophyllene (BCP) in models of seizures and cognition in mice. METHODS: Dose-dependent effects of BCP was studied in maximal electroshock seizure (MES) test, subcutaneous pentylenetetrazole (scPTZ) test and Morris water maze test. Phenytoin and diazepam were used as reference drugs in seizure tests. The effect of sub-chronic treatment with BCP for 7 days (50 and 100 mg kg-1) was assessed on status epilepticus (SE) induced by kainic acid (KA) model and oxidative stress through measurement of malondialdehyde (MDA) level in the hippocampus. The acute neurotoxicity was determined by a rotarod test. RESULTS: The BCP exerted a protection in the MES test at the lowest dose of 30 mg kg-1 at the 4-h interval tested comparable to that of the referent drug phenytoin. The CB2 agonist was ineffective in the scPTZ test. The BCP displayed no neurotoxicity in the rotarod test. The BCP decreased the seizure scores in the KA-induced SE, which effect correlated with a diminished lipid peroxidation. The CB2 agonist exerted a dose-dependent decrease of latency to cross the target area during the three days of testing in the Morris water maze test. CONCLUSION: Our results suggest that the CB2 receptor agonists might be clinically useful as an adjunct treatment against seizure spread and status epilepticus and concomitant oxidative stress, neurotoxicity and cognitive impairments.

Search for new potential anticonvulsants with anxiolytic and antidepressant properties among derivatives of 4,4-diphenylpyrrolidin-2-one.

BACKGROUND: The aim of this study was to synthesize a series of new N-Mannich bases derived from 4,4-diphenylpyrrolidin-2-one having differently substituted 4-phenylpiperazines as potential anticonvulsant agents with additional (beneficial) pharmacological properties. METHODS: The target compounds 8-12 were prepared in one step from the 4-substituted phenylpiperazines, paraformaldehyde, and synthesized 4,4-diphenylpyrrolodin-2-one (7) by a Mannich-type reaction. The obtained compounds were assessed and tested for their anticonvulsant activity in two screening mouse models of seizures, i.e., the maximal electroshock (MES) test and in the subcutaneous pentylenetetrazole (scPTZ) test. The effect of these compounds on animals' motor coordination was measured in the rotarod test. A selected 4,4-diphenyl-1-((4-phenylpiperazin-1-yl)methyl)pyrrolidin-2-one (8) was evaluated in vivo for its anxiolytic- and antidepressant-like properties. Its impact on animals' locomotor activity was also evaluated. RESULTS: Compound 8 showed protection (25%) in the MES and in the scPTZ tests at the dose of 100mg/kg and was not neurotoxic. In the four-plate test, compound 8 at the dose of 30mg/kg showed a statistically significant (p<0.05) anxiolytic-like activity. In the forced swim test, it reduced the immobility time by 24.3% (significant at p<0.05), which indicates its potential antidepressant-like properties. In the locomotor activity test, compound 8 significantly reduced animals' locomotor activity by 79.9%. CONCLUSION: The results obtained make a new derivative of 4,4-diphenyl-1-((4-phenylpiperazin-1-yl)methyl)pyrrolidin-2-one (8) a promising lead structure for further development.

Design, synthesis and pharmacological evaluation of novel N-(2-(1, 1-dimethyl-5, 7-dioxo-4, 6-diazaspiro[2.4]heptan-6-yl)ethyl) sulfonamide derivatives as potential anticonvulsant agents.

A series of new N-(2-(1,1-dimethyl-5,7-dioxo-4,6-diazaspiro[2.4]heptan-6-yl)ethyl) sulfonamide derivatives (8a-i) and ethyl 2,2-dimethyl-1-(3-(2-(sulfonamido)ethyl)ureido) cyclopropanecarbox-ylate derivatives (9a-i) were designed, synthesized and evaluated for their anticonvulsant activities using maximal electroshock shock (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure models in mice. N-(2-(1,1-dimethyl-5,7-dioxo-4,6-diazaspiro[2.4]heptan-6-yl)ethyl)-4-fluoroben- zenesulfonamide (8f) and N-(2-(1,1-dimethyl-5,7-dioxo-4,6-diazaspiro[2.4]heptan-6-yl)ethyl)-4- methylbenzenesulfonamide (8e) have shown promising anticonvulsant activities in MES model. The most active compound 8f has shown the MES-induced seizures with ED50 value of 28.05 mg/kg and TD50 value of 561 mg/kg after intraperitoneal injection to mice, which provided compound 8f with a protective index (TD50/ED50) of 20 in the MES test. Further, rotarod toxicity method was used to study the acute neurotoxicity profile of selected compounds.