Pentylenetetrazole Injection Research Articles

2-Arachidonoylglycerol enrichment Reduced Epileptiform Activity of the Rat Hippocampus induced with Pentylenetetrazol

Background and Objective: 2-arachidonoylglycerol (2-AG) and anandamide (AEA) are two major endocannabinoids. Using inhibitors of the enzymatic pathways involved in the elimination of 2-AG and AEA as well as synthetic 2-AG, we examined the effectiveness of these endocannabinoids on epileptiform activity induced in Wistar rats by pentylenetetrazol (PTZ). Material and Methods: Adult male Wistar rats were used in this study. Epileptiform activity was induced in dult male Wistar rats by PTZ injection (20 mg/kg, i.p.). To inhibit 2-AG degradation WWL70 and JJKK048 (JJKK048: 1 mg/kg, WWL70: 5 mg/kg, i.p.) were used. To inhibit AEA elimination, URB597 and LY2183240 (URB597: 1 mg/kg, LY2183240: 2.5 mg/kg, i.p.) were used. Synthetic 2-AG was also examined (1 mg/kg, i.p.) before the PTZ injection. All drugs were dissolved in DMSO as vehicle and injected (i.p.) 15 minutes before the PTZ injection. Latency to onset and duration of the epileptiform activity were considered for statistical analysis. Results: Injection of (JJKK048+WWL70) before the PTZ significantly increased latency to onset of the epileptiform activity (p less-than 0.01), while reduced duration of the epileptiform activity in comparison to the vehicle (p less-than 0.05). In addition, 2-AG administration significantly increased latency to onset of the epileptiform activity (p less-than 0.05) and reduced duration of the epileptiform activity in comparison to the vehicle (p less-than 0.01). However, these indexes did not show significant changes when URB597+LY2183240 were injected before the PTZ (p greater-than 0.05). Conclusion: It seems increased level of 2-AG but not AEA,effectively decreases PTZ induced epileptiform activity of the hippocampus.

Влияние сочетанного применения цитиколина и антител к глутамату на развитие острых генерализованных судорог, вызванных пентилентетразолом у мышей

Цель исследования. На 2 моделях острых генерализованных судорог (ОГС), вызванных конвульсантом пентилентетразолом (ПТЗ), изучить эффективность сочетанного применения ноотропа цитиколина - препарата с противосудорожным действием, нейрорегенеративной, нейропротекторной активностью и антител (АТ) к глутамату, обладающих противосудорожной активностью. Методика. Эксперименты выполнены на мышах-самцах линии C57Bl/6 (n = 87) массой 22-28 г. Эффективность сочетанного применения цитиколина и АТ к глутамату изучали на двух моделях ОГС. Выполнено 2 серии экспериментов. В 1-й серии ОГС вызывали внутривенным введением 1% раствора ПТЗ со скоростью 0,01 мл/с. Для изучения эффективности сочетанного применения препаратов определяли минимальное противосудорожное действие цитиколина (Цераксон, «Nicomed Ferrer Internaсional, S.A.») и АТ к глутамату при их внутрибрюшинном введении. С этой целью цитиколин вводили в дозах 500 и 300 мг/кг за 1 ч до введения ПТЗ, АТ к глутамату - в дозах 5 и 2,5 мг/кг за 1 ч 30 мин до введения ПТЗ. АТ к глутамату получали путем гипериммунизации кроликов соответствующим конъюгированным антигеном. Во 2-й серии ОГС вызывали подкожным введением ПТЗ в дозе 85 мг/кг. Для изучения эффективности сочетанного действия изучаемых препаратов последние вводили в минимально действующих дозах, установленных в 1-й серии экспериментов. Контролем во всех сериях опытов служили животные, которым вводили в аналогичных условиях и в том же объеме физиологический раствор. Результаты. Показано, что сочетанное применение цитиколина и АТ к глутамату в минимально действующих дозах (300 и 2,5 мг/кг соответственно) при моделировании ОГС не вызывало повышения судорожной активности мозга и усиления противосудорожных свойств препаратов. Заключение. Cочетанное применение цитиколина и АТ к глутамату в минимально действующих дозах не вызывало повышения судорожной активности мозга, что свидетельствует о безопасности совместного применения препаратов. Проведенное исследование может служить также экспериментальным обоснованием возможности использования сочетанного применения данных препаратов при судорогах с целью замедления прогрессирования нейродегенеративных процессов и благоприятного влияния на когнитивные функции. Aim. To study the effectivity of a combination of citicoline, a nootropic substance with neuroregenerative, neuroprotective, and anticonvulsant actions, and glutamate antibodies (АB) with an anticonvulsant action in two models of acute generalized convulsions (AGC) caused by the convulsant pentylenetetrazole (PTZ). Methods. Experiments were conducted on C57Bl/6 mice (n = 87) weighing 22-28 g. Effects of combined citicoline and glutamate АB were studied on two models of AGС. In the first series of experiments, AGС was induced by intravenous infusion of a 1% PTZ solution at 0.01 ml/sec. In the second series, AGС was induced by a subcutaneous injection of PTZ 85 mg/kg. To evaluate efficacy of the drug combination minimum intraperitoneal anticonvulsant doses of citicoline (Tserakson, Nicomed Ferrer Internacional, S.A.) and glutamate АB were determined. To this purpose, citicoline was administered at 500 and 300 mg/kg 1 h prior to PTZ, and glutamate АB was administered at 5 and 2.5 mg/kg 90 min prior to PTZ. Glutamate АB was obtained by hyperimmunization of rabbits with a respective conjugated antigen. In the second series of experiments, AGС was induced by a subcutaneous injection of PTZ 85 mg/kg. To evaluate the effect of the drug combination, the drugs were administered at the minimum effective doses determined in the first series of experiment. Control animals were injected with the same volume of saline in the same experimental conditions. Results. The combination of citicoline and glutamate AB used at minimum effective doses of 300 and 2.5 mg/kg, respectively, did not increase the seizure activity in the brain and enhanced anticonvulsant properties of the drugs in two models of AGС. Conclusion. The combination of citicoline and glutamate AT at minimum effective doses did not increase the convulsive activity in the brain, which supported safety of the drug combination. Besides, this study can serve as an experimental justification for using the drug combination in convulsions to favorably influence cognitive functions and slow progression of neurodegenerative processes.

Upregulation of klotho and erythropoietin contributes to the neuroprotection induced by curcumin-loaded nanoparticles in experimental model of chronic epilepsy

Klotho, which is a life extension factor, and erythropoietin (EPO) have been introduced as effective neuroprotective factors in several neurological disorders. The present study is an attempt to examine the potential role of klotho and EPO in therapeutic effect of curcumin-loaded nanoparticles (NPs) in pentylenetetrazol (PTZ)-induced kindling model. In order to induce the kindling model, PTZ was administrated intraperitoneally (i.p.) at dose of 36.5 mg/kg every other day for 20 days. Male NMRI mice received pre-treatment of free curcumin or curcumin-loaded NPs (12.5 mg/kg, i.p.) 10 days before PTZ injection and this was continued until 1 h before each PTZ injection. Immunostaining against NeuN, as a marker of neuronal maturation, and EPO was performed on hippocampal brain sections. Quantitative real time polymerase chain reaction (qRT-PCR) was conducted to assess the expression levels of tumor necrosis factor-α (TNF-α), klotho and EPO in the hippocampus. Immunostaining data indicated that treatment with curcumin-loaded NPs significantly alleviates the neuronal cell death in PTZ receiving animals. Curcumin-loaded NPs effectively upregulated the levels of EPO and klotho in PTZ receiving animals. Furthermore, mRNA level of TNF-α was considerably reduced in animals undergone curcumin-loaded NPs treatment. Overall, the results of this study suggest that downregulation of TNF-α and consequent upregulation of klotho and EPO might contribute to the neuroprotective effect of curcumin-loaded NPs in experimental model of epilepsy.

Positive effect of moderate-intensity aerobic activity on pentylenetetrazol-induced epileptic behaviors in pregnant mice and cognitive performance in adult male offspring

Epilepsy is one of the common neurological disorders. It has been reported that physical activity can be a complementary therapy to treat seizures. Therefore, the present study was designed to investigate the effect of aerobic training on pentylenetetrazol (PTZ)-induced seizure in pregnant mice. The kindled female mice were divided into eight groups including (1) pregnant mice (PC) treated with PTZ without physical training (PT), (2) PC treated with PTZ with aerobic training (AT), (3) PC treated with normal saline (NS), (4) PC without any injection in pregnancy, (5) non-PC treated with PTZ without PT, (6) non-PC treated with PTZ with AT, (7) non-PC treated with NS and (8) non-PC without any injection. The seizure activity was measured for half an hour after PTZ injection and anxiety activity was assessed 2 h after PTZ injection. Also, at postnatal day 94, cognitive performance at male offspring of the groups was evaluated. The results showed that aerobic training reduced seizure severity and restored seizure-induced anxiety in pregnant and non-pregnant mice to control levels. It was also observed that aerobic activity during pregnancy would restore the cognitive function of the offspring in pregnant mice treated with PTZ to the male offspring’s level in control group. Generally, the results of this study showed that moderate-intensity AT is an appropriate treatment strategy for reducing the severity of seizure, seizure-induced anxiety and also prevents cognitive impairment due to seizure induction during pregnancy in the male offspring.

Effect of Aerobic Training During Pregnancy on Seizure-Induced Depression- in Mouse

Introduction: Depression during pregnancy is not uncommon. In addition, depression is more common in patients suffering from epilepsy. Aerobic activity has been reported to alleviate depression. The purpose of this study was to investigate the effect of aerobic training during pregnancy on seizure-induced depression. Materials and Methods: Pregnant mice were randomly divided to control, sham, and experiment groups. The pentylenetetrazol (PTZ) kindling was induced on days 14 to19 after pregnancy in the experiment group. Experiment group was divided to mice with and without aerobic activities. Aerobic activity was performed every day during pregnancy. The rate of depression in pregnant mice was measured between the 14th and 19th days of pregnancy once in 48 hours and two hours after PTZ injection. Results: Treatment with aerobic training significantly decreased seizure-induced depression as well as seizure severity in pregnant mice. Conclusion: The present study showed that aerobic training during pregnancy is positively associated with decreasing depression and severity of seizure in PTZ-treated mice.

UCH-L1 inhibition aggravates mossy fiber sprouting in the pentylenetetrazole kindling model

Mossy fiber sprouting (MFS) is a pathological phenomenon that is commonly observed in epilepsy, and plentiful data reveal that abnormal phosphorylated modification of tau protein plays a critical role in MSF by the regulation of microtubule dynamics and axonal transport. Ubiquitin C-terminal hydrolase L1 (UCH-L1), a proteasomal deubiquitinating enzyme, has been proved to be associated with tau aggregation through mediating degradation of ubiquitinated and hyperphosphorylated tau. Thus, this study aimed to determine the expression of UCH-L1 in the rat hippocampus during the pentylenetetrazole (PTZ)-induced process and to demonstrate the possible correlation with MFS in epileptogenesis. Seizures were established by intraperitoneal injection of PTZ and LDN-57444 was used to inhibit the hydrolase activity of UCH-L1. We used western blot, immunofluorescence, immunoprecipitation, and timm staining to detect phosphorylated modification of tau and MSF. The results presented that LDN-57444 induced the deteriorated severity of seizures, increased phosphorylation of tau and increased distribution of Timm granules in both the supragranular region of the dentate gyrus (DG) and the stratum pyramidale of CA3 subfield. Our results suggest that UCH-L1 may be associated with hippocampal MSF followed the epileptogenesis through mediating phosphorylation of tau. UCH-L1 may be a potential and novel therapeutic target to limit epileptogenesis.

Pentylenetetrazole-Induced Kindling Mouse Model.

Pentylenetetrazole (PTZ) is a GABA-A receptor antagonist. An intraperitoneal injection of PTZ into an animal induces an acute, severe seizure at a high dose, whereas sequential injections of a subconvulsive dose have been used for the development of chemical kindling, an epilepsy model. A single low-dose injection of PTZ induces a mild seizure without convulsion. However, repetitive low-dose injections of PTZ decrease the threshold to evoke a convulsive seizure. Finally, continuous low-dose administration of PTZ induces a severe tonic-clonic seizure. This method is simple and widely applicable to investigate the pathophysiology of epilepsy, which is defined as a chronic disease that involves repetitive seizures. This chemical kindling protocol causes repetitive seizures in animals. With this method, vulnerability to PTZ-mediated seizures or the degree of aggravation of epileptic seizures was estimated. These advantages have led to the use of this method for screening anti-epileptic drugs and epilepsy-related genes. In addition, this method has been used to investigate neuronal damage after epileptic seizures because the histological changes observed in the brains of epileptic patients also appear in the brains of chemical-kindled animals. Thus, this protocol is useful for conveniently producing animal models of epilepsy.

Apigenin reverses behavioural impairments and cognitive decline in kindled mice via CREB-BDNF upregulation in the hippocampus

Objectives: Apigenin is the most common bioflavonoid known to be biologically active after systemic administration and show multiple pharmacological effects. The present study was designed to explore the role of apigenin in pentylenetetrazole (PTZ) kindling associated cognitive and behavioural impairments in the mouse model. Methods: The animals were kindled by injecting a sub-convulsive dose of PTZ (35 mg/kg) on every alternate day, followed by 20 days treatment with apigenin at two different doses (10 and 20 mg/kg). Seizure severity was assessed on every 5th, 10th, 15th, and 20th day during apigenin treatment after a PTZ injection, followed by analysis of cognitive and behavioural functions. Results: Apigenin treatment displayed insignificant effect on seizure severity in kindled mice at both the tested doses, in comparison to control. However, the treatment showed marked increase in per cent spontaneous alterations and decline in the anxiety index in T-maze and elevated plus maze tests, respectively. Apigenin-treated groups showed significant decrease in immobility period in both forced swim and tail suspension tests, without any change in the total locomotor activity in the open field test. Furthermore, increase in the hippocampus protein expression of brain-derived neurotrophic factor (BDNF), cAMP response element binding protein (CREB), and phosphorylated CREB, with increased serotonin level were also observed in the treated animals. Discussion: The results of the present study showed that apigenin treatment prevents cognitive deficit and reverses behaviour impairments, without altering seizures severity in kindled mice. The observed effects can be attributed to CREB-BDNF upregulation in the hippocampus.

NADPH oxidases as potential pharmacological targets against increased seizure susceptibility after systemic inflammation

BackgroundSystemic inflammation associated with sepsis can induce neuronal hyperexcitability, leading to enhanced seizure predisposition and occurrence. Brain microglia are rapidly activated in response to systemic inflammation and, in this activated state, release multiple cytokines and signaling factors that amplify the inflammatory response and increase neuronal excitability. NADPH oxidase (NOX) enzymes promote microglial activation through the generation of reactive oxygen species (ROS), such as superoxide anion. We hypothesized that NOX isoforms, particularly NOX2, are potential targets for prevention of sepsis-associated seizures.MethodsTo reduce NADPH oxidase 2-derived ROS production, mice with deficits of NOX regulatory subunit/NOX2 organizer p47phox (p47phox−/−) or NOX2 major subunit gp91phox (gp91phox−/−) were used or the NOX2-selective inhibitor diphenyleneiodonium (DPI) was used to treat wild-type (WT) mice. Systemic inflammation was induced by intraperitoneal injection of lipopolysaccharide (LPS). Seizure susceptibility was compared among mouse groups in response to intraperitoneal injection of pentylenetetrazole (PTZ). Brain tissues were assayed for proinflammatory gene and protein expression, and immunofluorescence staining was used to estimate the proportion of activated microglia.ResultsIncreased susceptibility to PTZ-induced seizures following sepsis was significantly attenuated in gp91phox−/− and p47phox−/− mice compared with WT mice. Both gp91phox−/− and p47phox−/− mice exhibited reduced microglia activation and lower brain induction of multiple proconvulsive cytokines, including TNFα, IL-1β, IL-6, and CCL2, compared with WT mice. Administration of DPI following LPS injection significantly attenuated the increased susceptibility to PTZ-induced seizures and reduced both microglia activation and brain proconvulsive cytokine concentrations compared with vehicle-treated controls. DPI also inhibited the upregulation of gp91phox transcripts following LPS injection.ConclusionsOur results indicate that NADPH oxidases contribute to the development of increased seizure susceptibility in mice after sepsis. Pharmacologic inhibition of NOX may be a promising therapeutic approach to reducing sepsis-associated neuroinflammation, neuronal hyperexcitability, and seizures.

Satb2 ablation decreases PTZ-induced seizure susceptibility and pyramidal neuronal excitability

Special AT-rich sequence-binding protein 2 (Satb2) is a transcriptional regulator and people with SATB2 mutation or duplication could display epilepsy. However, whether Satb2 is related with epilepsy and its mechanisms are largely unexplored. Here we found that the expression of Satb2 was decreased following the neuronal hyperactivities. Ablation of Satb2 in mice would decrease incidence and stage of seizure induced by intraperitoneal injection of pentylenetetrazol (PTZ). At cellular levels, we found pyramidal neuronal excitability and excitatory synaptic inputs in CA1 were decreased in Satb2 mutant mice. Taking together, we proved that deletion of Satb2 in mice increased PTZ seizure threshold probably by modulating neuronal excitability.

Corilagin Reduces the Frequency of Seizures and Improves Cognitive Function in a Rat Model of Chronic Epilepsy.

BackgroundWorldwide, epilepsy is an important chronic neurological condition. The aim of this study was to evaluate the effects of corilagin, an ellagitannin extracted from medicinal plants, on the frequency of seizures and cognitive function in a rat model of chronic epilepsy.Material/MethodsChronic epilepsy was induced in male Wistar rats by intraperitoneal (IP) injection of pentylenetetrazol (PTZ) for 36 days. Corilagin, 10 mg/kg and 20 mg/kg, was injected IP into treated rats, 24 days before the start of PTZ treatment, until the end of the protocol. The effects of corilagin were assessed by the pattern of epileptic seizures; cognitive function was assessed using the Morris water maze (MWM) navigation test. The mechanism of action of corilagin was investigated by measuring cytokine levels and oxidative stress parameters, including reactive oxygen species (ROS) production, and carbonic anhydrase inhibitory (CAI) activity. Histological analysis of fixed brain tissue sections included cresyl violet acetate staining (Nissl staining) for Nissl substance in the neuronal cytoplasm.ResultsThe corilagin-treated rats, compared with the control group, showed a significantly lower rate of epileptic events, improved cognitive function, reduced level of cytokines, reduced ROS production reduced CAI activity in the brain tissues (P<0.01). Histology of the rat brain tissues study showed that corilagin treatment maintained the neuronal cellular structure and number of surviving cells compared with the control group of rats.ConclusionsThe findings of this study showed that corilagin reduced the frequency of seizures and improved the cognitive function in a rat model of chronic epilepsy.

Anticonvulsive effects of endocannabinoids; an investigation to determine the role of regulatory components of endocannabinoid metabolism in the Pentylenetetrazol induced tonic- clonic seizures.

2-Arachidonoylglycerol (2-AG) and anandamide are two major endocannabinoids produced, released and eliminated by metabolic pathways. Anticonvulsive effect of 2-AG and CB1 receptor is well-established. Herein, we designed to investigate the anticonvulsive influence of key components of the 2-AG and anandamide metabolism. Tonic-clonic seizures were induced by an injection of Pentylenetetrazol (80mg/kg, i.p.) in adult male Wistar rats. Delay and duration for the seizure stages were considered for analysis. Monoacylglycerol lipase blocker (JJKK048; 1mg/kg) or alpha/beta hydroxylase domain 6 blocker (WWL70; 5mg/kg) were administrated alone or with 2-AG to evaluate the anticonvulsive potential of these enzymes. To determine the CB1 receptor involvement, its blocker (MJ15; 3mg/kg) was administrated associated with JJKK048 or WWL70. To assess anandamide anticonvulsive effect, anandamide membrane transporter blocker (LY21813240; 2.5mg/kg) was used alone or associated with MJ15. Also, fatty acid amide hydrolase blocker (URB597; 1mg/kg; to prevent intracellular anandamide hydrolysis) were used alone or with AMG21629 (transient receptor potential vanilloid; TRPV1 antagonist; 3mg/kg). All compounds were dissolved in DMSO and injected i.p., before the Pentylenetetrazol. Both JJKK048 and WWL70 revealed anticonvulsive effect. Anticonvulsive effect of JJKK048 but not WWL70 was CB1 receptor dependent. LY2183240 showed CB1 receptor dependent anticonvulsive effect. However, URB597 revealed a TRPV1 dependent proconvulsive effect. It seems extracellular accumulation of 2-AG or anandamide has anticonvulsive effect through the CB1 receptor, while intracellular anandamide accumulation is proconvulsive through TRPV1.

Amelioration of Pentylenetetrazole-Induced Seizures by Modulators of Sigma, N-Methyl-D-Aspartate, and Ryanodine Receptors in Mice.

Sigma receptors, N-methyl-D-aspartate (NMDA) antagonist, and modulators of intracellular calcium may be useful for seizure control. Therefore, we aimed to evaluate the antiepileptic effects of opipramol, a sigma receptor agonist, against pentylenetetrazole (PTZ)-induced seizures in mice and assess ketamine and caffeine interaction with the antiepileptic effects of opipramol. PTZ (100 mg/kg) was used for the induction of seizure in 72 male albino Swiss strain of mice (n=8). Opipramole (10, 20, and 50 mg/kg), ketamine (50 mg/kg), caffeine (200 mg/kg), opipramole (20 mg/kg) plus ketamine (50 mg/kg), opipramole (20 mg/kg) plus caffeine (200 mg/kg), diazepam (5 mg/kg as a positive control), and the vehicle were administered interaperitoneally 30 minutes before the injection of PTZ. The latency was recorded for the clonic, tonic-clonic seizures, and death of animals after the injection of PTZ. Kruskal-Wallis test followed by Dunn's test was used for the analysis of data. Statistical analysis was performed with the SPSS software version 23.0 and P<0.05 was considered as the significant level. Opipramol (20 mg/kg) increased the latency for the PTZ-induced clonic (44%, P=0.021) and tonic-clonic (130.80%, P=0.043) seizures compared with the vehicle-treated group. Animals treated with opipramol (20 mg/kg) plus caffeine (200 mg/kg) had a significantly higher onset of PTZ-induced clonic and tonic-clonic seizures compared with the control (P=0.046 and <0.001, respectively). Ketamine combined with opipramol increased the onset of tonic-clonic seizure compared with the vehicle-treated groups (P<0.001). Opipramol attenuated the seizures induced by the PTZ. Ketamine and caffeine had no effect on the anticonvulsant activity of opipramol.

Role of miR-34c in the cognitive function of epileptic rats induced by pentylenetetrazol.

Studies suggest that microRNA (miR)-34c may serve a role in cognitive function in rodent and primate groups. A previous study demonstrated an increase in miR-34c expression in chronic epileptic rats with memory disorders, induced by pentylenetetrazol (PTZ). However, the mechanism underlying the effects of miR-34c on cognitive function in epileptic rats remains unclear. Therefore, the present study investigated alterations in cognitive function in temporal lobe epileptic rats, induced by repeated injections of PTZ, following treatment with an miR-34c agomir compared with a scramble group. Increased expression of miR-34c was observed in the agomir group, in addition to an increased deficit in learning and memory function in the Morris water maze test. Glutamate receptor ionotropic N-methyl-D-aspartate (NMDA) 2B (NR2B), phosphorylated (p)-reduced nicotinamide-adenine dinucleotide phosphate-dependent diflavin oxidoreductase 1 (NR1) and p-glutamate receptor 1 (GluR1) protein expression was detected in the hippocampus using western blotting. Additionally, the downregulation of NR2B, p-NR1 and p-GluR1 in the miR-34c agomir group demonstrated that miR-34c may serve a negative role in cognitive function in epileptic seizures, by dysregulating NMDA and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, which are associated with long-term potentiation.

Antiepileptogenic and Neuroprotective effects of Ziziphus jujuba leaves methanolic extract against pentylenetetrazole-induced kindling model in mice

Ziziphus jujubahas been used for many years for its medicinal and culinary properties. The present study aimed to investigate the antiepileptogenic activity of methanolic extract of Ziziphus jujubaleaves (MEZJ) and subsequently its neuro protective action against excitotoxicity and reactive oxygen species (ROS) generation in the brain of pentylenetetrazole (PTZ) –induced kindled mice. MEZJ was studied for its suppressive action on convulsion and seizure scores (antiepileptogenic effect) and protection of neurons against PTZ-induced oxidative stress injury (neuro protective effect) when given during kindling acquisition as a pretreatment before every PTZ injection. A major antiepileptic drug Diazepam was also tested for comparison. Both MEZJ and Diazepam showed antiepileptogenic activity as they caused reduction in development of seizure scores and reduced the sensitivity of kindled mice to the convulsive and lethal effects of PTZ. MEZJ and Diazepam significantly decreased oxidative stress injury in the mice brain as compared to PTZ-kindled group. MEZJ showed more neuroprotective action as compared to Diazepam as it enhanced the antioxidant enzyme levels more in the mice brain. The results obtained from the study support the hypothesis that neuro protective action of MEZJ not only correlate with its ability to inhibit ROS formation but also for its ability to suppress seizure generation.

Maerua angolensis DC. (Capparaceae) Stem Bark Extract Protects against Pentylenetetrazole-Induced Oxidative Stress and Seizures in Rats.

Introduction The stem bark of Maerua angolensis DC. (Capparaceae) is traditionally used for management of epilepsy. Our aim was to evaluate the antiseizure potential and identify possible mechanisms by which the effects are registered. Methods The petroleum ether/ethyl acetate extract (100–1000 mg kg−1) was administered per os to male Sprague-Dawley rats after pretreatment with flumazenil (0.3 mg kg−1) or L-arginine (150 mg kg−1) or sildenafil (5 mg kg−1) and they subsequently received a subcutaneous injection of pentylenetetrazole (65 mg kg−1). Rats were observed for latency to and duration of myoclonic seizures and additionally the level of protection against oxidant markers and products was assessed in vitro and in vivo. Results The extract (300 and 1000 mg kg−1, p.o.) significantly delayed the onset and decreased the duration and frequency of PTZ-induced convulsions. The anticonvulsant effect of MAE (300 mg kg−1, p.o.) was reversed by pretreatment with flumazenil, L-arginine, or sildenafil. Also, MAE (300 mg kg−1) treatment reversed significantly PTZ-induced oxidative stress in rat brain tissue. Conclusion The petroleum ether/ethyl acetate fraction exhibits antiseizure activity by affecting GABAergic and nitric oxide-cGMP pathways. In addition, the extract protects against the generation of free radicals and the oxidative products of the PTZ-induced seizures.

Anti-convulsant Effects of Bongardia chrysogonum L. Tuber in the Pentylenetetrazole-induced Seizure Model

Background and Objective: The dried tuber of Bongardia chrysogonum (L.) is a popular folk remedy for its use in the treatment of epilepsy in traditional medicine. The study aimed to evaluate the anti-oxidant and anti-convulsant activity of B. chrysogonum ethanolic-aqueous extract using the Pentylenetetrazole (PTZ) kindling animal model. Materials and Methods: Male mice were randomly selected and divided into 9 experimental groups including: Control group, pentylenetetrazole kindled mice, positive mice group receiving valproate (200 mg kg–1 p.o.) a classic anticonvulsant drug and 3 groups receiving B. chrysogonum tuber-ethanolic or aqueous extract at a doses of (600, 900 and 1200 mg kg–1 p.o.). All groups, except the control, were kindled by 11 injections of PTZ (40 mg kg–1, i.p.). All groups, except the control group, were tested at 12th PTZ challenge dose (75 mg kg–1 i.p.). The exhibited phases of seizure (0-6) were observed and noted; moreover, anti-oxidant effect of these extract was examined in in vitro study by using a spectrophotometric technique. The significance of differences between groups were determined using one-way analysis of variance (ANOVA) followed by post hoc test, Dunnett’s multiple comparison tests. Results: The data showed that both valproate and B. chrysogonum tuber extracts delay the onset of convulsions, decrease duration of the seizure and reduced mortality significantly (p<0.05). In addition, B. chrysogonum showed a wide range of scavenging capacities for free radicals, which may underpin the effective in vivo seizure suppression. Conclusion: It was concluded that B. chrysogonum L. tuber extracts display anti-oxidant, free radical scavenging properties in vitro and, in mice, provides new scientific evidence for the anti-seizure properties of B. chrysogonum.

Calcitonin potentiates the anticonvulsant and antinociceptive effects of valproic acid and pregabalin in pentylenetetrazole-kindled mice

Antiepileptic drugs are the backbone for epilepsy management. Epilepsy may be accompanied by decreased pain threshold. Thus, anticonvulsant agents with antinociceptive properties are of great importance. This study investigated the possible anticonvulsant and antinociceptive effects of calcitonin in combination with either valproic acid or pregabalin and whether these effects might occur through γ-aminobutyric acid (GABA) modulation.Eighty-four male Balb/C mice were divided into 7 groups: control-naïve, pentylenetetrazole (PTZ)-induced seizures, PTZ-calcitonin, PTZ-valproic acid, PTZ-pregabalin, PTZ-calcitonin-valproic acid (PCV) combination, and PTZ-calcitonin-pregabalin (PCP) combination. PTZ was used in a sub-convulsive dosage, every other day for 11 injections. Drugs were given i.p. 30min before PTZ. After each PTZ injection, mice were put under observation and PTZ-provoked seizures were assessed. After the last dose of PTZ, the hot plate test was used to assess antinociceptive properties. Also, brain GABA neurotransmitter was evaluated by immunoassay.Repeated injection of PTZ induced chemical kindling. Calcitonin was found to have significant antinociceptive property as shown by hot plate latency. The beneficial effects of PCV and PCP combination were statistically significant in epilepsy and pain models as compared to valproic acid and pregabalin. The antiepileptic and antinociceptive activity of calcitonin may not relate to the GABAergic system.Calcitonin enhanced the anticonvulsant and antinociceptive effects of either valproic acid or pregabalin. This new treatment “calcitonin add-on” may provide an improved range of options for patients with refractory epilepsy which is still an important risk factor for sudden death.

PROTECTIVE EFFECT OF MONTELUKAST AGAINST PENTYLENETETRAZOLE-INDUCED ACUTE SEIZURES AND KINDLING IN MICE

Montelukast, a selective reversible cysteinyl leukotriene1 (CysLT1) receptor antagonist, is used in treatment of asthma, exercise induced-bronchospasm, allergic rhinitis and urticaria. It was shown to protect against cerebral ischemia/reperfusion injury. Objectives: To examine the possible anticonvulsant effect of montelukast, either alone or in combination with a known antiepileptic drug against pentylenetetrazole (PTZ)-induced seizures. Methods: 112 adult male Swiss albino mice were used in the study and divided into two main groups, each containing 5 subgroups (Gp). The first main PTZ model (PTZ-a) contains: Gp1 vehicle-treated group was injected with saline (10 ml/kg, intraperitoneally i.p. in a single dose ), Gp2 PTZ-control injected with a single dose of PTZ (60 mg/kg, i.p.), Gp3 injected with valproate (50 mg/kg, i.p.) 30 minutes before PTZ, Gp4 injected with a single dose of montelukast (10 mg/kg, i.p.) 30 minutes before PTZ and Gp5 injected with both montelukast and valproate 30 minutes before PTZ administration. The second main kindling model (PTZ-k) contains: Gp1 was injected with saline (i.p.) every other day for 17 days, Gp2 PTZ-kindled received 9 PTZ injections in a dose of (40 mg/kg, i.p.) on alternate days for 17 days, Gp3 injected with valproate (50 mg/kg, i.p.) for 17 days, 30 minutes before PTZ, Gp4 daily injected with montelukast (10 mg/kg, i.p.) for 17 days 30 minutes before PTZ and Gp5 received both montelukast (10 mg/kg, i.p.) and valproate (50 mg/kg, i.p.) daily for 17 days, 30 minutes before administration of PTZ. Results: Single and repeated PTZ administration produced stage 4 seizures associated with a significant reduction in the brain level of reduced glutathione (GSH), concomittent with significant elevation in the brain levels of malondialdehyde (MDA), inteleukin1β (IL1β), tumor necrosis factor α (TNFα) and leukotriene D4 (LtD4). The use of valproate alone and its combination with montelukast suppressed the incidence of stage 4 seizures in acute PTZ induced convulsion while montelukast, valproate and their combination decreased the percentage of animals reaching stage 4 seizures in kindled mice. In both PTZ acute and kindled models, montelukast, valproate and their combined administration significantly elevated brain level of GSH and significantly decreased brain levels of MDA, IL1β, TNFα and LtD4 as compared to PTZ control groups. Interestingly, co-administration of valproate and montelukast resulted in a significant elevation in the brain level of GSH concomitant with a significant reduction in the brain levels of MDA, IL1β, TNFα and LtD4 as compared to each of the valproate and the montelukast groups in both models. Conclusion: Montelukast, either alone or in combination with valproate protects against PTZ induced seizures via blockade of leukotreine receptors & amelioration of oxidative stress and inflammatory cascades.

Anticonvulsant effect of nifedipine, dizepam and in combination on pentylenetetrazol induced experimental models of epilepsy on albino rats

Background: In many patients, the presently available antiepileptic drugs such as phenobarbital, phenytoin, benzodiazepines, sodium valproate, etc., are unable to control seizures efficiently and the problem of adverse effects has also not been circumvented completely and approximately 30% of the patients continue to have seizures with current antiepileptic drugs therapy. Hence, search should continue to develop newer, more effective, and safer neuro-protective agents for treatment of epilepsy. Aim of the study was to investigate the activity of nifedipine, the dihydropyridine calcium channel blocker, diazepam, the benzodiazepine anti- convulsant of established efficacy and their combinations against rat models of pentylenetetrazol (PTZ) induced convulsions. Method: Wister albino rats of either sex, weighing between 150-220gm were used. Rats were divided into 10 groups, in each group n=6 total N=60.Methods: PTZ was administration 30 min after test drug administration. Intraperitoneal injection of PTZ at the dose of 80mg/Kg body weight were administered to the rats to produce chemically-induced seizure. The effect of nifedipine and diazepam were assessed on such seizure model. The onset and duration of clonic convulsion were recorded.Results: The onset time of PTZ-induced clonic convulsion was significantly prolonged with the Nifedipine in the doses of 4mg and 8mg per Kg. in comparison to nifedipine in dose of 2mg per Kg. The interesting observation was that while Diazepam in 1mg/Kg. dose significantly (P&lt;0.05) prolonged the onset time, there was significant decrease (P &lt;0.001) in the onset time of PTZ-induced clonic convulsion with diazepam in doses of 2 and 4mg per Kg. in comparison to Diazepam 1mg per Kg. But the combination of diazepam 2.5 mg and Nifedipine 2.6mg and 5.3mg exhibited significant prolongation of the onset time. Diazepam 1 and 2mg per Kg was found to be equally effective in reduction of convulsion time, while 4mg dose showed more reduction of convulsion time. The combination of diazepam and nifedipine showed no better reduction in the convulsion time and also valproic acid in doses of 135mg. Kg.Conclusions: Nifedipine (3-5mg/Kg) and diazepam (2.5mg/Kg.) combination delayed the onset of convulsion. Diazepam 2mg / Kg. alone was effective in reduction of duration of convulsion. The combination dose having 2.6mg of nifedipine showed comparable protection with valproic acid 135mg per Kg. while the combination having 5.3mg of nifedipine showed significantly better protection.